--- /dev/null
- * Modified 2009 by Guido Vollbeding.
+/*
+ * jdatadst-tj.c
+ *
+ * This file was part of the Independent JPEG Group's software:
+ * Copyright (C) 1994-1996, Thomas G. Lane.
- nextbuffer = malloc(nextsize);
++ * Modified 2009-2012 by Guido Vollbeding.
+ * Modifications:
+ * Copyright (C) 2011, D. R. Commander.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains compression data destination routines for the case of
+ * emitting JPEG data to memory or to a file (or any stdio stream).
+ * While these routines are sufficient for most applications,
+ * some will want to use a different destination manager.
+ * IMPORTANT: we assume that fwrite() will correctly transcribe an array of
+ * JOCTETs into 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"
+
+#ifndef HAVE_STDLIB_H /* <stdlib.h> should declare malloc(),free() */
+extern void * malloc JPP((size_t size));
+extern void free JPP((void *ptr));
+#endif
+
+
+#define OUTPUT_BUF_SIZE 4096 /* choose an efficiently fwrite'able size */
+
+
+/* Expanded data destination object for memory output */
+
+typedef struct {
+ struct jpeg_destination_mgr pub; /* public fields */
+
+ unsigned char ** outbuffer; /* target buffer */
+ unsigned long * outsize;
+ unsigned char * newbuffer; /* newly allocated buffer */
+ JOCTET * buffer; /* start of buffer */
+ size_t bufsize;
+ boolean alloc;
+} my_mem_destination_mgr;
+
+typedef my_mem_destination_mgr * my_mem_dest_ptr;
+
+
+/*
+ * Initialize destination --- called by jpeg_start_compress
+ * before any data is actually written.
+ */
+
+METHODDEF(void)
+init_mem_destination (j_compress_ptr cinfo)
+{
+ /* no work necessary here */
+}
+
+
+/*
+ * Empty the output buffer --- called whenever buffer fills up.
+ *
+ * In typical applications, this should write the entire output buffer
+ * (ignoring the current state of next_output_byte & free_in_buffer),
+ * reset the pointer & count to the start of the buffer, and return TRUE
+ * indicating that the buffer has been dumped.
+ *
+ * In applications that need to be able to suspend compression due to output
+ * overrun, a FALSE return indicates that the buffer cannot be emptied now.
+ * In this situation, the compressor will return to its caller (possibly with
+ * an indication that it has not accepted all the supplied scanlines). The
+ * application should resume compression after it has made more room in the
+ * output buffer. Note that there are substantial restrictions on the use of
+ * suspension --- see the documentation.
+ *
+ * When suspending, the compressor will back up to a convenient restart point
+ * (typically the start of the current MCU). next_output_byte & free_in_buffer
+ * indicate where the restart point will be if the current call returns FALSE.
+ * Data beyond this point will be regenerated after resumption, so do not
+ * write it out when emptying the buffer externally.
+ */
+
+METHODDEF(boolean)
+empty_mem_output_buffer (j_compress_ptr cinfo)
+{
+ size_t nextsize;
+ JOCTET * nextbuffer;
+ my_mem_dest_ptr dest = (my_mem_dest_ptr) cinfo->dest;
+
+ if (!dest->alloc) ERREXIT(cinfo, JERR_BUFFER_SIZE);
+
+ /* Try to allocate new buffer with double size */
+ nextsize = dest->bufsize * 2;
- dest->newbuffer = *outbuffer = malloc(OUTPUT_BUF_SIZE);
++ nextbuffer = (JOCTET *) malloc(nextsize);
+
+ if (nextbuffer == NULL)
+ ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 10);
+
+ MEMCOPY(nextbuffer, dest->buffer, dest->bufsize);
+
+ if (dest->newbuffer != NULL)
+ free(dest->newbuffer);
+
+ dest->newbuffer = nextbuffer;
+
+ dest->pub.next_output_byte = nextbuffer + dest->bufsize;
+ dest->pub.free_in_buffer = dest->bufsize;
+
+ dest->buffer = nextbuffer;
+ dest->bufsize = nextsize;
+
+ return TRUE;
+}
+
+
+/*
+ * Terminate destination --- called by jpeg_finish_compress
+ * after all data has been written. Usually needs to flush buffer.
+ *
+ * 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_mem_destination (j_compress_ptr cinfo)
+{
+ my_mem_dest_ptr dest = (my_mem_dest_ptr) cinfo->dest;
+
+ if(dest->alloc) *dest->outbuffer = dest->buffer;
+ *dest->outsize = (unsigned long)(dest->bufsize - dest->pub.free_in_buffer);
+}
+
+
+/*
+ * Prepare for output to a memory buffer.
+ * The caller may supply an own initial buffer with appropriate size.
+ * Otherwise, or when the actual data output exceeds the given size,
+ * the library adapts the buffer size as necessary.
+ * The standard library functions malloc/free are used for allocating
+ * larger memory, so the buffer is available to the application after
+ * finishing compression, and then the application is responsible for
+ * freeing the requested memory.
+ */
+
+GLOBAL(void)
+jpeg_mem_dest_tj (j_compress_ptr cinfo,
+ unsigned char ** outbuffer, unsigned long * outsize,
+ boolean alloc)
+{
+ my_mem_dest_ptr dest;
+
+ if (outbuffer == NULL || outsize == NULL) /* sanity check */
+ ERREXIT(cinfo, JERR_BUFFER_SIZE);
+
+ /* The destination object is made permanent so that multiple JPEG images
+ * can be written to the same buffer without re-executing jpeg_mem_dest.
+ */
+ if (cinfo->dest == NULL) { /* first time for this JPEG object? */
+ cinfo->dest = (struct jpeg_destination_mgr *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
+ SIZEOF(my_mem_destination_mgr));
+ dest = (my_mem_dest_ptr) cinfo->dest;
+ dest->newbuffer = NULL;
+ }
+
+ dest = (my_mem_dest_ptr) cinfo->dest;
+ dest->pub.init_destination = init_mem_destination;
+ dest->pub.empty_output_buffer = empty_mem_output_buffer;
+ dest->pub.term_destination = term_mem_destination;
+ dest->outbuffer = outbuffer;
+ dest->outsize = outsize;
+ dest->alloc = alloc;
+
+ if (*outbuffer == NULL || *outsize == 0) {
+ if (alloc) {
+ /* Allocate initial buffer */
++ dest->newbuffer = *outbuffer = (unsigned char *) malloc(OUTPUT_BUF_SIZE);
+ if (dest->newbuffer == NULL)
+ ERREXIT1(cinfo, JERR_OUT_OF_MEMORY, 10);
+ *outsize = OUTPUT_BUF_SIZE;
+ }
+ else ERREXIT(cinfo, JERR_BUFFER_SIZE);
+ }
+
+ dest->pub.next_output_byte = dest->buffer = *outbuffer;
+ dest->pub.free_in_buffer = dest->bufsize = *outsize;
+}
--- /dev/null
- * Modified 2009-2010 by Guido Vollbeding.
+/*
+ * jdatasrc-tj.c
+ *
+ * This file was part of the Independent JPEG Group's software:
+ * Copyright (C) 1994-1996, Thomas G. Lane.
- static JOCTET mybuffer[4];
++ * Modified 2009-2011 by Guido Vollbeding.
+ * Modifications:
+ * Copyright (C) 2011, D. R. Commander.
+ * 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 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"
+
+
+/*
+ * Initialize source --- called by jpeg_read_header
+ * before any data is actually read.
+ */
+
+METHODDEF(void)
+init_mem_source (j_decompress_ptr cinfo)
+{
+ /* no work necessary here */
+}
+
+
+/*
+ * 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_mem_input_buffer (j_decompress_ptr cinfo)
+{
- mybuffer[0] = (JOCTET) 0xFF;
- mybuffer[1] = (JOCTET) JPEG_EOI;
++ static const JOCTET mybuffer[4] = {
++ (JOCTET) 0xFF, (JOCTET) JPEG_EOI, 0, 0
++ };
+
+ /* 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 */
+
+ cinfo->src->next_input_byte = mybuffer;
+ cinfo->src->bytes_in_buffer = 2;
+
+ 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)
+{
+ 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->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->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.
+ */
+
+
+/*
+ * 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 supplied memory buffer.
+ * The buffer must contain the whole JPEG data.
+ */
+
+GLOBAL(void)
+jpeg_mem_src_tj (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;
+}
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