+++ /dev/null
-/*
- * jdatadst.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 compression data destination routines for the case of
- * emitting JPEG data 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"
-
-
-/* Expanded data destination object for stdio output */
-
-typedef struct {
- struct jpeg_destination_mgr pub; /* public fields */
-
- FILE * outfile; /* target stream */
- JOCTET * buffer; /* start of buffer */
-} my_destination_mgr;
-
-typedef my_destination_mgr * my_dest_ptr;
-
-#define OUTPUT_BUF_SIZE 4096 /* choose an efficiently fwrite'able size */
-
-
-/*
- * Initialize destination --- called by jpeg_start_compress
- * before any data is actually written.
- */
-
-METHODDEF(void)
-init_destination (j_compress_ptr cinfo)
-{
- my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
-
- /* Allocate the output buffer --- it will be released when done with image */
- dest->buffer = (JOCTET *)
- (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
- OUTPUT_BUF_SIZE * SIZEOF(JOCTET));
-
- dest->pub.next_output_byte = dest->buffer;
- dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
-}
-
-
-/*
- * 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_output_buffer (j_compress_ptr cinfo)
-{
- my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
-
- if (JFWRITE(dest->outfile, dest->buffer, OUTPUT_BUF_SIZE) !=
- (size_t) OUTPUT_BUF_SIZE)
- ERREXIT(cinfo, JERR_FILE_WRITE);
-
- dest->pub.next_output_byte = dest->buffer;
- dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
-
- 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_destination (j_compress_ptr cinfo)
-{
- my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
- size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
-
- /* Write any data remaining in the buffer */
- if (datacount > 0) {
- if (JFWRITE(dest->outfile, dest->buffer, datacount) != datacount)
- ERREXIT(cinfo, JERR_FILE_WRITE);
- }
- fflush(dest->outfile);
- /* Make sure we wrote the output file OK */
- if (ferror(dest->outfile))
- ERREXIT(cinfo, JERR_FILE_WRITE);
-}
-
-
-/*
- * Prepare for output to a stdio stream.
- * The caller must have already opened the stream, and is responsible
- * for closing it after finishing compression.
- */
-
-GLOBAL(void)
-jpeg_stdio_dest (j_compress_ptr cinfo, FILE * outfile)
-{
- my_dest_ptr dest;
-
- /* The destination object is made permanent so that multiple JPEG images
- * can be written to the same file without re-executing jpeg_stdio_dest.
- * This makes it dangerous to use this manager and a different destination
- * manager serially with the same JPEG object, because their private object
- * sizes may be different. Caveat programmer.
- */
- 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_destination_mgr));
- }
-
- dest = (my_dest_ptr) cinfo->dest;
- dest->pub.init_destination = init_destination;
- dest->pub.empty_output_buffer = empty_output_buffer;
- dest->pub.term_destination = term_destination;
- dest->outfile = outfile;
-}
projects / reactos.git / blobdiff