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remuxing.c
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1 /*
2  * Copyright (c) 2013 Stefano Sabatini
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a copy
5  * of this software and associated documentation files (the "Software"), to deal
6  * in the Software without restriction, including without limitation the rights
7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8  * copies of the Software, and to permit persons to whom the Software is
9  * furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
20  * THE SOFTWARE.
21  */
22 
23 /**
24  * @file
25  * libavformat/libavcodec demuxing and muxing API example.
26  *
27  * Remux streams from one container format to another.
28  * @example remuxing.c
29  */
30 
31 #include <libavutil/timestamp.h>
32 #include <libavformat/avformat.h>
33 
34 static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt, const char *tag)
35 {
36  AVRational *time_base = &fmt_ctx->streams[pkt->stream_index]->time_base;
37 
38  printf("%s: pts:%s pts_time:%s dts:%s dts_time:%s duration:%s duration_time:%s stream_index:%d\n",
39  tag,
40  av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, time_base),
41  av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, time_base),
42  av_ts2str(pkt->duration), av_ts2timestr(pkt->duration, time_base),
43  pkt->stream_index);
44 }
45 
46 int main(int argc, char **argv)
47 {
48  AVOutputFormat *ofmt = NULL;
49  AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL;
50  AVPacket pkt;
51  const char *in_filename, *out_filename;
52  int ret, i;
53 
54  if (argc < 3) {
55  printf("usage: %s input output\n"
56  "API example program to remux a media file with libavformat and libavcodec.\n"
57  "The output format is guessed according to the file extension.\n"
58  "\n", argv[0]);
59  return 1;
60  }
61 
62  in_filename = argv[1];
63  out_filename = argv[2];
64 
66 
67  if ((ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0)) < 0) {
68  fprintf(stderr, "Could not open input file '%s'", in_filename);
69  goto end;
70  }
71 
72  if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0) {
73  fprintf(stderr, "Failed to retrieve input stream information");
74  goto end;
75  }
76 
77  av_dump_format(ifmt_ctx, 0, in_filename, 0);
78 
79  avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, out_filename);
80  if (!ofmt_ctx) {
81  fprintf(stderr, "Could not create output context\n");
82  ret = AVERROR_UNKNOWN;
83  goto end;
84  }
85 
86  ofmt = ofmt_ctx->oformat;
87 
88  for (i = 0; i < ifmt_ctx->nb_streams; i++) {
89  AVStream *in_stream = ifmt_ctx->streams[i];
90  AVStream *out_stream = avformat_new_stream(ofmt_ctx, in_stream->codec->codec);
91  if (!out_stream) {
92  fprintf(stderr, "Failed allocating output stream\n");
93  ret = AVERROR_UNKNOWN;
94  goto end;
95  }
96 
97  ret = avcodec_copy_context(out_stream->codec, in_stream->codec);
98  if (ret < 0) {
99  fprintf(stderr, "Failed to copy context from input to output stream codec context\n");
100  goto end;
101  }
102  out_stream->codec->codec_tag = 0;
103  if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
104  out_stream->codec->flags |= CODEC_FLAG_GLOBAL_HEADER;
105  }
106  av_dump_format(ofmt_ctx, 0, out_filename, 1);
107 
108  if (!(ofmt->flags & AVFMT_NOFILE)) {
109  ret = avio_open(&ofmt_ctx->pb, out_filename, AVIO_FLAG_WRITE);
110  if (ret < 0) {
111  fprintf(stderr, "Could not open output file '%s'", out_filename);
112  goto end;
113  }
114  }
115 
116  ret = avformat_write_header(ofmt_ctx, NULL);
117  if (ret < 0) {
118  fprintf(stderr, "Error occurred when opening output file\n");
119  goto end;
120  }
121 
122  while (1) {
123  AVStream *in_stream, *out_stream;
124 
125  ret = av_read_frame(ifmt_ctx, &pkt);
126  if (ret < 0)
127  break;
128 
129  in_stream = ifmt_ctx->streams[pkt.stream_index];
130  out_stream = ofmt_ctx->streams[pkt.stream_index];
131 
132  log_packet(ifmt_ctx, &pkt, "in");
133 
134  /* copy packet */
137  pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);
138  pkt.pos = -1;
139  log_packet(ofmt_ctx, &pkt, "out");
140 
141  ret = av_interleaved_write_frame(ofmt_ctx, &pkt);
142  if (ret < 0) {
143  fprintf(stderr, "Error muxing packet\n");
144  break;
145  }
146  av_free_packet(&pkt);
147  }
148 
149  av_write_trailer(ofmt_ctx);
150 end:
151 
152  avformat_close_input(&ifmt_ctx);
153 
154  /* close output */
155  if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE))
156  avio_close(ofmt_ctx->pb);
157  avformat_free_context(ofmt_ctx);
158 
159  if (ret < 0 && ret != AVERROR_EOF) {
160  fprintf(stderr, "Error occurred: %s\n", av_err2str(ret));
161  return 1;
162  }
163 
164  return 0;
165 }