demux.h

/*
 * This file is part of mpv.
 *
 * mpv 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.
 *
 * mpv 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 mpv.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef MPLAYER_DEMUXER_H
#define MPLAYER_DEMUXER_H

#include <sys/types.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>

#include "misc/bstr.h"
#include "common/common.h"
#include "common/tags.h"
#include "packet.h"
#include "stheader.h"

#define MAX_SEEK_RANGES 10

struct demux_seek_range {
    double start, end;
};

struct demux_reader_state {
    bool eof, underrun, idle;
    bool bof_cached, eof_cached;
    double ts_duration;
    double ts_reader; // approx. timerstamp of decoder position
    double ts_end; // approx. timestamp of end of buffered range
    int64_t total_bytes;
    int64_t fw_bytes;
    double seeking; // current low level seek target, or NOPTS
    int low_level_seeks; // number of started low level seeks
    double ts_last; // approx. timestamp of demuxer position
    uint64_t bytes_per_second; // low level statistics
    // Positions that can be seeked to without incurring the latency of a low
    // level seek.
    int num_seek_ranges;
    struct demux_seek_range seek_ranges[MAX_SEEK_RANGES];
};

#define SEEK_FACTOR   (1 << 1)      // argument is in range [0,1]
#define SEEK_FORWARD  (1 << 2)      // prefer later time if not exact
                                    // (if unset, prefer earlier time)
#define SEEK_CACHED   (1 << 3)      // allow packet cache seeks only
#define SEEK_SATAN    (1 << 4)      // enable backward demuxing
#define SEEK_HR       (1 << 5)      // hr-seek (this is a weak hint only)

// Strictness of the demuxer open format check.
// demux.c will try by default: NORMAL, UNSAFE (in this order)
// Using "-demuxer format" will try REQUEST
// Using "-demuxer +format" will try FORCE
// REQUEST can be used as special value for raw demuxers which have no file
// header check; then they should fail if check!=FORCE && check!=REQUEST.
//
// In general, the list is sorted from weakest check to normal check.
// You can use relation operators to compare the check level.
enum demux_check {
    DEMUX_CHECK_FORCE,  // force format if possible
    DEMUX_CHECK_UNSAFE, // risky/fuzzy detection
    DEMUX_CHECK_REQUEST,// requested by user or stream implementation
    DEMUX_CHECK_NORMAL, // normal, safe detection
};

enum demux_event {
    DEMUX_EVENT_INIT = 1 << 0,      // complete (re-)initialization
    DEMUX_EVENT_STREAMS = 1 << 1,   // a stream was added
    DEMUX_EVENT_METADATA = 1 << 2,  // metadata or stream_metadata changed
    DEMUX_EVENT_DURATION = 1 << 3,  // duration updated
    DEMUX_EVENT_ALL = 0xFFFF,
};

struct demuxer;
struct timeline;

/**
 * Demuxer description structure
 */
typedef struct demuxer_desc {
    const char *name;      // Demuxer name, used with -demuxer switch
    const char *desc;      // Displayed to user

    // Return 0 on success, otherwise -1
    int (*open)(struct demuxer *demuxer, enum demux_check check);
    // The following functions are all optional
    // Try to read a packet. Return false on EOF. If true is returned, the
    // demuxer may set *pkt to a new packet (the reference goes to the caller).
    // If *pkt is NULL (the value when this function is called), the call
    // will be repeated.
    bool (*read_packet)(struct demuxer *demuxer, struct demux_packet **pkt);
    void (*close)(struct demuxer *demuxer);
    void (*seek)(struct demuxer *demuxer, double rel_seek_secs, int flags);
    void (*switched_tracks)(struct demuxer *demuxer);
    // See timeline.c
    void (*load_timeline)(struct timeline *tl);
} demuxer_desc_t;

typedef struct demux_chapter
{
    int original_index;
    double pts;
    struct mp_tags *metadata;
    uint64_t demuxer_id; // for mapping to internal demuxer data structures
} demux_chapter_t;

struct demux_edition {
    uint64_t demuxer_id;
    bool default_edition;
    struct mp_tags *metadata;
};

struct matroska_segment_uid {
    unsigned char segment[16];
    uint64_t edition;
};

struct matroska_data {
    struct matroska_segment_uid uid;
    // Ordered chapter information if any
    struct matroska_chapter {
        uint64_t start;
        uint64_t end;
        bool has_segment_uid;
        struct matroska_segment_uid uid;
        char *name;
    } *ordered_chapters;
    int num_ordered_chapters;
};

struct replaygain_data {
    float track_gain;
    float track_peak;
    float album_gain;
    float album_peak;
};

typedef struct demux_attachment
{
    char *name;
    char *type;
    void *data;
    unsigned int data_size;
} demux_attachment_t;

struct demuxer_params {
    char *force_format;
    int matroska_num_wanted_uids;
    struct matroska_segment_uid *matroska_wanted_uids;
    int matroska_wanted_segment;
    bool *matroska_was_valid;
    struct timeline *timeline;
    bool disable_timeline;
    bstr init_fragment;
    bool skip_lavf_probing;
    bool stream_record; // if true, enable stream recording if option is set
    int stream_flags;
    // result
    bool demuxer_failed;
};

typedef struct demuxer {
    const demuxer_desc_t *desc; ///< Demuxer description structure
    const char *filetype; // format name when not identified by demuxer (libavformat)
    int64_t filepos;  // input stream current pos.
    int64_t filesize;
    char *filename;  // same as stream->url
    bool seekable;
    bool partially_seekable; // true if _maybe_ seekable; implies seekable=true
    double start_time;
    double duration;  // -1 if unknown
    // File format allows PTS resets (even if the current file is without)
    bool ts_resets_possible;
    // The file data was fully read, and there is no need to keep the stream
    // open, keep the cache active, or to run the demuxer thread. Generating
    // packets is not slow either (unlike e.g. libavdevice pseudo-demuxers).
    // Typical examples: text subtitles, playlists
    bool fully_read;
    bool is_network; // opened directly from a network stream
    bool access_references; // allow opening other files/URLs

    // Bitmask of DEMUX_EVENT_*
    int events;

    struct demux_edition *editions;
    int num_editions;
    int edition;

    struct demux_chapter *chapters;
    int num_chapters;

    struct demux_attachment *attachments;
    int num_attachments;

    struct matroska_data matroska_data;

    // If the file is a playlist file
    struct playlist *playlist;

    struct mp_tags *metadata;

    void *priv;   // demuxer-specific internal data
    struct mpv_global *global;
    struct mp_log *log, *glog;
    struct demuxer_params *params;

    // internal to demux.c
    struct demux_internal *in;

    // Triggered when ending demuxing forcefully. Usually bound to the stream too.
    struct mp_cancel *cancel;

    // Since the demuxer can run in its own thread, and the stream is not
    // thread-safe, only the demuxer is allowed to access the stream directly.
    // Also note that the stream can get replaced if fully_read is set.
    struct stream *stream;
} demuxer_t;

void demux_free(struct demuxer *demuxer);
void demux_cancel_and_free(struct demuxer *demuxer);

struct demux_free_async_state;
struct demux_free_async_state *demux_free_async(struct demuxer *demuxer);
void demux_free_async_force(struct demux_free_async_state *state);
bool demux_free_async_finish(struct demux_free_async_state *state);

void demuxer_feed_caption(struct sh_stream *stream, demux_packet_t *dp);

int demux_read_packet_async(struct sh_stream *sh, struct demux_packet **out_pkt);
bool demux_stream_is_selected(struct sh_stream *stream);
void demux_set_stream_wakeup_cb(struct sh_stream *sh,
                                void (*cb)(void *ctx), void *ctx);
struct demux_packet *demux_read_any_packet(struct demuxer *demuxer);

struct sh_stream *demux_get_stream(struct demuxer *demuxer, int index);
int demux_get_num_stream(struct demuxer *demuxer);

struct sh_stream *demux_alloc_sh_stream(enum stream_type type);
void demux_add_sh_stream(struct demuxer *demuxer, struct sh_stream *sh);

struct mp_cancel;
struct demuxer *demux_open_url(const char *url,
                               struct demuxer_params *params,
                               struct mp_cancel *cancel,
                               struct mpv_global *global);

void demux_start_thread(struct demuxer *demuxer);
void demux_stop_thread(struct demuxer *demuxer);
void demux_set_wakeup_cb(struct demuxer *demuxer, void (*cb)(void *ctx), void *ctx);
void demux_start_prefetch(struct demuxer *demuxer);

bool demux_cancel_test(struct demuxer *demuxer);

void demux_flush(struct demuxer *demuxer);
int demux_seek(struct demuxer *demuxer, double rel_seek_secs, int flags);
void demux_set_ts_offset(struct demuxer *demuxer, double offset);

void demux_get_bitrate_stats(struct demuxer *demuxer, double *rates);
void demux_get_reader_state(struct demuxer *demuxer, struct demux_reader_state *r);

void demux_block_reading(struct demuxer *demuxer, bool block);

void demuxer_select_track(struct demuxer *demuxer, struct sh_stream *stream,
                          double ref_pts, bool selected);

void demuxer_help(struct mp_log *log);

int demuxer_add_attachment(struct demuxer *demuxer, char *name,
                           char *type, void *data, size_t data_size);
int demuxer_add_chapter(demuxer_t *demuxer, char *name,
                        double pts, uint64_t demuxer_id);
void demux_set_stream_tags(struct demuxer *demuxer, struct sh_stream *sh,
                           struct mp_tags *tags);
void demux_close_stream(struct demuxer *demuxer);

void demux_metadata_changed(demuxer_t *demuxer);
void demux_update(demuxer_t *demuxer);

void demux_disable_cache(demuxer_t *demuxer);
bool demux_is_network_cached(demuxer_t *demuxer);

void demux_report_unbuffered_read_bytes(struct demuxer *demuxer, int64_t new);
int64_t demux_get_bytes_read_hack(struct demuxer *demuxer);

struct sh_stream *demuxer_stream_by_demuxer_id(struct demuxer *d,
                                               enum stream_type t, int id);

struct demux_chapter *demux_copy_chapter_data(struct demux_chapter *c, int num);

bool demux_matroska_uid_cmp(struct matroska_segment_uid *a,
                            struct matroska_segment_uid *b);

const char *stream_type_name(enum stream_type type);

void mp_packet_tags_unref(struct mp_packet_tags *tags);
void mp_packet_tags_setref(struct mp_packet_tags **dst, struct mp_packet_tags *src);

#endif /* MPLAYER_DEMUXER_H */