4
* Copyright (C) 2001, Dorian Goldstein, Thomas G. Lane.
6
* This file contains compression data destination routines for the case of
7
* This file is identicle with IJG's built in destination file manager in
8
* every respect but 1... instead fo emmiting data to a file
9
* it facilitates definition of a callback function.
12
/* this is not a core library module, so it doesn't define JPEG_INTERNALS */
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/* Expanded data destination object for stdio output */
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struct jpeg_destination_mgr pub; /* public fields */
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JOCTET * outbuff; // target output buffer
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JOCTET * buffer; // start of internal buffer
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UINT16 size_outbuff; // current size of target output buffer
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JMETHOD (void, flush_output_buffer_callback, (JOCTET *outbuf, JOCTET* buffer, size_t size));
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typedef my_destination_mgr * my_dest_ptr;
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#define OUTPUT_BUF_SIZE 4096 /* choose an efficiently fwrite'able size */
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* Initialize destination --- called by jpeg_start_compress
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* before any data is actually written.
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init_destination (j_compress_ptr cinfo)
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my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
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/* Allocate the output buffer --- it will be released when done with image */
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dest->buffer = (JOCTET *)
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(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
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OUTPUT_BUF_SIZE * SIZEOF(JOCTET));
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dest->pub.next_output_byte = dest->buffer;
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dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
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* Empty the output buffer --- called whenever buffer fills up.
57
* In typical applications, this should write the entire output buffer
58
* (ignoring the current state of next_output_byte & free_in_buffer),
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* reset the pointer & count to the start of the buffer, and return TRUE
60
* indicating that the buffer has been dumped.
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* In applications that need to be able to suspend compression due to output
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* overrun, a FALSE return indicates that the buffer cannot be emptied now.
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* In this situation, the compressor will return to its caller (possibly with
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* an indication that it has not accepted all the supplied scanlines). The
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* application should resume compression after it has made more room in the
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* output buffer. Note that there are substantial restrictions on the use of
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* suspension --- see the documentation.
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* When suspending, the compressor will back up to a convenient restart point
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* (typically the start of the current MCU). next_output_byte & free_in_buffer
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* indicate where the restart point will be if the current call returns FALSE.
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* Data beyond this point will be regenerated after resumption, so do not
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* write it out when emptying the buffer externally.
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empty_output_buffer (j_compress_ptr cinfo)
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my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
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// DG Temp if (dest->flush_output_buffer_callback == NULL) {
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// DG Temp if (dest->outbuff) {
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// DG Temp MEMCOPY(dest->outbuff + dest->size_outbuff, dest->buffer, OUTPUT_BUF_SIZE);
85
// DG Temp dest->size_outbuff += OUTPUT_BUF_SIZE;
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// DG Temp (*dest->flush_output_buffer_callback)(dest->buffer, OUTPUT_BUF_SIZE);
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(*dest->flush_output_buffer_callback)(dest->outbuff, dest->buffer, OUTPUT_BUF_SIZE);
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dest->pub.next_output_byte = dest->buffer;
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dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
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* Terminate destination --- called by jpeg_finish_compress
103
* after all data has been written. Usually needs to flush buffer.
105
* NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
106
* application must deal with any cleanup that should happen even
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term_destination (j_compress_ptr cinfo)
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my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
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size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;
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/* Write any data remaining in the buffer */
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// DG Temp if (dest->flush_output_buffer_callback == NULL) {
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// DG Temp if (dest->outbuff) {
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// DG Temp MEMCOPY(dest->outbuff + dest->size_outbuff, dest->buffer, datacount);
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// DG Temp dest->size_outbuff += datacount;
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// DG Temp (*dest->flush_output_buffer_callback)(dest->buffer, datacount);
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(*dest->flush_output_buffer_callback)(dest->outbuff, dest->buffer, datacount);
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* Prepare for output to a stdio stream.
134
* The caller must have already opened the stream, and is responsible
135
* for closing it after finishing compression.
139
jpeg_buffer_dest (j_compress_ptr cinfo, JOCTET* outbuff, void* flush_output_buffer_callback)
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/* The destination object is made permanent so that multiple JPEG images
144
* can be written to the same file without re-executing jpeg_stdio_dest.
145
* This makes it dangerous to use this manager and a different destination
146
* manager serially with the same JPEG object, because their private object
147
* sizes may be different. Caveat programmer.
149
if (cinfo->dest == NULL) { /* first time for this JPEG object? */
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cinfo->dest = (struct jpeg_destination_mgr *)
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(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
152
SIZEOF(my_destination_mgr));
155
dest = (my_dest_ptr) cinfo->dest;
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dest->pub.init_destination = init_destination;
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dest->pub.empty_output_buffer = empty_output_buffer;
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dest->pub.term_destination = term_destination;
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dest->outbuff = outbuff;
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dest->size_outbuff = 0;
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dest->flush_output_buffer_callback = flush_output_buffer_callback;
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//(*dest->flush_output_buffer_callback)(-1 , -1);
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jpeg_buffer_size_dest (j_compress_ptr cinfo)
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my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
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return dest->size_outbuff;
added
removed
prnt/hpcups/jdatadbf.c
