Remove libjpeg and libjpeg_turbo.

third_party/libjpeg/jdatasrc.c

-/*
- * jdatasrc.c
- *
- * Copyright (C) 1994-1996, Thomas G. Lane.
- * This file is part of the Independent JPEG Group's software.
- * For conditions of distribution and use, see the accompanying README file.
- *
- * This file contains decompression data source routines for the case of
- * reading JPEG data from a file (or any stdio stream).  While these routines
- * are sufficient for most applications, some will want to use a different
- * source manager.
- * IMPORTANT: we assume that fread() will correctly transcribe an array of
- * JOCTETs from 8-bit-wide elements on external storage.  If char is wider
- * than 8 bits on your machine, you may need to do some tweaking.
- */
-
-/* this is not a core library module, so it doesn't define JPEG_INTERNALS */
-#include "jinclude.h"
-#include "jpeglib.h"
-#include "jerror.h"
-
-
-/* Expanded data source object for stdio input */
-
-typedef struct {
-  struct jpeg_source_mgr pub;   /* public fields */
-
-  FILE * infile;                /* source stream */
-  JOCTET * buffer;              /* start of buffer */
-  boolean start_of_file;        /* have we gotten any data yet? */
-} my_source_mgr;
-
-typedef my_source_mgr * my_src_ptr;
-
-#define INPUT_BUF_SIZE  4096    /* choose an efficiently fread'able size */
-
-
-/*
- * Initialize source --- called by jpeg_read_header
- * before any data is actually read.
- */
-
-METHODDEF(void)
-init_source (j_decompress_ptr cinfo)
-{
-  my_src_ptr src = (my_src_ptr) cinfo->src;
-
-  /* We reset the empty-input-file flag for each image,
-   * but we don't clear the input buffer.
-   * This is correct behavior for reading a series of images from one source.
-   */
-  src->start_of_file = TRUE;
-}
-
-
-/*
- * Fill the input buffer --- called whenever buffer is emptied.
- *
- * In typical applications, this should read fresh data into the buffer
- * (ignoring the current state of next_input_byte & bytes_in_buffer),
- * reset the pointer & count to the start of the buffer, and return TRUE
- * indicating that the buffer has been reloaded.  It is not necessary to
- * fill the buffer entirely, only to obtain at least one more byte.
- *
- * There is no such thing as an EOF return.  If the end of the file has been
- * reached, the routine has a choice of ERREXIT() or inserting fake data into
- * the buffer.  In most cases, generating a warning message and inserting a
- * fake EOI marker is the best course of action --- this will allow the
- * decompressor to output however much of the image is there.  However,
- * the resulting error message is misleading if the real problem is an empty
- * input file, so we handle that case specially.
- *
- * In applications that need to be able to suspend compression due to input
- * not being available yet, a FALSE return indicates that no more data can be
- * obtained right now, but more may be forthcoming later.  In this situation,
- * the decompressor will return to its caller (with an indication of the
- * number of scanlines it has read, if any).  The application should resume
- * decompression after it has loaded more data into the input buffer.  Note
- * that there are substantial restrictions on the use of suspension --- see
- * the documentation.
- *
- * When suspending, the decompressor will back up to a convenient restart point
- * (typically the start of the current MCU). next_input_byte & bytes_in_buffer
- * indicate where the restart point will be if the current call returns FALSE.
- * Data beyond this point must be rescanned after resumption, so move it to
- * the front of the buffer rather than discarding it.
- */
-
-METHODDEF(boolean)
-fill_input_buffer (j_decompress_ptr cinfo)
-{
-  my_src_ptr src = (my_src_ptr) cinfo->src;
-  size_t nbytes;
-
-  nbytes = JFREAD(src->infile, src->buffer, INPUT_BUF_SIZE);
-
-  if (nbytes <= 0) {
-    if (src->start_of_file)     /* Treat empty input file as fatal error */
-      ERREXIT(cinfo, JERR_INPUT_EMPTY);
-    WARNMS(cinfo, JWRN_JPEG_EOF);
-    /* Insert a fake EOI marker */
-    src->buffer[0] = (JOCTET) 0xFF;
-    src->buffer[1] = (JOCTET) JPEG_EOI;
-    nbytes = 2;
-  }
-
-  src->pub.next_input_byte = src->buffer;
-  src->pub.bytes_in_buffer = nbytes;
-  src->start_of_file = FALSE;
-
-  return TRUE;
-}
-
-
-/*
- * Skip data --- used to skip over a potentially large amount of
- * uninteresting data (such as an APPn marker).
- *
- * Writers of suspendable-input applications must note that skip_input_data
- * is not granted the right to give a suspension return.  If the skip extends
- * beyond the data currently in the buffer, the buffer can be marked empty so
- * that the next read will cause a fill_input_buffer call that can suspend.
- * Arranging for additional bytes to be discarded before reloading the input
- * buffer is the application writer's problem.
- */
-
-METHODDEF(void)
-skip_input_data (j_decompress_ptr cinfo, long num_bytes)
-{
-  my_src_ptr src = (my_src_ptr) cinfo->src;
-
-  /* Just a dumb implementation for now.  Could use fseek() except
-   * it doesn't work on pipes.  Not clear that being smart is worth
-   * any trouble anyway --- large skips are infrequent.
-   */
-  if (num_bytes > 0) {
-    while (num_bytes > (long) src->pub.bytes_in_buffer) {
-      num_bytes -= (long) src->pub.bytes_in_buffer;
-      (void) fill_input_buffer(cinfo);
-      /* note we assume that fill_input_buffer will never return FALSE,
-       * so suspension need not be handled.
-       */
-    }
-    src->pub.next_input_byte += (size_t) num_bytes;
-    src->pub.bytes_in_buffer -= (size_t) num_bytes;
-  }
-}
-
-
-/*
- * An additional method that can be provided by data source modules is the
- * resync_to_restart method for error recovery in the presence of RST markers.
- * For the moment, this source module just uses the default resync method
- * provided by the JPEG library.  That method assumes that no backtracking
- * is possible.
- */
-
-
-/*
- * Terminate source --- called by jpeg_finish_decompress
- * after all data has been read.  Often a no-op.
- *
- * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
- * application must deal with any cleanup that should happen even
- * for error exit.
- */
-
-METHODDEF(void)
-term_source (j_decompress_ptr cinfo)
-{
-  /* no work necessary here */
-}
-
-
-/*
- * Prepare for input from a stdio stream.
- * The caller must have already opened the stream, and is responsible
- * for closing it after finishing decompression.
- */
-
-GLOBAL(void)
-jpeg_stdio_src (j_decompress_ptr cinfo, FILE * infile)
-{
-  my_src_ptr src;
-
-  /* The source object and input buffer are made permanent so that a series
-   * of JPEG images can be read from the same file by calling jpeg_stdio_src
-   * only before the first one.  (If we discarded the buffer at the end of
-   * one image, we'd likely lose the start of the next one.)
-   * This makes it unsafe to use this manager and a different source
-   * manager serially with the same JPEG object.  Caveat programmer.
-   */
-  if (cinfo->src == NULL) {     /* first time for this JPEG object? */
-    cinfo->src = (struct jpeg_source_mgr *)
-      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
-                                  SIZEOF(my_source_mgr));
-    src = (my_src_ptr) cinfo->src;
-    src->buffer = (JOCTET *)
-      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
-                                  INPUT_BUF_SIZE * SIZEOF(JOCTET));
-  }
-
-  src = (my_src_ptr) cinfo->src;
-  src->pub.init_source = init_source;
-  src->pub.fill_input_buffer = fill_input_buffer;
-  src->pub.skip_input_data = skip_input_data;
-  src->pub.resync_to_restart = jpeg_resync_to_restart; /* use default method */
-  src->pub.term_source = term_source;
-  src->infile = infile;
-  src->pub.bytes_in_buffer = 0; /* forces fill_input_buffer on first read */
-  src->pub.next_input_byte = NULL; /* until buffer loaded */
-}