FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
remuxing.c
Go to the documentation of this file.
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;
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_closep(&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 }
int avio_open(AVIOContext **s, const char *url, int flags)
Create and initialize a AVIOContext for accessing the resource indicated by url.
Definition: aviobuf.c:909
#define NULL
Definition: coverity.c:32
const struct AVCodec * codec
Definition: avcodec.h:1250
void av_free_packet(AVPacket *pkt)
Free a packet.
Definition: avpacket.c:280
int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file ensuring correct interleaving.
Definition: mux.c:913
int avformat_write_header(AVFormatContext *s, AVDictionary **options)
Allocate the stream private data and write the stream header to an output media file.
Definition: mux.c:428
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1187
int avformat_open_input(AVFormatContext **ps, const char *filename, AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
Definition: utils.c:402
static AVFormatContext * fmt_ctx
#define AVIO_FLAG_WRITE
write-only
Definition: avio.h:461
static AVPacket pkt
int avcodec_copy_context(AVCodecContext *dest, const AVCodecContext *src)
Copy the settings of the source AVCodecContext into the destination AVCodecContext.
Definition: options.c:180
int main(int argc, char **argv)
Definition: remuxing.c:46
Format I/O context.
Definition: avformat.h:1272
int flags
can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_RAWPICTURE, AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS, AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH, AVFMT_TS_NONSTRICT
Definition: avformat.h:532
timestamp utils, mostly useful for debugging/logging purposes
#define CODEC_FLAG_GLOBAL_HEADER
Place global headers in extradata instead of every keyframe.
Definition: avcodec.h:758
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:67
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:3672
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1340
uint32_t tag
Definition: movenc.c:1333
#define AVERROR_EOF
End of file.
Definition: error.h:55
int duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1180
int avformat_alloc_output_context2(AVFormatContext **ctx, AVOutputFormat *oformat, const char *format_name, const char *filename)
Allocate an AVFormatContext for an output format.
Definition: mux.c:148
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
Definition: mathematics.c:140
void av_dump_format(AVFormatContext *ic, int index, const char *url, int is_output)
Print detailed information about the input or output format, such as duration, bitrate, streams, container, programs, metadata, side data, codec and time base.
Definition: dump.c:477
static AVFormatContext * ifmt_ctx
Definition: transcoding.c:40
#define av_ts2timestr(ts, tb)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: timestamp.h:76
int flags
CODEC_FLAG_*.
Definition: avcodec.h:1335
Round to nearest and halfway cases away from zero.
Definition: mathematics.h:75
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:861
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1328
int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq, enum AVRounding rnd)
Rescale a 64-bit integer by 2 rational numbers with specified rounding.
Definition: mathematics.c:132
ret
Definition: avfilter.c:974
#define AVFMT_GLOBALHEADER
Format wants global header.
Definition: avformat.h:471
#define av_err2str(errnum)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: error.h:119
Stream structure.
Definition: avformat.h:842
static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt, const char *tag)
Definition: remuxing.c:34
unsigned int codec_tag
fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
Definition: avcodec.h:1273
rational number numerator/denominator
Definition: rational.h:43
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
Definition: utils.c:3609
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: utils.c:1475
Main libavformat public API header.
#define AVFMT_NOFILE
Demuxer will use avio_open, no opened file should be provided by the caller.
Definition: avformat.h:465
int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
Read packets of a media file to get stream information.
Definition: utils.c:3024
#define AVERROR_UNKNOWN
Unknown error, typically from an external library.
Definition: error.h:71
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: utils.c:3644
Flag to pass INT64_MIN/MAX through instead of rescaling, this avoids special cases for AV_NOPTS_VALUE...
Definition: mathematics.h:76
#define av_ts2str(ts)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: timestamp.h:54
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed...
Definition: avcodec.h:1161
int av_write_trailer(AVFormatContext *s)
Write the stream trailer to an output media file and free the file private data.
Definition: mux.c:967
int stream_index
Definition: avcodec.h:1164
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented...
Definition: avformat.h:884
This structure stores compressed data.
Definition: avcodec.h:1139
void av_register_all(void)
Initialize libavformat and register all the muxers, demuxers and protocols.
Definition: allformats.c:51
int avio_closep(AVIOContext **s)
Close the resource accessed by the AVIOContext *s, free it and set the pointer pointing to it to NULL...
Definition: aviobuf.c:955
static AVFormatContext * ofmt_ctx
Definition: transcoding.c:41
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1155