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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;
50  AVPacket pkt;
51  const char *in_filename, *out_filename;
52  int ret, i;
53  int stream_index = 0;
54  int *stream_mapping = NULL;
55  int stream_mapping_size = 0;
56 
57  if (argc < 3) {
58  printf("usage: %s input output\n"
59  "API example program to remux a media file with libavformat and libavcodec.\n"
60  "The output format is guessed according to the file extension.\n"
61  "\n", argv[0]);
62  return 1;
63  }
64 
65  in_filename = argv[1];
66  out_filename = argv[2];
67 
69 
70  if ((ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0)) < 0) {
71  fprintf(stderr, "Could not open input file '%s'", in_filename);
72  goto end;
73  }
74 
75  if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0) {
76  fprintf(stderr, "Failed to retrieve input stream information");
77  goto end;
78  }
79 
80  av_dump_format(ifmt_ctx, 0, in_filename, 0);
81 
82  avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, out_filename);
83  if (!ofmt_ctx) {
84  fprintf(stderr, "Could not create output context\n");
85  ret = AVERROR_UNKNOWN;
86  goto end;
87  }
88 
89  stream_mapping_size = ifmt_ctx->nb_streams;
90  stream_mapping = av_mallocz_array(stream_mapping_size, sizeof(*stream_mapping));
91  if (!stream_mapping) {
92  ret = AVERROR(ENOMEM);
93  goto end;
94  }
95 
96  ofmt = ofmt_ctx->oformat;
97 
98  for (i = 0; i < ifmt_ctx->nb_streams; i++) {
99  AVStream *out_stream;
100  AVStream *in_stream = ifmt_ctx->streams[i];
101  AVCodecParameters *in_codecpar = in_stream->codecpar;
102 
103  if (in_codecpar->codec_type != AVMEDIA_TYPE_AUDIO &&
104  in_codecpar->codec_type != AVMEDIA_TYPE_VIDEO &&
105  in_codecpar->codec_type != AVMEDIA_TYPE_SUBTITLE) {
106  stream_mapping[i] = -1;
107  continue;
108  }
109 
110  stream_mapping[i] = stream_index++;
111 
112  out_stream = avformat_new_stream(ofmt_ctx, NULL);
113  if (!out_stream) {
114  fprintf(stderr, "Failed allocating output stream\n");
115  ret = AVERROR_UNKNOWN;
116  goto end;
117  }
118 
119  ret = avcodec_parameters_copy(out_stream->codecpar, in_codecpar);
120  if (ret < 0) {
121  fprintf(stderr, "Failed to copy codec parameters\n");
122  goto end;
123  }
124  out_stream->codecpar->codec_tag = 0;
125  }
126  av_dump_format(ofmt_ctx, 0, out_filename, 1);
127 
128  if (!(ofmt->flags & AVFMT_NOFILE)) {
129  ret = avio_open(&ofmt_ctx->pb, out_filename, AVIO_FLAG_WRITE);
130  if (ret < 0) {
131  fprintf(stderr, "Could not open output file '%s'", out_filename);
132  goto end;
133  }
134  }
135 
136  ret = avformat_write_header(ofmt_ctx, NULL);
137  if (ret < 0) {
138  fprintf(stderr, "Error occurred when opening output file\n");
139  goto end;
140  }
141 
142  while (1) {
143  AVStream *in_stream, *out_stream;
144 
145  ret = av_read_frame(ifmt_ctx, &pkt);
146  if (ret < 0)
147  break;
148 
149  in_stream = ifmt_ctx->streams[pkt.stream_index];
150  if (pkt.stream_index >= stream_mapping_size ||
151  stream_mapping[pkt.stream_index] < 0) {
152  av_packet_unref(&pkt);
153  continue;
154  }
155 
156  pkt.stream_index = stream_mapping[pkt.stream_index];
157  out_stream = ofmt_ctx->streams[pkt.stream_index];
158  log_packet(ifmt_ctx, &pkt, "in");
159 
160  /* copy packet */
163  pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);
164  pkt.pos = -1;
165  log_packet(ofmt_ctx, &pkt, "out");
166 
167  ret = av_interleaved_write_frame(ofmt_ctx, &pkt);
168  if (ret < 0) {
169  fprintf(stderr, "Error muxing packet\n");
170  break;
171  }
172  av_packet_unref(&pkt);
173  }
174 
175  av_write_trailer(ofmt_ctx);
176 end:
177 
178  avformat_close_input(&ifmt_ctx);
179 
180  /* close output */
181  if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE))
182  avio_closep(&ofmt_ctx->pb);
183  avformat_free_context(ofmt_ctx);
184 
185  av_freep(&stream_mapping);
186 
187  if (ret < 0 && ret != AVERROR_EOF) {
188  fprintf(stderr, "Error occurred: %s\n", av_err2str(ret));
189  return 1;
190  }
191 
192  return 0;
193 }
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:1098
#define NULL
Definition: coverity.c:32
int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file ensuring correct interleaving.
Definition: mux.c:1166
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1420
static AVFormatContext * fmt_ctx
#define AVIO_FLAG_WRITE
write-only
Definition: avio.h:655
static AVPacket pkt
This struct describes the properties of an encoded stream.
Definition: avcodec.h:3804
int main(int argc, char **argv)
Definition: remuxing.c:46
Format I/O context.
Definition: avformat.h:1325
int flags
can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS, AVFMT_VARIABLE_FPS, AVFMT_NODIMENSIONS, AVFMT_NOSTREAMS, AVFMT_ALLOW_FLUSH, AVFMT_TS_NONSTRICT, AVFMT_TS_NEGATIVE
Definition: avformat.h:526
timestamp utils, mostly useful for debugging/logging purposes
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1418
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4378
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1393
uint32_t tag
Definition: movenc.c:1448
#define AVERROR_EOF
End of file.
Definition: error.h:55
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:142
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:555
int avcodec_parameters_copy(AVCodecParameters *dst, const AVCodecParameters *src)
Copy the contents of src to dst.
Definition: utils.c:2231
static AVFormatContext * ifmt_ctx
Definition: transcoding.c:38
#define AVERROR(e)
Definition: error.h:43
#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
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3808
Round to nearest and halfway cases away from zero.
Definition: mathematics.h:84
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1381
av_warn_unused_result 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:489
#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:872
static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt, const char *tag)
Definition: remuxing.c:34
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:590
Rational number (pair of numerator and denominator).
Definition: rational.h:58
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
Definition: utils.c:4313
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: utils.c:1712
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:3497
#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:4350
Flag telling rescaling functions to pass INT64_MIN/MAX through unchanged, avoiding special cases for ...
Definition: mathematics.h:108
#define av_ts2str(ts)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: timestamp.h:54
int avformat_open_input(AVFormatContext **ps, const char *url, AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
Definition: utils.c:515
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed...
Definition: avcodec.h:1399
int av_write_trailer(AVFormatContext *s)
Write the stream trailer to an output media file and free the file private data.
Definition: mux.c:1228
#define av_freep(p)
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1014
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:134
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: avcodec.h:3816
int stream_index
Definition: avcodec.h:1402
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented...
Definition: avformat.h:901
This structure stores compressed data.
Definition: avcodec.h:1377
void av_register_all(void)
Initialize libavformat and register all the muxers, demuxers and protocols.
Definition: allformats.c:395
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:1159
static AVFormatContext * ofmt_ctx
Definition: transcoding.c:39
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1393
void * av_mallocz_array(size_t nmemb, size_t size)
Definition: mem.c:191