Updates libjpeg-turbo to 1.1.90 (r677)

third_party/libjpeg_turbo/jdatasrc.c

 /*
  * jdatasrc.c
  *
  * Copyright (C) 1994-1996, Thomas G. Lane.
+ * Modified 2009-2010 by Guido Vollbeding.
  * 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.
+ * reading JPEG data from memory or 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"
 
@@ skipping 23 matching lines @@
 {
   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;
 }
 
+#if JPEG_LIB_VERSION >= 80
+METHODDEF(void)
+init_mem_source (j_decompress_ptr cinfo)
+{
+  /* no work necessary here */
+}
+#endif
+
 
 /*
  * 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.
  *
@@ skipping 39 matching lines @@
     nbytes = 2;
   }
 
   src->pub.next_input_byte = src->buffer;
   src->pub.bytes_in_buffer = nbytes;
   src->start_of_file = FALSE;
 
   return TRUE;
 }
 
+#if JPEG_LIB_VERSION >= 80
+METHODDEF(boolean)
+fill_mem_input_buffer (j_decompress_ptr cinfo)
+{
+  static JOCTET mybuffer[4];
+
+  /* The whole JPEG data is expected to reside in the supplied memory
+   * buffer, so any request for more data beyond the given buffer size
+   * is treated as an error.
+   */
+  WARNMS(cinfo, JWRN_JPEG_EOF);
+  /* Insert a fake EOI marker */
+  mybuffer[0] = (JOCTET) 0xFF;
+  mybuffer[1] = (JOCTET) JPEG_EOI;
+
+  cinfo->src->next_input_byte = mybuffer;
+  cinfo->src->bytes_in_buffer = 2;
+
+  return TRUE;
+}
+#endif
+
 
 /*
  * 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;
+  struct jpeg_source_mgr * src = 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);
+    while (num_bytes > (long) src->bytes_in_buffer) {
+      num_bytes -= (long) src->bytes_in_buffer;
+      (void) (*src->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;
+    src->next_input_byte += (size_t) num_bytes;
+    src->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.
@@ skipping 47 matching lines @@
   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 */
 }
+
+
+#if JPEG_LIB_VERSION >= 80
+/*
+ * Prepare for input from a supplied memory buffer.
+ * The buffer must contain the whole JPEG data.
+ */
+
+GLOBAL(void)
+jpeg_mem_src (j_decompress_ptr cinfo,
+              unsigned char * inbuffer, unsigned long insize)
+{
+  struct jpeg_source_mgr * src;
+
+  if (inbuffer == NULL || insize == 0)  /* Treat empty input as fatal error */
+    ERREXIT(cinfo, JERR_INPUT_EMPTY);
+
+  /* The source object is made permanent so that a series of JPEG images
+   * can be read from the same buffer by calling jpeg_mem_src only before
+   * the first one.
+   */
+  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(struct jpeg_source_mgr));
+  }
+
+  src = cinfo->src;
+  src->init_source = init_mem_source;
+  src->fill_input_buffer = fill_mem_input_buffer;
+  src->skip_input_data = skip_input_data;
+  src->resync_to_restart = jpeg_resync_to_restart; /* use default method */
+  src->term_source = term_source;
+  src->bytes_in_buffer = (size_t) insize;
+  src->next_input_byte = (JOCTET *) inbuffer;
+}
+#endif