ffplay.c

            int64_t seek_target= is->seek_pos;

            if     (is->   video_stream >= 0) stream_index= is->   video_stream;
            else if(is->   audio_stream >= 0) stream_index= is->   audio_stream;
            else if(is->subtitle_stream >= 0) stream_index= is->subtitle_stream;

            if(stream_index>=0){
                seek_target= av_rescale_q(seek_target, AV_TIME_BASE_Q, ic->streams[stream_index]->time_base);
            }

            ret = av_seek_frame(is->ic, stream_index, seek_target, is->seek_flags);
            if (ret < 0) {
                fprintf(stderr, "%s: error while seeking\n", is->ic->filename);
            }else{
                if (is->audio_stream >= 0) {
                    packet_queue_flush(&is->audioq);
                    packet_queue_put(&is->audioq, &flush_pkt);
                }
                if (is->subtitle_stream >= 0) {
                    packet_queue_flush(&is->subtitleq);
                    packet_queue_put(&is->subtitleq, &flush_pkt);
                }
                if (is->video_stream >= 0) {
                    packet_queue_flush(&is->videoq);
                    packet_queue_put(&is->videoq, &flush_pkt);
                }
            }
            is->seek_req = 0;
        }

        /* if the queue are full, no need to read more */
        if (is->audioq.size > MAX_AUDIOQ_SIZE ||
            is->videoq.size > MAX_VIDEOQ_SIZE ||
            is->subtitleq.size > MAX_SUBTITLEQ_SIZE ||
            url_feof(ic->pb)) {
            /* wait 10 ms */
            SDL_Delay(10);
            continue;
        }
        ret = av_read_frame(ic, pkt);
        if (ret < 0) {
            if (url_ferror(ic->pb) == 0) {
                SDL_Delay(100); /* wait for user event */
                continue;
            } else
                break;
        }
        if (pkt->stream_index == is->audio_stream) {
            packet_queue_put(&is->audioq, pkt);
        } else if (pkt->stream_index == is->video_stream) {
            packet_queue_put(&is->videoq, pkt);
        } else if (pkt->stream_index == is->subtitle_stream) {
            packet_queue_put(&is->subtitleq, pkt);
        } else {
            av_free_packet(pkt);
        }
    }
    /* wait until the end */
    while (!is->abort_request) {
        SDL_Delay(100);
    }

    ret = 0;
 fail:
    /* disable interrupting */
    global_video_state = NULL;

    /* close each stream */
    if (is->audio_stream >= 0)
        stream_component_close(is, is->audio_stream);
    if (is->video_stream >= 0)
        stream_component_close(is, is->video_stream);
    if (is->subtitle_stream >= 0)
        stream_component_close(is, is->subtitle_stream);
    if (is->ic) {
        av_close_input_file(is->ic);
        is->ic = NULL; /* safety */
    }
    url_set_interrupt_cb(NULL);

    if (ret != 0) {
        SDL_Event event;

        event.type = FF_QUIT_EVENT;
        event.user.data1 = is;
        SDL_PushEvent(&event);
    }
    return 0;
}

static VideoState *stream_open(const char *filename, AVInputFormat *iformat)
{
    VideoState *is;

    is = av_mallocz(sizeof(VideoState));
    if (!is)
        return NULL;
    av_strlcpy(is->filename, filename, sizeof(is->filename));
    is->iformat = iformat;
    is->ytop = 0;
    is->xleft = 0;

    /* start video display */
    is->pictq_mutex = SDL_CreateMutex();
    is->pictq_cond = SDL_CreateCond();

    is->subpq_mutex = SDL_CreateMutex();
    is->subpq_cond = SDL_CreateCond();

    /* add the refresh timer to draw the picture */
    schedule_refresh(is, 40);

    is->av_sync_type = av_sync_type;
    is->parse_tid = SDL_CreateThread(decode_thread, is);
    if (!is->parse_tid) {
        av_free(is);
        return NULL;
    }
    return is;
}

static void stream_close(VideoState *is)
{
    VideoPicture *vp;
    int i;
    /* XXX: use a special url_shutdown call to abort parse cleanly */
    is->abort_request = 1;
    SDL_WaitThread(is->parse_tid, NULL);

    /* free all pictures */
    for(i=0;i<VIDEO_PICTURE_QUEUE_SIZE; i++) {
        vp = &is->pictq[i];
        if (vp->bmp) {
            SDL_FreeYUVOverlay(vp->bmp);
            vp->bmp = NULL;
        }
    }
    SDL_DestroyMutex(is->pictq_mutex);
    SDL_DestroyCond(is->pictq_cond);
    SDL_DestroyMutex(is->subpq_mutex);
    SDL_DestroyCond(is->subpq_cond);
}

static void stream_cycle_channel(VideoState *is, int codec_type)
{
    AVFormatContext *ic = is->ic;
    int start_index, stream_index;
    AVStream *st;

    if (codec_type == CODEC_TYPE_VIDEO)
        start_index = is->video_stream;
    else if (codec_type == CODEC_TYPE_AUDIO)
        start_index = is->audio_stream;
    else
        start_index = is->subtitle_stream;
    if (start_index < (codec_type == CODEC_TYPE_SUBTITLE ? -1 : 0))
        return;
    stream_index = start_index;
    for(;;) {
        if (++stream_index >= is->ic->nb_streams)
        {
            if (codec_type == CODEC_TYPE_SUBTITLE)
            {
                stream_index = -1;
                goto the_end;
            } else
                stream_index = 0;
        }
        if (stream_index == start_index)
            return;
        st = ic->streams[stream_index];
        if (st->codec->codec_type == codec_type) {
            /* check that parameters are OK */
            switch(codec_type) {
            case CODEC_TYPE_AUDIO:
                if (st->codec->sample_rate != 0 &&
                    st->codec->channels != 0)
                    goto the_end;
                break;
            case CODEC_TYPE_VIDEO:
            case CODEC_TYPE_SUBTITLE:
                goto the_end;
            default:
                break;
            }
        }
    }
 the_end:
    stream_component_close(is, start_index);
    stream_component_open(is, stream_index);
}


static void toggle_full_screen(void)
{
    is_full_screen = !is_full_screen;
    if (!fs_screen_width) {
        /* use default SDL method */
//        SDL_WM_ToggleFullScreen(screen);
    }
    video_open(cur_stream);
}

static void toggle_pause(void)
{
    if (cur_stream)
        stream_pause(cur_stream);
    step = 0;
}

static void step_to_next_frame(void)
{
    if (cur_stream) {
        /* if the stream is paused unpause it, then step */
        if (cur_stream->paused)
            stream_pause(cur_stream);
    }
    step = 1;
}

static void do_exit(void)
{
    if (cur_stream) {
        stream_close(cur_stream);
        cur_stream = NULL;
    }
    if (show_status)
        printf("\n");
    SDL_Quit();
    exit(0);
}

static void toggle_audio_display(void)
{
    if (cur_stream) {
        cur_stream->show_audio = !cur_stream->show_audio;
    }
}

/* handle an event sent by the GUI */
static void event_loop(void)
{
    SDL_Event event;
    double incr, pos, frac;

    for(;;) {
        SDL_WaitEvent(&event);
        switch(event.type) {
        case SDL_KEYDOWN:
            switch(event.key.keysym.sym) {
            case SDLK_ESCAPE:
            case SDLK_q:
                do_exit();
                break;
            case SDLK_f:
                toggle_full_screen();
                break;
            case SDLK_p:
            case SDLK_SPACE:
                toggle_pause();
                break;
            case SDLK_s: //S: Step to next frame
                step_to_next_frame();
                break;
            case SDLK_a:
                if (cur_stream)
                    stream_cycle_channel(cur_stream, CODEC_TYPE_AUDIO);
                break;
            case SDLK_v:
                if (cur_stream)
                    stream_cycle_channel(cur_stream, CODEC_TYPE_VIDEO);
                break;
            case SDLK_t:
                if (cur_stream)
                    stream_cycle_channel(cur_stream, CODEC_TYPE_SUBTITLE);
                break;
            case SDLK_w:
                toggle_audio_display();
                break;
            case SDLK_LEFT:
                incr = -10.0;
                goto do_seek;
            case SDLK_RIGHT:
                incr = 10.0;
                goto do_seek;
            case SDLK_UP:
                incr = 60.0;
                goto do_seek;
            case SDLK_DOWN:
                incr = -60.0;
            do_seek:
                if (cur_stream) {
                    if (seek_by_bytes) {
                        pos = url_ftell(cur_stream->ic->pb);
                        if (cur_stream->ic->bit_rate)
                            incr *= cur_stream->ic->bit_rate / 60.0;
                        else
                            incr *= 180000.0;
                        pos += incr;
                        stream_seek(cur_stream, pos, incr);
                    } else {
                        pos = get_master_clock(cur_stream);
                        pos += incr;
                        stream_seek(cur_stream, (int64_t)(pos * AV_TIME_BASE), incr);
                    }
                }
                break;
            default:
                break;
            }
            break;
        case SDL_MOUSEBUTTONDOWN:
            if (cur_stream) {
                int ns, hh, mm, ss;
                int tns, thh, tmm, tss;
                tns = cur_stream->ic->duration/1000000LL;
                thh = tns/3600;
                tmm = (tns%3600)/60;
                tss = (tns%60);
                frac = (double)event.button.x/(double)cur_stream->width;
                ns = frac*tns;
                hh = ns/3600;
                mm = (ns%3600)/60;
                ss = (ns%60);
                fprintf(stderr, "Seek to %2.0f%% (%2d:%02d:%02d) of total duration (%2d:%02d:%02d)       \n", frac*100,
                        hh, mm, ss, thh, tmm, tss);
                stream_seek(cur_stream, (int64_t)(cur_stream->ic->start_time+frac*cur_stream->ic->duration), 0);
            }
            break;
        case SDL_VIDEORESIZE:
            if (cur_stream) {
                screen = SDL_SetVideoMode(event.resize.w, event.resize.h, 0,
                                          SDL_HWSURFACE|SDL_RESIZABLE|SDL_ASYNCBLIT|SDL_HWACCEL);
                screen_width = cur_stream->width = event.resize.w;
                screen_height= cur_stream->height= event.resize.h;
            }
            break;
        case SDL_QUIT:
        case FF_QUIT_EVENT:
            do_exit();
            break;
        case FF_ALLOC_EVENT:
            video_open(event.user.data1);
            alloc_picture(event.user.data1);
            break;
        case FF_REFRESH_EVENT:
            video_refresh_timer(event.user.data1);
            break;
        default:
            break;
        }
    }
}

static void opt_frame_size(const char *arg)
{
    if (av_parse_video_frame_size(&frame_width, &frame_height, arg) < 0) {
        fprintf(stderr, "Incorrect frame size\n");
        exit(1);
    }
    if ((frame_width % 2) != 0 || (frame_height % 2) != 0) {
        fprintf(stderr, "Frame size must be a multiple of 2\n");
        exit(1);
    }
}

static int opt_width(const char *opt, const char *arg)
{
    screen_width = parse_number_or_die(opt, arg, OPT_INT64, 1, INT_MAX);
    return 0;
}

static int opt_height(const char *opt, const char *arg)
{
    screen_height = parse_number_or_die(opt, arg, OPT_INT64, 1, INT_MAX);
    return 0;
}

static void opt_format(const char *arg)
{
    file_iformat = av_find_input_format(arg);
    if (!file_iformat) {
        fprintf(stderr, "Unknown input format: %s\n", arg);
        exit(1);
    }
}

static void opt_frame_pix_fmt(const char *arg)
{
    frame_pix_fmt = avcodec_get_pix_fmt(arg);
}

static void opt_sync(const char *arg)
{
    if (!strcmp(arg, "audio"))
        av_sync_type = AV_SYNC_AUDIO_MASTER;
    else if (!strcmp(arg, "video"))
        av_sync_type = AV_SYNC_VIDEO_MASTER;
    else if (!strcmp(arg, "ext"))
        av_sync_type = AV_SYNC_EXTERNAL_CLOCK;
    else {
        show_help();
        exit(1);
    }
}

static int opt_seek(const char *opt, const char *arg)
{
    start_time = parse_time_or_die(opt, arg, 1);
    return 0;
}

static int opt_debug(const char *opt, const char *arg)
{
    av_log_set_level(99);
    debug = parse_number_or_die(opt, arg, OPT_INT64, 0, INT_MAX);
    return 0;
}

static int opt_vismv(const char *opt, const char *arg)
{
    debug_mv = parse_number_or_die(opt, arg, OPT_INT64, INT_MIN, INT_MAX);
    return 0;
}

static int opt_thread_count(const char *opt, const char *arg)
{
    thread_count= parse_number_or_die(opt, arg, OPT_INT64, 0, INT_MAX);
#if !defined(HAVE_THREADS)
    fprintf(stderr, "Warning: not compiled with thread support, using thread emulation\n");
#endif
    return 0;
}

static const OptionDef options[] = {
    { "h", OPT_EXIT, {(void*)show_help}, "show help" },
    { "version", OPT_EXIT, {(void*)show_version}, "show version" },
    { "L", OPT_EXIT, {(void*)show_license}, "show license" },
    { "formats", OPT_EXIT, {(void*)show_formats}, "show available formats, codecs, protocols, ..." },
    { "x", HAS_ARG | OPT_FUNC2, {(void*)opt_width}, "force displayed width", "width" },
    { "y", HAS_ARG | OPT_FUNC2, {(void*)opt_height}, "force displayed height", "height" },
    { "s", HAS_ARG | OPT_VIDEO, {(void*)opt_frame_size}, "set frame size (WxH or abbreviation)", "size" },
    { "fs", OPT_BOOL, {(void*)&is_full_screen}, "force full screen" },
    { "an", OPT_BOOL, {(void*)&audio_disable}, "disable audio" },
    { "vn", OPT_BOOL, {(void*)&video_disable}, "disable video" },
    { "ast", OPT_INT | HAS_ARG | OPT_EXPERT, {(void*)&wanted_audio_stream}, "", "" },
    { "vst", OPT_INT | HAS_ARG | OPT_EXPERT, {(void*)&wanted_video_stream}, "", "" },
    { "ss", HAS_ARG | OPT_FUNC2, {(void*)&opt_seek}, "seek to a given position in seconds", "pos" },
    { "bytes", OPT_BOOL, {(void*)&seek_by_bytes}, "seek by bytes" },
    { "nodisp", OPT_BOOL, {(void*)&display_disable}, "disable graphical display" },
    { "f", HAS_ARG, {(void*)opt_format}, "force format", "fmt" },
    { "pix_fmt", HAS_ARG | OPT_EXPERT | OPT_VIDEO, {(void*)opt_frame_pix_fmt}, "set pixel format", "format" },
    { "stats", OPT_BOOL | OPT_EXPERT, {(void*)&show_status}, "show status", "" },
    { "debug", HAS_ARG | OPT_FUNC2 | OPT_EXPERT, {(void*)opt_debug}, "print specific debug info", "" },
    { "bug", OPT_INT | HAS_ARG | OPT_EXPERT, {(void*)&workaround_bugs}, "workaround bugs", "" },
    { "vismv", HAS_ARG | OPT_FUNC2 | OPT_EXPERT, {(void*)opt_vismv}, "visualize motion vectors", "" },
    { "fast", OPT_BOOL | OPT_EXPERT, {(void*)&fast}, "non spec compliant optimizations", "" },
    { "genpts", OPT_BOOL | OPT_EXPERT, {(void*)&genpts}, "generate pts", "" },
    { "drp", OPT_BOOL |OPT_EXPERT, {(void*)&decoder_reorder_pts}, "let decoder reorder pts", ""},
    { "lowres", OPT_INT | HAS_ARG | OPT_EXPERT, {(void*)&lowres}, "", "" },
    { "skiploop", OPT_INT | HAS_ARG | OPT_EXPERT, {(void*)&skip_loop_filter}, "", "" },
    { "skipframe", OPT_INT | HAS_ARG | OPT_EXPERT, {(void*)&skip_frame}, "", "" },
    { "skipidct", OPT_INT | HAS_ARG | OPT_EXPERT, {(void*)&skip_idct}, "", "" },
    { "idct", OPT_INT | HAS_ARG | OPT_EXPERT, {(void*)&idct}, "set idct algo",  "algo" },
    { "er", OPT_INT | HAS_ARG | OPT_EXPERT, {(void*)&error_resilience}, "set error detection threshold (0-4)",  "threshold" },
    { "ec", OPT_INT | HAS_ARG | OPT_EXPERT, {(void*)&error_concealment}, "set error concealment options",  "bit_mask" },
    { "sync", HAS_ARG | OPT_EXPERT, {(void*)opt_sync}, "set audio-video sync. type (type=audio/video/ext)", "type" },
    { "threads", HAS_ARG | OPT_FUNC2 | OPT_EXPERT, {(void*)opt_thread_count}, "thread count", "count" },
    { NULL, },
};

static void show_help(void)
{
    printf("usage: ffplay [options] input_file\n"
           "Simple media player\n");
    printf("\n");
    show_help_options(options, "Main options:\n",
                      OPT_EXPERT, 0);
    show_help_options(options, "\nAdvanced options:\n",
                      OPT_EXPERT, OPT_EXPERT);
    printf("\nWhile playing:\n"
           "q, ESC              quit\n"
           "f                   toggle full screen\n"
           "p, SPC              pause\n"
           "a                   cycle audio channel\n"
           "v                   cycle video channel\n"
           "t                   cycle subtitle channel\n"
           "w                   show audio waves\n"
           "left/right          seek backward/forward 10 seconds\n"
           "down/up             seek backward/forward 1 minute\n"
           "mouse click         seek to percentage in file corresponding to fraction of width\n"
           );
}

static void opt_input_file(const char *filename)
{
    if (!strcmp(filename, "-"))
        filename = "pipe:";
    input_filename = filename;
}

/* Called from the main */
int main(int argc, char **argv)
{
    int flags;

    /* register all codecs, demux and protocols */
    avcodec_register_all();
    avdevice_register_all();
    av_register_all();

    show_banner(program_name, program_birth_year);

    parse_options(argc, argv, options, opt_input_file);

    if (!input_filename) {
        show_help();
        exit(1);
    }

    if (display_disable) {
        video_disable = 1;
    }
    flags = SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER;
#if !defined(__MINGW32__) && !defined(__APPLE__)
    flags |= SDL_INIT_EVENTTHREAD; /* Not supported on Windows or Mac OS X */
#endif
    if (SDL_Init (flags)) {
        fprintf(stderr, "Could not initialize SDL - %s\n", SDL_GetError());
        exit(1);
    }

    if (!display_disable) {
#ifdef HAVE_SDL_VIDEO_SIZE
        const SDL_VideoInfo *vi = SDL_GetVideoInfo();
        fs_screen_width = vi->current_w;
        fs_screen_height = vi->current_h;
#endif
    }

    SDL_EventState(SDL_ACTIVEEVENT, SDL_IGNORE);
    SDL_EventState(SDL_MOUSEMOTION, SDL_IGNORE);
    SDL_EventState(SDL_SYSWMEVENT, SDL_IGNORE);
    SDL_EventState(SDL_USEREVENT, SDL_IGNORE);

    av_init_packet(&flush_pkt);
    flush_pkt.data= "FLUSH";

    cur_stream = stream_open(input_filename, file_iformat);

    event_loop();

    /* never returns */

    return 0;
}