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- #include "jinclude.h"
- #include "jpeglib.h"
- #include "jerror.h"
- typedef struct {
- struct jpeg_source_mgr pub;
- FILE *infile;
- JOCTET *buffer;
- boolean start_of_file;
- } my_source_mgr;
- typedef my_source_mgr *my_src_ptr;
- #define INPUT_BUF_SIZE 4096
- METHODDEF(void)
- init_source(j_decompress_ptr cinfo)
- {
- my_src_ptr src = (my_src_ptr)cinfo->src;
-
- src->start_of_file = TRUE;
- }
- #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED)
- METHODDEF(void)
- init_mem_source(j_decompress_ptr cinfo)
- {
-
- }
- #endif
- 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)
- ERREXIT(cinfo, JERR_INPUT_EMPTY);
- WARNMS(cinfo, JWRN_JPEG_EOF);
-
- 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;
- }
- #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED)
- METHODDEF(boolean)
- fill_mem_input_buffer(j_decompress_ptr cinfo)
- {
- static const JOCTET mybuffer[4] = {
- (JOCTET)0xFF, (JOCTET)JPEG_EOI, 0, 0
- };
-
- WARNMS(cinfo, JWRN_JPEG_EOF);
-
- cinfo->src->next_input_byte = mybuffer;
- cinfo->src->bytes_in_buffer = 2;
- return TRUE;
- }
- #endif
- METHODDEF(void)
- skip_input_data(j_decompress_ptr cinfo, long num_bytes)
- {
- struct jpeg_source_mgr *src = cinfo->src;
-
- 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);
-
- }
- src->next_input_byte += (size_t)num_bytes;
- src->bytes_in_buffer -= (size_t)num_bytes;
- }
- }
- METHODDEF(void)
- term_source(j_decompress_ptr cinfo)
- {
-
- }
- GLOBAL(void)
- jpeg_stdio_src(j_decompress_ptr cinfo, FILE *infile)
- {
- my_src_ptr src;
-
- if (cinfo->src == NULL) {
- 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));
- } else if (cinfo->src->init_source != init_source) {
-
- ERREXIT(cinfo, JERR_BUFFER_SIZE);
- }
- 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;
- src->pub.term_source = term_source;
- src->infile = infile;
- src->pub.bytes_in_buffer = 0;
- src->pub.next_input_byte = NULL;
- }
- #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED)
- GLOBAL(void)
- jpeg_mem_src(j_decompress_ptr cinfo, const unsigned char *inbuffer,
- unsigned long insize)
- {
- struct jpeg_source_mgr *src;
- if (inbuffer == NULL || insize == 0)
- ERREXIT(cinfo, JERR_INPUT_EMPTY);
-
- if (cinfo->src == NULL) {
- cinfo->src = (struct jpeg_source_mgr *)
- (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_PERMANENT,
- sizeof(struct jpeg_source_mgr));
- } else if (cinfo->src->init_source != init_mem_source) {
-
- ERREXIT(cinfo, JERR_BUFFER_SIZE);
- }
- 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;
- src->term_source = term_source;
- src->bytes_in_buffer = (size_t)insize;
- src->next_input_byte = (const JOCTET *)inbuffer;
- }
- #endif
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