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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_INTERNAL_H
22 #define AVFORMAT_INTERNAL_H
23 
24 #include <stdint.h>
25 
26 #include "libavutil/bprint.h"
27 #include "avformat.h"
28 #include "os_support.h"
29 
30 #define MAX_URL_SIZE 4096
31 
32 /** size of probe buffer, for guessing file type from file contents */
33 #define PROBE_BUF_MIN 2048
34 #define PROBE_BUF_MAX (1 << 20)
35 
36 #ifdef DEBUG
37 #    define hex_dump_debug(class, buf, size) av_hex_dump_log(class, AV_LOG_DEBUG, buf, size)
38 #else
39 #    define hex_dump_debug(class, buf, size) do { if (0) av_hex_dump_log(class, AV_LOG_DEBUG, buf, size); } while(0)
40 #endif
41 
42 typedef struct AVCodecTag {
43     enum AVCodecID id;
44     unsigned int tag;
45 } AVCodecTag;
46 
47 typedef struct CodecMime{
48     char str[32];
49     enum AVCodecID id;
50 } CodecMime;
51 
52 /*************************************************/
53 /* fractional numbers for exact pts handling */
54 
55 /**
56  * The exact value of the fractional number is: 'val + num / den'.
57  * num is assumed to be 0 <= num < den.
58  */
59 typedef struct FFFrac {
60     int64_t val, num, den;
61 } FFFrac;
62 
63 
64 struct AVFormatInternal {
65     /**
66      * Number of streams relevant for interleaving.
67      * Muxing only.
68      */
69     int nb_interleaved_streams;
70 
71     /**
72      * This buffer is only needed when packets were already buffered but
73      * not decoded, for example to get the codec parameters in MPEG
74      * streams.
75      */
76     struct PacketList *packet_buffer;
77     struct PacketList *packet_buffer_end;
78 
79     /* av_seek_frame() support */
80     int64_t data_offset; /**< offset of the first packet */
81 
82     /**
83      * Raw packets from the demuxer, prior to parsing and decoding.
84      * This buffer is used for buffering packets until the codec can
85      * be identified, as parsing cannot be done without knowing the
86      * codec.
87      */
88     struct PacketList *raw_packet_buffer;
89     struct PacketList *raw_packet_buffer_end;
90     /**
91      * Packets split by the parser get queued here.
92      */
93     AVPacket *parse_pkt;
94     struct PacketList *parse_queue;
95     struct PacketList *parse_queue_end;
96 
97     /**
98      * Used to hold temporary packets.
99      */
100     AVPacket *pkt;
101     /**
102      * Remaining size available for raw_packet_buffer, in bytes.
103      */
104 #define RAW_PACKET_BUFFER_SIZE 2500000
105     int raw_packet_buffer_remaining_size;
106 
107     /**
108      * Offset to remap timestamps to be non-negative.
109      * Expressed in timebase units.
110      * @see AVStream.mux_ts_offset
111      */
112     int64_t offset;
113 
114     /**
115      * Timebase for the timestamp offset.
116      */
117     AVRational offset_timebase;
118 
119 #if FF_API_COMPUTE_PKT_FIELDS2
120     int missing_ts_warning;
121 #endif
122 
123     int inject_global_side_data;
124 
125     int avoid_negative_ts_use_pts;
126 
127     /**
128      * Timestamp of the end of the shortest stream.
129      */
130     int64_t shortest_end;
131 
132     /**
133      * Whether or not avformat_init_output has already been called
134      */
135     int initialized;
136 
137     /**
138      * Whether or not avformat_init_output fully initialized streams
139      */
140     int streams_initialized;
141 
142     /**
143      * ID3v2 tag useful for MP3 demuxing
144      */
145     AVDictionary *id3v2_meta;
146 
147     /*
148      * Prefer the codec framerate for avg_frame_rate computation.
149      */
150     int prefer_codec_framerate;
151 
152     /**
153      * Set if chapter ids are strictly monotonic.
154      */
155     int chapter_ids_monotonic;
156 };
157 
158 struct AVStreamInternal {
159     /**
160      * Set to 1 if the codec allows reordering, so pts can be different
161      * from dts.
162      */
163     int reorder;
164 
165     /**
166      * bitstream filter to run on stream
167      * - encoding: Set by muxer using ff_stream_add_bitstream_filter
168      * - decoding: unused
169      */
170     AVBSFContext *bsfc;
171 
172     /**
173      * Whether or not check_bitstream should still be run on each packet
174      */
175     int bitstream_checked;
176 
177     /**
178      * The codec context used by avformat_find_stream_info, the parser, etc.
179      */
180     AVCodecContext *avctx;
181     /**
182      * 1 if avctx has been initialized with the values from the codec parameters
183      */
184     int avctx_inited;
185 
186     enum AVCodecID orig_codec_id;
187 
188     /* the context for extracting extradata in find_stream_info()
189      * inited=1/bsf=NULL signals that extracting is not possible (codec not
190      * supported) */
191     struct {
192         AVBSFContext *bsf;
193         AVPacket     *pkt;
194         int inited;
195     } extract_extradata;
196 
197     /**
198      * Whether the internal avctx needs to be updated from codecpar (after a late change to codecpar)
199      */
200     int need_context_update;
201 
202     int is_intra_only;
203 
204     FFFrac *priv_pts;
205 
206 #define MAX_STD_TIMEBASES (30*12+30+3+6)
207     /**
208      * Stream information used internally by avformat_find_stream_info()
209      */
210     struct {
211         int64_t last_dts;
212         int64_t duration_gcd;
213         int duration_count;
214         int64_t rfps_duration_sum;
215         double (*duration_error)[2][MAX_STD_TIMEBASES];
216         int64_t codec_info_duration;
217         int64_t codec_info_duration_fields;
218         int frame_delay_evidence;
219 
220         /**
221          * 0  -> decoder has not been searched for yet.
222          * >0 -> decoder found
223          * <0 -> decoder with codec_id == -found_decoder has not been found
224          */
225         int found_decoder;
226 
227         int64_t last_duration;
228 
229         /**
230          * Those are used for average framerate estimation.
231          */
232         int64_t fps_first_dts;
233         int     fps_first_dts_idx;
234         int64_t fps_last_dts;
235         int     fps_last_dts_idx;
236 
237     } *info;
238 
239     int64_t interleaver_chunk_size;
240     int64_t interleaver_chunk_duration;
241 
242     /**
243      * stream probing state
244      * -1   -> probing finished
245      *  0   -> no probing requested
246      * rest -> perform probing with request_probe being the minimum score to accept.
247      */
248     int request_probe;
249     /**
250      * Indicates that everything up to the next keyframe
251      * should be discarded.
252      */
253     int skip_to_keyframe;
254 
255     /**
256      * Number of samples to skip at the start of the frame decoded from the next packet.
257      */
258     int skip_samples;
259 
260     /**
261      * If not 0, the number of samples that should be skipped from the start of
262      * the stream (the samples are removed from packets with pts==0, which also
263      * assumes negative timestamps do not happen).
264      * Intended for use with formats such as mp3 with ad-hoc gapless audio
265      * support.
266      */
267     int64_t start_skip_samples;
268 
269     /**
270      * If not 0, the first audio sample that should be discarded from the stream.
271      * This is broken by design (needs global sample count), but can't be
272      * avoided for broken by design formats such as mp3 with ad-hoc gapless
273      * audio support.
274      */
275     int64_t first_discard_sample;
276 
277     /**
278      * The sample after last sample that is intended to be discarded after
279      * first_discard_sample. Works on frame boundaries only. Used to prevent
280      * early EOF if the gapless info is broken (considered concatenated mp3s).
281      */
282     int64_t last_discard_sample;
283 
284     /**
285      * Number of internally decoded frames, used internally in libavformat, do not access
286      * its lifetime differs from info which is why it is not in that structure.
287      */
288     int nb_decoded_frames;
289 
290     /**
291      * Timestamp offset added to timestamps before muxing
292      */
293     int64_t mux_ts_offset;
294 
295     /**
296      * Internal data to check for wrapping of the time stamp
297      */
298     int64_t pts_wrap_reference;
299 
300     /**
301      * Options for behavior, when a wrap is detected.
302      *
303      * Defined by AV_PTS_WRAP_ values.
304      *
305      * If correction is enabled, there are two possibilities:
306      * If the first time stamp is near the wrap point, the wrap offset
307      * will be subtracted, which will create negative time stamps.
308      * Otherwise the offset will be added.
309      */
310     int pts_wrap_behavior;
311 
312     /**
313      * Internal data to prevent doing update_initial_durations() twice
314      */
315     int update_initial_durations_done;
316 
317 #define MAX_REORDER_DELAY 16
318 
319     /**
320      * Internal data to generate dts from pts
321      */
322     int64_t pts_reorder_error[MAX_REORDER_DELAY+1];
323     uint8_t pts_reorder_error_count[MAX_REORDER_DELAY+1];
324 
325     int64_t pts_buffer[MAX_REORDER_DELAY+1];
326 
327     /**
328      * Internal data to analyze DTS and detect faulty mpeg streams
329      */
330     int64_t last_dts_for_order_check;
331     uint8_t dts_ordered;
332     uint8_t dts_misordered;
333 
334     /**
335      * Internal data to inject global side data
336      */
337     int inject_global_side_data;
338 
339     /**
340      * display aspect ratio (0 if unknown)
341      * - encoding: unused
342      * - decoding: Set by libavformat to calculate sample_aspect_ratio internally
343      */
344     AVRational display_aspect_ratio;
345 
346     AVProbeData probe_data;
347 
348     /**
349      * last packet in packet_buffer for this stream when muxing.
350      */
351     struct PacketList *last_in_packet_buffer;
352 };
353 
354 #ifdef __GNUC__
355 #define dynarray_add(tab, nb_ptr, elem)\
356 do {\
357     __typeof__(tab) _tab = (tab);\
358     __typeof__(elem) _elem = (elem);\
359     (void)sizeof(**_tab == _elem); /* check that types are compatible */\
360     av_dynarray_add(_tab, nb_ptr, _elem);\
361 } while(0)
362 #else
363 #define dynarray_add(tab, nb_ptr, elem)\
364 do {\
365     av_dynarray_add((tab), nb_ptr, (elem));\
366 } while(0)
367 #endif
368 
369 /**
370  * Automatically create sub-directories
371  *
372  * @param path will create sub-directories by path
373  * @return 0, or < 0 on error
374  */
375 int ff_mkdir_p(const char *path);
376 
377 char *ff_data_to_hex(char *buf, const uint8_t *src, int size, int lowercase);
378 
379 /**
380  * Parse a string of hexadecimal strings. Any space between the hexadecimal
381  * digits is ignored.
382  *
383  * @param data if non-null, the parsed data is written to this pointer
384  * @param p the string to parse
385  * @return the number of bytes written (or to be written, if data is null)
386  */
387 int ff_hex_to_data(uint8_t *data, const char *p);
388 
389 /**
390  * Add packet to an AVFormatContext's packet_buffer list, determining its
391  * interleaved position using compare() function argument.
392  * @return 0 on success, < 0 on error. pkt will always be blank on return.
393  */
394 int ff_interleave_add_packet(AVFormatContext *s, AVPacket *pkt,
395                              int (*compare)(AVFormatContext *, const AVPacket *, const AVPacket *));
396 
397 void ff_read_frame_flush(AVFormatContext *s);
398 
399 #define NTP_OFFSET 2208988800ULL
400 #define NTP_OFFSET_US (NTP_OFFSET * 1000000ULL)
401 
402 /** Get the current time since NTP epoch in microseconds. */
403 uint64_t ff_ntp_time(void);
404 
405 /**
406  * Get the NTP time stamp formatted as per the RFC-5905.
407  *
408  * @param ntp_time NTP time in micro seconds (since NTP epoch)
409  * @return the formatted NTP time stamp
410  */
411 uint64_t ff_get_formatted_ntp_time(uint64_t ntp_time_us);
412 
413 /**
414  * Append the media-specific SDP fragment for the media stream c
415  * to the buffer buff.
416  *
417  * Note, the buffer needs to be initialized, since it is appended to
418  * existing content.
419  *
420  * @param buff the buffer to append the SDP fragment to
421  * @param size the size of the buff buffer
422  * @param st the AVStream of the media to describe
423  * @param idx the global stream index
424  * @param dest_addr the destination address of the media stream, may be NULL
425  * @param dest_type the destination address type, may be NULL
426  * @param port the destination port of the media stream, 0 if unknown
427  * @param ttl the time to live of the stream, 0 if not multicast
428  * @param fmt the AVFormatContext, which might contain options modifying
429  *            the generated SDP
430  */
431 void ff_sdp_write_media(char *buff, int size, AVStream *st, int idx,
432                         const char *dest_addr, const char *dest_type,
433                         int port, int ttl, AVFormatContext *fmt);
434 
435 /**
436  * Write a packet to another muxer than the one the user originally
437  * intended. Useful when chaining muxers, where one muxer internally
438  * writes a received packet to another muxer.
439  *
440  * @param dst the muxer to write the packet to
441  * @param dst_stream the stream index within dst to write the packet to
442  * @param pkt the packet to be written
443  * @param src the muxer the packet originally was intended for
444  * @param interleave 0->use av_write_frame, 1->av_interleaved_write_frame
445  * @return the value av_write_frame returned
446  */
447 int ff_write_chained(AVFormatContext *dst, int dst_stream, AVPacket *pkt,
448                      AVFormatContext *src, int interleave);
449 
450 /**
451  * Read a whole line of text from AVIOContext. Stop reading after reaching
452  * either a \\n, a \\0 or EOF. The returned string is always \\0-terminated,
453  * and may be truncated if the buffer is too small.
454  *
455  * @param s the read-only AVIOContext
456  * @param buf buffer to store the read line
457  * @param maxlen size of the buffer
458  * @return the length of the string written in the buffer, not including the
459  *         final \\0
460  */
461 int ff_get_line(AVIOContext *s, char *buf, int maxlen);
462 
463 /**
464  * Same as ff_get_line but strip the white-space characters in the text tail
465  *
466  * @param s the read-only AVIOContext
467  * @param buf buffer to store the read line
468  * @param maxlen size of the buffer
469  * @return the length of the string written in the buffer
470  */
471 int ff_get_chomp_line(AVIOContext *s, char *buf, int maxlen);
472 
473 /**
474  * Read a whole line of text from AVIOContext to an AVBPrint buffer. Stop
475  * reading after reaching a \\r, a \\n, a \\r\\n, a \\0 or EOF.  The line
476  * ending characters are NOT included in the buffer, but they are skipped on
477  * the input.
478  *
479  * @param s the read-only AVIOContext
480  * @param bp the AVBPrint buffer
481  * @return the length of the read line, not including the line endings,
482  *         negative on error.
483  */
484 int64_t ff_read_line_to_bprint(AVIOContext *s, AVBPrint *bp);
485 
486 /**
487  * Read a whole line of text from AVIOContext to an AVBPrint buffer overwriting
488  * its contents. Stop reading after reaching a \\r, a \\n, a \\r\\n, a \\0 or
489  * EOF. The line ending characters are NOT included in the buffer, but they
490  * are skipped on the input.
491  *
492  * @param s the read-only AVIOContext
493  * @param bp the AVBPrint buffer
494  * @return the length of the read line not including the line endings,
495  *         negative on error, or if the buffer becomes truncated.
496  */
497 int64_t ff_read_line_to_bprint_overwrite(AVIOContext *s, AVBPrint *bp);
498 
499 #define SPACE_CHARS " \t\r\n"
500 
501 /**
502  * Callback function type for ff_parse_key_value.
503  *
504  * @param key a pointer to the key
505  * @param key_len the number of bytes that belong to the key, including the '='
506  *                char
507  * @param dest return the destination pointer for the value in *dest, may
508  *             be null to ignore the value
509  * @param dest_len the length of the *dest buffer
510  */
511 typedef void (*ff_parse_key_val_cb)(void *context, const char *key,
512                                     int key_len, char **dest, int *dest_len);
513 /**
514  * Parse a string with comma-separated key=value pairs. The value strings
515  * may be quoted and may contain escaped characters within quoted strings.
516  *
517  * @param str the string to parse
518  * @param callback_get_buf function that returns where to store the
519  *                         unescaped value string.
520  * @param context the opaque context pointer to pass to callback_get_buf
521  */
522 void ff_parse_key_value(const char *str, ff_parse_key_val_cb callback_get_buf,
523                         void *context);
524 
525 /**
526  * Find stream index based on format-specific stream ID
527  * @return stream index, or < 0 on error
528  */
529 int ff_find_stream_index(AVFormatContext *s, int id);
530 
531 /**
532  * Internal version of av_index_search_timestamp
533  */
534 int ff_index_search_timestamp(const AVIndexEntry *entries, int nb_entries,
535                               int64_t wanted_timestamp, int flags);
536 
537 /**
538  * Internal version of av_add_index_entry
539  */
540 int ff_add_index_entry(AVIndexEntry **index_entries,
541                        int *nb_index_entries,
542                        unsigned int *index_entries_allocated_size,
543                        int64_t pos, int64_t timestamp, int size, int distance, int flags);
544 
545 void ff_configure_buffers_for_index(AVFormatContext *s, int64_t time_tolerance);
546 
547 /**
548  * Add a new chapter.
549  *
550  * @param s media file handle
551  * @param id unique ID for this chapter
552  * @param start chapter start time in time_base units
553  * @param end chapter end time in time_base units
554  * @param title chapter title
555  *
556  * @return AVChapter or NULL on error
557  */
558 #if FF_API_CHAPTER_ID_INT
559 AVChapter *avpriv_new_chapter(AVFormatContext *s, int id, AVRational time_base,
560 #else
561 AVChapter *avpriv_new_chapter(AVFormatContext *s, int64_t id, AVRational time_base,
562 #endif
563                               int64_t start, int64_t end, const char *title);
564 
565 /**
566  * Ensure the index uses less memory than the maximum specified in
567  * AVFormatContext.max_index_size by discarding entries if it grows
568  * too large.
569  */
570 void ff_reduce_index(AVFormatContext *s, int stream_index);
571 
572 enum AVCodecID ff_guess_image2_codec(const char *filename);
573 
574 /**
575  * Perform a binary search using av_index_search_timestamp() and
576  * AVInputFormat.read_timestamp().
577  *
578  * @param target_ts target timestamp in the time base of the given stream
579  * @param stream_index stream number
580  */
581 int ff_seek_frame_binary(AVFormatContext *s, int stream_index,
582                          int64_t target_ts, int flags);
583 
584 /**
585  * Update cur_dts of all streams based on the given timestamp and AVStream.
586  *
587  * Stream ref_st unchanged, others set cur_dts in their native time base.
588  * Only needed for timestamp wrapping or if (dts not set and pts!=dts).
589  * @param timestamp new dts expressed in time_base of param ref_st
590  * @param ref_st reference stream giving time_base of param timestamp
591  */
592 void ff_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp);
593 
594 int ff_find_last_ts(AVFormatContext *s, int stream_index, int64_t *ts, int64_t *pos,
595                     int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ));
596 
597 /**
598  * Perform a binary search using read_timestamp().
599  *
600  * @param target_ts target timestamp in the time base of the given stream
601  * @param stream_index stream number
602  */
603 int64_t ff_gen_search(AVFormatContext *s, int stream_index,
604                       int64_t target_ts, int64_t pos_min,
605                       int64_t pos_max, int64_t pos_limit,
606                       int64_t ts_min, int64_t ts_max,
607                       int flags, int64_t *ts_ret,
608                       int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ));
609 
610 /**
611  * Set the time base and wrapping info for a given stream. This will be used
612  * to interpret the stream's timestamps. If the new time base is invalid
613  * (numerator or denominator are non-positive), it leaves the stream
614  * unchanged.
615  *
616  * @param s stream
617  * @param pts_wrap_bits number of bits effectively used by the pts
618  *        (used for wrap control)
619  * @param pts_num time base numerator
620  * @param pts_den time base denominator
621  */
622 void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits,
623                          unsigned int pts_num, unsigned int pts_den);
624 
625 /**
626  * Add side data to a packet for changing parameters to the given values.
627  * Parameters set to 0 aren't included in the change.
628  */
629 int ff_add_param_change(AVPacket *pkt, int32_t channels,
630                         uint64_t channel_layout, int32_t sample_rate,
631                         int32_t width, int32_t height);
632 
633 /**
634  * Set the timebase for each stream from the corresponding codec timebase and
635  * print it.
636  */
637 int ff_framehash_write_header(AVFormatContext *s);
638 
639 /**
640  * Read a transport packet from a media file.
641  *
642  * @param s media file handle
643  * @param pkt is filled
644  * @return 0 if OK, AVERROR_xxx on error
645  */
646 int ff_read_packet(AVFormatContext *s, AVPacket *pkt);
647 
648 /**
649  * Interleave an AVPacket per dts so it can be muxed.
650  *
651  * @param s   an AVFormatContext for output. pkt resp. out will be added to
652  *            resp. taken from its packet buffer.
653  * @param out the interleaved packet will be output here
654  * @param pkt the input packet; will be blank on return if not NULL
655  * @param flush 1 if no further packets are available as input and all
656  *              remaining packets should be output
657  * @return 1 if a packet was output, 0 if no packet could be output
658  *         (in which case out may be uninitialized), < 0 if an error occurred
659  */
660 int ff_interleave_packet_per_dts(AVFormatContext *s, AVPacket *out,
661                                  AVPacket *pkt, int flush);
662 
663 void ff_free_stream(AVFormatContext *s, AVStream *st);
664 
665 /**
666  * Return the frame duration in seconds. Return 0 if not available.
667  */
668 void ff_compute_frame_duration(AVFormatContext *s, int *pnum, int *pden, AVStream *st,
669                                AVCodecParserContext *pc, AVPacket *pkt);
670 
671 unsigned int ff_codec_get_tag(const AVCodecTag *tags, enum AVCodecID id);
672 
673 enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag);
674 
675 int ff_is_intra_only(enum AVCodecID id);
676 
677 /**
678  * Select a PCM codec based on the given parameters.
679  *
680  * @param bps     bits-per-sample
681  * @param flt     floating-point
682  * @param be      big-endian
683  * @param sflags  signed flags. each bit corresponds to one byte of bit depth.
684  *                e.g. the 1st bit indicates if 8-bit should be signed or
685  *                unsigned, the 2nd bit indicates if 16-bit should be signed or
686  *                unsigned, etc... This is useful for formats such as WAVE where
687  *                only 8-bit is unsigned and all other bit depths are signed.
688  * @return        a PCM codec id or AV_CODEC_ID_NONE
689  */
690 enum AVCodecID ff_get_pcm_codec_id(int bps, int flt, int be, int sflags);
691 
692 /**
693  * Chooses a timebase for muxing the specified stream.
694  *
695  * The chosen timebase allows sample accurate timestamps based
696  * on the framerate or sample rate for audio streams. It also is
697  * at least as precise as 1/min_precision would be.
698  */
699 AVRational ff_choose_timebase(AVFormatContext *s, AVStream *st, int min_precision);
700 
701 /**
702  * Chooses a timebase for muxing the specified stream.
703  */
704 enum AVChromaLocation ff_choose_chroma_location(AVFormatContext *s, AVStream *st);
705 
706 /**
707  * Generate standard extradata for AVC-Intra based on width/height and field
708  * order.
709  */
710 int ff_generate_avci_extradata(AVStream *st);
711 
712 /**
713  * Add a bitstream filter to a stream.
714  *
715  * @param st output stream to add a filter to
716  * @param name the name of the filter to add
717  * @param args filter-specific argument string
718  * @return  >0 on success;
719  *          AVERROR code on failure
720  */
721 int ff_stream_add_bitstream_filter(AVStream *st, const char *name, const char *args);
722 
723 /**
724  * Copy encoding parameters from source to destination stream
725  *
726  * @param dst pointer to destination AVStream
727  * @param src pointer to source AVStream
728  * @return >=0 on success, AVERROR code on error
729  */
730 int ff_stream_encode_params_copy(AVStream *dst, const AVStream *src);
731 
732 /**
733  * Wrap avpriv_io_move and log if error happens.
734  *
735  * @param url_src source path
736  * @param url_dst destination path
737  * @return        0 or AVERROR on failure
738  */
739 int ff_rename(const char *url_src, const char *url_dst, void *logctx);
740 
741 /**
742  * Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end
743  * which is always set to 0.
744  *
745  * Previously allocated extradata in par will be freed.
746  *
747  * @param size size of extradata
748  * @return 0 if OK, AVERROR_xxx on error
749  */
750 int ff_alloc_extradata(AVCodecParameters *par, int size);
751 
752 /**
753  * Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end
754  * which is always set to 0 and fill it from pb.
755  *
756  * @param size size of extradata
757  * @return >= 0 if OK, AVERROR_xxx on error
758  */
759 int ff_get_extradata(AVFormatContext *s, AVCodecParameters *par, AVIOContext *pb, int size);
760 
761 /**
762  * add frame for rfps calculation.
763  *
764  * @param dts timestamp of the i-th frame
765  * @return 0 if OK, AVERROR_xxx on error
766  */
767 int ff_rfps_add_frame(AVFormatContext *ic, AVStream *st, int64_t dts);
768 
769 void ff_rfps_calculate(AVFormatContext *ic);
770 
771 /**
772  * Flags for AVFormatContext.write_uncoded_frame()
773  */
774 enum AVWriteUncodedFrameFlags {
775 
776     /**
777      * Query whether the feature is possible on this stream.
778      * The frame argument is ignored.
779      */
780     AV_WRITE_UNCODED_FRAME_QUERY           = 0x0001,
781 
782 };
783 
784 /**
785  * Copies the whilelists from one context to the other
786  */
787 int ff_copy_whiteblacklists(AVFormatContext *dst, const AVFormatContext *src);
788 
789 /**
790  * Returned by demuxers to indicate that data was consumed but discarded
791  * (ignored streams or junk data). The framework will re-call the demuxer.
792  */
793 #define FFERROR_REDO FFERRTAG('R','E','D','O')
794 
795 /**
796  * Utility function to open IO stream of output format.
797  *
798  * @param s AVFormatContext
799  * @param url URL or file name to open for writing
800  * @options optional options which will be passed to io_open callback
801  * @return >=0 on success, negative AVERROR in case of failure
802  */
803 int ff_format_output_open(AVFormatContext *s, const char *url, AVDictionary **options);
804 
805 /*
806  * A wrapper around AVFormatContext.io_close that should be used
807  * instead of calling the pointer directly.
808  */
809 void ff_format_io_close(AVFormatContext *s, AVIOContext **pb);
810 
811 /**
812  * Utility function to check if the file uses http or https protocol
813  *
814  * @param s AVFormatContext
815  * @param filename URL or file name to open for writing
816  */
817 int ff_is_http_proto(char *filename);
818 
819 /**
820  * Parse creation_time in AVFormatContext metadata if exists and warn if the
821  * parsing fails.
822  *
823  * @param s AVFormatContext
824  * @param timestamp parsed timestamp in microseconds, only set on successful parsing
825  * @param return_seconds set this to get the number of seconds in timestamp instead of microseconds
826  * @return 1 if OK, 0 if the metadata was not present, AVERROR(EINVAL) on parse error
827  */
828 int ff_parse_creation_time_metadata(AVFormatContext *s, int64_t *timestamp, int return_seconds);
829 
830 /**
831  * Standardize creation_time metadata in AVFormatContext to an ISO-8601
832  * timestamp string.
833  *
834  * @param s AVFormatContext
835  * @return <0 on error
836  */
837 int ff_standardize_creation_time(AVFormatContext *s);
838 
839 #define CONTAINS_PAL 2
840 /**
841  * Reshuffles the lines to use the user specified stride.
842  *
843  * @param ppkt input and output packet
844  * @return negative error code or
845  *         0 if no new packet was allocated
846  *         non-zero if a new packet was allocated and ppkt has to be freed
847  *         CONTAINS_PAL if in addition to a new packet the old contained a palette
848  */
849 int ff_reshuffle_raw_rgb(AVFormatContext *s, AVPacket **ppkt, AVCodecParameters *par, int expected_stride);
850 
851 /**
852  * Retrieves the palette from a packet, either from side data, or
853  * appended to the video data in the packet itself (raw video only).
854  * It is commonly used after a call to ff_reshuffle_raw_rgb().
855  *
856  * Use 0 for the ret parameter to check for side data only.
857  *
858  * @param pkt pointer to packet before calling ff_reshuffle_raw_rgb()
859  * @param ret return value from ff_reshuffle_raw_rgb(), or 0
860  * @param palette pointer to palette buffer
861  * @return negative error code or
862  *         1 if the packet has a palette, else 0
863  */
864 int ff_get_packet_palette(AVFormatContext *s, AVPacket *pkt, int ret, uint32_t *palette);
865 
866 /**
867  * Finalize buf into extradata and set its size appropriately.
868  */
869 int ff_bprint_to_codecpar_extradata(AVCodecParameters *par, struct AVBPrint *buf);
870 
871 /**
872  * Find the next packet in the interleaving queue for the given stream.
873  *
874  * @return a pointer to a packet if one was found, NULL otherwise.
875  */
876 const AVPacket *ff_interleaved_peek(AVFormatContext *s, int stream);
877 
878 int ff_get_muxer_ts_offset(AVFormatContext *s, int stream_index, int64_t *offset);
879 
880 int ff_lock_avformat(void);
881 int ff_unlock_avformat(void);
882 
883 /**
884  * Set AVFormatContext url field to the provided pointer. The pointer must
885  * point to a valid string. The existing url field is freed if necessary. Also
886  * set the legacy filename field to the same string which was provided in url.
887  */
888 void ff_format_set_url(AVFormatContext *s, char *url);
889 
890 void avpriv_register_devices(const AVOutputFormat * const o[], const AVInputFormat * const i[]);
891 
892 #endif /* AVFORMAT_INTERNAL_H */
893