avformat.h

包裝ffmpeg中的codecs成為DirectShow中的transform filter

/*
 * copyright (c) 2001 Fabrice Bellard
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef FFMPEG_AVFORMAT_H
#define FFMPEG_AVFORMAT_H

#define LIBAVFORMAT_VERSION_MAJOR 52
#define LIBAVFORMAT_VERSION_MINOR 13
#define LIBAVFORMAT_VERSION_MICRO  0

#define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
                                               LIBAVFORMAT_VERSION_MINOR, \
                                               LIBAVFORMAT_VERSION_MICRO)
#define LIBAVFORMAT_VERSION     AV_VERSION(LIBAVFORMAT_VERSION_MAJOR,   \
                                           LIBAVFORMAT_VERSION_MINOR,   \
                                           LIBAVFORMAT_VERSION_MICRO)
#define LIBAVFORMAT_BUILD       LIBAVFORMAT_VERSION_INT

#define LIBAVFORMAT_IDENT       "Lavf" AV_STRINGIFY(LIBAVFORMAT_VERSION)

#include <time.h>
#include <stdio.h>  /* FILE */
#include "libavcodec/avcodec.h"

#include "avio.h"

/* packet functions */

typedef struct AVPacket {
    int64_t pts;                            ///< presentation time stamp in time_base units
    int64_t dts;                            ///< decompression time stamp in time_base units
    uint8_t *data;
    int   size;
    int   stream_index;
    int   flags;
    int   duration;                         ///< presentation duration in time_base units (0 if not available)
    void  (*destruct)(struct AVPacket *);
    void  *priv;
    int64_t pos;                            ///< byte position in stream, -1 if unknown
} AVPacket;
#define PKT_FLAG_KEY   0x0001

void av_destruct_packet_nofree(AVPacket *pkt);

/**
 * Default packet destructor.
 */
void av_destruct_packet(AVPacket *pkt);

/**
 * Initialize optional fields of a packet to default values.
 *
 * @param pkt packet
 */
void av_init_packet(AVPacket *pkt);

/**
 * Allocate the payload of a packet and initialize its fields to default values.
 *
 * @param pkt packet
 * @param size wanted payload size
 * @return 0 if OK. AVERROR_xxx otherwise.
 */
int av_new_packet(AVPacket *pkt, int size);

/**
 * Allocate and read the payload of a packet and initialize its fields to default values.
 *
 * @param pkt packet
 * @param size wanted payload size
 * @return >0 (read size) if OK. AVERROR_xxx otherwise.
 */
int av_get_packet(ByteIOContext *s, AVPacket *pkt, int size);

/**
 * @warning This is a hack - the packet memory allocation stuff is broken. The
 * packet is allocated if it was not really allocated
 */
int av_dup_packet(AVPacket *pkt);

/**
 * Free a packet
 *
 * @param pkt packet to free
 */
static inline void av_free_packet(AVPacket *pkt)
{
    if (pkt && pkt->destruct) {
        pkt->destruct(pkt);
    }
}

/*************************************************/
/* fractional numbers for exact pts handling */

/**
 * the exact value of the fractional number is: 'val + num / den'.
 * num is assumed to be such as 0 <= num < den
 * @deprecated Use AVRational instead
*/
typedef struct AVFrac {
    int64_t val, num, den;
} AVFrac attribute_deprecated;

/*************************************************/
/* input/output formats */

struct AVCodecTag;

struct AVFormatContext;

/** this structure contains the data a format has to probe a file */
typedef struct AVProbeData {
    const char *filename;
    unsigned char *buf;
    int buf_size;
} AVProbeData;

#define AVPROBE_SCORE_MAX 100               ///< max score, half of that is used for file extension based detection
#define AVPROBE_PADDING_SIZE 32             ///< extra allocated bytes at the end of the probe buffer

typedef struct AVFormatParameters {
    AVRational time_base;
    int sample_rate;
    int channels;
    int width;
    int height;
    enum PixelFormat pix_fmt;
    int channel; /**< used to select dv channel */
    const char *standard; /**< tv standard, NTSC, PAL, SECAM */
    int mpeg2ts_raw:1;  /**< force raw MPEG2 transport stream output, if possible */
    int mpeg2ts_compute_pcr:1; /**< compute exact PCR for each transport
                                  stream packet (only meaningful if
                                  mpeg2ts_raw is TRUE) */
    int initial_pause:1;       /**< do not begin to play the stream
                                  immediately (RTSP only) */
    int prealloced_context:1;
#if LIBAVFORMAT_VERSION_INT < (53<<16)
    enum CodecID video_codec_id;
    enum CodecID audio_codec_id;
#endif
} AVFormatParameters;

//! demuxer will use url_fopen, no opened file should be provided by the caller
#define AVFMT_NOFILE        0x0001
#define AVFMT_NEEDNUMBER    0x0002 /**< needs '%d' in filename */
#define AVFMT_SHOW_IDS      0x0008 /**< show format stream IDs numbers */
#define AVFMT_RAWPICTURE    0x0020 /**< format wants AVPicture structure for
                                      raw picture data */
#define AVFMT_GLOBALHEADER  0x0040 /**< format wants global header */
#define AVFMT_NOTIMESTAMPS  0x0080 /**< format does not need / have any timestamps */
#define AVFMT_GENERIC_INDEX 0x0100 /**< use generic index building code */

typedef struct AVOutputFormat {
    const char *name;
    const char *long_name;
    const char *mime_type;
    const char *extensions; /**< comma separated filename extensions */
    /** size of private data so that it can be allocated in the wrapper */
    int priv_data_size;
    /* output support */
    enum CodecID audio_codec; /**< default audio codec */
    enum CodecID video_codec; /**< default video codec */
    int (*write_header)(struct AVFormatContext *);
    int (*write_packet)(struct AVFormatContext *, AVPacket *pkt);
    int (*write_trailer)(struct AVFormatContext *);
    /** can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_GLOBALHEADER */
    int flags;
    /** currently only used to set pixel format if not YUV420P */
    int (*set_parameters)(struct AVFormatContext *, AVFormatParameters *);
    int (*interleave_packet)(struct AVFormatContext *, AVPacket *out, AVPacket *in, int flush);

    /**
     * list of supported codec_id-codec_tag pairs, ordered by "better choice first"
     * the arrays are all CODEC_ID_NONE terminated
     */
    const struct AVCodecTag **codec_tag;

    enum CodecID subtitle_codec; /**< default subtitle codec */

    /* private fields */
    struct AVOutputFormat *next;
} AVOutputFormat;

typedef struct AVInputFormat {
    const char *name;
    const char *long_name;
    /** size of private data so that it can be allocated in the wrapper */
    int priv_data_size;
    /**
     * Tell if a given file has a chance of being parsed by this format.
     * The buffer provided is guaranteed to be AVPROBE_PADDING_SIZE bytes
     * big so you do not have to check for that unless you need more.
     */
    int (*read_probe)(AVProbeData *);
    /** read the format header and initialize the AVFormatContext
       structure. Return 0 if OK. 'ap' if non NULL contains
       additional paramters. Only used in raw format right
       now. 'av_new_stream' should be called to create new streams.  */
    int (*read_header)(struct AVFormatContext *,
                       AVFormatParameters *ap);
    /** read one packet and put it in 'pkt'. pts and flags are also
       set. 'av_new_stream' can be called only if the flag
       AVFMTCTX_NOHEADER is used. */
    int (*read_packet)(struct AVFormatContext *, AVPacket *pkt);
    /** close the stream. The AVFormatContext and AVStreams are not
       freed by this function */
    int (*read_close)(struct AVFormatContext *);
    /**
     * seek to a given timestamp relative to the frames in
     * stream component stream_index
     * @param stream_index must not be -1
     * @param flags selects which direction should be preferred if no exact
     *              match is available
     * @return >= 0 on success (but not necessarily the new offset)
     */
    int (*read_seek)(struct AVFormatContext *,
                     int stream_index, int64_t timestamp, int flags);
    /**
     * gets the next timestamp in stream[stream_index].time_base units.
     * @return the timestamp or AV_NOPTS_VALUE if an error occurred
     */
    int64_t (*read_timestamp)(struct AVFormatContext *s, int stream_index,
                              int64_t *pos, int64_t pos_limit);
    /** can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER */
    int flags;
    /** if extensions are defined, then no probe is done. You should
       usually not use extension format guessing because it is not
       reliable enough */
    const char *extensions;
    /** general purpose read only value that the format can use */
    int value;

    /** start/resume playing - only meaningful if using a network based format
       (RTSP) */
    int (*read_play)(struct AVFormatContext *);

    /** pause playing - only meaningful if using a network based format
       (RTSP) */
    int (*read_pause)(struct AVFormatContext *);

    const struct AVCodecTag **codec_tag;

    /* private fields */
    struct AVInputFormat *next;
} AVInputFormat;

enum AVStreamParseType {
    AVSTREAM_PARSE_NONE,
    AVSTREAM_PARSE_FULL,       /**< full parsing and repack */
    AVSTREAM_PARSE_HEADERS,    /**< only parse headers, don't repack */
    AVSTREAM_PARSE_TIMESTAMPS, /**< full parsing and interpolation of timestamps for frames not starting on packet boundary */
};

typedef struct AVIndexEntry {
    int64_t pos;
    int64_t timestamp;
#define AVINDEX_KEYFRAME 0x0001
    int flags:2;
    int size:30; //Yeah, trying to keep the size of this small to reduce memory requirements (it is 24 vs 32 byte due to possible 8byte align).
    int min_distance;         /**< min distance between this and the previous keyframe, used to avoid unneeded searching */
} AVIndexEntry;

#define AV_DISPOSITION_DEFAULT   0x0001
#define AV_DISPOSITION_DUB       0x0002
#define AV_DISPOSITION_ORIGINAL  0x0004
#define AV_DISPOSITION_COMMENT   0x0008
#define AV_DISPOSITION_LYRICS    0x0010
#define AV_DISPOSITION_KARAOKE   0x0020

/**
 * Stream structure.
 * New fields can be added to the end with minor version bumps.
 * Removal, reordering and changes to existing fields require a major
 * version bump.
 * sizeof(AVStream) must not be used outside libav*.
 */
typedef struct AVStream {
    int index;    /**< stream index in AVFormatContext */
    int id;       /**< format specific stream id */
    AVCodecContext *codec; /**< codec context */
    /**
     * Real base frame rate of the stream.
     * This is the lowest frame rate with which all timestamps can be
     * represented accurately (it is the least common multiple of all
     * frame rates in the stream), Note, this value is just a guess!
     * For example if the timebase is 1/90000 and all frames have either
     * approximately 3600 or 1800 timer ticks then r_frame_rate will be 50/1.
     */
    AVRational r_frame_rate;
    void *priv_data;

    /* internal data used in av_find_stream_info() */
    int64_t first_dts;
    /** encoding: PTS generation when outputing stream */
    struct AVFrac pts;

    /**
     * This is the fundamental unit of time (in seconds) in terms
     * of which frame timestamps are represented. For fixed-fps content,
     * timebase should be 1/frame rate and timestamp increments should be
     * identically 1.
     */
    AVRational time_base;
    int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
    /* ffmpeg.c private use */
    int stream_copy; /**< if set, just copy stream */
    enum AVDiscard discard; ///< selects which packets can be discarded at will and do not need to be demuxed
    //FIXME move stuff to a flags field?
    /** quality, as it has been removed from AVCodecContext and put in AVVideoFrame
     * MN: dunno if that is the right place for it */
    float quality;
    /**
     * Decoding: pts of the first frame of the stream, in stream time base.
     * Only set this if you are absolutely 100% sure that the value you set
     * it to really is the pts of the first frame.
     * This may be undefined (AV_NOPTS_VALUE).
     * @note The ASF header does NOT contain a correct start_time the ASF
     * demuxer must NOT set this.
     */
    int64_t start_time;
    /**
     * Decoding: duration of the stream, in stream time base.
     * If a source file does not specify a duration, but does specify