From c1e99b4951bd5e376cfab14cb6870869e60b91a2 Mon Sep 17 00:00:00 2001 From: deva Date: Thu, 28 Jul 2005 15:09:52 +0000 Subject: *** empty log message *** --- src/img_encoder.cc | 126 ++++------------------------------------------------- 1 file changed, 9 insertions(+), 117 deletions(-) (limited to 'src/img_encoder.cc') diff --git a/src/img_encoder.cc b/src/img_encoder.cc index 1e8f4a6..1516fc0 100644 --- a/src/img_encoder.cc +++ b/src/img_encoder.cc @@ -37,6 +37,8 @@ #include "debug.h" +#include "jpeg_mem_dest.h" + // Use libdv #include #include @@ -104,114 +106,6 @@ void ImgEncoder::encode(Frame *dvframe, int quality) writeJPEGFile(quality, (JSAMPLE*)rgb, 720, 576); } -#define OUTPUT_BUF_SIZE 4096 /* choose an efficiently ?? size */ - -/* Expanded data destination object for stdio output */ -typedef struct { - struct jpeg_destination_mgr pub; /* public fields */ - - JOCTET * outbuff; /* target buffer */ - size_t * size; -} mem_destination_mgr; - -typedef mem_destination_mgr * mem_dest_ptr; - -/* - * Initialize destination --- called by jpeg_start_compress - * before any data is actually written. - */ -void init_destination (j_compress_ptr cinfo) -{ - mem_dest_ptr dest = (mem_dest_ptr) cinfo->dest; - - *dest->size = 0; - dest->pub.next_output_byte = dest->outbuff; - dest->pub.free_in_buffer = OUTPUT_BUF_SIZE; -} - -/* - * 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. - */ -void term_destination (j_compress_ptr cinfo) -{ - mem_dest_ptr dest = (mem_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) { - dest->outbuff+=datacount; - *dest->size+=datacount; - } -} - -/* - * 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. - */ -boolean empty_output_buffer (j_compress_ptr cinfo) -{ - mem_dest_ptr dest = (mem_dest_ptr) cinfo->dest; - - dest->outbuff+=OUTPUT_BUF_SIZE; - *dest->size+=OUTPUT_BUF_SIZE; - - dest->pub.next_output_byte = dest->outbuff; - dest->pub.free_in_buffer = OUTPUT_BUF_SIZE; - - return TRUE; -} - -/* - * Prepare for output to a memory buffer. - . The caller must have already allocated the buffer, and is responsible - * for closing it after finishing compression. - */ -void jpeg_mem_dest (j_compress_ptr cinfo, char * outbuff, size_t * size) -{ - mem_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(mem_destination_mgr)); - } - - dest = (mem_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->outbuff = (JOCTET *)outbuff; - dest->size = (size_t *)size; -} void ImgEncoder::writeJPEGFile(int quality, JSAMPLE * image_buffer, int image_width, int image_height) { @@ -223,29 +117,27 @@ void ImgEncoder::writeJPEGFile(int quality, JSAMPLE * image_buffer, int image_wi JSAMPROW row_pointer[1]; // pointer to JSAMPLE row[s] int row_stride; // physical row width in image buffer - // Step 1: allocate and initialize JPEG compression object + // Allocate and initialize JPEG compression object cinfo.err = jpeg_std_error(&jerr); jpeg_create_compress(&cinfo); - // Step 2: specify data destination (eg, a file) - //jpeg_stdio_dest(&cinfo, file->getFP()); + // Specify data destination (see jpeg_mem_dest) jpeg_mem_dest(&cinfo, jpeg_output_buffer, &buffersize); - // Step 3: set parameters for compression + // Set compression parameters cinfo.image_width = image_width; // image width and height, in pixels cinfo.image_height = image_height; cinfo.input_components = 3; // # of color components per pixel - cinfo.in_color_space = JCS_RGB; // colorspace of input image jpeg_set_defaults(&cinfo); jpeg_set_quality(&cinfo, quality, TRUE); // limit to baseline-JPEG values - // Step 4: Start compressor + // Start compressor jpeg_start_compress(&cinfo, TRUE); - // Step 5: while (scan lines remain to be written) + // While (scan lines remain to be written) row_stride = image_width * 3; // JSAMPLEs per row in image_buffer while (cinfo.next_scanline < cinfo.image_height) { @@ -253,10 +145,10 @@ void ImgEncoder::writeJPEGFile(int quality, JSAMPLE * image_buffer, int image_wi (void) jpeg_write_scanlines(&cinfo, row_pointer, 1); } - // Step 6: Finish compression + // Finish compression jpeg_finish_compress(&cinfo); - // Step 7: release JPEG compression object + // Release JPEG compression object jpeg_destroy_compress(&cinfo); info->info("JPEG buffersize: %d", buffersize); -- cgit v1.2.3