Update FLAC to 1.3.1

src/libFLAC/metadata_object.c

+/* libFLAC - Free Lossless Audio Codec library
+ * Copyright (C) 2001-2009  Josh Coalson
+ * Copyright (C) 2011-2014  Xiph.Org Foundation
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * - Neither the name of the Xiph.org Foundation nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "private/metadata.h"
+#include "private/memory.h"
+
+#include "FLAC/assert.h"
+#include "share/alloc.h"
+#include "share/compat.h"
+
+/* Alias the first (in share/alloc.h) to the second (in src/libFLAC/memory.c). */
+#define safe_malloc_mul_2op_ safe_malloc_mul_2op_p
+
+
+/****************************************************************************
+ *
+ * Local routines
+ *
+ ***************************************************************************/
+
+/* copy bytes:
+ *  from = NULL  && bytes = 0
+ *       to <- NULL
+ *  from != NULL && bytes > 0
+ *       to <- copy of from
+ *  else ASSERT
+ * malloc error leaves 'to' unchanged
+ */
+static FLAC__bool copy_bytes_(FLAC__byte **to, const FLAC__byte *from, unsigned bytes)
+{
+        FLAC__ASSERT(0 != to);
+        if(bytes > 0 && 0 != from) {
+                FLAC__byte *x;
+                if(0 == (x = safe_malloc_(bytes)))
+                        return false;
+                memcpy(x, from, bytes);
+                *to = x;
+        }
+        else {
+                FLAC__ASSERT(0 == from);
+                FLAC__ASSERT(bytes == 0);
+                *to = 0;
+        }
+        return true;
+}
+
+#if 0 /* UNUSED */
+/* like copy_bytes_(), but free()s the original '*to' if the copy succeeds and the original '*to' is non-NULL */
+static FLAC__bool free_copy_bytes_(FLAC__byte **to, const FLAC__byte *from, unsigned bytes)
+{
+        FLAC__byte *copy;
+        FLAC__ASSERT(0 != to);
+        if(copy_bytes_(&copy, from, bytes)) {
+                if(*to)
+                        free(*to);
+                *to = copy;
+                return true;
+        }
+        else
+                return false;
+}
+#endif
+
+/* reallocate entry to 1 byte larger and add a terminating NUL */
+/* realloc() failure leaves entry unchanged */
+static FLAC__bool ensure_null_terminated_(FLAC__byte **entry, unsigned length)
+{
+        FLAC__byte *x = safe_realloc_add_2op_(*entry, length, /*+*/1);
+        if(0 != x) {
+                x[length] = '\0';
+                *entry = x;
+                return true;
+        }
+        else
+                return false;
+}
+
+/* copies the NUL-terminated C-string 'from' to '*to', leaving '*to'
+ * unchanged if malloc fails, free()ing the original '*to' if it
+ * succeeds and the original '*to' was not NULL
+ */
+static FLAC__bool copy_cstring_(char **to, const char *from)
+{
+        char *copy = strdup(from);
+        FLAC__ASSERT(to);
+        if(copy) {
+                if(*to)
+                        free(*to);
+                *to = copy;
+                return true;
+        }
+        else
+                return false;
+}
+
+static FLAC__bool copy_vcentry_(FLAC__StreamMetadata_VorbisComment_Entry *to, const FLAC__StreamMetadata_VorbisComment_Entry *from)
+{
+        to->length = from->length;
+        if(0 == from->entry) {
+                FLAC__ASSERT(from->length == 0);
+                to->entry = 0;
+        }
+        else {
+                FLAC__byte *x;
+                FLAC__ASSERT(from->length > 0);
+                if(0 == (x = safe_malloc_add_2op_(from->length, /*+*/1)))
+                        return false;
+                memcpy(x, from->entry, from->length);
+                x[from->length] = '\0';
+                to->entry = x;
+        }
+        return true;
+}
+
+static FLAC__bool copy_track_(FLAC__StreamMetadata_CueSheet_Track *to, const FLAC__StreamMetadata_CueSheet_Track *from)
+{
+        memcpy(to, from, sizeof(FLAC__StreamMetadata_CueSheet_Track));
+        if(0 == from->indices) {
+                FLAC__ASSERT(from->num_indices == 0);
+        }
+        else {
+                FLAC__StreamMetadata_CueSheet_Index *x;
+                FLAC__ASSERT(from->num_indices > 0);
+                if(0 == (x = safe_malloc_mul_2op_p(from->num_indices, /*times*/sizeof(FLAC__StreamMetadata_CueSheet_Index))))
+                        return false;
+                memcpy(x, from->indices, from->num_indices * sizeof(FLAC__StreamMetadata_CueSheet_Index));
+                to->indices = x;
+        }
+        return true;
+}
+
+static void seektable_calculate_length_(FLAC__StreamMetadata *object)
+{
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_SEEKTABLE);
+
+        object->length = object->data.seek_table.num_points * FLAC__STREAM_METADATA_SEEKPOINT_LENGTH;
+}
+
+static FLAC__StreamMetadata_SeekPoint *seekpoint_array_new_(unsigned num_points)
+{
+        FLAC__StreamMetadata_SeekPoint *object_array;
+
+        FLAC__ASSERT(num_points > 0);
+
+        object_array = safe_malloc_mul_2op_p(num_points, /*times*/sizeof(FLAC__StreamMetadata_SeekPoint));
+
+        if(0 != object_array) {
+                unsigned i;
+                for(i = 0; i < num_points; i++) {
+                        object_array[i].sample_number = FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER;
+                        object_array[i].stream_offset = 0;
+                        object_array[i].frame_samples = 0;
+                }
+        }
+
+        return object_array;
+}
+
+static void vorbiscomment_calculate_length_(FLAC__StreamMetadata *object)
+{
+        unsigned i;
+
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
+
+        object->length = (FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN) / 8;
+        object->length += object->data.vorbis_comment.vendor_string.length;
+        object->length += (FLAC__STREAM_METADATA_VORBIS_COMMENT_NUM_COMMENTS_LEN) / 8;
+        for(i = 0; i < object->data.vorbis_comment.num_comments; i++) {
+                object->length += (FLAC__STREAM_METADATA_VORBIS_COMMENT_ENTRY_LENGTH_LEN / 8);
+                object->length += object->data.vorbis_comment.comments[i].length;
+        }
+}
+
+static FLAC__StreamMetadata_VorbisComment_Entry *vorbiscomment_entry_array_new_(unsigned num_comments)
+{
+        FLAC__ASSERT(num_comments > 0);
+
+        return safe_calloc_(num_comments, sizeof(FLAC__StreamMetadata_VorbisComment_Entry));
+}
+
+static void vorbiscomment_entry_array_delete_(FLAC__StreamMetadata_VorbisComment_Entry *object_array, unsigned num_comments)
+{
+        unsigned i;
+
+        FLAC__ASSERT(0 != object_array && num_comments > 0);
+
+        for(i = 0; i < num_comments; i++)
+                if(0 != object_array[i].entry)
+                        free(object_array[i].entry);
+
+        if(0 != object_array)
+                free(object_array);
+}
+
+static FLAC__StreamMetadata_VorbisComment_Entry *vorbiscomment_entry_array_copy_(const FLAC__StreamMetadata_VorbisComment_Entry *object_array, unsigned num_comments)
+{
+        FLAC__StreamMetadata_VorbisComment_Entry *return_array;
+
+        FLAC__ASSERT(0 != object_array);
+        FLAC__ASSERT(num_comments > 0);
+
+        return_array = vorbiscomment_entry_array_new_(num_comments);
+
+        if(0 != return_array) {
+                unsigned i;
+
+                for(i = 0; i < num_comments; i++) {
+                        if(!copy_vcentry_(return_array+i, object_array+i)) {
+                                vorbiscomment_entry_array_delete_(return_array, num_comments);
+                                return 0;
+                        }
+                }
+        }
+
+        return return_array;
+}
+
+static FLAC__bool vorbiscomment_set_entry_(FLAC__StreamMetadata *object, FLAC__StreamMetadata_VorbisComment_Entry *dest, const FLAC__StreamMetadata_VorbisComment_Entry *src, FLAC__bool copy)
+{
+        FLAC__byte *save;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(0 != dest);
+        FLAC__ASSERT(0 != src);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
+        FLAC__ASSERT((0 != src->entry && src->length > 0) || (0 == src->entry && src->length == 0));
+
+        save = dest->entry;
+
+        if(0 != src->entry) {
+                if(copy) {
+                        /* do the copy first so that if we fail we leave the dest object untouched */
+                        if(!copy_vcentry_(dest, src))
+                                return false;
+                }
+                else {
+                        /* we have to make sure that the string we're taking over is null-terminated */
+
+                        /*
+                         * Stripping the const from src->entry is OK since we're taking
+                         * ownership of the pointer.  This is a hack around a deficiency
+                         * in the API where the same function is used for 'copy' and
+                         * 'own', but the source entry is a const pointer.  If we were
+                         * precise, the 'own' flavor would be a separate function with a
+                         * non-const source pointer.  But it's not, so we hack away.
+                         */
+                        if(!ensure_null_terminated_((FLAC__byte**)(&src->entry), src->length))
+                                return false;
+                        *dest = *src;
+                }
+        }
+        else {
+                /* the src is null */
+                *dest = *src;
+        }
+
+        if(0 != save)
+                free(save);
+
+        vorbiscomment_calculate_length_(object);
+        return true;
+}
+
+static int vorbiscomment_find_entry_from_(const FLAC__StreamMetadata *object, unsigned offset, const char *field_name, unsigned field_name_length)
+{
+        unsigned i;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
+        FLAC__ASSERT(0 != field_name);
+
+        for(i = offset; i < object->data.vorbis_comment.num_comments; i++) {
+                if(FLAC__metadata_object_vorbiscomment_entry_matches(object->data.vorbis_comment.comments[i], field_name, field_name_length))
+                        return (int)i;
+        }
+
+        return -1;
+}
+
+static void cuesheet_calculate_length_(FLAC__StreamMetadata *object)
+{
+        unsigned i;
+
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_CUESHEET);
+
+        object->length = (
+                FLAC__STREAM_METADATA_CUESHEET_MEDIA_CATALOG_NUMBER_LEN +
+                FLAC__STREAM_METADATA_CUESHEET_LEAD_IN_LEN +
+                FLAC__STREAM_METADATA_CUESHEET_IS_CD_LEN +
+                FLAC__STREAM_METADATA_CUESHEET_RESERVED_LEN +
+                FLAC__STREAM_METADATA_CUESHEET_NUM_TRACKS_LEN
+        ) / 8;
+
+        object->length += object->data.cue_sheet.num_tracks * (
+                FLAC__STREAM_METADATA_CUESHEET_TRACK_OFFSET_LEN +
+                FLAC__STREAM_METADATA_CUESHEET_TRACK_NUMBER_LEN +
+                FLAC__STREAM_METADATA_CUESHEET_TRACK_ISRC_LEN +
+                FLAC__STREAM_METADATA_CUESHEET_TRACK_TYPE_LEN +
+                FLAC__STREAM_METADATA_CUESHEET_TRACK_PRE_EMPHASIS_LEN +
+                FLAC__STREAM_METADATA_CUESHEET_TRACK_RESERVED_LEN +
+                FLAC__STREAM_METADATA_CUESHEET_TRACK_NUM_INDICES_LEN
+        ) / 8;
+
+        for(i = 0; i < object->data.cue_sheet.num_tracks; i++) {
+                object->length += object->data.cue_sheet.tracks[i].num_indices * (
+                        FLAC__STREAM_METADATA_CUESHEET_INDEX_OFFSET_LEN +
+                        FLAC__STREAM_METADATA_CUESHEET_INDEX_NUMBER_LEN +
+                        FLAC__STREAM_METADATA_CUESHEET_INDEX_RESERVED_LEN
+                ) / 8;
+        }
+}
+
+static FLAC__StreamMetadata_CueSheet_Index *cuesheet_track_index_array_new_(unsigned num_indices)
+{
+        FLAC__ASSERT(num_indices > 0);
+
+        return safe_calloc_(num_indices, sizeof(FLAC__StreamMetadata_CueSheet_Index));
+}
+
+static FLAC__StreamMetadata_CueSheet_Track *cuesheet_track_array_new_(unsigned num_tracks)
+{
+        FLAC__ASSERT(num_tracks > 0);
+
+        return safe_calloc_(num_tracks, sizeof(FLAC__StreamMetadata_CueSheet_Track));
+}
+
+static void cuesheet_track_array_delete_(FLAC__StreamMetadata_CueSheet_Track *object_array, unsigned num_tracks)
+{
+        unsigned i;
+
+        FLAC__ASSERT(0 != object_array && num_tracks > 0);
+
+        for(i = 0; i < num_tracks; i++) {
+                if(0 != object_array[i].indices) {
+                        FLAC__ASSERT(object_array[i].num_indices > 0);
+                        free(object_array[i].indices);
+                }
+        }
+
+        if(0 != object_array)
+                free(object_array);
+}
+
+static FLAC__StreamMetadata_CueSheet_Track *cuesheet_track_array_copy_(const FLAC__StreamMetadata_CueSheet_Track *object_array, unsigned num_tracks)
+{
+        FLAC__StreamMetadata_CueSheet_Track *return_array;
+
+        FLAC__ASSERT(0 != object_array);
+        FLAC__ASSERT(num_tracks > 0);
+
+        return_array = cuesheet_track_array_new_(num_tracks);
+
+        if(0 != return_array) {
+                unsigned i;
+
+                for(i = 0; i < num_tracks; i++) {
+                        if(!copy_track_(return_array+i, object_array+i)) {
+                                cuesheet_track_array_delete_(return_array, num_tracks);
+                                return 0;
+                        }
+                }
+        }
+
+        return return_array;
+}
+
+static FLAC__bool cuesheet_set_track_(FLAC__StreamMetadata *object, FLAC__StreamMetadata_CueSheet_Track *dest, const FLAC__StreamMetadata_CueSheet_Track *src, FLAC__bool copy)
+{
+        FLAC__StreamMetadata_CueSheet_Index *save;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(0 != dest);
+        FLAC__ASSERT(0 != src);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_CUESHEET);
+        FLAC__ASSERT((0 != src->indices && src->num_indices > 0) || (0 == src->indices && src->num_indices == 0));
+
+        save = dest->indices;
+
+        /* do the copy first so that if we fail we leave the object untouched */
+        if(copy) {
+                if(!copy_track_(dest, src))
+                        return false;
+        }
+        else {
+                *dest = *src;
+        }
+
+        if(0 != save)
+                free(save);
+
+        cuesheet_calculate_length_(object);
+        return true;
+}
+
+
+/****************************************************************************
+ *
+ * Metadata object routines
+ *
+ ***************************************************************************/
+
+FLAC_API FLAC__StreamMetadata *FLAC__metadata_object_new(FLAC__MetadataType type)
+{
+        FLAC__StreamMetadata *object;
+
+        if(type > FLAC__MAX_METADATA_TYPE)
+                return 0;
+
+        object = calloc(1, sizeof(FLAC__StreamMetadata));
+        if(0 != object) {
+                object->is_last = false;
+                object->type = type;
+                switch(type) {
+                        case FLAC__METADATA_TYPE_STREAMINFO:
+                                object->length = FLAC__STREAM_METADATA_STREAMINFO_LENGTH;
+                                break;
+                        case FLAC__METADATA_TYPE_PADDING:
+                                /* calloc() took care of this for us:
+                                object->length = 0;
+                                */
+                                break;
+                        case FLAC__METADATA_TYPE_APPLICATION:
+                                object->length = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8;
+                                /* calloc() took care of this for us:
+                                object->data.application.data = 0;
+                                */
+                                break;
+                        case FLAC__METADATA_TYPE_SEEKTABLE:
+                                /* calloc() took care of this for us:
+                                object->length = 0;
+                                object->data.seek_table.num_points = 0;
+                                object->data.seek_table.points = 0;
+                                */
+                                break;
+                        case FLAC__METADATA_TYPE_VORBIS_COMMENT:
+                                object->data.vorbis_comment.vendor_string.length = (unsigned)strlen(FLAC__VENDOR_STRING);
+                                if(!copy_bytes_(&object->data.vorbis_comment.vendor_string.entry, (const FLAC__byte*)FLAC__VENDOR_STRING, object->data.vorbis_comment.vendor_string.length+1)) {
+                                        free(object);
+                                        return 0;
+                                }
+                                vorbiscomment_calculate_length_(object);
+                                break;
+                        case FLAC__METADATA_TYPE_CUESHEET:
+                                cuesheet_calculate_length_(object);
+                                break;
+                        case FLAC__METADATA_TYPE_PICTURE:
+                                object->length = (
+                                        FLAC__STREAM_METADATA_PICTURE_TYPE_LEN +
+                                        FLAC__STREAM_METADATA_PICTURE_MIME_TYPE_LENGTH_LEN + /* empty mime_type string */
+                                        FLAC__STREAM_METADATA_PICTURE_DESCRIPTION_LENGTH_LEN + /* empty description string */
+                                        FLAC__STREAM_METADATA_PICTURE_WIDTH_LEN +
+                                        FLAC__STREAM_METADATA_PICTURE_HEIGHT_LEN +
+                                        FLAC__STREAM_METADATA_PICTURE_DEPTH_LEN +
+                                        FLAC__STREAM_METADATA_PICTURE_COLORS_LEN +
+                                        FLAC__STREAM_METADATA_PICTURE_DATA_LENGTH_LEN +
+                                        0 /* no data */
+                                ) / 8;
+                                object->data.picture.type = FLAC__STREAM_METADATA_PICTURE_TYPE_OTHER;
+                                object->data.picture.mime_type = 0;
+                                object->data.picture.description = 0;
+                                /* calloc() took care of this for us:
+                                object->data.picture.width = 0;
+                                object->data.picture.height = 0;
+                                object->data.picture.depth = 0;
+                                object->data.picture.colors = 0;
+                                object->data.picture.data_length = 0;
+                                object->data.picture.data = 0;
+                                */
+                                /* now initialize mime_type and description with empty strings to make things easier on the client */
+                                if(!copy_cstring_(&object->data.picture.mime_type, "")) {
+                                        free(object);
+                                        return 0;
+                                }
+                                if(!copy_cstring_((char**)(&object->data.picture.description), "")) {
+                                        if(object->data.picture.mime_type)
+                                                free(object->data.picture.mime_type);
+                                        free(object);
+                                        return 0;
+                                }
+                                break;
+                        default:
+                                /* calloc() took care of this for us:
+                                object->length = 0;
+                                object->data.unknown.data = 0;
+                                */
+                                break;
+                }
+        }
+
+        return object;
+}
+
+FLAC_API FLAC__StreamMetadata *FLAC__metadata_object_clone(const FLAC__StreamMetadata *object)
+{
+        FLAC__StreamMetadata *to;
+
+        FLAC__ASSERT(0 != object);
+
+        if(0 != (to = FLAC__metadata_object_new(object->type))) {
+                to->is_last = object->is_last;
+                to->type = object->type;
+                to->length = object->length;
+                switch(to->type) {
+                        case FLAC__METADATA_TYPE_STREAMINFO:
+                                memcpy(&to->data.stream_info, &object->data.stream_info, sizeof(FLAC__StreamMetadata_StreamInfo));
+                                break;
+                        case FLAC__METADATA_TYPE_PADDING:
+                                break;
+                        case FLAC__METADATA_TYPE_APPLICATION:
+                                if(to->length < FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8) { /* underflow check */
+                                        FLAC__metadata_object_delete(to);
+                                        return 0;
+                                }
+                                memcpy(&to->data.application.id, &object->data.application.id, FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8);
+                                if(!copy_bytes_(&to->data.application.data, object->data.application.data, object->length - FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8)) {
+                                        FLAC__metadata_object_delete(to);
+                                        return 0;
+                                }
+                                break;
+                        case FLAC__METADATA_TYPE_SEEKTABLE:
+                                to->data.seek_table.num_points = object->data.seek_table.num_points;
+                                if(to->data.seek_table.num_points > UINT32_MAX / sizeof(FLAC__StreamMetadata_SeekPoint)) { /* overflow check */
+                                        FLAC__metadata_object_delete(to);
+                                        return 0;
+                                }
+                                if(!copy_bytes_((FLAC__byte**)&to->data.seek_table.points, (FLAC__byte*)object->data.seek_table.points, object->data.seek_table.num_points * sizeof(FLAC__StreamMetadata_SeekPoint))) {
+                                        FLAC__metadata_object_delete(to);
+                                        return 0;
+                                }
+                                break;
+                        case FLAC__METADATA_TYPE_VORBIS_COMMENT:
+                                if(0 != to->data.vorbis_comment.vendor_string.entry) {
+                                        free(to->data.vorbis_comment.vendor_string.entry);
+                                        to->data.vorbis_comment.vendor_string.entry = 0;
+                                }
+                                if(!copy_vcentry_(&to->data.vorbis_comment.vendor_string, &object->data.vorbis_comment.vendor_string)) {
+                                        FLAC__metadata_object_delete(to);
+                                        return 0;
+                                }
+                                if(object->data.vorbis_comment.num_comments == 0) {
+                                        FLAC__ASSERT(0 == object->data.vorbis_comment.comments);
+                                        to->data.vorbis_comment.comments = 0;
+                                }
+                                else {
+                                        FLAC__ASSERT(0 != object->data.vorbis_comment.comments);
+                                        to->data.vorbis_comment.comments = vorbiscomment_entry_array_copy_(object->data.vorbis_comment.comments, object->data.vorbis_comment.num_comments);
+                                        if(0 == to->data.vorbis_comment.comments) {
+                                                FLAC__metadata_object_delete(to);
+                                                return 0;
+                                        }
+                                }
+                                to->data.vorbis_comment.num_comments = object->data.vorbis_comment.num_comments;
+                                break;
+                        case FLAC__METADATA_TYPE_CUESHEET:
+                                memcpy(&to->data.cue_sheet, &object->data.cue_sheet, sizeof(FLAC__StreamMetadata_CueSheet));
+                                if(object->data.cue_sheet.num_tracks == 0) {
+                                        FLAC__ASSERT(0 == object->data.cue_sheet.tracks);
+                                }
+                                else {
+                                        FLAC__ASSERT(0 != object->data.cue_sheet.tracks);
+                                        to->data.cue_sheet.tracks = cuesheet_track_array_copy_(object->data.cue_sheet.tracks, object->data.cue_sheet.num_tracks);
+                                        if(0 == to->data.cue_sheet.tracks) {
+                                                FLAC__metadata_object_delete(to);
+                                                return 0;
+                                        }
+                                }
+                                break;
+                        case FLAC__METADATA_TYPE_PICTURE:
+                                to->data.picture.type = object->data.picture.type;
+                                if(!copy_cstring_(&to->data.picture.mime_type, object->data.picture.mime_type)) {
+                                        FLAC__metadata_object_delete(to);
+                                        return 0;
+                                }
+                                if(!copy_cstring_((char**)(&to->data.picture.description), (const char*)object->data.picture.description)) {
+                                        FLAC__metadata_object_delete(to);
+                                        return 0;
+                                }
+                                to->data.picture.width = object->data.picture.width;
+                                to->data.picture.height = object->data.picture.height;
+                                to->data.picture.depth = object->data.picture.depth;
+                                to->data.picture.colors = object->data.picture.colors;
+                                to->data.picture.data_length = object->data.picture.data_length;
+                                if(!copy_bytes_((&to->data.picture.data), object->data.picture.data, object->data.picture.data_length)) {
+                                        FLAC__metadata_object_delete(to);
+                                        return 0;
+                                }
+                                break;
+                        default:
+                                if(!copy_bytes_(&to->data.unknown.data, object->data.unknown.data, object->length)) {
+                                        FLAC__metadata_object_delete(to);
+                                        return 0;
+                                }
+                                break;
+                }
+        }
+
+        return to;
+}
+
+void FLAC__metadata_object_delete_data(FLAC__StreamMetadata *object)
+{
+        FLAC__ASSERT(0 != object);
+
+        switch(object->type) {
+                case FLAC__METADATA_TYPE_STREAMINFO:
+                case FLAC__METADATA_TYPE_PADDING:
+                        break;
+                case FLAC__METADATA_TYPE_APPLICATION:
+                        if(0 != object->data.application.data) {
+                                free(object->data.application.data);
+                                object->data.application.data = 0;
+                        }
+                        break;
+                case FLAC__METADATA_TYPE_SEEKTABLE:
+                        if(0 != object->data.seek_table.points) {
+                                free(object->data.seek_table.points);
+                                object->data.seek_table.points = 0;
+                        }
+                        break;
+                case FLAC__METADATA_TYPE_VORBIS_COMMENT:
+                        if(0 != object->data.vorbis_comment.vendor_string.entry) {
+                                free(object->data.vorbis_comment.vendor_string.entry);
+                                object->data.vorbis_comment.vendor_string.entry = 0;
+                        }
+                        if(0 != object->data.vorbis_comment.comments) {
+                                FLAC__ASSERT(object->data.vorbis_comment.num_comments > 0);
+                                vorbiscomment_entry_array_delete_(object->data.vorbis_comment.comments, object->data.vorbis_comment.num_comments);
+                        }
+                        break;
+                case FLAC__METADATA_TYPE_CUESHEET:
+                        if(0 != object->data.cue_sheet.tracks) {
+                                FLAC__ASSERT(object->data.cue_sheet.num_tracks > 0);
+                                cuesheet_track_array_delete_(object->data.cue_sheet.tracks, object->data.cue_sheet.num_tracks);
+                        }
+                        break;
+                case FLAC__METADATA_TYPE_PICTURE:
+                        if(0 != object->data.picture.mime_type) {
+                                free(object->data.picture.mime_type);
+                                object->data.picture.mime_type = 0;
+                        }
+                        if(0 != object->data.picture.description) {
+                                free(object->data.picture.description);
+                                object->data.picture.description = 0;
+                        }
+                        if(0 != object->data.picture.data) {
+                                free(object->data.picture.data);
+                                object->data.picture.data = 0;
+                        }
+                        break;
+                default:
+                        if(0 != object->data.unknown.data) {
+                                free(object->data.unknown.data);
+                                object->data.unknown.data = 0;
+                        }
+                        break;
+        }
+}
+
+FLAC_API void FLAC__metadata_object_delete(FLAC__StreamMetadata *object)
+{
+        FLAC__metadata_object_delete_data(object);
+        free(object);
+}
+
+static FLAC__bool compare_block_data_streaminfo_(const FLAC__StreamMetadata_StreamInfo *block1, const FLAC__StreamMetadata_StreamInfo *block2)
+{
+        if(block1->min_blocksize != block2->min_blocksize)
+                return false;
+        if(block1->max_blocksize != block2->max_blocksize)
+                return false;
+        if(block1->min_framesize != block2->min_framesize)
+                return false;
+        if(block1->max_framesize != block2->max_framesize)
+                return false;
+        if(block1->sample_rate != block2->sample_rate)
+                return false;
+        if(block1->channels != block2->channels)
+                return false;
+        if(block1->bits_per_sample != block2->bits_per_sample)
+                return false;
+        if(block1->total_samples != block2->total_samples)
+                return false;
+        if(0 != memcmp(block1->md5sum, block2->md5sum, 16))
+                return false;
+        return true;
+}
+
+static FLAC__bool compare_block_data_application_(const FLAC__StreamMetadata_Application *block1, const FLAC__StreamMetadata_Application *block2, unsigned block_length)
+{
+        FLAC__ASSERT(0 != block1);
+        FLAC__ASSERT(0 != block2);
+        FLAC__ASSERT(block_length >= sizeof(block1->id));
+
+        if(0 != memcmp(block1->id, block2->id, sizeof(block1->id)))
+                return false;
+        if(0 != block1->data && 0 != block2->data)
+                return 0 == memcmp(block1->data, block2->data, block_length - sizeof(block1->id));
+        else
+                return block1->data == block2->data;
+}
+
+static FLAC__bool compare_block_data_seektable_(const FLAC__StreamMetadata_SeekTable *block1, const FLAC__StreamMetadata_SeekTable *block2)
+{
+        unsigned i;
+
+        FLAC__ASSERT(0 != block1);
+        FLAC__ASSERT(0 != block2);
+
+        if(block1->num_points != block2->num_points)
+                return false;
+
+        if(0 != block1->points && 0 != block2->points) {
+                for(i = 0; i < block1->num_points; i++) {
+                        if(block1->points[i].sample_number != block2->points[i].sample_number)
+                                return false;
+                        if(block1->points[i].stream_offset != block2->points[i].stream_offset)
+                                return false;
+                        if(block1->points[i].frame_samples != block2->points[i].frame_samples)
+                                return false;
+                }
+                return true;
+        }
+        else
+                return block1->points == block2->points;
+}
+
+static FLAC__bool compare_block_data_vorbiscomment_(const FLAC__StreamMetadata_VorbisComment *block1, const FLAC__StreamMetadata_VorbisComment *block2)
+{
+        unsigned i;
+
+        if(block1->vendor_string.length != block2->vendor_string.length)
+                return false;
+
+        if(0 != block1->vendor_string.entry && 0 != block2->vendor_string.entry) {
+                if(0 != memcmp(block1->vendor_string.entry, block2->vendor_string.entry, block1->vendor_string.length))
+                        return false;
+        }
+        else if(block1->vendor_string.entry != block2->vendor_string.entry)
+                return false;
+
+        if(block1->num_comments != block2->num_comments)
+                return false;
+
+        for(i = 0; i < block1->num_comments; i++) {
+                if(0 != block1->comments[i].entry && 0 != block2->comments[i].entry) {
+                        if(0 != memcmp(block1->comments[i].entry, block2->comments[i].entry, block1->comments[i].length))
+                                return false;
+                }
+                else if(block1->comments[i].entry != block2->comments[i].entry)
+                        return false;
+        }
+        return true;
+}
+
+static FLAC__bool compare_block_data_cuesheet_(const FLAC__StreamMetadata_CueSheet *block1, const FLAC__StreamMetadata_CueSheet *block2)
+{
+        unsigned i, j;
+
+        if(0 != strcmp(block1->media_catalog_number, block2->media_catalog_number))
+                return false;
+
+        if(block1->lead_in != block2->lead_in)
+                return false;
+
+        if(block1->is_cd != block2->is_cd)
+                return false;
+
+        if(block1->num_tracks != block2->num_tracks)
+                return false;
+
+        if(0 != block1->tracks && 0 != block2->tracks) {
+                FLAC__ASSERT(block1->num_tracks > 0);
+                for(i = 0; i < block1->num_tracks; i++) {
+                        if(block1->tracks[i].offset != block2->tracks[i].offset)
+                                return false;
+                        if(block1->tracks[i].number != block2->tracks[i].number)
+                                return false;
+                        if(0 != memcmp(block1->tracks[i].isrc, block2->tracks[i].isrc, sizeof(block1->tracks[i].isrc)))
+                                return false;
+                        if(block1->tracks[i].type != block2->tracks[i].type)
+                                return false;
+                        if(block1->tracks[i].pre_emphasis != block2->tracks[i].pre_emphasis)
+                                return false;
+                        if(block1->tracks[i].num_indices != block2->tracks[i].num_indices)
+                                return false;
+                        if(0 != block1->tracks[i].indices && 0 != block2->tracks[i].indices) {
+                                FLAC__ASSERT(block1->tracks[i].num_indices > 0);
+                                for(j = 0; j < block1->tracks[i].num_indices; j++) {
+                                        if(block1->tracks[i].indices[j].offset != block2->tracks[i].indices[j].offset)
+                                                return false;
+                                        if(block1->tracks[i].indices[j].number != block2->tracks[i].indices[j].number)
+                                                return false;
+                                }
+                        }
+                        else if(block1->tracks[i].indices != block2->tracks[i].indices)
+                                return false;
+                }
+        }
+        else if(block1->tracks != block2->tracks)
+                return false;
+        return true;
+}
+
+static FLAC__bool compare_block_data_picture_(const FLAC__StreamMetadata_Picture *block1, const FLAC__StreamMetadata_Picture *block2)
+{
+        if(block1->type != block2->type)
+                return false;
+        if(block1->mime_type != block2->mime_type && (0 == block1->mime_type || 0 == block2->mime_type || strcmp(block1->mime_type, block2->mime_type)))
+                return false;
+        if(block1->description != block2->description && (0 == block1->description || 0 == block2->description || strcmp((const char *)block1->description, (const char *)block2->description)))
+                return false;
+        if(block1->width != block2->width)
+                return false;
+        if(block1->height != block2->height)
+                return false;
+        if(block1->depth != block2->depth)
+                return false;
+        if(block1->colors != block2->colors)
+                return false;
+        if(block1->data_length != block2->data_length)
+                return false;
+        if(block1->data != block2->data && (0 == block1->data || 0 == block2->data || memcmp(block1->data, block2->data, block1->data_length)))
+                return false;
+        return true;
+}
+
+static FLAC__bool compare_block_data_unknown_(const FLAC__StreamMetadata_Unknown *block1, const FLAC__StreamMetadata_Unknown *block2, unsigned block_length)
+{
+        FLAC__ASSERT(0 != block1);
+        FLAC__ASSERT(0 != block2);
+
+        if(0 != block1->data && 0 != block2->data)
+                return 0 == memcmp(block1->data, block2->data, block_length);
+        else
+                return block1->data == block2->data;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_is_equal(const FLAC__StreamMetadata *block1, const FLAC__StreamMetadata *block2)
+{
+        FLAC__ASSERT(0 != block1);
+        FLAC__ASSERT(0 != block2);
+
+        if(block1->type != block2->type) {
+                return false;
+        }
+        if(block1->is_last != block2->is_last) {
+                return false;
+        }
+        if(block1->length != block2->length) {
+                return false;
+        }
+        switch(block1->type) {
+                case FLAC__METADATA_TYPE_STREAMINFO:
+                        return compare_block_data_streaminfo_(&block1->data.stream_info, &block2->data.stream_info);
+                case FLAC__METADATA_TYPE_PADDING:
+                        return true; /* we don't compare the padding guts */
+                case FLAC__METADATA_TYPE_APPLICATION:
+                        return compare_block_data_application_(&block1->data.application, &block2->data.application, block1->length);
+                case FLAC__METADATA_TYPE_SEEKTABLE:
+                        return compare_block_data_seektable_(&block1->data.seek_table, &block2->data.seek_table);
+                case FLAC__METADATA_TYPE_VORBIS_COMMENT:
+                        return compare_block_data_vorbiscomment_(&block1->data.vorbis_comment, &block2->data.vorbis_comment);
+                case FLAC__METADATA_TYPE_CUESHEET:
+                        return compare_block_data_cuesheet_(&block1->data.cue_sheet, &block2->data.cue_sheet);
+                case FLAC__METADATA_TYPE_PICTURE:
+                        return compare_block_data_picture_(&block1->data.picture, &block2->data.picture);
+                default:
+                        return compare_block_data_unknown_(&block1->data.unknown, &block2->data.unknown, block1->length);
+        }
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_application_set_data(FLAC__StreamMetadata *object, FLAC__byte *data, unsigned length, FLAC__bool copy)
+{
+        FLAC__byte *save;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_APPLICATION);
+        FLAC__ASSERT((0 != data && length > 0) || (0 == data && length == 0 && copy == false));
+
+        save = object->data.application.data;
+
+        /* do the copy first so that if we fail we leave the object untouched */
+        if(copy) {
+                if(!copy_bytes_(&object->data.application.data, data, length))
+                        return false;
+        }
+        else {
+                object->data.application.data = data;
+        }
+
+        if(0 != save)
+                free(save);
+
+        object->length = FLAC__STREAM_METADATA_APPLICATION_ID_LEN / 8 + length;
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_seektable_resize_points(FLAC__StreamMetadata *object, unsigned new_num_points)
+{
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_SEEKTABLE);
+
+        if(0 == object->data.seek_table.points) {
+                FLAC__ASSERT(object->data.seek_table.num_points == 0);
+                if(0 == new_num_points)
+                        return true;
+                else if(0 == (object->data.seek_table.points = seekpoint_array_new_(new_num_points)))
+                        return false;
+        }
+        else {
+                const size_t old_size = object->data.seek_table.num_points * sizeof(FLAC__StreamMetadata_SeekPoint);
+                const size_t new_size = new_num_points * sizeof(FLAC__StreamMetadata_SeekPoint);
+
+                /* overflow check */
+                if(new_num_points > UINT32_MAX / sizeof(FLAC__StreamMetadata_SeekPoint))
+                        return false;
+
+                FLAC__ASSERT(object->data.seek_table.num_points > 0);
+
+                if(new_size == 0) {
+                        free(object->data.seek_table.points);
+                        object->data.seek_table.points = 0;
+                }
+                else if(0 == (object->data.seek_table.points = realloc(object->data.seek_table.points, new_size)))
+                        return false;
+
+                /* if growing, set new elements to placeholders */
+                if(new_size > old_size) {
+                        unsigned i;
+                        for(i = object->data.seek_table.num_points; i < new_num_points; i++) {
+                                object->data.seek_table.points[i].sample_number = FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER;
+                                object->data.seek_table.points[i].stream_offset = 0;
+                                object->data.seek_table.points[i].frame_samples = 0;
+                        }
+                }
+        }
+
+        object->data.seek_table.num_points = new_num_points;
+
+        seektable_calculate_length_(object);
+        return true;
+}
+
+FLAC_API void FLAC__metadata_object_seektable_set_point(FLAC__StreamMetadata *object, unsigned point_num, FLAC__StreamMetadata_SeekPoint point)
+{
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_SEEKTABLE);
+        FLAC__ASSERT(point_num < object->data.seek_table.num_points);
+
+        object->data.seek_table.points[point_num] = point;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_seektable_insert_point(FLAC__StreamMetadata *object, unsigned point_num, FLAC__StreamMetadata_SeekPoint point)
+{
+        int i;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_SEEKTABLE);
+        FLAC__ASSERT(point_num <= object->data.seek_table.num_points);
+
+        if(!FLAC__metadata_object_seektable_resize_points(object, object->data.seek_table.num_points+1))
+                return false;
+
+        /* move all points >= point_num forward one space */
+        for(i = (int)object->data.seek_table.num_points-1; i > (int)point_num; i--)
+                object->data.seek_table.points[i] = object->data.seek_table.points[i-1];
+
+        FLAC__metadata_object_seektable_set_point(object, point_num, point);
+        seektable_calculate_length_(object);
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_seektable_delete_point(FLAC__StreamMetadata *object, unsigned point_num)
+{
+        unsigned i;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_SEEKTABLE);
+        FLAC__ASSERT(point_num < object->data.seek_table.num_points);
+
+        /* move all points > point_num backward one space */
+        for(i = point_num; i < object->data.seek_table.num_points-1; i++)
+                object->data.seek_table.points[i] = object->data.seek_table.points[i+1];
+
+        return FLAC__metadata_object_seektable_resize_points(object, object->data.seek_table.num_points-1);
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_seektable_is_legal(const FLAC__StreamMetadata *object)
+{
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_SEEKTABLE);
+
+        return FLAC__format_seektable_is_legal(&object->data.seek_table);
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_placeholders(FLAC__StreamMetadata *object, unsigned num)
+{
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_SEEKTABLE);
+
+        if(num > 0)
+                /* WATCHOUT: we rely on the fact that growing the array adds PLACEHOLDERS at the end */
+                return FLAC__metadata_object_seektable_resize_points(object, object->data.seek_table.num_points + num);
+        else
+                return true;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_point(FLAC__StreamMetadata *object, FLAC__uint64 sample_number)
+{
+        FLAC__StreamMetadata_SeekTable *seek_table;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_SEEKTABLE);
+
+        seek_table = &object->data.seek_table;
+
+        if(!FLAC__metadata_object_seektable_resize_points(object, seek_table->num_points + 1))
+                return false;
+
+        seek_table->points[seek_table->num_points - 1].sample_number = sample_number;
+        seek_table->points[seek_table->num_points - 1].stream_offset = 0;
+        seek_table->points[seek_table->num_points - 1].frame_samples = 0;
+
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_points(FLAC__StreamMetadata *object, FLAC__uint64 sample_numbers[], unsigned num)
+{
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_SEEKTABLE);
+        FLAC__ASSERT(0 != sample_numbers || num == 0);
+
+        if(num > 0) {
+                FLAC__StreamMetadata_SeekTable *seek_table = &object->data.seek_table;
+                unsigned i, j;
+
+                i = seek_table->num_points;
+
+                if(!FLAC__metadata_object_seektable_resize_points(object, seek_table->num_points + num))
+                        return false;
+
+                for(j = 0; j < num; i++, j++) {
+                        seek_table->points[i].sample_number = sample_numbers[j];
+                        seek_table->points[i].stream_offset = 0;
+                        seek_table->points[i].frame_samples = 0;
+                }
+        }
+
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_spaced_points(FLAC__StreamMetadata *object, unsigned num, FLAC__uint64 total_samples)
+{
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_SEEKTABLE);
+        FLAC__ASSERT(total_samples > 0);
+
+        if(num > 0 && total_samples > 0) {
+                FLAC__StreamMetadata_SeekTable *seek_table = &object->data.seek_table;
+                unsigned i, j;
+
+                i = seek_table->num_points;
+
+                if(!FLAC__metadata_object_seektable_resize_points(object, seek_table->num_points + num))
+                        return false;
+
+                for(j = 0; j < num; i++, j++) {
+                        seek_table->points[i].sample_number = total_samples * (FLAC__uint64)j / (FLAC__uint64)num;
+                        seek_table->points[i].stream_offset = 0;
+                        seek_table->points[i].frame_samples = 0;
+                }
+        }
+
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_append_spaced_points_by_samples(FLAC__StreamMetadata *object, unsigned samples, FLAC__uint64 total_samples)
+{
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_SEEKTABLE);
+        FLAC__ASSERT(samples > 0);
+        FLAC__ASSERT(total_samples > 0);
+
+        if(samples > 0 && total_samples > 0) {
+                FLAC__StreamMetadata_SeekTable *seek_table = &object->data.seek_table;
+                unsigned i, j;
+                FLAC__uint64 num, sample;
+
+                num = 1 + total_samples / samples; /* 1+ for the first sample at 0 */
+                /* now account for the fact that we don't place a seekpoint at "total_samples" since samples are number from 0: */
+                if(total_samples % samples == 0)
+                        num--;
+
+                i = seek_table->num_points;
+
+                if(!FLAC__metadata_object_seektable_resize_points(object, seek_table->num_points + (unsigned)num))
+                        return false;
+
+                sample = 0;
+                for(j = 0; j < num; i++, j++, sample += samples) {
+                        seek_table->points[i].sample_number = sample;
+                        seek_table->points[i].stream_offset = 0;
+                        seek_table->points[i].frame_samples = 0;
+                }
+        }
+
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_seektable_template_sort(FLAC__StreamMetadata *object, FLAC__bool compact)
+{
+        unsigned unique;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_SEEKTABLE);
+
+        unique = FLAC__format_seektable_sort(&object->data.seek_table);
+
+        return !compact || FLAC__metadata_object_seektable_resize_points(object, unique);
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_set_vendor_string(FLAC__StreamMetadata *object, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool copy)
+{
+        if(!FLAC__format_vorbiscomment_entry_value_is_legal(entry.entry, entry.length))
+                return false;
+        return vorbiscomment_set_entry_(object, &object->data.vorbis_comment.vendor_string, &entry, copy);
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_resize_comments(FLAC__StreamMetadata *object, unsigned new_num_comments)
+{
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
+
+        if(0 == object->data.vorbis_comment.comments) {
+                FLAC__ASSERT(object->data.vorbis_comment.num_comments == 0);
+                if(0 == new_num_comments)
+                        return true;
+                else if(0 == (object->data.vorbis_comment.comments = vorbiscomment_entry_array_new_(new_num_comments)))
+                        return false;
+        }
+        else {
+                const size_t old_size = object->data.vorbis_comment.num_comments * sizeof(FLAC__StreamMetadata_VorbisComment_Entry);
+                const size_t new_size = new_num_comments * sizeof(FLAC__StreamMetadata_VorbisComment_Entry);
+
+                /* overflow check */
+                if(new_num_comments > UINT32_MAX / sizeof(FLAC__StreamMetadata_VorbisComment_Entry))
+                        return false;
+
+                FLAC__ASSERT(object->data.vorbis_comment.num_comments > 0);
+
+                /* if shrinking, free the truncated entries */
+                if(new_num_comments < object->data.vorbis_comment.num_comments) {
+                        unsigned i;
+                        for(i = new_num_comments; i < object->data.vorbis_comment.num_comments; i++)
+                                if(0 != object->data.vorbis_comment.comments[i].entry)
+                                        free(object->data.vorbis_comment.comments[i].entry);
+                }
+
+                if(new_size == 0) {
+                        free(object->data.vorbis_comment.comments);
+                        object->data.vorbis_comment.comments = 0;
+                }
+                else if(0 == (object->data.vorbis_comment.comments = realloc(object->data.vorbis_comment.comments, new_size)))
+                        return false;
+
+                /* if growing, zero all the length/pointers of new elements */
+                if(new_size > old_size)
+                        memset(object->data.vorbis_comment.comments + object->data.vorbis_comment.num_comments, 0, new_size - old_size);
+        }
+
+        object->data.vorbis_comment.num_comments = new_num_comments;
+
+        vorbiscomment_calculate_length_(object);
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_set_comment(FLAC__StreamMetadata *object, unsigned comment_num, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool copy)
+{
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(comment_num < object->data.vorbis_comment.num_comments);
+
+        if(!FLAC__format_vorbiscomment_entry_is_legal(entry.entry, entry.length))
+                return false;
+        return vorbiscomment_set_entry_(object, &object->data.vorbis_comment.comments[comment_num], &entry, copy);
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_insert_comment(FLAC__StreamMetadata *object, unsigned comment_num, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool copy)
+{
+        FLAC__StreamMetadata_VorbisComment *vc;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
+        FLAC__ASSERT(comment_num <= object->data.vorbis_comment.num_comments);
+
+        if(!FLAC__format_vorbiscomment_entry_is_legal(entry.entry, entry.length))
+                return false;
+
+        vc = &object->data.vorbis_comment;
+
+        if(!FLAC__metadata_object_vorbiscomment_resize_comments(object, vc->num_comments+1))
+                return false;
+
+        /* move all comments >= comment_num forward one space */
+        memmove(&vc->comments[comment_num+1], &vc->comments[comment_num], sizeof(FLAC__StreamMetadata_VorbisComment_Entry)*(vc->num_comments-1-comment_num));
+        vc->comments[comment_num].length = 0;
+        vc->comments[comment_num].entry = 0;
+
+        return FLAC__metadata_object_vorbiscomment_set_comment(object, comment_num, entry, copy);
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_append_comment(FLAC__StreamMetadata *object, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool copy)
+{
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
+        return FLAC__metadata_object_vorbiscomment_insert_comment(object, object->data.vorbis_comment.num_comments, entry, copy);
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_replace_comment(FLAC__StreamMetadata *object, FLAC__StreamMetadata_VorbisComment_Entry entry, FLAC__bool all, FLAC__bool copy)
+{
+        FLAC__ASSERT(0 != entry.entry && entry.length > 0);
+
+        if(!FLAC__format_vorbiscomment_entry_is_legal(entry.entry, entry.length))
+                return false;
+
+        {
+                int i;
+                size_t field_name_length;
+                const FLAC__byte *eq = (FLAC__byte*)memchr(entry.entry, '=', entry.length);
+
+                FLAC__ASSERT(0 != eq);
+
+                if(0 == eq)
+                        return false; /* double protection */
+
+                field_name_length = eq-entry.entry;
+
+                i = vorbiscomment_find_entry_from_(object, 0, (const char *)entry.entry, field_name_length);
+                if(i >= 0) {
+                        unsigned indx = (unsigned)i;
+                        if(!FLAC__metadata_object_vorbiscomment_set_comment(object, indx, entry, copy))
+                                return false;
+                        entry = object->data.vorbis_comment.comments[indx];
+                        indx++; /* skip over replaced comment */
+                        if(all && indx < object->data.vorbis_comment.num_comments) {
+                                i = vorbiscomment_find_entry_from_(object, indx, (const char *)entry.entry, field_name_length);
+                                while(i >= 0) {
+                                        indx = (unsigned)i;
+                                        if(!FLAC__metadata_object_vorbiscomment_delete_comment(object, indx))
+                                                return false;
+                                        if(indx < object->data.vorbis_comment.num_comments)
+                                                i = vorbiscomment_find_entry_from_(object, indx, (const char *)entry.entry, field_name_length);
+                                        else
+                                                i = -1;
+                                }
+                        }
+                        return true;
+                }
+                else
+                        return FLAC__metadata_object_vorbiscomment_append_comment(object, entry, copy);
+        }
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_delete_comment(FLAC__StreamMetadata *object, unsigned comment_num)
+{
+        FLAC__StreamMetadata_VorbisComment *vc;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
+        FLAC__ASSERT(comment_num < object->data.vorbis_comment.num_comments);
+
+        vc = &object->data.vorbis_comment;
+
+        /* free the comment at comment_num */
+        if(0 != vc->comments[comment_num].entry)
+                free(vc->comments[comment_num].entry);
+
+        /* move all comments > comment_num backward one space */
+        memmove(&vc->comments[comment_num], &vc->comments[comment_num+1], sizeof(FLAC__StreamMetadata_VorbisComment_Entry)*(vc->num_comments-comment_num-1));
+        vc->comments[vc->num_comments-1].length = 0;
+        vc->comments[vc->num_comments-1].entry = 0;
+
+        return FLAC__metadata_object_vorbiscomment_resize_comments(object, vc->num_comments-1);
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_entry_from_name_value_pair(FLAC__StreamMetadata_VorbisComment_Entry *entry, const char *field_name, const char *field_value)
+{
+        FLAC__ASSERT(0 != entry);
+        FLAC__ASSERT(0 != field_name);
+        FLAC__ASSERT(0 != field_value);
+
+        if(!FLAC__format_vorbiscomment_entry_name_is_legal(field_name))
+                return false;
+        if(!FLAC__format_vorbiscomment_entry_value_is_legal((const FLAC__byte *)field_value, (unsigned)(-1)))
+                return false;
+
+        {
+                const size_t nn = strlen(field_name);
+                const size_t nv = strlen(field_value);
+                entry->length = nn + 1 /*=*/ + nv;
+                if(0 == (entry->entry = safe_malloc_add_4op_(nn, /*+*/1, /*+*/nv, /*+*/1)))
+                        return false;
+                memcpy(entry->entry, field_name, nn);
+                entry->entry[nn] = '=';
+                memcpy(entry->entry+nn+1, field_value, nv);
+                entry->entry[entry->length] = '\0';
+        }
+
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_entry_to_name_value_pair(const FLAC__StreamMetadata_VorbisComment_Entry entry, char **field_name, char **field_value)
+{
+        FLAC__ASSERT(0 != entry.entry && entry.length > 0);
+        FLAC__ASSERT(0 != field_name);
+        FLAC__ASSERT(0 != field_value);
+
+        if(!FLAC__format_vorbiscomment_entry_is_legal(entry.entry, entry.length))
+                return false;
+
+        {
+                const FLAC__byte *eq = (FLAC__byte*)memchr(entry.entry, '=', entry.length);
+                const size_t nn = eq-entry.entry;
+                const size_t nv = entry.length-nn-1; /* -1 for the '=' */
+                FLAC__ASSERT(0 != eq);
+                if(0 == eq)
+                        return false; /* double protection */
+                if(0 == (*field_name = safe_malloc_add_2op_(nn, /*+*/1)))
+                        return false;
+                if(0 == (*field_value = safe_malloc_add_2op_(nv, /*+*/1))) {
+                        free(*field_name);
+                        return false;
+                }
+                memcpy(*field_name, entry.entry, nn);
+                memcpy(*field_value, entry.entry+nn+1, nv);
+                (*field_name)[nn] = '\0';
+                (*field_value)[nv] = '\0';
+        }
+
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_vorbiscomment_entry_matches(const FLAC__StreamMetadata_VorbisComment_Entry entry, const char *field_name, unsigned field_name_length)
+{
+        FLAC__ASSERT(0 != entry.entry && entry.length > 0);
+        {
+                const FLAC__byte *eq = (FLAC__byte*)memchr(entry.entry, '=', entry.length);
+                return (0 != eq && (unsigned)(eq-entry.entry) == field_name_length && 0 == FLAC__STRNCASECMP(field_name, (const char *)entry.entry, field_name_length));
+        }
+}
+
+FLAC_API int FLAC__metadata_object_vorbiscomment_find_entry_from(const FLAC__StreamMetadata *object, unsigned offset, const char *field_name)
+{
+        FLAC__ASSERT(0 != field_name);
+
+        return vorbiscomment_find_entry_from_(object, offset, field_name, strlen(field_name));
+}
+
+FLAC_API int FLAC__metadata_object_vorbiscomment_remove_entry_matching(FLAC__StreamMetadata *object, const char *field_name)
+{
+        const unsigned field_name_length = strlen(field_name);
+        unsigned i;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
+
+        for(i = 0; i < object->data.vorbis_comment.num_comments; i++) {
+                if(FLAC__metadata_object_vorbiscomment_entry_matches(object->data.vorbis_comment.comments[i], field_name, field_name_length)) {
+                        if(!FLAC__metadata_object_vorbiscomment_delete_comment(object, i))
+                                return -1;
+                        else
+                                return 1;
+                }
+        }
+
+        return 0;
+}
+
+FLAC_API int FLAC__metadata_object_vorbiscomment_remove_entries_matching(FLAC__StreamMetadata *object, const char *field_name)
+{
+        FLAC__bool ok = true;
+        unsigned matching = 0;
+        const unsigned field_name_length = strlen(field_name);
+        int i;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_VORBIS_COMMENT);
+
+        /* must delete from end to start otherwise it will interfere with our iteration */
+        for(i = (int)object->data.vorbis_comment.num_comments - 1; ok && i >= 0; i--) {
+                if(FLAC__metadata_object_vorbiscomment_entry_matches(object->data.vorbis_comment.comments[i], field_name, field_name_length)) {
+                        matching++;
+                        ok &= FLAC__metadata_object_vorbiscomment_delete_comment(object, (unsigned)i);
+                }
+        }
+
+        return ok? (int)matching : -1;
+}
+
+FLAC_API FLAC__StreamMetadata_CueSheet_Track *FLAC__metadata_object_cuesheet_track_new(void)
+{
+        return calloc(1, sizeof(FLAC__StreamMetadata_CueSheet_Track));
+}
+
+FLAC_API FLAC__StreamMetadata_CueSheet_Track *FLAC__metadata_object_cuesheet_track_clone(const FLAC__StreamMetadata_CueSheet_Track *object)
+{
+        FLAC__StreamMetadata_CueSheet_Track *to;
+
+        FLAC__ASSERT(0 != object);
+
+        if(0 != (to = FLAC__metadata_object_cuesheet_track_new())) {
+                if(!copy_track_(to, object)) {
+                        FLAC__metadata_object_cuesheet_track_delete(to);
+                        return 0;
+                }
+        }
+
+        return to;
+}
+
+void FLAC__metadata_object_cuesheet_track_delete_data(FLAC__StreamMetadata_CueSheet_Track *object)
+{
+        FLAC__ASSERT(0 != object);
+
+        if(0 != object->indices) {
+                FLAC__ASSERT(object->num_indices > 0);
+                free(object->indices);
+        }
+}
+
+FLAC_API void FLAC__metadata_object_cuesheet_track_delete(FLAC__StreamMetadata_CueSheet_Track *object)
+{
+        FLAC__metadata_object_cuesheet_track_delete_data(object);
+        free(object);
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_track_resize_indices(FLAC__StreamMetadata *object, unsigned track_num, unsigned new_num_indices)
+{
+        FLAC__StreamMetadata_CueSheet_Track *track;
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_CUESHEET);
+        FLAC__ASSERT(track_num < object->data.cue_sheet.num_tracks);
+
+        track = &object->data.cue_sheet.tracks[track_num];
+
+        if(0 == track->indices) {
+                FLAC__ASSERT(track->num_indices == 0);
+                if(0 == new_num_indices)
+                        return true;
+                else if(0 == (track->indices = cuesheet_track_index_array_new_(new_num_indices)))
+                        return false;
+        }
+        else {
+                const size_t old_size = track->num_indices * sizeof(FLAC__StreamMetadata_CueSheet_Index);
+                const size_t new_size = new_num_indices * sizeof(FLAC__StreamMetadata_CueSheet_Index);
+
+                /* overflow check */
+                if(new_num_indices > UINT32_MAX / sizeof(FLAC__StreamMetadata_CueSheet_Index))
+                        return false;
+
+                FLAC__ASSERT(track->num_indices > 0);
+
+                if(new_size == 0) {
+                        free(track->indices);
+                        track->indices = 0;
+                }
+                else if(0 == (track->indices = realloc(track->indices, new_size)))
+                        return false;
+
+                /* if growing, zero all the lengths/pointers of new elements */
+                if(new_size > old_size)
+                        memset(track->indices + track->num_indices, 0, new_size - old_size);
+        }
+
+        track->num_indices = new_num_indices;
+
+        cuesheet_calculate_length_(object);
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_track_insert_index(FLAC__StreamMetadata *object, unsigned track_num, unsigned index_num, FLAC__StreamMetadata_CueSheet_Index indx)
+{
+        FLAC__StreamMetadata_CueSheet_Track *track;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_CUESHEET);
+        FLAC__ASSERT(track_num < object->data.cue_sheet.num_tracks);
+        FLAC__ASSERT(index_num <= object->data.cue_sheet.tracks[track_num].num_indices);
+
+        track = &object->data.cue_sheet.tracks[track_num];
+
+        if(!FLAC__metadata_object_cuesheet_track_resize_indices(object, track_num, track->num_indices+1))
+                return false;
+
+        /* move all indices >= index_num forward one space */
+        memmove(&track->indices[index_num+1], &track->indices[index_num], sizeof(FLAC__StreamMetadata_CueSheet_Index)*(track->num_indices-1-index_num));
+
+        track->indices[index_num] = indx;
+        cuesheet_calculate_length_(object);
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_track_insert_blank_index(FLAC__StreamMetadata *object, unsigned track_num, unsigned index_num)
+{
+        FLAC__StreamMetadata_CueSheet_Index indx;
+        memset(&indx, 0, sizeof(indx));
+        return FLAC__metadata_object_cuesheet_track_insert_index(object, track_num, index_num, indx);
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_track_delete_index(FLAC__StreamMetadata *object, unsigned track_num, unsigned index_num)
+{
+        FLAC__StreamMetadata_CueSheet_Track *track;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_CUESHEET);
+        FLAC__ASSERT(track_num < object->data.cue_sheet.num_tracks);
+        FLAC__ASSERT(index_num < object->data.cue_sheet.tracks[track_num].num_indices);
+
+        track = &object->data.cue_sheet.tracks[track_num];
+
+        /* move all indices > index_num backward one space */
+        memmove(&track->indices[index_num], &track->indices[index_num+1], sizeof(FLAC__StreamMetadata_CueSheet_Index)*(track->num_indices-index_num-1));
+
+        FLAC__metadata_object_cuesheet_track_resize_indices(object, track_num, track->num_indices-1);
+        cuesheet_calculate_length_(object);
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_resize_tracks(FLAC__StreamMetadata *object, unsigned new_num_tracks)
+{
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_CUESHEET);
+
+        if(0 == object->data.cue_sheet.tracks) {
+                FLAC__ASSERT(object->data.cue_sheet.num_tracks == 0);
+                if(0 == new_num_tracks)
+                        return true;
+                else if(0 == (object->data.cue_sheet.tracks = cuesheet_track_array_new_(new_num_tracks)))
+                        return false;
+        }
+        else {
+                const size_t old_size = object->data.cue_sheet.num_tracks * sizeof(FLAC__StreamMetadata_CueSheet_Track);
+                const size_t new_size = new_num_tracks * sizeof(FLAC__StreamMetadata_CueSheet_Track);
+
+                /* overflow check */
+                if(new_num_tracks > UINT32_MAX / sizeof(FLAC__StreamMetadata_CueSheet_Track))
+                        return false;
+
+                FLAC__ASSERT(object->data.cue_sheet.num_tracks > 0);
+
+                /* if shrinking, free the truncated entries */
+                if(new_num_tracks < object->data.cue_sheet.num_tracks) {
+                        unsigned i;
+                        for(i = new_num_tracks; i < object->data.cue_sheet.num_tracks; i++)
+                                if(0 != object->data.cue_sheet.tracks[i].indices)
+                                        free(object->data.cue_sheet.tracks[i].indices);
+                }
+
+                if(new_size == 0) {
+                        free(object->data.cue_sheet.tracks);
+                        object->data.cue_sheet.tracks = 0;
+                }
+                else if(0 == (object->data.cue_sheet.tracks = realloc(object->data.cue_sheet.tracks, new_size)))
+                        return false;
+
+                /* if growing, zero all the lengths/pointers of new elements */
+                if(new_size > old_size)
+                        memset(object->data.cue_sheet.tracks + object->data.cue_sheet.num_tracks, 0, new_size - old_size);
+        }
+
+        object->data.cue_sheet.num_tracks = new_num_tracks;
+
+        cuesheet_calculate_length_(object);
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_set_track(FLAC__StreamMetadata *object, unsigned track_num, FLAC__StreamMetadata_CueSheet_Track *track, FLAC__bool copy)
+{
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(track_num < object->data.cue_sheet.num_tracks);
+
+        return cuesheet_set_track_(object, object->data.cue_sheet.tracks + track_num, track, copy);
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_insert_track(FLAC__StreamMetadata *object, unsigned track_num, FLAC__StreamMetadata_CueSheet_Track *track, FLAC__bool copy)
+{
+        FLAC__StreamMetadata_CueSheet *cs;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_CUESHEET);
+        FLAC__ASSERT(track_num <= object->data.cue_sheet.num_tracks);
+
+        cs = &object->data.cue_sheet;
+
+        if(!FLAC__metadata_object_cuesheet_resize_tracks(object, cs->num_tracks+1))
+                return false;
+
+        /* move all tracks >= track_num forward one space */
+        memmove(&cs->tracks[track_num+1], &cs->tracks[track_num], sizeof(FLAC__StreamMetadata_CueSheet_Track)*(cs->num_tracks-1-track_num));
+        cs->tracks[track_num].num_indices = 0;
+        cs->tracks[track_num].indices = 0;
+
+        return FLAC__metadata_object_cuesheet_set_track(object, track_num, track, copy);
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_insert_blank_track(FLAC__StreamMetadata *object, unsigned track_num)
+{
+        FLAC__StreamMetadata_CueSheet_Track track;
+        memset(&track, 0, sizeof(track));
+        return FLAC__metadata_object_cuesheet_insert_track(object, track_num, &track, /*copy=*/false);
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_delete_track(FLAC__StreamMetadata *object, unsigned track_num)
+{
+        FLAC__StreamMetadata_CueSheet *cs;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_CUESHEET);
+        FLAC__ASSERT(track_num < object->data.cue_sheet.num_tracks);
+
+        cs = &object->data.cue_sheet;
+
+        /* free the track at track_num */
+        if(0 != cs->tracks[track_num].indices)
+                free(cs->tracks[track_num].indices);
+
+        /* move all tracks > track_num backward one space */
+        memmove(&cs->tracks[track_num], &cs->tracks[track_num+1], sizeof(FLAC__StreamMetadata_CueSheet_Track)*(cs->num_tracks-track_num-1));
+        cs->tracks[cs->num_tracks-1].num_indices = 0;
+        cs->tracks[cs->num_tracks-1].indices = 0;
+
+        return FLAC__metadata_object_cuesheet_resize_tracks(object, cs->num_tracks-1);
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_cuesheet_is_legal(const FLAC__StreamMetadata *object, FLAC__bool check_cd_da_subset, const char **violation)
+{
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_CUESHEET);
+
+        return FLAC__format_cuesheet_is_legal(&object->data.cue_sheet, check_cd_da_subset, violation);
+}
+
+static FLAC__uint64 get_index_01_offset_(const FLAC__StreamMetadata_CueSheet *cs, unsigned track)
+{
+        if (track >= (cs->num_tracks-1) || cs->tracks[track].num_indices < 1)
+                return 0;
+        else if (cs->tracks[track].indices[0].number == 1)
+                return cs->tracks[track].indices[0].offset + cs->tracks[track].offset + cs->lead_in;
+        else if (cs->tracks[track].num_indices < 2)
+                return 0;
+        else if (cs->tracks[track].indices[1].number == 1)
+                return cs->tracks[track].indices[1].offset + cs->tracks[track].offset + cs->lead_in;
+        else
+                return 0;
+}
+
+static FLAC__uint32 cddb_add_digits_(FLAC__uint32 x)
+{
+        FLAC__uint32 n = 0;
+        while (x) {
+                n += (x%10);
+                x /= 10;
+        }
+        return n;
+}
+
+/*@@@@add to tests*/
+FLAC_API FLAC__uint32 FLAC__metadata_object_cuesheet_calculate_cddb_id(const FLAC__StreamMetadata *object)
+{
+        const FLAC__StreamMetadata_CueSheet *cs;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_CUESHEET);
+
+        cs = &object->data.cue_sheet;
+
+        if (cs->num_tracks < 2) /* need at least one real track and the lead-out track */
+                return 0;
+
+        {
+                FLAC__uint32 i, length, sum = 0;
+                for (i = 0; i < (cs->num_tracks-1); i++) /* -1 to avoid counting the lead-out */
+                        sum += cddb_add_digits_((FLAC__uint32)(get_index_01_offset_(cs, i) / 44100));
+                length = (FLAC__uint32)((cs->tracks[cs->num_tracks-1].offset+cs->lead_in) / 44100) - (FLAC__uint32)(get_index_01_offset_(cs, 0) / 44100);
+
+                return (sum % 0xFF) << 24 | length << 8 | (FLAC__uint32)(cs->num_tracks-1);
+        }
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_picture_set_mime_type(FLAC__StreamMetadata *object, char *mime_type, FLAC__bool copy)
+{
+        char *old;
+        size_t old_length, new_length;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_PICTURE);
+        FLAC__ASSERT(0 != mime_type);
+
+        old = object->data.picture.mime_type;
+        old_length = old? strlen(old) : 0;
+        new_length = strlen(mime_type);
+
+        /* do the copy first so that if we fail we leave the object untouched */
+        if(copy) {
+                if(new_length >= SIZE_MAX) /* overflow check */
+                        return false;
+                if(!copy_bytes_((FLAC__byte**)(&object->data.picture.mime_type), (FLAC__byte*)mime_type, new_length+1))
+                        return false;
+        }
+        else {
+                object->data.picture.mime_type = mime_type;
+        }
+
+        if(0 != old)
+                free(old);
+
+        object->length -= old_length;
+        object->length += new_length;
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_picture_set_description(FLAC__StreamMetadata *object, FLAC__byte *description, FLAC__bool copy)
+{
+        FLAC__byte *old;
+        size_t old_length, new_length;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_PICTURE);
+        FLAC__ASSERT(0 != description);
+
+        old = object->data.picture.description;
+        old_length = old? strlen((const char *)old) : 0;
+        new_length = strlen((const char *)description);
+
+        /* do the copy first so that if we fail we leave the object untouched */
+        if(copy) {
+                if(new_length >= SIZE_MAX) /* overflow check */
+                        return false;
+                if(!copy_bytes_(&object->data.picture.description, description, new_length+1))
+                        return false;
+        }
+        else {
+                object->data.picture.description = description;
+        }
+
+        if(0 != old)
+                free(old);
+
+        object->length -= old_length;
+        object->length += new_length;
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_picture_set_data(FLAC__StreamMetadata *object, FLAC__byte *data, FLAC__uint32 length, FLAC__bool copy)
+{
+        FLAC__byte *old;
+
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_PICTURE);
+        FLAC__ASSERT((0 != data && length > 0) || (0 == data && length == 0 && copy == false));
+
+        old = object->data.picture.data;
+
+        /* do the copy first so that if we fail we leave the object untouched */
+        if(copy) {
+                if(!copy_bytes_(&object->data.picture.data, data, length))
+                        return false;
+        }
+        else {
+                object->data.picture.data = data;
+        }
+
+        if(0 != old)
+                free(old);
+
+        object->length -= object->data.picture.data_length;
+        object->data.picture.data_length = length;
+        object->length += length;
+        return true;
+}
+
+FLAC_API FLAC__bool FLAC__metadata_object_picture_is_legal(const FLAC__StreamMetadata *object, const char **violation)
+{
+        FLAC__ASSERT(0 != object);
+        FLAC__ASSERT(object->type == FLAC__METADATA_TYPE_PICTURE);
+
+        return FLAC__format_picture_is_legal(&object->data.picture, violation);
+}