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- /*
- * Copyright (c) 2012 Stefano Sabatini
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
- /**
- * @file libswscale API usage example
- * @example scale_video.c
- *
- * Generate a synthetic video signal and use libswscale to perform rescaling.
- */
- #include <libavutil/imgutils.h>
- #include <libavutil/parseutils.h>
- #include <libswscale/swscale.h>
- static void fill_yuv_image(uint8_t *data[4], int linesize[4],
- int width, int height, int frame_index)
- {
- int x, y;
- /* Y */
- for (y = 0; y < height; y++)
- for (x = 0; x < width; x++)
- data[0][y * linesize[0] + x] = x + y + frame_index * 3;
- /* Cb and Cr */
- for (y = 0; y < height / 2; y++) {
- for (x = 0; x < width / 2; x++) {
- data[1][y * linesize[1] + x] = 128 + y + frame_index * 2;
- data[2][y * linesize[2] + x] = 64 + x + frame_index * 5;
- }
- }
- }
- int main(int argc, char **argv)
- {
- uint8_t *src_data[4], *dst_data[4];
- int src_linesize[4], dst_linesize[4];
- int src_w = 320, src_h = 240, dst_w, dst_h;
- enum AVPixelFormat src_pix_fmt = AV_PIX_FMT_YUV420P, dst_pix_fmt = AV_PIX_FMT_RGB24;
- const char *dst_size = NULL;
- const char *dst_filename = NULL;
- FILE *dst_file;
- int dst_bufsize;
- struct SwsContext *sws_ctx;
- int i, ret;
- if (argc != 3) {
- fprintf(stderr, "Usage: %s output_file output_size\n"
- "API example program to show how to scale an image with libswscale.\n"
- "This program generates a series of pictures, rescales them to the given "
- "output_size and saves them to an output file named output_file\n."
- "\n", argv[0]);
- exit(1);
- }
- dst_filename = argv[1];
- dst_size = argv[2];
- if (av_parse_video_size(&dst_w, &dst_h, dst_size) < 0) {
- fprintf(stderr,
- "Invalid size '%s', must be in the form WxH or a valid size abbreviation\n",
- dst_size);
- exit(1);
- }
- dst_file = fopen(dst_filename, "wb");
- if (!dst_file) {
- fprintf(stderr, "Could not open destination file %s\n", dst_filename);
- exit(1);
- }
- /* create scaling context */
- sws_ctx = sws_getContext(src_w, src_h, src_pix_fmt,
- dst_w, dst_h, dst_pix_fmt,
- SWS_BILINEAR, NULL, NULL, NULL);
- if (!sws_ctx) {
- fprintf(stderr,
- "Impossible to create scale context for the conversion "
- "fmt:%s s:%dx%d -> fmt:%s s:%dx%d\n",
- av_get_pix_fmt_name(src_pix_fmt), src_w, src_h,
- av_get_pix_fmt_name(dst_pix_fmt), dst_w, dst_h);
- ret = AVERROR(EINVAL);
- goto end;
- }
- /* allocate source and destination image buffers */
- if ((ret = av_image_alloc(src_data, src_linesize,
- src_w, src_h, src_pix_fmt, 16)) < 0) {
- fprintf(stderr, "Could not allocate source image\n");
- goto end;
- }
- /* buffer is going to be written to rawvideo file, no alignment */
- if ((ret = av_image_alloc(dst_data, dst_linesize,
- dst_w, dst_h, dst_pix_fmt, 1)) < 0) {
- fprintf(stderr, "Could not allocate destination image\n");
- goto end;
- }
- dst_bufsize = ret;
- for (i = 0; i < 100; i++) {
- /* generate synthetic video */
- fill_yuv_image(src_data, src_linesize, src_w, src_h, i);
- /* convert to destination format */
- sws_scale(sws_ctx, (const uint8_t * const*)src_data,
- src_linesize, 0, src_h, dst_data, dst_linesize);
- /* write scaled image to file */
- fwrite(dst_data[0], 1, dst_bufsize, dst_file);
- }
- fprintf(stderr, "Scaling succeeded. Play the output file with the command:\n"
- "ffplay -f rawvideo -pix_fmt %s -video_size %dx%d %s\n",
- av_get_pix_fmt_name(dst_pix_fmt), dst_w, dst_h, dst_filename);
- end:
- fclose(dst_file);
- av_freep(&src_data[0]);
- av_freep(&dst_data[0]);
- sws_freeContext(sws_ctx);
- return ret < 0;
- }
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