path: root/player/playloop.c

/*
 * This file is part of MPlayer.
 *
 * MPlayer 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.
 *
 * MPlayer 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 MPlayer; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <stddef.h>
#include <stdbool.h>
#include <inttypes.h>
#include <math.h>
#include <assert.h>

#include "config.h"
#include "talloc.h"

#include "common/msg.h"
#include "options/options.h"
#include "common/common.h"
#include "common/encode.h"
#include "options/m_property.h"
#include "common/playlist.h"
#include "input/input.h"

#include "osdep/terminal.h"
#include "osdep/threads.h"
#include "osdep/timer.h"

#include "audio/mixer.h"
#include "audio/decode/dec_audio.h"
#include "audio/filter/af.h"
#include "audio/out/ao.h"
#include "demux/demux.h"
#include "stream/stream.h"
#include "sub/osd.h"
#include "video/filter/vf.h"
#include "video/decode/dec_video.h"
#include "video/out/vo.h"

#include "core.h"
#include "screenshot.h"
#include "command.h"

#define WAKEUP_PERIOD 0.5

static const char av_desync_help_text[] =
"\n\n"
"           *************************************************\n"
"           **** Audio/Video desynchronisation detected! ****\n"
"           *************************************************\n\n"
"This means either the audio or the video is played too slowly.\n"
"Possible reasons, problems, workarounds:\n"
"- Your system is simply too slow for this file.\n"
"     Transcode it to a lower bitrate file with tools like HandBrake.\n"
"- Broken/buggy _audio_ driver.\n"
"     Experiment with different values for --autosync, 30 is a good start.\n"
"     If you have PulseAudio, try --ao=alsa .\n"
"- Slow video output.\n"
"     Try a different --vo driver (--vo=help for a list) or try --framedrop!\n"
"- Playing a video file with --vo=opengl with higher FPS than the monitor.\n"
"     This is due to vsync limiting the framerate.\n"
"- Playing from a slow network source.\n"
"     Download the file instead.\n"
"- Try to find out whether audio/video/subs are causing this by experimenting\n"
"  with --no-video, --no-audio, or --no-sub.\n"
"- If you swiched audio or video tracks, try seeking to force synchronization.\n"
"If none of this helps you, file a bug report.\n\n";


void pause_player(struct MPContext *mpctx, mpv_event_pause_reason reason)
{
    mpctx->opts->pause = 1;

    if (mpctx->video_out)
        vo_control(mpctx->video_out, VOCTRL_RESTORE_SCREENSAVER, NULL);

    if (mpctx->paused)
        goto end;
    mpctx->paused = true;
    mpctx->step_frames = 0;
    mpctx->time_frame -= get_relative_time(mpctx);
    mpctx->osd_function = 0;
    mpctx->paused_for_cache = false;

    if (mpctx->video_out && mpctx->d_video && mpctx->video_out->config_ok)
        vo_control(mpctx->video_out, VOCTRL_PAUSE, NULL);

    if (mpctx->ao && mpctx->d_audio)
        ao_pause(mpctx->ao);    // pause audio, keep data if possible

    // Only print status if there's actually a file being played.
    if (mpctx->num_sources)
        print_status(mpctx);

    if (!mpctx->opts->quiet)
        MP_SMODE(mpctx, "ID_PAUSED\n");

end:
    reason.user_paused = !!mpctx->opts->pause;
    reason.real_paused = !!mpctx->paused;
    mp_notify(mpctx, MPV_EVENT_PAUSE, &reason);
}

void unpause_player(struct MPContext *mpctx, mpv_event_pause_reason reason)
{
    mpctx->opts->pause = 0;

    if (mpctx->video_out && mpctx->opts->stop_screensaver)
        vo_control(mpctx->video_out, VOCTRL_KILL_SCREENSAVER, NULL);

    if (!mpctx->paused)
        goto end;
    // Don't actually unpause while cache is loading.
    if (mpctx->paused_for_cache)
        goto end;
    mpctx->paused = false;
    mpctx->osd_function = 0;

    if (mpctx->ao && mpctx->d_audio)
        ao_resume(mpctx->ao);
    if (mpctx->video_out && mpctx->d_video && mpctx->video_out->config_ok)
        vo_control(mpctx->video_out, VOCTRL_RESUME, NULL);      // resume video
    (void)get_relative_time(mpctx);     // ignore time that passed during pause

end:
    reason.user_paused = !!mpctx->opts->pause;
    reason.real_paused = !!mpctx->paused;
    mp_notify(mpctx, MPV_EVENT_UNPAUSE, &reason);
}

static void draw_osd(struct MPContext *mpctx)
{
    struct vo *vo = mpctx->video_out;

    osd_set_vo_pts(mpctx->osd, mpctx->video_pts);
    vo_draw_osd(vo, mpctx->osd);
}

static bool redraw_osd(struct MPContext *mpctx)
{
    struct vo *vo = mpctx->video_out;
    if (vo_redraw_frame(vo) < 0)
        return false;

    draw_osd(mpctx);

    vo_flip_page(vo, 0, -1);
    return true;
}

void add_step_frame(struct MPContext *mpctx, int dir)
{
    if (!mpctx->d_video)
        return;
    if (dir > 0) {
        mpctx->step_frames += 1;
        unpause_player(mpctx, PAUSE_BY_COMMAND);
    } else if (dir < 0) {
        if (!mpctx->backstep_active && !mpctx->hrseek_active) {
            mpctx->backstep_active = true;
            mpctx->backstep_start_seek_ts = mpctx->vo_pts_history_seek_ts;
            pause_player(mpctx, PAUSE_BY_COMMAND);
        }
    }
}

static void seek_reset(struct MPContext *mpctx, bool reset_ao, bool reset_ac)
{
    if (mpctx->d_video) {
        video_reset_decoding(mpctx->d_video);
        vo_seek_reset(mpctx->video_out);
    }

    if (mpctx->d_audio && reset_ac) {
        audio_reset_decoding(mpctx->d_audio);
        if (reset_ao)
            clear_audio_output_buffers(mpctx);
    }

    reset_subtitles(mpctx, 0);
    reset_subtitles(mpctx, 1);

    mpctx->video_pts = MP_NOPTS_VALUE;
    mpctx->video_next_pts = MP_NOPTS_VALUE;
    mpctx->playing_last_frame = false;
    mpctx->last_frame_duration = 0;
    mpctx->delay = 0;
    mpctx->time_frame = 0;
    mpctx->restart_playback = true;
    mpctx->hrseek_active = false;
    mpctx->hrseek_framedrop = false;
    mpctx->total_avsync_change = 0;
    mpctx->drop_frame_cnt = 0;
    mpctx->dropped_frames = 0;
    mpctx->playback_pts = MP_NOPTS_VALUE;

#if HAVE_ENCODING
    encode_lavc_discontinuity(mpctx->encode_lavc_ctx);
#endif

    mp_notify(mpctx, MPV_EVENT_SEEK, NULL);
}

// return -1 if seek failed (non-seekable stream?), 0 otherwise
static int mp_seek(MPContext *mpctx, struct seek_params seek,
                   bool timeline_fallthrough)
{
    struct MPOpts *opts = mpctx->opts;
    uint64_t prev_seek_ts = mpctx->vo_pts_history_seek_ts;

    if (!mpctx->demuxer)
        return -1;

    if (!mpctx->demuxer->seekable) {
        MP_ERR(mpctx, "Can't seek in this file.\n");
        return -1;
    }

    if (mpctx->stop_play == AT_END_OF_FILE)
        mpctx->stop_play = KEEP_PLAYING;

    double hr_seek_offset = opts->hr_seek_demuxer_offset;
    // Always try to compensate for possibly bad demuxers in "special"
    // situations where we need more robustness from the hr-seek code, even
    // if the user doesn't use --hr-seek-demuxer-offset.
    // The value is arbitrary, but should be "good enough" in most situations.
    if (seek.exact > 1)
        hr_seek_offset = MPMAX(hr_seek_offset, 0.5); // arbitrary

    bool hr_seek = mpctx->demuxer->accurate_seek && opts->correct_pts;
    hr_seek &= seek.exact >= 0 && seek.type != MPSEEK_FACTOR;
    hr_seek &= (opts->hr_seek == 0 && seek.type == MPSEEK_ABSOLUTE) ||
               opts->hr_seek > 0 || seek.exact > 0;
    if (seek.type == MPSEEK_FACTOR || seek.amount < 0 ||
        (seek.type == MPSEEK_ABSOLUTE && seek.amount < mpctx->last_chapter_pts))
        mpctx->last_chapter_seek = -2;
    if (seek.type == MPSEEK_FACTOR) {
        double len = get_time_length(mpctx);
        if (len > 0 && !mpctx->demuxer->ts_resets_possible) {
            seek.amount = seek.amount * len + get_start_time(mpctx);
            seek.type = MPSEEK_ABSOLUTE;
        }
    }
    if ((mpctx->demuxer->accurate_seek || mpctx->timeline)
        && seek.type == MPSEEK_RELATIVE) {
        seek.type = MPSEEK_ABSOLUTE;
        seek.direction = seek.amount > 0 ? 1 : -1;
        seek.amount += get_current_time(mpctx);
    }

    /* At least the liba52 decoder wants to read from the input stream
     * during initialization, so reinit must be done after the demux_seek()
     * call that clears possible stream EOF. */
    bool need_reset = false;
    double demuxer_amount = seek.amount;
    if (mpctx->timeline) {
        demuxer_amount = timeline_set_from_time(mpctx, seek.amount,
                                                &need_reset);
        if (demuxer_amount == -1) {
            assert(!need_reset);
            mpctx->stop_play = AT_END_OF_FILE;
            if (mpctx->d_audio && !timeline_fallthrough) {
                // Seek outside of the file -> clear audio from current position
                clear_audio_decode_buffers(mpctx);
                clear_audio_output_buffers(mpctx);
            }
            return -1;
        }
    }
    if (need_reset) {
        reinit_video_chain(mpctx);
        reinit_subs(mpctx, 0);
        reinit_subs(mpctx, 1);
    }

    int demuxer_style = 0;
    switch (seek.type) {
    case MPSEEK_FACTOR:
        demuxer_style |= SEEK_ABSOLUTE | SEEK_FACTOR;
        break;
    case MPSEEK_ABSOLUTE:
        demuxer_style |= SEEK_ABSOLUTE;
        break;
    }
    if (hr_seek || seek.direction < 0)
        demuxer_style |= SEEK_BACKWARD;
    else if (seek.direction > 0)
        demuxer_style |= SEEK_FORWARD;
    if (hr_seek || opts->mkv_subtitle_preroll)
        demuxer_style |= SEEK_SUBPREROLL;

    if (hr_seek)
        demuxer_amount -= hr_seek_offset;
    int seekresult = demux_seek(mpctx->demuxer, demuxer_amount, demuxer_style);
    if (seekresult == 0) {
        if (need_reset) {
            reinit_audio_chain(mpctx);
            seek_reset(mpctx, !timeline_fallthrough, false);
        }
        return -1;
    }

    // Seek external, extra files too:
    for (int t = 0; t < mpctx->num_tracks; t++) {
        struct track *track = mpctx->tracks[t];
        if (track->selected && track->is_external && track->demuxer) {
            double main_new_pos;
            if (seek.type == MPSEEK_ABSOLUTE) {
                main_new_pos = seek.amount - mpctx->video_offset;
            } else {
                main_new_pos = get_main_demux_pts(mpctx);
            }
            demux_seek(track->demuxer, main_new_pos, SEEK_ABSOLUTE);
        }
    }

    if (need_reset)
        reinit_audio_chain(mpctx);
    /* If we just reinitialized audio it doesn't need to be reset,
     * and resetting could lose audio some decoders produce during init. */
    seek_reset(mpctx, !timeline_fallthrough, !need_reset);

    if (timeline_fallthrough) {
        // Important if video reinit happens.
        mpctx->vo_pts_history_seek_ts = prev_seek_ts;
    } else {
        mpctx->vo_pts_history_seek_ts++;
        mpctx->backstep_active = false;
    }

    /* Use the target time as "current position" for further relative
     * seeks etc until a new video frame has been decoded */
    if (seek.type == MPSEEK_ABSOLUTE) {
        mpctx->video_pts = seek.amount;
        mpctx->last_seek_pts = seek.amount;
    } else
        mpctx->last_seek_pts = MP_NOPTS_VALUE;

    // The hr_seek==false case is for skipping frames with PTS before the
    // current timeline chapter start. It's not really known where the demuxer
    // level seek will end up, so the hrseek mechanism is abused to skip all
    // frames before chapter start by setting hrseek_pts to the chapter start.
    // It does nothing when the seek is inside of the current chapter, and
    // seeking past the chapter is handled elsewhere.
    if (hr_seek || mpctx->timeline) {
        mpctx->hrseek_active = true;
        mpctx->hrseek_framedrop = true;
        mpctx->hrseek_pts = hr_seek ? seek.amount
                                 : mpctx->timeline[mpctx->timeline_part].start;
    }

    mpctx->start_timestamp = mp_time_sec();

    return 0;
}

// This combines consecutive seek requests.
void queue_seek(struct MPContext *mpctx, enum seek_type type, double amount,
                int exact, bool immediate)
{
    struct seek_params *seek = &mpctx->seek;
    switch (type) {
    case MPSEEK_RELATIVE:
        seek->immediate |= immediate;
        if (seek->type == MPSEEK_FACTOR)
            return;  // Well... not common enough to bother doing better
        seek->amount += amount;
        seek->exact = MPMAX(seek->exact, exact);
        if (seek->type == MPSEEK_NONE)
            seek->exact = exact;
        if (seek->type == MPSEEK_ABSOLUTE)
            return;
        if (seek->amount == 0) {
            *seek = (struct seek_params){ 0 };
            return;
        }
        seek->type = MPSEEK_RELATIVE;
        return;
    case MPSEEK_ABSOLUTE:
    case MPSEEK_FACTOR:
        *seek = (struct seek_params) {
            .type = type,
            .amount = amount,
            .exact = exact,
            .immediate = immediate,
        };
        return;
    case MPSEEK_NONE:
        *seek = (struct seek_params){ 0 };
        return;
    }
    abort();
}

void execute_queued_seek(struct MPContext *mpctx)
{
    if (mpctx->seek.type) {
        /* If the user seeks continuously (keeps arrow key down)
         * try to finish showing a frame from one location before doing
         * another seek (which could lead to unchanging display). */
        if (!mpctx->see