libavformat/demux.h

   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 /**
  32  * For an FFInputFormat with this flag set read_close() needs to be called
  33  * by the caller upon read_header() failure.
  34  */
  35 #define FF_INFMT_FLAG_INIT_CLEANUP                             (1 << 0)
  36
  37 /*
  38  * Prefer the codec framerate for avg_frame_rate computation.
  39  */
  40 #define FF_INFMT_FLAG_PREFER_CODEC_FRAMERATE                   (1 << 1)
  41
  42 /**
  43  * Automatically parse ID3v2 metadata
  44  */
  45 #define FF_INFMT_FLAG_ID3V2_AUTO                               (1 << 2)
  46
  47 typedef struct FFInputFormat {
  48     /**
  49      * The public AVInputFormat. See avformat.h for it.
  50      */
  51     AVInputFormat p;
  52
  53     /**
  54      * Raw demuxers store their codec ID here.
  55      */
  56     enum AVCodecID raw_codec_id;
  57
  58     /**
  59      * Size of private data so that it can be allocated in the wrapper.
  60      */
  61     int priv_data_size;
  62
  63     /**
  64      * Internal flags. See FF_INFMT_FLAG_* above and FF_FMT_FLAG_* in internal.h.
  65      */
  66     int flags_internal;
  67
  68     /**
  69      * Tell if a given file has a chance of being parsed as this format.
  70      * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
  71      * big so you do not have to check for that unless you need more.
  72      */
  73     int (*read_probe)(const AVProbeData *);
  74
  75     /**
  76      * Read the format header and initialize the AVFormatContext
  77      * structure. Return 0 if OK. 'avformat_new_stream' should be
  78      * called to create new streams.
  79      */
  80     int (*read_header)(struct AVFormatContext *);
  81
  82     /**
  83      * Read one packet and put it in 'pkt'. pts and flags are also
  84      * set. 'avformat_new_stream' can be called only if the flag
  85      * AVFMTCTX_NOHEADER is used and only in the calling thread (not in a
  86      * background thread).
  87      * @return 0 on success, < 0 on error.
  88      *         Upon returning an error, pkt must be unreferenced by the caller.
  89      */
  90     int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
  91
  92     /**
  93      * Close the stream. The AVFormatContext and AVStreams are not
  94      * freed by this function
  95      */
  96     int (*read_close)(struct AVFormatContext *);
  97
  98     /**
  99      * Seek to a given timestamp relative to the frames in
 100      * stream component stream_index.
 101      * @param stream_index Must not be -1.
 102      * @param flags Selects which direction should be preferred if no exact
 103      *              match is available.
 104      * @return >= 0 on success (but not necessarily the new offset)
 105      */
 106     int (*read_seek)(struct AVFormatContext *,
 107                      int stream_index, int64_t timestamp, int flags);
 108
 109     /**
 110      * Get the next timestamp in stream[stream_index].time_base units.
 111      * @return the timestamp or AV_NOPTS_VALUE if an error occurred
 112      */
 113     int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
 114                               int64_t *pos, int64_t pos_limit);
 115
 116     /**
 117      * Start/resume playing - only meaningful if using a network-based format
 118      * (RTSP).
 119      */
 120     int (*read_play)(struct AVFormatContext *);
 121
 122     /**
 123      * Pause playing - only meaningful if using a network-based format
 124      * (RTSP).
 125      */
 126     int (*read_pause)(struct AVFormatContext *);
 127
 128     /**
 129      * Seek to timestamp ts.
 130      * Seeking will be done so that the point from which all active streams
 131      * can be presented successfully will be closest to ts and within min/max_ts.
 132      * Active streams are all streams that have AVStream.discard < AVDISCARD_ALL.
 133      */
 134     int (*read_seek2)(struct AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags);
 135
 136     /**
 137      * Returns device list with it properties.
 138      * @see avdevice_list_devices() for more details.
 139      */
 140     int (*get_device_list)(struct AVFormatContext *s, struct AVDeviceInfoList *device_list);
 141 } FFInputFormat;
 142
 143 static inline const FFInputFormat *ffifmt(const AVInputFormat *fmt)
 144 {
 145     return (const FFInputFormat*)fmt;
 146 }
 147
 148 #define MAX_STD_TIMEBASES (30*12+30+3+6)
 149 typedef struct FFStreamInfo {
 150     int64_t last_dts;
 151     int64_t duration_gcd;
 152     int duration_count;
 153     int64_t rfps_duration_sum;
 154     double (*duration_error)[2][MAX_STD_TIMEBASES];
 155     int64_t codec_info_duration;
 156     int64_t codec_info_duration_fields;
 157     int frame_delay_evidence;
 158
 159     /**
 160      * 0  -> decoder has not been searched for yet.
 161      * >0 -> decoder found
 162      * <0 -> decoder with codec_id == -found_decoder has not been found
 163      */
 164     int found_decoder;
 165
 166     int64_t last_duration;
 167
 168     /**
 169      * Those are used for average framerate estimation.
 170      */
 171     int64_t fps_first_dts;
 172     int     fps_first_dts_idx;
 173     int64_t fps_last_dts;
 174     int     fps_last_dts_idx;
 175 } FFStreamInfo;
 176
 177 /**
 178  * Returned by demuxers to indicate that data was consumed but discarded
 179  * (ignored streams or junk data). The framework will re-call the demuxer.
 180  */
 181 #define FFERROR_REDO FFERRTAG('R','E','D','O')
 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  */
 190 int ff_read_packet(AVFormatContext *s, AVPacket *pkt);
 191
 192 void ff_read_frame_flush(AVFormatContext *s);
 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
 261 void ff_rfps_calculate(AVFormatContext *ic);
 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 input 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
 283 void avpriv_stream_set_need_parsing(AVStream *st, enum AVStreamParseType type);
 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  */
 312 int ff_add_attached_pic(AVFormatContext *s, AVStream *st, AVIOContext *pb,
 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  */
 319 int ff_add_param_change(AVPacket *pkt, int32_t channels,
 320                         uint64_t channel_layout, int32_t sample_rate,
 321                         int32_t width, int32_t height);
 322
 323 /**
 324  * Generate standard extradata for AVC-Intra based on width/height and field
 325  * order.
 326  */
 327 int ff_generate_avci_extradata(AVStream *st);
 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
 344 int ff_buffer_packet(AVFormatContext *s, AVPacket *pkt);
 345
 346 #endif /* AVFORMAT_DEMUX_H */