path: root/demux/demux.c

/*
 * This file is part of mpv.
 *
 * mpv is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with mpv.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <unistd.h>
#include <pthread.h>

#include <math.h>

#include <sys/types.h>
#include <sys/stat.h>

#include "config.h"
#include "options/options.h"
#include "talloc.h"
#include "common/msg.h"
#include "common/global.h"
#include "osdep/threads.h"

#include "stream/stream.h"
#include "demux.h"
#include "stheader.h"

#include "audio/format.h"

// Demuxer list
extern const struct demuxer_desc demuxer_desc_edl;
extern const struct demuxer_desc demuxer_desc_cue;
extern const demuxer_desc_t demuxer_desc_rawaudio;
extern const demuxer_desc_t demuxer_desc_rawvideo;
extern const demuxer_desc_t demuxer_desc_tv;
extern const demuxer_desc_t demuxer_desc_mf;
extern const demuxer_desc_t demuxer_desc_matroska;
extern const demuxer_desc_t demuxer_desc_lavf;
extern const demuxer_desc_t demuxer_desc_libass;
extern const demuxer_desc_t demuxer_desc_subreader;
extern const demuxer_desc_t demuxer_desc_playlist;
extern const demuxer_desc_t demuxer_desc_disc;
extern const demuxer_desc_t demuxer_desc_rar;

/* Please do not add any new demuxers here. If you want to implement a new
 * demuxer, add it to libavformat, except for wrappers around external
 * libraries and demuxers requiring binary support. */

const demuxer_desc_t *const demuxer_list[] = {
    &demuxer_desc_disc,
    &demuxer_desc_edl,
    &demuxer_desc_cue,
    &demuxer_desc_rawaudio,
    &demuxer_desc_rawvideo,
#if HAVE_TV
    &demuxer_desc_tv,
#endif
#if HAVE_LIBASS
    &demuxer_desc_libass,
#endif
    &demuxer_desc_matroska,
    &demuxer_desc_rar,
    &demuxer_desc_lavf,
    &demuxer_desc_mf,
    &demuxer_desc_playlist,
    // Pretty aggressive, so should be last.
    &demuxer_desc_subreader,
    NULL
};

struct demux_internal {
    struct mp_log *log;

    // The demuxer runs potentially in another thread, so we keep two demuxer
    // structs; the real demuxer can access the shadow struct only.
    // Since demuxer and user threads both don't use locks, a third demuxer
    // struct d_buffer is used to copy data between them in a synchronized way.
    struct demuxer *d_thread;   // accessed by demuxer impl. (producer)
    struct demuxer *d_user;     // accessed by player (consumer)
    struct demuxer *d_buffer;   // protected by lock; used to sync d_user/thread

    // The lock protects the packet queues (struct demux_stream), d_buffer,
    // and some minor fields like thread_paused.
    pthread_mutex_t lock;
    pthread_cond_t wakeup;
    pthread_t thread;

    // -- All the following fields are protected by lock.

    bool thread_paused;
    int thread_request_pause;   // counter, if >0, make demuxer thread pause
    bool thread_terminate;
    bool threading;
    void (*wakeup_cb)(void *ctx);
    void *wakeup_cb_ctx;

    bool warned_queue_overflow;
    bool last_eof;              // last actual global EOF status
    bool eof;                   // whether we're in EOF state (reset for retry)
    bool idle;
    bool autoselect;
    double min_secs;
    int min_packs;
    int min_bytes;

    bool tracks_switched;       // thread needs to inform demuxer of this

    bool seeking;               // there's a seek queued
    int seek_flags;             // flags for next seek (if seeking==true)
    double seek_pts;

    bool refresh_seeks_enabled;
    bool start_refresh_seek;

    // Cached state.
    bool force_cache_update;
    double time_length;
    struct mp_nav_event *nav_event;
    struct mp_tags *stream_metadata;
    int64_t stream_size;
    int64_t stream_cache_size;
    int64_t stream_cache_fill;
    int stream_cache_idle;
    // Updated during init only.
    char *stream_base_filename;
};

struct demux_stream {
    struct demux_internal *in;
    enum stream_type type;
    // all fields are protected by in->lock
    bool selected;          // user wants packets from this stream
    bool active;            // try to keep at least 1 packet queued
                            // if false, this stream is disabled, or passively
                            // read (like subtitles)
    bool eof;               // end of demuxed stream? (true if all buffer empty)
    bool refreshing;
    size_t packs;           // number of packets in buffer
    size_t bytes;           // total bytes of packets in buffer
    double base_ts;         // timestamp of the last packet returned to decoder
    double last_ts;         // timestamp of the last packet added to queue
    double last_br_ts;      // timestamp of last packet bitrate was calculated
    size_t last_br_bytes;   // summed packet sizes since last bitrate calculation
    double bitrate;
    int64_t last_pos;
    struct demux_packet *head;
    struct demux_packet *tail;
};

// Return "a", or if that is NOPTS, return "def".
#define PTS_OR_DEF(a, def) ((a) == MP_NOPTS_VALUE ? (def) : (a))
// If one of the values is NOPTS, always pick the other one.
#define MP_PTS_MIN(a, b) MPMIN(PTS_OR_DEF(a, b), PTS_OR_DEF(b, a))
#define MP_PTS_MAX(a, b) MPMAX(PTS_OR_DEF(a, b), PTS_OR_DEF(b, a))

static void demuxer_sort_chapters(demuxer_t *demuxer);
static void *demux_thread(void *pctx);
static void update_cache(struct demux_internal *in);

// called locked
static void ds_flush(struct demux_stream *ds)
{
    demux_packet_t *dp = ds->head;
    while (dp) {
        demux_packet_t *dn = dp->next;
        free_demux_packet(dp);
        dp = dn;
    }
    ds->head = ds->tail = NULL;
    ds->packs = 0;
    ds->bytes = 0;
    ds->last_ts = ds->base_ts = ds->last_br_ts = MP_NOPTS_VALUE;
    ds->last_br_bytes = 0;
    ds->bitrate = -1;
    ds->eof = false;
    ds->active = false;
    ds->refreshing = false;
    ds->last_pos = -1;
}

struct sh_stream *new_sh_stream(demuxer_t *demuxer, enum stream_type type)
{
    assert(demuxer == demuxer->in->d_thread);

    if (demuxer->num_streams > MAX_SH_STREAMS) {
        MP_WARN(demuxer, "Too many streams.\n");
        return NULL;
    }

    int demuxer_id = 0;
    for (int n = 0; n < demuxer->num_streams; n++) {
        if (demuxer->streams[n]->type == type)
            demuxer_id++;
    }

    struct sh_stream *sh = talloc_ptrtype(demuxer, sh);
    *sh = (struct sh_stream) {
        .type = type,
        .index = demuxer->num_streams,
        .ff_index = demuxer->num_streams,
        .demuxer_id = demuxer_id, // may be overwritten by demuxer
        .ds = talloc(sh, struct demux_stream),
    };
    *sh->ds = (struct demux_stream) {
        .in = demuxer->in,
        .type = sh->type,
        .selected = demuxer->in->autoselect,
    };
    MP_TARRAY_APPEND(demuxer, demuxer->streams, demuxer->num_streams, sh);
    switch (sh->type) {
    case STREAM_VIDEO: sh->video = talloc_zero(demuxer, struct sh_video); break;
    case STREAM_AUDIO: sh->audio = talloc_zero(demuxer, struct sh_audio); break;
    case STREAM_SUB:   sh->sub = talloc_zero(demuxer, struct sh_sub); break;
    }

    return sh;
}

void free_demuxer(demuxer_t *demuxer)
{
    if (!demuxer)
        return;
    struct demux_internal *in = demuxer->in;
    assert(demuxer == in->d_user);

    demux_stop_thread(demuxer);

    if (demuxer->desc->close)
        demuxer->desc->close(in->d_thread);
    for (int n = 0; n < demuxer->num_streams; n++)
        ds_flush(demuxer->streams[n]->ds);
    pthread_mutex_destroy(&in->lock);
    pthread_cond_destroy(&in-