mirror of
https://github.com/webmproject/libwebp.git
synced 2024-11-20 04:18:26 +01:00
118 lines
2.7 KiB
C
118 lines
2.7 KiB
C
// Copyright 2012 Google Inc. All Rights Reserved.
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//
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// This code is licensed under the same terms as WebM:
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// Software License Agreement: http://www.webmproject.org/license/software/
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// Additional IP Rights Grant: http://www.webmproject.org/license/additional/
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// -----------------------------------------------------------------------------
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//
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// JPEG decode.
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#include "./jpegdec.h"
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <stdio.h>
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#ifdef WEBP_HAVE_JPEG
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#include <jpeglib.h>
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#include <setjmp.h>
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#include <stdlib.h>
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#include <string.h>
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#include "webp/encode.h"
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struct my_error_mgr {
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struct jpeg_error_mgr pub;
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jmp_buf setjmp_buffer;
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};
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static void my_error_exit(j_common_ptr dinfo) {
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struct my_error_mgr* myerr = (struct my_error_mgr*) dinfo->err;
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(*dinfo->err->output_message) (dinfo);
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longjmp(myerr->setjmp_buffer, 1);
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}
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int ReadJPEG(FILE* in_file, WebPPicture* const pic) {
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int ok = 0;
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int stride, width, height;
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uint8_t* rgb = NULL;
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uint8_t* row_ptr = NULL;
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struct jpeg_decompress_struct dinfo;
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struct my_error_mgr jerr;
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JSAMPARRAY buffer;
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dinfo.err = jpeg_std_error(&jerr.pub);
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jerr.pub.error_exit = my_error_exit;
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if (setjmp(jerr.setjmp_buffer)) {
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Error:
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jpeg_destroy_decompress(&dinfo);
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goto End;
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}
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jpeg_create_decompress(&dinfo);
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jpeg_stdio_src(&dinfo, in_file);
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jpeg_read_header(&dinfo, TRUE);
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dinfo.out_color_space = JCS_RGB;
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dinfo.dct_method = JDCT_IFAST;
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dinfo.do_fancy_upsampling = TRUE;
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jpeg_start_decompress(&dinfo);
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if (dinfo.output_components != 3) {
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goto Error;
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}
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width = dinfo.output_width;
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height = dinfo.output_height;
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stride = dinfo.output_width * dinfo.output_components * sizeof(*rgb);
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rgb = (uint8_t*)malloc(stride * height);
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if (rgb == NULL) {
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goto End;
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}
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row_ptr = rgb;
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buffer = (*dinfo.mem->alloc_sarray) ((j_common_ptr) &dinfo,
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JPOOL_IMAGE, stride, 1);
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if (buffer == NULL) {
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goto End;
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}
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while (dinfo.output_scanline < dinfo.output_height) {
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if (jpeg_read_scanlines(&dinfo, buffer, 1) != 1) {
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goto End;
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}
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memcpy(row_ptr, buffer[0], stride);
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row_ptr += stride;
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}
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jpeg_finish_decompress(&dinfo);
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jpeg_destroy_decompress(&dinfo);
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// WebP conversion.
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pic->width = width;
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pic->height = height;
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ok = WebPPictureImportRGB(pic, rgb, stride);
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End:
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if (rgb) {
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free(rgb);
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}
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return ok;
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}
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#else // !WEBP_HAVE_JPEG
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int ReadJPEG(FILE* in_file, struct WebPPicture* const pic) {
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(void)in_file;
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(void)pic;
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fprintf(stderr, "JPEG support not compiled. Please install the libjpeg "
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"development package before building.\n");
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return 0;
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}
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#endif // WEBP_HAVE_JPEG
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// -----------------------------------------------------------------------------
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