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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
* libavformat demuxing API use example.
*
* Show how to use the libavformat and libavcodec API to demux and
* decode video data.
*/
#include <libavutil/imgutils.h>
#include <libavutil/timestamp.h>
#include <libavformat/avformat.h>
static AVFormatContext *fmt_ctx = NULL;
static AVCodecContext *dec_ctx = NULL;
static AVCodec *dec = NULL;
static AVStream *stream = NULL;
static const char *src_filename = NULL;
static const char *dst_filename = NULL;
static FILE *dst_file = NULL;
static uint8_t *dst_data[4] = {NULL};
static int dst_linesize[4];
static int dst_bufsize;
static int stream_idx;
static AVFrame *frame = NULL;
static AVPacket pkt;
static int frame_count = 0;
static int decode_packet(int *got_frame, int cached)
{
int ret;
if (pkt.stream_index != stream_idx)
return 0;
/* decode video frame */
ret = avcodec_decode_video2(dec_ctx, frame, got_frame, &pkt);
if (ret < 0) {
fprintf(stderr, "Error decoding video frame\n");
return ret;
}
if (*got_frame) {
printf("frame%s n:%d coded_n:%d pts:%s\n",
cached ? "(cached)" : "",
frame_count++, frame->coded_picture_number,
av_ts2timestr(frame->pts, &dec_ctx->time_base));
/* copy decoded frame to destination buffer:
* this is required since rawvideo expect non aligned data */
av_image_copy(dst_data, dst_linesize,
(const uint8_t **)(frame->data), frame->linesize,
dec_ctx->pix_fmt, dec_ctx->width, dec_ctx->height);
/* write to rawvideo file */
fwrite(dst_data[0], 1, dst_bufsize, dst_file);
}
return ret;
}
int main (int argc, char **argv)
{
int ret, got_frame;
if (argc != 3) {
fprintf(stderr, "usage: %s input_file output_file\n"
"API example program to show how to read frames from an input file.\n"
"This program reads frames from a file, decode them, and write them "
"to a rawvideo file named like output_file."
"\n", argv[0]);
exit(1);
}
src_filename = argv[1];
dst_filename = argv[2];
/* register all formats and codecs */
av_register_all();
/* open input file, and allocated format context */
if (avformat_open_input(&fmt_ctx, src_filename, NULL, NULL) < 0) {
fprintf(stderr, "Could not open source file %s\n", src_filename);
exit(1);
}
/* retrieve stream information */
if (avformat_find_stream_info(fmt_ctx, NULL) < 0) {
fprintf(stderr, "Could not find stream information\n");
exit(1);
}
ret = av_find_best_stream(fmt_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, NULL, 0);
if (ret < 0) {
fprintf(stderr, "Could not find video stream in file\n");
goto end;
}
stream_idx = ret;
stream = fmt_ctx->streams[stream_idx];
/* find decoder for the stream */
dec_ctx = stream->codec;
dec = avcodec_find_decoder(dec_ctx->codec_id);
if (!dec) {
fprintf(stderr, "Failed to find any codec\n");
ret = 1;
goto end;
}
if ((ret = avcodec_open2(dec_ctx, dec, NULL)) < 0) {
fprintf(stderr, "Failed to open codec\n");
goto end;
}
/* dump input information to stderr */
av_dump_format(fmt_ctx, 0, src_filename, 0);
dst_file = fopen(dst_filename, "wb");
if (!dst_file) {
fprintf(stderr, "Could not open destination file %s\n", dst_filename);
ret = 1;
goto end;
}
frame = avcodec_alloc_frame();
if (!frame) {
fprintf(stderr, "Could not allocate video frame\n");
ret = 1;
goto end;
}
/* allocate image where the decoded image will be put */
ret = av_image_alloc(dst_data, dst_linesize,
dec_ctx->width, dec_ctx->height, dec_ctx->pix_fmt, 1);
if (ret < 0) {
fprintf(stderr, "Could not alloc raw video buffer\n");
goto end;
}
dst_bufsize = ret;
/* initialize packet, set data to NULL, let the demuxer fill it */
av_init_packet(&pkt);
pkt.size = 0;
pkt.data = NULL;
printf("Demuxing file '%s' to '%s'\n", src_filename, dst_filename);
/* read frames from the file */
while (av_read_frame(fmt_ctx, &pkt) >= 0)
decode_packet(&got_frame, 0);
/* flush cached frames */
pkt.data = NULL;
pkt.size = 0;
do {
decode_packet(&got_frame, 1);
} while (got_frame);
printf("Demuxing 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(dec_ctx->pix_fmt), dec_ctx->width, dec_ctx->height,
dst_filename);
end:
avcodec_close(dec_ctx);
avformat_close_input(&fmt_ctx);
if (dst_file)
fclose(dst_file);
av_free(frame);
av_free(dst_data[0]);
return ret < 0;
}
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