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  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 
68  if ((ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0)) < 0) {
69  fprintf(stderr, "Could not open input file '%s'", in_filename);
70  goto end;
71  }
72 
73  if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0) {
74  fprintf(stderr, "Failed to retrieve input stream information");
75  goto end;
76  }
77 
78  av_dump_format(ifmt_ctx, 0, in_filename, 0);
79 
81  if (!ofmt_ctx) {
82  fprintf(stderr, "Could not create output context\n");
84  goto end;
85  }
86 
87  stream_mapping_size = ifmt_ctx->nb_streams;
88  stream_mapping = av_mallocz_array(stream_mapping_size, sizeof(*stream_mapping));
89  if (!stream_mapping) {
90  ret = AVERROR(ENOMEM);
91  goto end;
92  }
93 
94  ofmt = ofmt_ctx->oformat;
95 
96  for (i = 0; i < ifmt_ctx->nb_streams; i++) {
97  AVStream *out_stream;
98  AVStream *in_stream = ifmt_ctx->streams[i];
99  AVCodecParameters *in_codecpar = in_stream->codecpar;
100 
101  if (in_codecpar->codec_type != AVMEDIA_TYPE_AUDIO &&
102  in_codecpar->codec_type != AVMEDIA_TYPE_VIDEO &&
103  in_codecpar->codec_type != AVMEDIA_TYPE_SUBTITLE) {
104  stream_mapping[i] = -1;
105  continue;
106  }
107 
108  stream_mapping[i] = stream_index++;
109 
110  out_stream = avformat_new_stream(ofmt_ctx, NULL);
111  if (!out_stream) {
112  fprintf(stderr, "Failed allocating output stream\n");
114  goto end;
115  }
116 
117  ret = avcodec_parameters_copy(out_stream->codecpar, in_codecpar);
118  if (ret < 0) {
119  fprintf(stderr, "Failed to copy codec parameters\n");
120  goto end;
121  }
122  out_stream->codecpar->codec_tag = 0;
123  }
124  av_dump_format(ofmt_ctx, 0, out_filename, 1);
125 
126  if (!(ofmt->flags & AVFMT_NOFILE)) {
127  ret = avio_open(&ofmt_ctx->pb, out_filename, AVIO_FLAG_WRITE);
128  if (ret < 0) {
129  fprintf(stderr, "Could not open output file '%s'", out_filename);
130  goto end;
131  }
132  }
133 
135  if (ret < 0) {
136  fprintf(stderr, "Error occurred when opening output file\n");
137  goto end;
138  }
139 
140  while (1) {
141  AVStream *in_stream, *out_stream;
142 
144  if (ret < 0)
145  break;
146 
147  in_stream = ifmt_ctx->streams[pkt.stream_index];
148  if (pkt.stream_index >= stream_mapping_size ||
149  stream_mapping[pkt.stream_index] < 0) {
151  continue;
152  }
153 
154  pkt.stream_index = stream_mapping[pkt.stream_index];
155  out_stream = ofmt_ctx->streams[pkt.stream_index];
156  log_packet(ifmt_ctx, &pkt, "in");
157 
158  /* copy packet */
161  pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);
162  pkt.pos = -1;
163  log_packet(ofmt_ctx, &pkt, "out");
164 
166  if (ret < 0) {
167  fprintf(stderr, "Error muxing packet\n");
168  break;
169  }
171  }
172 
174 end:
175 
177 
178  /* close output */
179  if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE))
182 
183  av_freep(&stream_mapping);
184 
185  if (ret < 0 && ret != AVERROR_EOF) {
186  fprintf(stderr, "Error occurred: %s\n", av_err2str(ret));
187  return 1;
188  }
189 
190  return 0;
191 }
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:599
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:4480
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3953
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: avcodec.h:3949
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:55
end
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
AVFormatContext::streams
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1410
ofmt_ctx
static AVFormatContext * ofmt_ctx
Definition: transcoding.c:39
av_mallocz_array
void * av_mallocz_array(size_t nmemb, size_t size)
Definition: mem.c:191
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1495
AVCodecParameters::codec_tag
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: avcodec.h:3961
av_read_frame
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: utils.c:1785
AVERROR_UNKNOWN
#define AVERROR_UNKNOWN
Unknown error, typically from an external library.
Definition: error.h:71
log_packet
static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt, const char *tag)
Definition: remuxing.c:34
avformat_close_input
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: utils.c:4452
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:571
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
AVIO_FLAG_WRITE
#define AVIO_FLAG_WRITE
write-only
Definition: avio.h:655
av_rescale_q
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
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:508
AVFormatContext
Format I/O context.
Definition: avformat.h:1342
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1017
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:899
NULL
#define NULL
Definition: coverity.c:32
fmt_ctx
static AVFormatContext * fmt_ctx
Definition: demuxing_decoding.c:37
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVFormatContext::pb
AVIOContext * pb
I/O context.
Definition: avformat.h:1384
AV_ROUND_NEAR_INF
@ AV_ROUND_NEAR_INF
Round to nearest and halfway cases away from zero.
Definition: mathematics.h:84
AVFormatContext::oformat
ff_const59 struct AVOutputFormat * oformat
The output container format.
Definition: avformat.h:1361
AVFormatContext::nb_streams
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1398
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: utils.c:3588
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:119
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: avcodec.h:1476
avformat_alloc_output_context2
int avformat_alloc_output_context2(AVFormatContext **ctx, ff_const59 AVOutputFormat *oformat, const char *format_name, const char *filename)
Allocate an AVFormatContext for an output format.
Definition: mux.c:148
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:1210
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:1254
AVOutputFormat
Definition: avformat.h:495
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1470
avformat_open_input
int avformat_open_input(AVFormatContext **ps, const char *url, ff_const59 AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
Definition: utils.c:540
tag
uint32_t tag
Definition: movenc.c:1496
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:870
avformat.h
pkt
static AVPacket pkt
Definition: demuxing_decoding.c:54
avformat_free_context
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
Definition: utils.c:4414
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:1153
AVPacket::stream_index
int stream_index
Definition: avcodec.h:1479
ifmt_ctx
static AVFormatContext * ifmt_ctx
Definition: transcoding.c:38
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AV_ROUND_PASS_MINMAX
@ AV_ROUND_PASS_MINMAX
Flag telling rescaling functions to pass INT64_MIN/MAX through unchanged, avoiding special cases for ...
Definition: mathematics.h:108
AVPacket
This structure stores compressed data.
Definition: avcodec.h:1454
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:1192
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:35
AVPacket::pos
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1497
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
av_rescale_q_rnd
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
avcodec_parameters_copy
int avcodec_parameters_copy(AVCodecParameters *dst, const AVCodecParameters *src)
Copy the contents of src to dst.
Definition: utils.c:2080