FFmpeg
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 {
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),
43  pkt->stream_index);
44 }
45 
46 int main(int argc, char **argv)
47 {
48  const AVOutputFormat *ofmt = NULL;
50  AVPacket *pkt = NULL;
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 
68  pkt = av_packet_alloc();
69  if (!pkt) {
70  fprintf(stderr, "Could not allocate AVPacket\n");
71  return 1;
72  }
73 
74  if ((ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0)) < 0) {
75  fprintf(stderr, "Could not open input file '%s'", in_filename);
76  goto end;
77  }
78 
79  if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0) {
80  fprintf(stderr, "Failed to retrieve input stream information");
81  goto end;
82  }
83 
84  av_dump_format(ifmt_ctx, 0, in_filename, 0);
85 
87  if (!ofmt_ctx) {
88  fprintf(stderr, "Could not create output context\n");
90  goto end;
91  }
92 
93  stream_mapping_size = ifmt_ctx->nb_streams;
94  stream_mapping = av_calloc(stream_mapping_size, sizeof(*stream_mapping));
95  if (!stream_mapping) {
96  ret = AVERROR(ENOMEM);
97  goto end;
98  }
99 
100  ofmt = ofmt_ctx->oformat;
101 
102  for (i = 0; i < ifmt_ctx->nb_streams; i++) {
103  AVStream *out_stream;
104  AVStream *in_stream = ifmt_ctx->streams[i];
105  AVCodecParameters *in_codecpar = in_stream->codecpar;
106 
107  if (in_codecpar->codec_type != AVMEDIA_TYPE_AUDIO &&
108  in_codecpar->codec_type != AVMEDIA_TYPE_VIDEO &&
109  in_codecpar->codec_type != AVMEDIA_TYPE_SUBTITLE) {
110  stream_mapping[i] = -1;
111  continue;
112  }
113 
114  stream_mapping[i] = stream_index++;
115 
116  out_stream = avformat_new_stream(ofmt_ctx, NULL);
117  if (!out_stream) {
118  fprintf(stderr, "Failed allocating output stream\n");
120  goto end;
121  }
122 
123  ret = avcodec_parameters_copy(out_stream->codecpar, in_codecpar);
124  if (ret < 0) {
125  fprintf(stderr, "Failed to copy codec parameters\n");
126  goto end;
127  }
128  out_stream->codecpar->codec_tag = 0;
129  }
130  av_dump_format(ofmt_ctx, 0, out_filename, 1);
131 
132  if (!(ofmt->flags & AVFMT_NOFILE)) {
133  ret = avio_open(&ofmt_ctx->pb, out_filename, AVIO_FLAG_WRITE);
134  if (ret < 0) {
135  fprintf(stderr, "Could not open output file '%s'", out_filename);
136  goto end;
137  }
138  }
139 
141  if (ret < 0) {
142  fprintf(stderr, "Error occurred when opening output file\n");
143  goto end;
144  }
145 
146  while (1) {
147  AVStream *in_stream, *out_stream;
148 
150  if (ret < 0)
151  break;
152 
153  in_stream = ifmt_ctx->streams[pkt->stream_index];
154  if (pkt->stream_index >= stream_mapping_size ||
155  stream_mapping[pkt->stream_index] < 0) {
157  continue;
158  }
159 
160  pkt->stream_index = stream_mapping[pkt->stream_index];
161  out_stream = ofmt_ctx->streams[pkt->stream_index];
162  log_packet(ifmt_ctx, pkt, "in");
163 
164  /* copy packet */
165  av_packet_rescale_ts(pkt, in_stream->time_base, out_stream->time_base);
166  pkt->pos = -1;
167  log_packet(ofmt_ctx, pkt, "out");
168 
170  /* pkt is now blank (av_interleaved_write_frame() takes ownership of
171  * its contents and resets pkt), so that no unreferencing is necessary.
172  * This would be different if one used av_write_frame(). */
173  if (ret < 0) {
174  fprintf(stderr, "Error muxing packet\n");
175  break;
176  }
177  }
178 
180 end:
182 
184 
185  /* close output */
186  if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE))
189 
190  av_freep(&stream_mapping);
191 
192  if (ret < 0 && ret != AVERROR_EOF) {
193  fprintf(stderr, "Error occurred: %s\n", av_err2str(ret));
194  return 1;
195  }
196 
197  return 0;
198 }
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:417
AVMEDIA_TYPE_SUBTITLE
@ AVMEDIA_TYPE_SUBTITLE
Definition: avutil.h:204
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:724
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: codec_par.h:52
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
AVFormatContext::streams
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1177
ofmt_ctx
static AVFormatContext * ofmt_ctx
Definition: transcoding.c:40
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:391
AVCodecParameters::codec_tag
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: codec_par.h:64
av_read_frame
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: demux.c:1414
AVERROR_UNKNOWN
#define AVERROR_UNKNOWN
Unknown error, typically from an external library.
Definition: error.h:73
log_packet
static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt, const char *tag)
Definition: remuxing.c:34
av_packet_free
void av_packet_free(AVPacket **pkt)
Free the packet, if the packet is reference counted, it will be unreferenced first.
Definition: avpacket.c:75
avformat_close_input
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: demux.c:355
pkt
AVPacket * pkt
Definition: movenc.c:59
av_dump_format
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,...
Definition: dump.c:621
avformat_open_input
int avformat_open_input(AVFormatContext **ps, const char *url, const AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
Definition: demux.c:207
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
AVIO_FLAG_WRITE
#define AVIO_FLAG_WRITE
write-only
Definition: avio.h:604
avformat_write_header
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:467
AVFormatContext
Format I/O context.
Definition: avformat.h:1109
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1004
AVStream::time_base
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.
Definition: avformat.h:880
NULL
#define NULL
Definition: coverity.c:32
fmt_ctx
static AVFormatContext * fmt_ctx
Definition: demuxing_decoding.c:38
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVFormatContext::pb
AVIOContext * pb
I/O context.
Definition: avformat.h:1151
AVFormatContext::nb_streams
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1165
AVOutputFormat::flags
int flags
can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_GLOBALHEADER, AVFMT_NOTIMESTAMPS,...
Definition: avformat.h:515
avformat_find_stream_info
int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
Read packets of a media file to get stream information.
Definition: demux.c:2396
av_ts2timestr
#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
av_err2str
#define av_err2str(errnum)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: error.h:121
AVFMT_NOFILE
#define AVFMT_NOFILE
Demuxer will use avio_open, no opened file should be provided by the caller.
Definition: avformat.h:463
printf
printf("static const uint8_t my_array[100] = {\n")
main
int main(int argc, char **argv)
Definition: remuxing.c:46
AVPacket::dts
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed.
Definition: packet.h:372
av_packet_alloc
AVPacket * av_packet_alloc(void)
Allocate an AVPacket and set its fields to default values.
Definition: avpacket.c:64
av_packet_rescale_ts
void av_packet_rescale_ts(AVPacket *pkt, AVRational src_tb, AVRational dst_tb)
Convert valid timing fields (timestamps / durations) in a packet from one timebase to another.
Definition: avpacket.c:521
avcodec_parameters_copy
int avcodec_parameters_copy(AVCodecParameters *dst, const AVCodecParameters *src)
Copy the contents of src to dst.
Definition: codec_par.c:72
avio_closep
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:1239
av_write_trailer
int av_write_trailer(AVFormatContext *s)
Write the stream trailer to an output media file and free the file private data.
Definition: mux.c:1250
AVOutputFormat
Definition: avformat.h:495
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:271
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:366
av_calloc
void * av_calloc(size_t nmemb, size_t size)
Definition: mem.c:271
tag
uint32_t tag
Definition: movenc.c:1595
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:857
AVFormatContext::oformat
const struct AVOutputFormat * oformat
The output container format.
Definition: avformat.h:1128
avformat.h
avformat_free_context
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
Definition: utils.c:679
avio_open
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:1181
AVPacket::stream_index
int stream_index
Definition: packet.h:375
ifmt_ctx
static AVFormatContext * ifmt_ctx
Definition: transcoding.c:39
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVPacket
This structure stores compressed data.
Definition: packet.h:350
av_interleaved_write_frame
int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file ensuring correct interleaving.
Definition: mux.c:1235
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:35
AVPacket::pos
int64_t pos
byte position in stream, -1 if unknown
Definition: packet.h:393
timestamp.h
av_ts2str
#define av_ts2str(ts)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: timestamp.h:54
avformat_alloc_output_context2
int avformat_alloc_output_context2(AVFormatContext **ctx, const AVOutputFormat *oformat, const char *format_name, const char *filename)
Allocate an AVFormatContext for an output format.
Definition: mux.c:136