Compile Skia image encoders

third_party/libwebp/mux/muxread.c

Index: third_party/libwebp/mux/muxread.c
diff --git a/third_party/libwebp/mux/muxread.c b/third_party/libwebp/mux/muxread.c
new file mode 100644
index 0000000000000000000000000000000000000000..410acd9119cb66a6435497f37d5642b294e4de03
--- /dev/null
+++ b/third_party/libwebp/mux/muxread.c
@@ -0,0 +1,536 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the COPYING file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS. All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+// -----------------------------------------------------------------------------
+//
+// Read APIs for mux.
+//
+// Authors: Urvang (urvang@google.com)
+//          Vikas (vikasa@google.com)
+
+#include <assert.h>
+#include "./muxi.h"
+#include "../utils/utils.h"
+
+//------------------------------------------------------------------------------
+// Helper method(s).
+
+// Handy MACRO.
+#define SWITCH_ID_LIST(INDEX, LIST)                                           \
+  if (idx == (INDEX)) {                                                       \
+    const WebPChunk* const chunk = ChunkSearchList((LIST), nth,               \
+                                                   kChunks[(INDEX)].tag);     \
+    if (chunk) {                                                              \
+      *data = chunk->data_;                                                   \
+      return WEBP_MUX_OK;                                                     \
+    } else {                                                                  \
+      return WEBP_MUX_NOT_FOUND;                                              \
+    }                                                                         \
+  }
+
+static WebPMuxError MuxGet(const WebPMux* const mux, CHUNK_INDEX idx,
+                           uint32_t nth, WebPData* const data) {
+  assert(mux != NULL);
+  assert(!IsWPI(kChunks[idx].id));
+  WebPDataInit(data);
+
+  SWITCH_ID_LIST(IDX_VP8X, mux->vp8x_);
+  SWITCH_ID_LIST(IDX_ICCP, mux->iccp_);
+  SWITCH_ID_LIST(IDX_ANIM, mux->anim_);
+  SWITCH_ID_LIST(IDX_EXIF, mux->exif_);
+  SWITCH_ID_LIST(IDX_XMP, mux->xmp_);
+  SWITCH_ID_LIST(IDX_UNKNOWN, mux->unknown_);
+  return WEBP_MUX_NOT_FOUND;
+}
+#undef SWITCH_ID_LIST
+
+// Fill the chunk with the given data (includes chunk header bytes), after some
+// verifications.
+static WebPMuxError ChunkVerifyAndAssign(WebPChunk* chunk,
+                                         const uint8_t* data, size_t data_size,
+                                         size_t riff_size, int copy_data) {
+  uint32_t chunk_size;
+  WebPData chunk_data;
+
+  // Sanity checks.
+  if (data_size < CHUNK_HEADER_SIZE) return WEBP_MUX_NOT_ENOUGH_DATA;
+  chunk_size = GetLE32(data + TAG_SIZE);
+
+  {
+    const size_t chunk_disk_size = SizeWithPadding(chunk_size);
+    if (chunk_disk_size > riff_size) return WEBP_MUX_BAD_DATA;
+    if (chunk_disk_size > data_size) return WEBP_MUX_NOT_ENOUGH_DATA;
+  }
+
+  // Data assignment.
+  chunk_data.bytes = data + CHUNK_HEADER_SIZE;
+  chunk_data.size = chunk_size;
+  return ChunkAssignData(chunk, &chunk_data, copy_data, GetLE32(data + 0));
+}
+
+int MuxImageFinalize(WebPMuxImage* const wpi) {
+  const WebPChunk* const img = wpi->img_;
+  const WebPData* const image = &img->data_;
+  const int is_lossless = (img->tag_ == kChunks[IDX_VP8L].tag);
+  int w, h;
+  int vp8l_has_alpha = 0;
+  const int ok = is_lossless ?
+      VP8LGetInfo(image->bytes, image->size, &w, &h, &vp8l_has_alpha) :
+      VP8GetInfo(image->bytes, image->size, image->size, &w, &h);
+  assert(img != NULL);
+  if (ok) {
+    // Ignore ALPH chunk accompanying VP8L.
+    if (is_lossless && (wpi->alpha_ != NULL)) {
+      ChunkDelete(wpi->alpha_);
+      wpi->alpha_ = NULL;
+    }
+    wpi->width_ = w;
+    wpi->height_ = h;
+    wpi->has_alpha_ = vp8l_has_alpha || (wpi->alpha_ != NULL);
+  }
+  return ok;
+}
+
+static int MuxImageParse(const WebPChunk* const chunk, int copy_data,
+                         WebPMuxImage* const wpi) {
+  const uint8_t* bytes = chunk->data_.bytes;
+  size_t size = chunk->data_.size;
+  const uint8_t* const last = bytes + size;
+  WebPChunk subchunk;
+  size_t subchunk_size;
+  ChunkInit(&subchunk);
+
+  assert(chunk->tag_ == kChunks[IDX_ANMF].tag);
+  assert(!wpi->is_partial_);
+
+  // ANMF.
+  {
+    const size_t hdr_size = ANMF_CHUNK_SIZE;
+    const WebPData temp = { bytes, hdr_size };
+    // Each of ANMF chunk contain a header at the beginning. So, its size should
+    // be at least 'hdr_size'.
+    if (size < hdr_size) goto Fail;
+    ChunkAssignData(&subchunk, &temp, copy_data, chunk->tag_);
+  }
+  ChunkSetNth(&subchunk, &wpi->header_, 1);
+  wpi->is_partial_ = 1;  // Waiting for ALPH and/or VP8/VP8L chunks.
+
+  // Rest of the chunks.
+  subchunk_size = ChunkDiskSize(&subchunk) - CHUNK_HEADER_SIZE;
+  bytes += subchunk_size;
+  size -= subchunk_size;
+
+  while (bytes != last) {
+    ChunkInit(&subchunk);
+    if (ChunkVerifyAndAssign(&subchunk, bytes, size, size,
+                             copy_data) != WEBP_MUX_OK) {
+      goto Fail;
+    }
+    switch (ChunkGetIdFromTag(subchunk.tag_)) {
+      case WEBP_CHUNK_ALPHA:
+        if (wpi->alpha_ != NULL) goto Fail;  // Consecutive ALPH chunks.
+        if (ChunkSetNth(&subchunk, &wpi->alpha_, 1) != WEBP_MUX_OK) goto Fail;
+        wpi->is_partial_ = 1;  // Waiting for a VP8 chunk.
+        break;
+      case WEBP_CHUNK_IMAGE:
+        if (ChunkSetNth(&subchunk, &wpi->img_, 1) != WEBP_MUX_OK) goto Fail;
+        if (!MuxImageFinalize(wpi)) goto Fail;
+        wpi->is_partial_ = 0;  // wpi is completely filled.
+        break;
+      case WEBP_CHUNK_UNKNOWN:
+        if (wpi->is_partial_) goto Fail;  // Encountered an unknown chunk
+                                          // before some image chunks.
+        if (ChunkSetNth(&subchunk, &wpi->unknown_, 0) != WEBP_MUX_OK) goto Fail;
+        break;
+      default:
+        goto Fail;
+        break;
+    }
+    subchunk_size = ChunkDiskSize(&subchunk);
+    bytes += subchunk_size;
+    size -= subchunk_size;
+  }
+  if (wpi->is_partial_) goto Fail;
+  return 1;
+
+ Fail:
+  ChunkRelease(&subchunk);
+  return 0;
+}
+
+//------------------------------------------------------------------------------
+// Create a mux object from WebP-RIFF data.
+
+WebPMux* WebPMuxCreateInternal(const WebPData* bitstream, int copy_data,
+                               int version) {
+  size_t riff_size;
+  uint32_t tag;
+  const uint8_t* end;
+  WebPMux* mux = NULL;
+  WebPMuxImage* wpi = NULL;
+  const uint8_t* data;
+  size_t size;
+  WebPChunk chunk;
+  ChunkInit(&chunk);
+
+  // Sanity checks.
+  if (WEBP_ABI_IS_INCOMPATIBLE(version, WEBP_MUX_ABI_VERSION)) {
+    return NULL;  // version mismatch
+  }
+  if (bitstream == NULL) return NULL;
+
+  data = bitstream->bytes;
+  size = bitstream->size;
+
+  if (data == NULL) return NULL;
+  if (size < RIFF_HEADER_SIZE) return NULL;
+  if (GetLE32(data + 0) != MKFOURCC('R', 'I', 'F', 'F') ||
+      GetLE32(data + CHUNK_HEADER_SIZE) != MKFOURCC('W', 'E', 'B', 'P')) {
+    return NULL;
+  }
+
+  mux = WebPMuxNew();
+  if (mux == NULL) return NULL;
+
+  if (size < RIFF_HEADER_SIZE + TAG_SIZE) goto Err;
+
+  tag = GetLE32(data + RIFF_HEADER_SIZE);
+  if (tag != kChunks[IDX_VP8].tag &&
+      tag != kChunks[IDX_VP8L].tag &&
+      tag != kChunks[IDX_VP8X].tag) {
+    goto Err;  // First chunk should be VP8, VP8L or VP8X.
+  }
+
+  riff_size = SizeWithPadding(GetLE32(data + TAG_SIZE));
+  if (riff_size > MAX_CHUNK_PAYLOAD || riff_size > size) {
+    goto Err;
+  } else {
+    if (riff_size < size) {  // Redundant data after last chunk.
+      size = riff_size;  // To make sure we don't read any data beyond mux_size.
+    }
+  }
+
+  end = data + size;
+  data += RIFF_HEADER_SIZE;
+  size -= RIFF_HEADER_SIZE;
+
+  wpi = (WebPMuxImage*)WebPSafeMalloc(1ULL, sizeof(*wpi));
+  if (wpi == NULL) goto Err;
+  MuxImageInit(wpi);
+
+  // Loop over chunks.
+  while (data != end) {
+    size_t data_size;
+    WebPChunkId id;
+    WebPChunk** chunk_list;
+    if (ChunkVerifyAndAssign(&chunk, data, size, riff_size,
+                             copy_data) != WEBP_MUX_OK) {
+      goto Err;
+    }
+    data_size = ChunkDiskSize(&chunk);
+    id = ChunkGetIdFromTag(chunk.tag_);
+    switch (id) {
+      case WEBP_CHUNK_ALPHA:
+        if (wpi->alpha_ != NULL) goto Err;  // Consecutive ALPH chunks.
+        if (ChunkSetNth(&chunk, &wpi->alpha_, 1) != WEBP_MUX_OK) goto Err;
+        wpi->is_partial_ = 1;  // Waiting for a VP8 chunk.
+        break;
+      case WEBP_CHUNK_IMAGE:
+        if (ChunkSetNth(&chunk, &wpi->img_, 1) != WEBP_MUX_OK) goto Err;
+        if (!MuxImageFinalize(wpi)) goto Err;
+        wpi->is_partial_ = 0;  // wpi is completely filled.
+ PushImage:
+        // Add this to mux->images_ list.
+        if (MuxImagePush(wpi, &mux->images_) != WEBP_MUX_OK) goto Err;
+        MuxImageInit(wpi);  // Reset for reading next image.
+        break;
+      case WEBP_CHUNK_ANMF:
+        if (wpi->is_partial_) goto Err;  // Previous wpi is still incomplete.
+        if (!MuxImageParse(&chunk, copy_data, wpi)) goto Err;
+        ChunkRelease(&chunk);
+        goto PushImage;
+        break;
+      default:  // A non-image chunk.
+        if (wpi->is_partial_) goto Err;  // Encountered a non-image chunk before
+                                         // getting all chunks of an image.
+        chunk_list = MuxGetChunkListFromId(mux, id);  // List to add this chunk.
+        if (ChunkSetNth(&chunk, chunk_list, 0) != WEBP_MUX_OK) goto Err;
+        if (id == WEBP_CHUNK_VP8X) {  // grab global specs
+          mux->canvas_width_ = GetLE24(data + 12) + 1;
+          mux->canvas_height_ = GetLE24(data + 15) + 1;
+        }
+        break;
+    }
+    data += data_size;
+    size -= data_size;
+    ChunkInit(&chunk);
+  }
+
+  // Validate mux if complete.
+  if (MuxValidate(mux) != WEBP_MUX_OK) goto Err;
+
+  MuxImageDelete(wpi);
+  return mux;  // All OK;
+
+ Err:  // Something bad happened.
+  ChunkRelease(&chunk);
+  MuxImageDelete(wpi);
+  WebPMuxDelete(mux);
+  return NULL;
+}
+
+//------------------------------------------------------------------------------
+// Get API(s).
+
+// Validates that the given mux has a single image.
+static WebPMuxError ValidateForSingleImage(const WebPMux* const mux) {
+  const int num_images = MuxImageCount(mux->images_, WEBP_CHUNK_IMAGE);
+  const int num_frames = MuxImageCount(mux->images_, WEBP_CHUNK_ANMF);
+
+  if (num_images == 0) {
+    // No images in mux.
+    return WEBP_MUX_NOT_FOUND;
+  } else if (num_images == 1 && num_frames == 0) {
+    // Valid case (single image).
+    return WEBP_MUX_OK;
+  } else {
+    // Frame case OR an invalid mux.
+    return WEBP_MUX_INVALID_ARGUMENT;
+  }
+}
+
+// Get the canvas width, height and flags after validating that VP8X/VP8/VP8L
+// chunk and canvas size are valid.
+static WebPMuxError MuxGetCanvasInfo(const WebPMux* const mux,
+                                     int* width, int* height, uint32_t* flags) {
+  int w, h;
+  uint32_t f = 0;
+  WebPData data;
+  assert(mux != NULL);
+
+  // Check if VP8X chunk is present.
+  if (MuxGet(mux, IDX_VP8X, 1, &data) == WEBP_MUX_OK) {
+    if (data.size < VP8X_CHUNK_SIZE) return WEBP_MUX_BAD_DATA;
+    f = GetLE32(data.bytes + 0);
+    w = GetLE24(data.bytes + 4) + 1;
+    h = GetLE24(data.bytes + 7) + 1;
+  } else {
+    const WebPMuxImage* const wpi = mux->images_;
+    // Grab user-forced canvas size as default.
+    w = mux->canvas_width_;
+    h = mux->canvas_height_;
+    if (w == 0 && h == 0 && ValidateForSingleImage(mux) == WEBP_MUX_OK) {
+      // single image and not forced canvas size => use dimension of first frame
+      assert(wpi != NULL);
+      w = wpi->width_;
+      h = wpi->height_;
+    }
+    if (wpi != NULL) {
+      if (wpi->has_alpha_) f |= ALPHA_FLAG;
+    }
+  }
+  if (w * (uint64_t)h >= MAX_IMAGE_AREA) return WEBP_MUX_BAD_DATA;
+
+  if (width != NULL) *width = w;
+  if (height != NULL) *height = h;
+  if (flags != NULL) *flags = f;
+  return WEBP_MUX_OK;
+}
+
+WebPMuxError WebPMuxGetCanvasSize(const WebPMux* mux, int* width, int* height) {
+  if (mux == NULL || width == NULL || height == NULL) {
+    return WEBP_MUX_INVALID_ARGUMENT;
+  }
+  return MuxGetCanvasInfo(mux, width, height, NULL);
+}
+
+WebPMuxError WebPMuxGetFeatures(const WebPMux* mux, uint32_t* flags) {
+  if (mux == NULL || flags == NULL) return WEBP_MUX_INVALID_ARGUMENT;
+  return MuxGetCanvasInfo(mux, NULL, NULL, flags);
+}
+
+static uint8_t* EmitVP8XChunk(uint8_t* const dst, int width,
+                              int height, uint32_t flags) {
+  const size_t vp8x_size = CHUNK_HEADER_SIZE + VP8X_CHUNK_SIZE;
+  assert(width >= 1 && height >= 1);
+  assert(width <= MAX_CANVAS_SIZE && height <= MAX_CANVAS_SIZE);
+  assert(width * (uint64_t)height < MAX_IMAGE_AREA);
+  PutLE32(dst, MKFOURCC('V', 'P', '8', 'X'));
+  PutLE32(dst + TAG_SIZE, VP8X_CHUNK_SIZE);
+  PutLE32(dst + CHUNK_HEADER_SIZE, flags);
+  PutLE24(dst + CHUNK_HEADER_SIZE + 4, width - 1);
+  PutLE24(dst + CHUNK_HEADER_SIZE + 7, height - 1);
+  return dst + vp8x_size;
+}
+
+// Assemble a single image WebP bitstream from 'wpi'.
+static WebPMuxError SynthesizeBitstream(const WebPMuxImage* const wpi,
+                                        WebPData* const bitstream) {
+  uint8_t* dst;
+
+  // Allocate data.
+  const int need_vp8x = (wpi->alpha_ != NULL);
+  const size_t vp8x_size = need_vp8x ? CHUNK_HEADER_SIZE + VP8X_CHUNK_SIZE : 0;
+  const size_t alpha_size = need_vp8x ? ChunkDiskSize(wpi->alpha_) : 0;
+  // Note: No need to output ANMF chunk for a single image.
+  const size_t size = RIFF_HEADER_SIZE + vp8x_size + alpha_size +
+                      ChunkDiskSize(wpi->img_);
+  uint8_t* const data = (uint8_t*)WebPSafeMalloc(1ULL, size);
+  if (data == NULL) return WEBP_MUX_MEMORY_ERROR;
+
+  // Main RIFF header.
+  dst = MuxEmitRiffHeader(data, size);
+
+  if (need_vp8x) {
+    dst = EmitVP8XChunk(dst, wpi->width_, wpi->height_, ALPHA_FLAG);  // VP8X.
+    dst = ChunkListEmit(wpi->alpha_, dst);       // ALPH.
+  }
+
+  // Bitstream.
+  dst = ChunkListEmit(wpi->img_, dst);
+  assert(dst == data + size);
+
+  // Output.
+  bitstream->bytes = data;
+  bitstream->size = size;
+  return WEBP_MUX_OK;
+}
+
+WebPMuxError WebPMuxGetChunk(const WebPMux* mux, const char fourcc[4],
+                             WebPData* chunk_data) {
+  CHUNK_INDEX idx;
+  if (mux == NULL || fourcc == NULL || chunk_data == NULL) {
+    return WEBP_MUX_INVALID_ARGUMENT;
+  }
+  idx = ChunkGetIndexFromFourCC(fourcc);
+  if (IsWPI(kChunks[idx].id)) {     // An image chunk.
+    return WEBP_MUX_INVALID_ARGUMENT;
+  } else if (idx != IDX_UNKNOWN) {  // A known chunk type.
+    return MuxGet(mux, idx, 1, chunk_data);
+  } else {                          // An unknown chunk type.
+    const WebPChunk* const chunk =
+        ChunkSearchList(mux->unknown_, 1, ChunkGetTagFromFourCC(fourcc));
+    if (chunk == NULL) return WEBP_MUX_NOT_FOUND;
+    *chunk_data = chunk->data_;
+    return WEBP_MUX_OK;
+  }
+}
+
+static WebPMuxError MuxGetImageInternal(const WebPMuxImage* const wpi,
+                                        WebPMuxFrameInfo* const info) {
+  // Set some defaults for unrelated fields.
+  info->x_offset = 0;
+  info->y_offset = 0;
+  info->duration = 1;
+  info->dispose_method = WEBP_MUX_DISPOSE_NONE;
+  info->blend_method = WEBP_MUX_BLEND;
+  // Extract data for related fields.
+  info->id = ChunkGetIdFromTag(wpi->img_->tag_);
+  return SynthesizeBitstream(wpi, &info->bitstream);
+}
+
+static WebPMuxError MuxGetFrameInternal(const WebPMuxImage* const wpi,
+                                        WebPMuxFrameInfo* const frame) {
+  const int is_frame = (wpi->header_->tag_ == kChunks[IDX_ANMF].tag);
+  const WebPData* frame_data;
+  if (!is_frame) return WEBP_MUX_INVALID_ARGUMENT;
+  assert(wpi->header_ != NULL);  // Already checked by WebPMuxGetFrame().
+  // Get frame chunk.
+  frame_data = &wpi->header_->data_;
+  if (frame_data->size < kChunks[IDX_ANMF].size) return WEBP_MUX_BAD_DATA;
+  // Extract info.
+  frame->x_offset = 2 * GetLE24(frame_data->bytes + 0);
+  frame->y_offset = 2 * GetLE24(frame_data->bytes + 3);
+  {
+    const uint8_t bits = frame_data->bytes[15];
+    frame->duration = GetLE24(frame_data->bytes + 12);
+    frame->dispose_method =
+        (bits & 1) ? WEBP_MUX_DISPOSE_BACKGROUND : WEBP_MUX_DISPOSE_NONE;
+    frame->blend_method = (bits & 2) ? WEBP_MUX_NO_BLEND : WEBP_MUX_BLEND;
+  }
+  frame->id = ChunkGetIdFromTag(wpi->header_->tag_);
+  return SynthesizeBitstream(wpi, &frame->bitstream);
+}
+
+WebPMuxError WebPMuxGetFrame(
+    const WebPMux* mux, uint32_t nth, WebPMuxFrameInfo* frame) {
+  WebPMuxError err;
+  WebPMuxImage* wpi;
+
+  // Sanity checks.
+  if (mux == NULL || frame == NULL) {
+    return WEBP_MUX_INVALID_ARGUMENT;
+  }
+
+  // Get the nth WebPMuxImage.
+  err = MuxImageGetNth((const WebPMuxImage**)&mux->images_, nth, &wpi);
+  if (err != WEBP_MUX_OK) return err;
+
+  // Get frame info.
+  if (wpi->header_ == NULL) {
+    return MuxGetImageInternal(wpi, frame);
+  } else {
+    return MuxGetFrameInternal(wpi, frame);
+  }
+}
+
+WebPMuxError WebPMuxGetAnimationParams(const WebPMux* mux,
+                                       WebPMuxAnimParams* params) {
+  WebPData anim;
+  WebPMuxError err;
+
+  if (mux == NULL || params == NULL) return WEBP_MUX_INVALID_ARGUMENT;
+
+  err = MuxGet(mux, IDX_ANIM, 1, &anim);
+  if (err != WEBP_MUX_OK) return err;
+  if (anim.size < kChunks[WEBP_CHUNK_ANIM].size) return WEBP_MUX_BAD_DATA;
+  params->bgcolor = GetLE32(anim.bytes);
+  params->loop_count = GetLE16(anim.bytes + 4);
+
+  return WEBP_MUX_OK;
+}
+
+// Get chunk index from chunk id. Returns IDX_NIL if not found.
+static CHUNK_INDEX ChunkGetIndexFromId(WebPChunkId id) {
+  int i;
+  for (i = 0; kChunks[i].id != WEBP_CHUNK_NIL; ++i) {
+    if (id == kChunks[i].id) return (CHUNK_INDEX)i;
+  }
+  return IDX_NIL;
+}
+
+// Count number of chunks matching 'tag' in the 'chunk_list'.
+// If tag == NIL_TAG, any tag will be matched.
+static int CountChunks(const WebPChunk* const chunk_list, uint32_t tag) {
+  int count = 0;
+  const WebPChunk* current;
+  for (current = chunk_list; current != NULL; current = current->next_) {
+    if (tag == NIL_TAG || current->tag_ == tag) {
+      count++;  // Count chunks whose tags match.
+    }
+  }
+  return count;
+}
+
+WebPMuxError WebPMuxNumChunks(const WebPMux* mux,
+                              WebPChunkId id, int* num_elements) {
+  if (mux == NULL || num_elements == NULL) {
+    return WEBP_MUX_INVALID_ARGUMENT;
+  }
+
+  if (IsWPI(id)) {
+    *num_elements = MuxImageCount(mux->images_, id);
+  } else {
+    WebPChunk* const* chunk_list = MuxGetChunkListFromId(mux, id);
+    const CHUNK_INDEX idx = ChunkGetIndexFromId(id);
+    *num_elements = CountChunks(*chunk_list, kChunks[idx].tag);
+  }
+
+  return WEBP_MUX_OK;
+}
+
+//------------------------------------------------------------------------------