FFmpeg
webm_chunk.c
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1 /*
2  * Copyright (c) 2015, Vignesh Venkatasubramanian
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file WebM Chunk Muxer
23  * The chunk muxer enables writing WebM Live chunks where there is a header
24  * chunk, followed by data chunks where each Cluster is written out as a Chunk.
25  */
26 
27 #include "avformat.h"
28 #include "avio.h"
29 #include "avio_internal.h"
30 #include "internal.h"
31 #include "mux.h"
32 
33 #include "libavutil/bprint.h"
34 #include "libavutil/log.h"
35 #include "libavutil/mem.h"
36 #include "libavutil/opt.h"
37 #include "libavutil/mathematics.h"
38 
39 typedef struct WebMChunkContext {
40  const AVClass *class;
41  char *header_filename;
42  int chunk_duration;
43  int chunk_index;
44  char *http_method;
45  uint64_t duration_written;
46  int64_t prev_pts;
47  AVFormatContext *avf;
48  int header_written;
49 } WebMChunkContext;
50 
51 static int webm_chunk_init(AVFormatContext *s)
52 {
53  WebMChunkContext *wc = s->priv_data;
54  const AVOutputFormat *oformat;
55  AVFormatContext *oc;
56  AVStream *st, *ost = s->streams[0];
57  AVDictionary *dict = NULL;
58  int ret;
59 
60  // DASH Streams can only have one track per file.
61  if (s->nb_streams != 1)
62  return AVERROR(EINVAL);
63 
64  if (!wc->header_filename) {
65  av_log(s, AV_LOG_ERROR, "No header filename provided\n");
66  return AVERROR(EINVAL);
67  }
68 
69  wc->prev_pts = AV_NOPTS_VALUE;
70 
71  oformat = av_guess_format("webm", s->url, "video/webm");
72  if (!oformat)
73  return AVERROR_MUXER_NOT_FOUND;
74 
75  ret = avformat_alloc_output_context2(&wc->avf, oformat, NULL, NULL);
76  if (ret < 0)
77  return ret;
78  oc = wc->avf;
79 
80  ff_format_set_url(oc, wc->header_filename);
81  wc->header_filename = NULL;
82 
83  oc->interrupt_callback = s->interrupt_callback;
84  oc->max_delay = s->max_delay;
85  oc->flags = s->flags & ~AVFMT_FLAG_FLUSH_PACKETS;
86  oc->strict_std_compliance = s->strict_std_compliance;
87  oc->avoid_negative_ts = s->avoid_negative_ts;
88 
89  oc->flush_packets = 0;
90 
91  if ((ret = av_dict_copy(&oc->metadata, s->metadata, 0)) < 0)
92  return ret;
93 
94  st = ff_stream_clone(oc, ost);
95  if (!st)
96  return AVERROR(ENOMEM);
97 
98  if (wc->http_method)
99  if ((ret = av_dict_set(&dict, "method", wc->http_method, 0)) < 0)
100  return ret;
101  ret = s->io_open(s, &oc->pb, oc->url, AVIO_FLAG_WRITE, &dict);
102  av_dict_free(&dict);
103  if (ret < 0)
104  return ret;
105  oc->pb->seekable = 0;
106 
107  if ((ret = av_dict_set_int(&dict, "dash", 1, 0)) < 0 ||
108  (ret = av_dict_set_int(&dict, "cluster_time_limit",
109  wc->chunk_duration, 0)) < 0 ||
110  (ret = av_dict_set_int(&dict, "live", 1, 0)) < 0)
111  goto fail;
112 
113  ret = avformat_init_output(oc, &dict);
114 fail:
115  av_dict_free(&dict);
116  if (ret < 0)
117  return ret;
118 
119  // Copy the timing info back to the original stream
120  // so that the timestamps of the packets are directly usable
121  avpriv_set_pts_info(ost, st->pts_wrap_bits, st->time_base.num,
122  st->time_base.den);
123 
124  // This ensures that the timestamps will already be properly shifted
125  // when the packets arrive here, so we don't need to shift again.
126  s->avoid_negative_ts = oc->avoid_negative_ts;
127  ffformatcontext(s)->avoid_negative_ts_use_pts =
128  ffformatcontext(oc)->avoid_negative_ts_use_pts;
129  oc->avoid_negative_ts = AVFMT_AVOID_NEG_TS_DISABLED;
130  ffformatcontext(oc)->avoid_negative_ts_status = AVOID_NEGATIVE_TS_DISABLED;
131 
132  return 0;
133 }
134 
135 static int get_chunk_filename(AVFormatContext *s, AVBPrint *filename)
136 {
137  WebMChunkContext *wc = s->priv_data;
138  int ret = ff_bprint_get_frame_filename(filename, s->url, wc->chunk_index - 1, 0);
139  if (ret < 0) {
140  av_log(s, AV_LOG_ERROR, "Invalid chunk filename template '%s'\n", s->url);
141  return ret;
142  }
143  return 0;
144 }
145 
146 static int webm_chunk_write_header(AVFormatContext *s)
147 {
148  WebMChunkContext *wc = s->priv_data;
149  AVFormatContext *oc = wc->avf;
150  AVStream *st = s->streams[0], *ost = oc->streams[0];
151  int ret;
152 
153  ret = avformat_write_header(oc, NULL);
154  ff_format_io_close(s, &oc->pb);
155  ffstream(st)->lowest_ts_allowed = ffstream(ost)->lowest_ts_allowed;
156  ffstream(ost)->lowest_ts_allowed = 0;
157  wc->header_written = 1;
158  if (ret < 0)
159  return ret;
160  return 0;
161 }
162 
163 static int chunk_start(AVFormatContext *s)
164 {
165  WebMChunkContext *wc = s->priv_data;
166  AVFormatContext *oc = wc->avf;
167  int ret;
168 
169  ret = avio_open_dyn_buf(&oc->pb);
170  if (ret < 0)
171  return ret;
172  wc->chunk_index++;
173  return 0;
174 }
175 
176 static int chunk_end(AVFormatContext *s, int flush)
177 {
178  WebMChunkContext *wc = s->priv_data;
179  AVFormatContext *oc = wc->avf;
180  int ret;
181  int buffer_size;
182  uint8_t *buffer;
183  AVIOContext *pb;
184  AVBPrint filename;
185  AVDictionary *options = NULL;
186 
187  if (!oc->pb)
188  return 0;
189 
190  if (flush)
191  // Flush the cluster in WebM muxer.
192  av_write_frame(oc, NULL);
193  buffer_size = avio_close_dyn_buf(oc->pb, &buffer);
194  oc->pb = NULL;
195  av_bprint_init(&filename, 0, AV_BPRINT_SIZE_UNLIMITED);
196  ret = get_chunk_filename(s, &filename);
197  if (ret < 0)
198  goto fail;
199  if (wc->http_method)
200  if ((ret = av_dict_set(&options, "method", wc->http_method, 0)) < 0)
201  goto fail;
202  ret = s->io_open(s, &pb, filename.str, AVIO_FLAG_WRITE, &options);
203  av_dict_free(&options);
204  if (ret < 0)
205  goto fail;
206  avio_write(pb, buffer, buffer_size);
207  ff_format_io_close(s, &pb);
208 fail:
209  av_bprint_finalize(&filename, NULL);
210  av_free(buffer);
211  return (ret < 0) ? ret : 0;
212 }
213 
214 static int webm_chunk_write_packet(AVFormatContext *s, AVPacket *pkt)
215 {
216  WebMChunkContext *wc = s->priv_data;
217  AVFormatContext *oc = wc->avf;
218  AVStream *st = s->streams[pkt->stream_index];
219  int ret;
220 
221  if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
222  if (wc->prev_pts != AV_NOPTS_VALUE)
223  wc->duration_written += av_rescale_q(pkt->pts - wc->prev_pts,
224  st->time_base,
225  (AVRational) {1, 1000});
226  wc->prev_pts = pkt->pts;
227  }
228 
229  // For video, a new chunk is started only on key frames. For audio, a new
230  // chunk is started based on chunk_duration. Also, a new chunk is started
231  // unconditionally if there is no currently open chunk.
232  if (!oc->pb || (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO &&
233  (pkt->flags & AV_PKT_FLAG_KEY)) ||
234  (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO &&
235  wc->duration_written >= wc->chunk_duration)) {
236  wc->duration_written = 0;
237  if ((ret = chunk_end(s, 1)) < 0 || (ret = chunk_start(s)) < 0) {
238  return ret;
239  }
240  }
241 
242  // We only have one stream, so use the non-interleaving av_write_frame.
243  return av_write_frame(oc, pkt);
244 }
245 
246 static int webm_chunk_write_trailer(AVFormatContext *s)
247 {
248  WebMChunkContext *wc = s->priv_data;
249  AVFormatContext *oc = wc->avf;
250  int ret;
251 
252  if (!oc->pb) {
253  ret = chunk_start(s);
254  if (ret < 0)
255  return ret;
256  }
257  ret = av_write_trailer(oc);
258  if (ret < 0)
259  return ret;
260  return chunk_end(s, 0);
261 }
262 
263 static void webm_chunk_deinit(AVFormatContext *s)
264 {
265  WebMChunkContext *wc = s->priv_data;
266 
267  if (!wc->avf)
268  return;
269 
270  if (wc->header_written)
271  ffio_free_dyn_buf(&wc->avf->pb);
272  else
273  ff_format_io_close(s, &wc->avf->pb);
274  avformat_free_context(wc->avf);
275  wc->avf = NULL;
276 }
277 
278 #define OFFSET(x) offsetof(WebMChunkContext, x)
279 static const AVOption options[] = {
280  { "chunk_start_index", "start index of the chunk", OFFSET(chunk_index), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
281  { "header", "filename of the header where the initialization data will be written", OFFSET(header_filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },
282  { "audio_chunk_duration", "duration of each chunk in milliseconds", OFFSET(chunk_duration), AV_OPT_TYPE_INT, {.i64 = 5000}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
283  { "method", "set the HTTP method", OFFSET(http_method), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },
284  { NULL },
285 };
286 
287 static const AVClass webm_chunk_class = {
288  .class_name = "WebM Chunk Muxer",
289  .item_name = av_default_item_name,
290  .option = options,
291  .version = LIBAVUTIL_VERSION_INT,
292 };
293 
294 const FFOutputFormat ff_webm_chunk_muxer = {
295  .p.name = "webm_chunk",
296  .p.long_name = NULL_IF_CONFIG_SMALL("WebM Chunk Muxer"),
297  .p.mime_type = "video/webm",
298  .p.extensions = "chk",
299  .p.flags = AVFMT_NOFILE | AVFMT_GLOBALHEADER | AVFMT_NEEDNUMBER |
300  AVFMT_TS_NONSTRICT,
301  .p.priv_class = &webm_chunk_class,
302  .priv_data_size = sizeof(WebMChunkContext),
303  .init = webm_chunk_init,
304  .write_header = webm_chunk_write_header,
305  .write_packet = webm_chunk_write_packet,
306  .write_trailer = webm_chunk_write_trailer,
307  .deinit = webm_chunk_deinit,
308 };
AV_BPRINT_SIZE_UNLIMITED
#define AV_BPRINT_SIZE_UNLIMITED
webm_chunk_class
static const AVClass webm_chunk_class
Definition: webm_chunk.c:287
get_chunk_filename
static int get_chunk_filename(AVFormatContext *s, AVBPrint *filename)
Definition: webm_chunk.c:135
chunk_start
static int chunk_start(AVFormatContext *s)
Definition: webm_chunk.c:163
AVOutputFormat::name
const char * name
Definition: avformat.h:506
AVERROR
Filter the word β€œframe” 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
opt.h
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:51
webm_chunk_write_header
static int webm_chunk_write_header(AVFormatContext *s)
Definition: webm_chunk.c:146
WebMChunkContext::chunk_index
int chunk_index
Definition: webm_chunk.c:43
av_bprint_init
void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max)
Definition: bprint.c:69
ffformatcontext
static av_always_inline FFFormatContext * ffformatcontext(AVFormatContext *s)
Definition: internal.h:123
WebMChunkContext::prev_pts
int64_t prev_pts
Definition: webm_chunk.c:46
int64_t
long long int64_t
Definition: coverity.c:34
WebMChunkContext::http_method
char * http_method
Definition: webm_chunk.c:44
AVFormatContext::streams
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1332
deinit
static void deinit(AVFormatContext *s)
Definition: chromaprint.c:52
AVFormatContext::strict_std_compliance
int strict_std_compliance
Allow non-standard and experimental extension.
Definition: avformat.h:1618
AVOption
AVOption.
Definition: opt.h:429
ff_webm_chunk_muxer
const FFOutputFormat ff_webm_chunk_muxer
Definition: webm_chunk.c:294
mathematics.h
AVDictionary
Definition: dict.c:32
avformat_init_output
av_warn_unused_result int avformat_init_output(AVFormatContext *s, AVDictionary **options)
Allocate the stream private data and initialize the codec, but do not write the header.
Definition: mux.c:446
WebMChunkContext
Definition: webm_chunk.c:39
ost
static AVStream * ost
Definition: vaapi_transcode.c:42
AV_PKT_FLAG_KEY
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: packet.h:613
FFOutputFormat::p
AVOutputFormat p
The public AVOutputFormat.
Definition: mux.h:65
AVFormatContext::interrupt_callback
AVIOInterruptCB interrupt_callback
Custom interrupt callbacks for the I/O layer.
Definition: avformat.h:1534
webm_chunk_write_trailer
static int webm_chunk_write_trailer(AVFormatContext *s)
Definition: webm_chunk.c:246
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:777
AVFormatContext::flush_packets
int flush_packets
Flush the I/O context after each packet.
Definition: avformat.h:1720
ffstream
static av_always_inline FFStream * ffstream(AVStream *st)
Definition: internal.h:347
fail
#define fail()
Definition: checkasm.h:200
ff_bprint_get_frame_filename
int ff_bprint_get_frame_filename(struct AVBPrint *buf, const char *path, int64_t number, int flags)
Return in 'buf' the path with 'd' replaced by a number.
Definition: utils.c:289
AVRational::num
int num
Numerator.
Definition: rational.h:59
avio_close_dyn_buf
int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
Return the written size and a pointer to the buffer.
Definition: aviobuf.c:1410
chunk_end
static int chunk_end(AVFormatContext *s, int flush)
Definition: webm_chunk.c:176
pkt
AVPacket * pkt
Definition: movenc.c:60
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:210
AVFormatContext::metadata
AVDictionary * metadata
Metadata that applies to the whole file.
Definition: avformat.h:1496
WebMChunkContext::header_filename
char * header_filename
Definition: webm_chunk.c:41
avio_open_dyn_buf
int avio_open_dyn_buf(AVIOContext **s)
Open a write only memory stream.
Definition: aviobuf.c:1365
s
#define s(width, name)
Definition: cbs_vp9.c:198
AVFormatContext::flags
int flags
Flags modifying the (de)muxer behaviour.
Definition: avformat.h:1415
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:201
AVIO_FLAG_WRITE
#define AVIO_FLAG_WRITE
write-only
Definition: avio.h:618
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
webm_chunk_write_packet
static int webm_chunk_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: webm_chunk.c:214
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
AVFMT_NEEDNUMBER
#define AVFMT_NEEDNUMBER
Needs 'd' in filename.
Definition: avformat.h:469
AVFormatContext
Format I/O context.
Definition: avformat.h:1264
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:767
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:76
AVFMT_AVOID_NEG_TS_DISABLED
#define AVFMT_AVOID_NEG_TS_DISABLED
Do not shift timestamps even when they are negative.
Definition: avformat.h:1650
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:783
NULL
#define NULL
Definition: coverity.c:32
write_trailer
static int write_trailer(AVFormatContext *s1)
Definition: v4l2enc.c:101
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:241
AVFormatContext::pb
AVIOContext * pb
I/O context.
Definition: avformat.h:1306
flush
void(* flush)(AVBSFContext *ctx)
Definition: dts2pts.c:370
options
Definition: swscale.c:43
FFOutputFormat
Definition: mux.h:61
av_write_frame
int av_write_frame(AVFormatContext *s, AVPacket *pkt)
Write a packet to an output media file.
Definition: mux.c:1176
AV_OPT_FLAG_ENCODING_PARAM
#define AV_OPT_FLAG_ENCODING_PARAM
A generic parameter which can be set by the user for muxing or encoding.
Definition: opt.h:352
webm_chunk_init
static int webm_chunk_init(AVFormatContext *s)
Definition: webm_chunk.c:51
options
static const AVOption options[]
Definition: webm_chunk.c:279
AVIOContext
Bytestream IO Context.
Definition: avio.h:160
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts.c:368
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:94
AVIOContext::seekable
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:261
av_bprint_finalize
int av_bprint_finalize(AVBPrint *buf, char **ret_str)
Finalize a print buffer.
Definition: bprint.c:235
AVFormatContext::url
char * url
input or output URL.
Definition: avformat.h:1380
avio.h
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:247
AVFMT_NOFILE
#define AVFMT_NOFILE
Demuxer will use avio_open, no opened file should be provided by the caller.
Definition: avformat.h:468
ff_format_io_close
int ff_format_io_close(AVFormatContext *s, AVIOContext **pb)
Definition: avformat.c:868
avio_write
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:206
AVPacket::flags
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:564
av_dict_free
void av_dict_free(AVDictionary **pm)
Free all the memory allocated for an AVDictionary struct and all keys and values.
Definition: dict.c:233
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:1238
bprint.h
log.h
AVFMT_GLOBALHEADER
#define AVFMT_GLOBALHEADER
Format wants global header.
Definition: avformat.h:477
AVOutputFormat
Definition: avformat.h:505
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:551
avio_internal.h
AVERROR_MUXER_NOT_FOUND
#define AVERROR_MUXER_NOT_FOUND
Muxer not found.
Definition: error.h:62
AVFormatContext::avoid_negative_ts
int avoid_negative_ts
Avoid negative timestamps during muxing.
Definition: avformat.h:1648
AVFormatContext::max_delay
int max_delay
Definition: avformat.h:1409
write_packet
static int write_packet(Muxer *mux, OutputStream *ost, AVPacket *pkt)
Definition: ffmpeg_mux.c:209
AVFMT_TS_NONSTRICT
#define AVFMT_TS_NONSTRICT
Format does not require strictly increasing timestamps, but they must still be monotonic.
Definition: avformat.h:487
ffio_free_dyn_buf
void ffio_free_dyn_buf(AVIOContext **s)
Free a dynamic buffer.
Definition: aviobuf.c:1438
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:744
AVClass::class_name
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:81
avformat.h
WebMChunkContext::header_written
int header_written
Definition: webm_chunk.c:48
buffer
the frame and frame reference mechanism is intended to as much as expensive copies of that data while still allowing the filters to produce correct results The data is stored in buffers represented by AVFrame structures Several references can point to the same frame buffer
Definition: filter_design.txt:49
AVRational::den
int den
Denominator.
Definition: rational.h:60
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Underlying C type is int.
Definition: opt.h:259
avformat_free_context
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
Definition: avformat.c:141
AVPacket::stream_index
int stream_index
Definition: packet.h:560
FFFormatContext::avoid_negative_ts_status
enum FFFormatContext::@434 avoid_negative_ts_status
Whether the timestamp shift offset has already been determined.
av_dict_set_int
int av_dict_set_int(AVDictionary **pm, const char *key, int64_t value, int flags)
Convenience wrapper for av_dict_set() that converts the value to a string and stores it.
Definition: dict.c:177
webm_chunk_deinit
static void webm_chunk_deinit(AVFormatContext *s)
Definition: webm_chunk.c:263
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:200
av_guess_format
const AVOutputFormat * av_guess_format(const char *short_name, const char *filename, const char *mime_type)
Return the output format in the list of registered output formats which best matches the provided par...
Definition: format.c:79
mem.h
av_free
#define av_free(p)
Definition: tableprint_vlc.h:34
ff_stream_clone
AVStream * ff_stream_clone(AVFormatContext *dst_ctx, const AVStream *src)
Create a new stream and copy to it all parameters from a source stream, with the exception of the ind...
Definition: avformat.c:238
AVPacket
This structure stores compressed data.
Definition: packet.h:535
av_dict_set
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:86
av_dict_copy
int av_dict_copy(AVDictionary **dst, const AVDictionary *src, int flags)
Copy entries from one AVDictionary struct into another.
Definition: dict.c:247
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVFMT_FLAG_FLUSH_PACKETS
#define AVFMT_FLAG_FLUSH_PACKETS
Flush the AVIOContext every packet.
Definition: avformat.h:1425
OFFSET
#define OFFSET(x)
Definition: webm_chunk.c:278
WebMChunkContext::avf
AVFormatContext * avf
Definition: webm_chunk.c:47
AV_OPT_TYPE_STRING
@ AV_OPT_TYPE_STRING
Underlying C type is a uint8_t* that is either NULL or points to a C string allocated with the av_mal...
Definition: opt.h:276
write_header
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:384
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:95
AVStream::pts_wrap_bits
int pts_wrap_bits
Number of bits in timestamps.
Definition: avformat.h:887
ff_format_set_url
void ff_format_set_url(AVFormatContext *s, char *url)
Set AVFormatContext url field to the provided pointer.
Definition: avformat.c:861
FFStream::lowest_ts_allowed
int64_t lowest_ts_allowed
This is the lowest ts allowed in this track; it may be set by the muxer during init or write_header a...
Definition: internal.h:250
WebMChunkContext::duration_written
uint64_t duration_written
Definition: webm_chunk.c:45
WebMChunkContext::chunk_duration
int chunk_duration
Definition: webm_chunk.c:42
mux.h
FFFormatContext::avoid_negative_ts_use_pts
int avoid_negative_ts_use_pts
Definition: internal.h:113
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