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 #define MAX_STD_TIMEBASES (30*12+30+3+6)
30 typedef struct FFStreamInfo {
31  int64_t last_dts;
32  int64_t duration_gcd;
39 
40  /**
41  * 0 -> decoder has not been searched for yet.
42  * >0 -> decoder found
43  * <0 -> decoder with codec_id == -found_decoder has not been found
44  */
46 
47  int64_t last_duration;
48 
49  /**
50  * Those are used for average framerate estimation.
51  */
52  int64_t fps_first_dts;
54  int64_t fps_last_dts;
56 } FFStreamInfo;
57 
58 /**
59  * Returned by demuxers to indicate that data was consumed but discarded
60  * (ignored streams or junk data). The framework will re-call the demuxer.
61  */
62 #define FFERROR_REDO FFERRTAG('R','E','D','O')
63 
64 #define RELATIVE_TS_BASE (INT64_MAX - (1LL << 48))
65 
66 static av_always_inline int is_relative(int64_t ts)
67 {
68  return ts > (RELATIVE_TS_BASE - (1LL << 48));
69 }
70 
71 /**
72  * Wrap a given time stamp, if there is an indication for an overflow
73  *
74  * @param st stream
75  * @param timestamp the time stamp to wrap
76  * @return resulting time stamp
77  */
78 int64_t ff_wrap_timestamp(const AVStream *st, int64_t timestamp);
79 
80 /**
81  * Read a transport packet from a media file.
82  *
83  * @param s media file handle
84  * @param pkt is filled
85  * @return 0 if OK, AVERROR_xxx on error
86  */
88 
90 
91 /**
92  * Perform a binary search using av_index_search_timestamp() and
93  * AVInputFormat.read_timestamp().
94  *
95  * @param target_ts target timestamp in the time base of the given stream
96  * @param stream_index stream number
97  */
98 int ff_seek_frame_binary(AVFormatContext *s, int stream_index,
99  int64_t target_ts, int flags);
100 
101 /**
102  * Update cur_dts of all streams based on the given timestamp and AVStream.
103  *
104  * Stream ref_st unchanged, others set cur_dts in their native time base.
105  * Only needed for timestamp wrapping or if (dts not set and pts!=dts).
106  * @param timestamp new dts expressed in time_base of param ref_st
107  * @param ref_st reference stream giving time_base of param timestamp
108  */
109 void avpriv_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp);
110 
111 int ff_find_last_ts(AVFormatContext *s, int stream_index, int64_t *ts, int64_t *pos,
112  int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ));
113 
114 /**
115  * Perform a binary search using read_timestamp().
116  *
117  * @param target_ts target timestamp in the time base of the given stream
118  * @param stream_index stream number
119  */
120 int64_t ff_gen_search(AVFormatContext *s, int stream_index,
121  int64_t target_ts, int64_t pos_min,
122  int64_t pos_max, int64_t pos_limit,
123  int64_t ts_min, int64_t ts_max,
124  int flags, int64_t *ts_ret,
125  int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ));
126 
127 /**
128  * Internal version of av_index_search_timestamp
129  */
130 int ff_index_search_timestamp(const AVIndexEntry *entries, int nb_entries,
131  int64_t wanted_timestamp, int flags);
132 
133 /**
134  * Internal version of av_add_index_entry
135  */
136 int ff_add_index_entry(AVIndexEntry **index_entries,
137  int *nb_index_entries,
138  unsigned int *index_entries_allocated_size,
139  int64_t pos, int64_t timestamp, int size, int distance, int flags);
140 
141 void ff_configure_buffers_for_index(AVFormatContext *s, int64_t time_tolerance);
142 
143 /**
144  * Ensure the index uses less memory than the maximum specified in
145  * AVFormatContext.max_index_size by discarding entries if it grows
146  * too large.
147  */
148 void ff_reduce_index(AVFormatContext *s, int stream_index);
149 
150 /**
151  * add frame for rfps calculation.
152  *
153  * @param dts timestamp of the i-th frame
154  * @return 0 if OK, AVERROR_xxx on error
155  */
156 int ff_rfps_add_frame(AVFormatContext *ic, AVStream *st, int64_t dts);
157 
159 
160 /**
161  * Rescales a timestamp and the endpoints of an interval to which the temstamp
162  * belongs, from a timebase `tb_in` to a timebase `tb_out`.
163  *
164  * The upper (lower) bound of the output interval is rounded up (down) such that
165  * the output interval always falls within the intput interval. The timestamp is
166  * rounded to the nearest integer and halfway cases away from zero, and can
167  * therefore fall outside of the output interval.
168  *
169  * Useful to simplify the rescaling of the arguments of AVInputFormat::read_seek2()
170  *
171  * @param[in] tb_in Timebase of the input `min_ts`, `ts` and `max_ts`
172  * @param[in] tb_out Timebase of the ouput `min_ts`, `ts` and `max_ts`
173  * @param[in,out] min_ts Lower bound of the interval
174  * @param[in,out] ts Timestamp
175  * @param[in,out] max_ts Upper bound of the interval
176  */
177 void ff_rescale_interval(AVRational tb_in, AVRational tb_out,
178  int64_t *min_ts, int64_t *ts, int64_t *max_ts);
179 
181 
182 /**
183  * Add a new chapter.
184  *
185  * @param s media file handle
186  * @param id unique ID for this chapter
187  * @param start chapter start time in time_base units
188  * @param end chapter end time in time_base units
189  * @param title chapter title
190  *
191  * @return AVChapter or NULL on error
192  */
193 AVChapter *avpriv_new_chapter(AVFormatContext *s, int64_t id, AVRational time_base,
194  int64_t start, int64_t end, const char *title);
195 
196 /**
197  * Add an attached pic to an AVStream.
198  *
199  * @param st if set, the stream to add the attached pic to;
200  * if unset, a new stream will be added to s.
201  * @param pb AVIOContext to read data from if buf is unset.
202  * @param buf if set, it contains the data and size information to be used
203  * for the attached pic; if unset, data is read from pb.
204  * @param size the size of the data to read if buf is unset.
205  *
206  * @return 0 on success, < 0 on error. On error, this function removes
207  * the stream it has added (if any).
208  */
210  AVBufferRef **buf, int size);
211 
212 /**
213  * Add side data to a packet for changing parameters to the given values.
214  * Parameters set to 0 aren't included in the change.
215  */
217  uint64_t channel_layout, int32_t sample_rate,
219 
220 /**
221  * Generate standard extradata for AVC-Intra based on width/height and field
222  * order.
223  */
225 
226 /**
227  * Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end
228  * which is always set to 0 and fill it from pb.
229  *
230  * @param size size of extradata
231  * @return >= 0 if OK, AVERROR_xxx on error
232  */
233 int ff_get_extradata(void *logctx, AVCodecParameters *par, AVIOContext *pb, int size);
234 
235 /**
236  * Find stream index based on format-specific stream ID
237  * @return stream index, or < 0 on error
238  */
239 int ff_find_stream_index(const AVFormatContext *s, int id);
240 
241 #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:393
FFStreamInfo::fps_last_dts
int64_t fps_last_dts
Definition: demux.h:54
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 AVInputFormat.read_timestamp().
Definition: seek.c:285
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: codec_par.h:54
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:355
rational.h
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:65
ff_read_frame_flush
void ff_read_frame_flush(AVFormatContext *s)
Flush the frame reader.
Definition: seek.c:717
sample_rate
sample_rate
Definition: ffmpeg_filter.c:156
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:807
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:220
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:355
MAX_STD_TIMEBASES
#define MAX_STD_TIMEBASES
Definition: demux.h:29
FFStreamInfo::fps_first_dts
int64_t fps_first_dts
Those are used for average framerate estimation.
Definition: demux.h:52
AVStreamParseType
AVStreamParseType
Definition: avformat.h:796
AVChapter
Definition: avformat.h:1175
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
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:256
FFStreamInfo::last_dts
int64_t last_dts
Definition: demux.h:31
RELATIVE_TS_BASE
#define RELATIVE_TS_BASE
Definition: demux.h:64
channels
channels
Definition: aptx.h:31
FFStreamInfo::found_decoder
int found_decoder
0 -> decoder has not been searched for yet.
Definition: demux.h:45
AVFormatContext
Format I/O context.
Definition: avformat.h:1216
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:36
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
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:758
double
double
Definition: af_crystalizer.c:132
FFStreamInfo::codec_info_duration_fields
int64_t codec_info_duration_fields
Definition: demux.h:37
AVIOContext
Bytestream IO Context.
Definition: avio.h:166
FFStreamInfo
Definition: demux.h:30
ff_rfps_add_frame
int ff_rfps_add_frame(AVFormatContext *ic, AVStream *st, int64_t dts)
add frame for rfps calculation.
Definition: demux.c:2174
FFStreamInfo::duration_count
int duration_count
Definition: demux.h:33
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:371
height
#define height
FFStreamInfo::last_duration
int64_t last_duration
Definition: demux.h:47
FFStreamInfo::rfps_duration_sum
int64_t rfps_duration_sum
Definition: demux.h:34
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:35
packet.h
ff_rfps_calculate
void ff_rfps_calculate(AVFormatContext *ic)
Definition: demux.c:2235
av_always_inline
#define av_always_inline
Definition: attributes.h:49
FFStreamInfo::frame_delay_evidence
int frame_delay_evidence
Definition: demux.h:38
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
AVStream
Stream structure.
Definition: avformat.h:948
pos
unsigned int pos
Definition: spdifenc.c:412
avformat.h
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:53
FFStreamInfo::duration_gcd
int64_t duration_gcd
Definition: demux.h:32
ff_read_packet
int ff_read_packet(AVFormatContext *s, AVPacket *pkt)
Read a transport packet from a media file.
Definition: demux.c:538
AVBufferRef
A reference to a data buffer.
Definition: buffer.h:82
AVPacket
This structure stores compressed data.
Definition: packet.h:351
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:561
FFStreamInfo::fps_last_dts_idx
int fps_last_dts_idx
Definition: demux.h:55
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:276
is_relative
static av_always_inline int is_relative(int64_t ts)
Definition: demux.h:66
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