FFmpeg
demux.h
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1 /*
2  * copyright (c) 2001 Fabrice Bellard
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 #ifndef AVFORMAT_DEMUX_H
22 #define AVFORMAT_DEMUX_H
23 
24 #include <stdint.h>
25 #include "libavutil/rational.h"
26 #include "libavcodec/packet.h"
27 #include "avformat.h"
28 
29 struct AVDeviceInfoList;
30 
31 typedef struct FFInputFormat {
32  /**
33  * The public AVInputFormat. See avformat.h for it.
34  */
36 
37  /**
38  * Raw demuxers store their codec ID here.
39  */
41 
42  /**
43  * Size of private data so that it can be allocated in the wrapper.
44  */
46 
47  /**
48  * Internal flags. See FF_FMT_FLAG_* in internal.h.
49  */
51 
52  /**
53  * Tell if a given file has a chance of being parsed as this format.
54  * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
55  * big so you do not have to check for that unless you need more.
56  */
57  int (*read_probe)(const AVProbeData *);
58 
59  /**
60  * Read the format header and initialize the AVFormatContext
61  * structure. Return 0 if OK. 'avformat_new_stream' should be
62  * called to create new streams.
63  */
65 
66  /**
67  * Read one packet and put it in 'pkt'. pts and flags are also
68  * set. 'avformat_new_stream' can be called only if the flag
69  * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
70  * background thread).
71  * @return 0 on success, < 0 on error.
72  * Upon returning an error, pkt must be unreferenced by the caller.
73  */
75 
76  /**
77  * Close the stream. The AVFormatContext and AVStreams are not
78  * freed by this function
79  */
81 
82  /**
83  * Seek to a given timestamp relative to the frames in
84  * stream component stream_index.
85  * @param stream_index Must not be -1.
86  * @param flags Selects which direction should be preferred if no exact
87  * match is available.
88  * @return >= 0 on success (but not necessarily the new offset)
89  */
91  int stream_index, int64_t timestamp, int flags);
92 
93  /**
94  * Get the next timestamp in stream[stream_index].time_base units.
95  * @return the timestamp or AV_NOPTS_VALUE if an error occurred
96  */
97  int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
98  int64_t *pos, int64_t pos_limit);
99 
100  /**
101  * Start/resume playing - only meaningful if using a network-based format
102  * (RTSP).
103  */
105 
106  /**
107  * Pause playing - only meaningful if using a network-based format
108  * (RTSP).
109  */
111 
112  /**
113  * Seek to timestamp ts.
114  * Seeking will be done so that the point from which all active streams
115  * can be presented successfully will be closest to ts and within min/max_ts.
116  * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
117  */
118  int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
119 
120  /**
121  * Returns device list with it properties.
122  * @see avdevice_list_devices() for more details.
123  */
124  int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
125 } FFInputFormat;
126 
127 static inline const FFInputFormat *ffifmt(const AVInputFormat *fmt)
128 {
129  return (const FFInputFormat*)fmt;
130 }
131 
132 #define MAX_STD_TIMEBASES (30*12+30+3+6)
133 typedef struct FFStreamInfo {
134  int64_t last_dts;
135  int64_t duration_gcd;
142 
143  /**
144  * 0 -> decoder has not been searched for yet.
145  * >0 -> decoder found
146  * <0 -> decoder with codec_id == -found_decoder has not been found
147  */
149 
150  int64_t last_duration;
151 
152  /**
153  * Those are used for average framerate estimation.
154  */
155  int64_t fps_first_dts;
157  int64_t fps_last_dts;
159 } FFStreamInfo;
160 
161 /**
162  * Returned by demuxers to indicate that data was consumed but discarded
163  * (ignored streams or junk data). The framework will re-call the demuxer.
164  */
165 #define FFERROR_REDO FFERRTAG('R','E','D','O')
166 
167 #define RELATIVE_TS_BASE (INT64_MAX - (1LL << 48))
168 
169 static av_always_inline int is_relative(int64_t ts)
170 {
171  return ts > (RELATIVE_TS_BASE - (1LL << 48));
172 }
173 
174 /**
175  * Wrap a given time stamp, if there is an indication for an overflow
176  *
177  * @param st stream
178  * @param timestamp the time stamp to wrap
179  * @return resulting time stamp
180  */
181 int64_t ff_wrap_timestamp(const AVStream *st, int64_t timestamp);
182 
183 /**
184  * Read a transport packet from a media file.
185  *
186  * @param s media file handle
187  * @param pkt is filled
188  * @return 0 if OK, AVERROR_xxx on error
189  */
191 
193 
194 /**
195  * Perform a binary search using av_index_search_timestamp() and
196  * FFInputFormat.read_timestamp().
197  *
198  * @param target_ts target timestamp in the time base of the given stream
199  * @param stream_index stream number
200  */
201 int ff_seek_frame_binary(AVFormatContext *s, int stream_index,
202  int64_t target_ts, int flags);
203 
204 /**
205  * Update cur_dts of all streams based on the given timestamp and AVStream.
206  *
207  * Stream ref_st unchanged, others set cur_dts in their native time base.
208  * Only needed for timestamp wrapping or if (dts not set and pts!=dts).
209  * @param timestamp new dts expressed in time_base of param ref_st
210  * @param ref_st reference stream giving time_base of param timestamp
211  */
212 void avpriv_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp);
213 
214 int ff_find_last_ts(AVFormatContext *s, int stream_index, int64_t *ts, int64_t *pos,
215  int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ));
216 
217 /**
218  * Perform a binary search using read_timestamp().
219  *
220  * @param target_ts target timestamp in the time base of the given stream
221  * @param stream_index stream number
222  */
223 int64_t ff_gen_search(AVFormatContext *s, int stream_index,
224  int64_t target_ts, int64_t pos_min,
225  int64_t pos_max, int64_t pos_limit,
226  int64_t ts_min, int64_t ts_max,
227  int flags, int64_t *ts_ret,
228  int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ));
229 
230 /**
231  * Internal version of av_index_search_timestamp
232  */
233 int ff_index_search_timestamp(const AVIndexEntry *entries, int nb_entries,
234  int64_t wanted_timestamp, int flags);
235 
236 /**
237  * Internal version of av_add_index_entry
238  */
239 int ff_add_index_entry(AVIndexEntry **index_entries,
240  int *nb_index_entries,
241  unsigned int *index_entries_allocated_size,
242  int64_t pos, int64_t timestamp, int size, int distance, int flags);
243 
244 void ff_configure_buffers_for_index(AVFormatContext *s, int64_t time_tolerance);
245 
246 /**
247  * Ensure the index uses less memory than the maximum specified in
248  * AVFormatContext.max_index_size by discarding entries if it grows
249  * too large.
250  */
251 void ff_reduce_index(AVFormatContext *s, int stream_index);
252 
253 /**
254  * add frame for rfps calculation.
255  *
256  * @param dts timestamp of the i-th frame
257  * @return 0 if OK, AVERROR_xxx on error
258  */
259 int ff_rfps_add_frame(AVFormatContext *ic, AVStream *st, int64_t dts);
260 
262 
263 /**
264  * Rescales a timestamp and the endpoints of an interval to which the temstamp
265  * belongs, from a timebase `tb_in` to a timebase `tb_out`.
266  *
267  * The upper (lower) bound of the output interval is rounded up (down) such that
268  * the output interval always falls within the intput interval. The timestamp is
269  * rounded to the nearest integer and halfway cases away from zero, and can
270  * therefore fall outside of the output interval.
271  *
272  * Useful to simplify the rescaling of the arguments of FFInputFormat::read_seek2()
273  *
274  * @param[in] tb_in Timebase of the input `min_ts`, `ts` and `max_ts`
275  * @param[in] tb_out Timebase of the output `min_ts`, `ts` and `max_ts`
276  * @param[in,out] min_ts Lower bound of the interval
277  * @param[in,out] ts Timestamp
278  * @param[in,out] max_ts Upper bound of the interval
279  */
280 void ff_rescale_interval(AVRational tb_in, AVRational tb_out,
281  int64_t *min_ts, int64_t *ts, int64_t *max_ts);
282 
284 
285 /**
286  * Add a new chapter.
287  *
288  * @param s media file handle
289  * @param id unique ID for this chapter
290  * @param start chapter start time in time_base units
291  * @param end chapter end time in time_base units
292  * @param title chapter title
293  *
294  * @return AVChapter or NULL on error
295  */
296 AVChapter *avpriv_new_chapter(AVFormatContext *s, int64_t id, AVRational time_base,
297  int64_t start, int64_t end, const char *title);
298 
299 /**
300  * Add an attached pic to an AVStream.
301  *
302  * @param st if set, the stream to add the attached pic to;
303  * if unset, a new stream will be added to s.
304  * @param pb AVIOContext to read data from if buf is unset.
305  * @param buf if set, it contains the data and size information to be used
306  * for the attached pic; if unset, data is read from pb.
307  * @param size the size of the data to read if buf is unset.
308  *
309  * @return 0 on success, < 0 on error. On error, this function removes
310  * the stream it has added (if any).
311  */
313  AVBufferRef **buf, int size);
314 
315 /**
316  * Add side data to a packet for changing parameters to the given values.
317  * Parameters set to 0 aren't included in the change.
318  */
320  uint64_t channel_layout, int32_t sample_rate,
322 
323 /**
324  * Generate standard extradata for AVC-Intra based on width/height and field
325  * order.
326  */
328 
329 /**
330  * Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end
331  * which is always set to 0 and fill it from pb.
332  *
333  * @param size size of extradata
334  * @return >= 0 if OK, AVERROR_xxx on error
335  */
336 int ff_get_extradata(void *logctx, AVCodecParameters *par, AVIOContext *pb, int size);
337 
338 /**
339  * Find stream index based on format-specific stream ID
340  * @return stream index, or < 0 on error
341  */
342 int ff_find_stream_index(const AVFormatContext *s, int id);
343 
345 
346 #endif /* AVFORMAT_DEMUX_H */
avpriv_new_chapter
AVChapter * avpriv_new_chapter(AVFormatContext *s, int64_t id, AVRational time_base, int64_t start, int64_t end, const char *title)
Add a new chapter.
Definition: demux_utils.c:42
ff_gen_search
int64_t ff_gen_search(AVFormatContext *s, int stream_index, int64_t target_ts, int64_t pos_min, int64_t pos_max, int64_t pos_limit, int64_t ts_min, int64_t ts_max, int flags, int64_t *ts_ret, int64_t(*read_timestamp)(struct AVFormatContext *, int, int64_t *, int64_t))
Perform a binary search using read_timestamp().
Definition: seek.c:396
FFStreamInfo::fps_last_dts
int64_t fps_last_dts
Definition: demux.h:157
ff_seek_frame_binary
int ff_seek_frame_binary(AVFormatContext *s, int stream_index, int64_t target_ts, int flags)
Perform a binary search using av_index_search_timestamp() and FFInputFormat.read_timestamp().
Definition: seek.c:288
FFInputFormat::read_probe
int(* read_probe)(const AVProbeData *)
Tell if a given file has a chance of being parsed as this format.
Definition: demux.h:57
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: codec_par.h:47
FFInputFormat::read_pause
int(* read_pause)(struct AVFormatContext *)
Pause playing - only meaningful if using a network-based format (RTSP).
Definition: demux.h:110
ff_find_last_ts
int ff_find_last_ts(AVFormatContext *s, int stream_index, int64_t *ts, int64_t *pos, int64_t(*read_timestamp)(struct AVFormatContext *, int, int64_t *, int64_t))
Definition: seek.c:358
rational.h
FFInputFormat::read_seek2
int(* read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Seek to timestamp ts.
Definition: demux.h:118
ff_wrap_timestamp
int64_t ff_wrap_timestamp(const AVStream *st, int64_t timestamp)
Wrap a given time stamp, if there is an indication for an overflow.
Definition: demux.c:66
FFInputFormat::priv_data_size
int priv_data_size
Size of private data so that it can be allocated in the wrapper.
Definition: demux.h:45
ff_read_frame_flush
void ff_read_frame_flush(AVFormatContext *s)
Flush the frame reader.
Definition: seek.c:720
FFInputFormat::read_header
int(* read_header)(struct AVFormatContext *)
Read the format header and initialize the AVFormatContext structure.
Definition: demux.h:64
sample_rate
sample_rate
Definition: ffmpeg_filter.c:425
avpriv_update_cur_dts
void avpriv_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp)
Update cur_dts of all streams based on the given timestamp and AVStream.
Definition: seek.c:35
AVIndexEntry
Definition: avformat.h:602
ff_generate_avci_extradata
int ff_generate_avci_extradata(AVStream *st)
Generate standard extradata for AVC-Intra based on width/height and field order.
Definition: demux_utils.c:200
ff_get_extradata
int ff_get_extradata(void *logctx, AVCodecParameters *par, AVIOContext *pb, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0 and f...
Definition: demux_utils.c:335
MAX_STD_TIMEBASES
#define MAX_STD_TIMEBASES
Definition: demux.h:132
FFStreamInfo::fps_first_dts
int64_t fps_first_dts
Those are used for average framerate estimation.
Definition: demux.h:155
AVStreamParseType
AVStreamParseType
Definition: avformat.h:591
AVChapter
Definition: avformat.h:1214
FFInputFormat::read_play
int(* read_play)(struct AVFormatContext *)
Start/resume playing - only meaningful if using a network-based format (RTSP).
Definition: demux.h:104
type
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf type
Definition: writing_filters.txt:86
pkt
AVPacket * pkt
Definition: movenc.c:59
AVInputFormat
Definition: avformat.h:548
ff_add_attached_pic
int ff_add_attached_pic(AVFormatContext *s, AVStream *st, AVIOContext *pb, AVBufferRef **buf, int size)
Add an attached pic to an AVStream.
Definition: demux_utils.c:116
width
#define width
s
#define s(width, name)
Definition: cbs_vp9.c:198
FFInputFormat::flags_internal
int flags_internal
Internal flags.
Definition: demux.h:50
FFStreamInfo::last_dts
int64_t last_dts
Definition: demux.h:134
RELATIVE_TS_BASE
#define RELATIVE_TS_BASE
Definition: demux.h:167
FFInputFormat::get_device_list
int(* get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list)
Returns device list with it properties.
Definition: demux.h:124
channels
channels
Definition: aptx.h:31
FFInputFormat::read_seek
int(* read_seek)(struct AVFormatContext *, int stream_index, int64_t timestamp, int flags)
Seek to a given timestamp relative to the frames in stream component stream_index.
Definition: demux.h:90
FFStreamInfo::found_decoder
int found_decoder
0 -> decoder has not been searched for yet.
Definition: demux.h:148
AVFormatContext
Format I/O context.
Definition: avformat.h:1255
ff_index_search_timestamp
int ff_index_search_timestamp(const AVIndexEntry *entries, int nb_entries, int64_t wanted_timestamp, int flags)
Internal version of av_index_search_timestamp.
Definition: seek.c:130
FFStreamInfo::codec_info_duration
int64_t codec_info_duration
Definition: demux.h:139
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:451
ff_rescale_interval
void ff_rescale_interval(AVRational tb_in, AVRational tb_out, int64_t *min_ts, int64_t *ts, int64_t *max_ts)
Rescales a timestamp and the endpoints of an interval to which the temstamp belongs,...
Definition: seek.c:763
double
double
Definition: af_crystalizer.c:131
FFStreamInfo::codec_info_duration_fields
int64_t codec_info_duration_fields
Definition: demux.h:140
AVCodecID
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:49
FFInputFormat::read_packet
int(* read_packet)(struct AVFormatContext *, AVPacket *pkt)
Read one packet and put it in 'pkt'.
Definition: demux.h:74
AVIOContext
Bytestream IO Context.
Definition: avio.h:160
FFStreamInfo
Definition: demux.h:133
ff_rfps_add_frame
int ff_rfps_add_frame(AVFormatContext *ic, AVStream *st, int64_t dts)
add frame for rfps calculation.
Definition: demux.c:2284
FFStreamInfo::duration_count
int duration_count
Definition: demux.h:136
size
int size
Definition: twinvq_data.h:10344
ff_add_param_change
int ff_add_param_change(AVPacket *pkt, int32_t channels, uint64_t channel_layout, int32_t sample_rate, int32_t width, int32_t height)
Add side data to a packet for changing parameters to the given values.
Definition: demux_utils.c:151
ff_find_stream_index
int ff_find_stream_index(const AVFormatContext *s, int id)
Find stream index based on format-specific stream ID.
Definition: demux_utils.c:351
FFInputFormat::p
AVInputFormat p
The public AVInputFormat.
Definition: demux.h:35
height
#define height
FFStreamInfo::last_duration
int64_t last_duration
Definition: demux.h:150
FFStreamInfo::rfps_duration_sum
int64_t rfps_duration_sum
Definition: demux.h:137
avpriv_stream_set_need_parsing
void avpriv_stream_set_need_parsing(AVStream *st, enum AVStreamParseType type)
Definition: demux_utils.c:37
FFStreamInfo::duration_error
double(* duration_error)[2][MAX_STD_TIMEBASES]
Definition: demux.h:138
packet.h
ff_rfps_calculate
void ff_rfps_calculate(AVFormatContext *ic)
Definition: demux.c:2345
av_always_inline
#define av_always_inline
Definition: attributes.h:49
FFInputFormat::raw_codec_id
enum AVCodecID raw_codec_id
Raw demuxers store their codec ID here.
Definition: demux.h:40
FFStreamInfo::frame_delay_evidence
int frame_delay_evidence
Definition: demux.h:141
ff_add_index_entry
int ff_add_index_entry(AVIndexEntry **index_entries, int *nb_index_entries, unsigned int *index_entries_allocated_size, int64_t pos, int64_t timestamp, int size, int distance, int flags)
Internal version of av_add_index_entry.
Definition: seek.c:62
FFInputFormat::read_timestamp
int64_t(* read_timestamp)(struct AVFormatContext *s, int stream_index, int64_t *pos, int64_t pos_limit)
Get the next timestamp in stream[stream_index].time_base units.
Definition: demux.h:97
AVStream
Stream structure.
Definition: avformat.h:743
AVDeviceInfoList
List of devices.
Definition: avdevice.h:343
pos
unsigned int pos
Definition: spdifenc.c:413
avformat.h
FFInputFormat::read_close
int(* read_close)(struct AVFormatContext *)
Close the stream.
Definition: demux.h:80
ff_configure_buffers_for_index
void ff_configure_buffers_for_index(AVFormatContext *s, int64_t time_tolerance)
Definition: seek.c:173
FFStreamInfo::fps_first_dts_idx
int fps_first_dts_idx
Definition: demux.h:156
FFStreamInfo::duration_gcd
int64_t duration_gcd
Definition: demux.h:135
ffifmt
static const FFInputFormat * ffifmt(const AVInputFormat *fmt)
Definition: demux.h:127
ff_read_packet
int ff_read_packet(AVFormatContext *s, AVPacket *pkt)
Read a transport packet from a media file.
Definition: demux.c:598
AVBufferRef
A reference to a data buffer.
Definition: buffer.h:82
ff_buffer_packet
int ff_buffer_packet(AVFormatContext *s, AVPacket *pkt)
Definition: demux.c:558
AVPacket
This structure stores compressed data.
Definition: packet.h:499
FFInputFormat
Definition: demux.h:31
int32_t
int32_t
Definition: audioconvert.c:56
distance
static float distance(float x, float y, int band)
Definition: nellymoserenc.c:230
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:474
FFStreamInfo::fps_last_dts_idx
int fps_last_dts_idx
Definition: demux.h:158
read_timestamp
static int64_t read_timestamp(AVFormatContext *s, int stream_index, int64_t *ppos, int64_t pos_limit, int64_t(*read_timestamp)(struct AVFormatContext *, int, int64_t *, int64_t))
Definition: seek.c:279
is_relative
static av_always_inline int is_relative(int64_t ts)
Definition: demux.h:169
ff_reduce_index
void ff_reduce_index(AVFormatContext *s, int stream_index)
Ensure the index uses less memory than the maximum specified in AVFormatContext.max_index_size by dis...
Definition: seek.c:48
int
int
Definition: ffmpeg_filter.c:425