ffplay.c

ffmpeg源码分析

        fprintf(stderr, "Year: %d\n", s->year);
    if (s->genre[0] != '\0')
        fprintf(stderr, "Genre: %s\n", s->genre);
}

/* since we have only one decoding thread, we can use a global
   variable instead of a thread local variable */
static VideoState *global_video_state;

static int decode_interrupt_cb(void)
{
    return (global_video_state && global_video_state->abort_request);
}

/* this thread gets the stream from the disk or the network */
static int decode_thread(void *arg)
{
    VideoState *is = arg;
    AVFormatContext *ic;
    int err, i, ret, video_index, audio_index, use_play;
    AVPacket pkt1, *pkt = &pkt1;
    AVFormatParameters params, *ap = &params;

    video_index = -1;
    audio_index = -1;
    is->video_stream = -1;
    is->audio_stream = -1;
    is->subtitle_stream = -1;

    global_video_state = is;
    url_set_interrupt_cb(decode_interrupt_cb);

    memset(ap, 0, sizeof(*ap));
    ap->image_format = image_format;
    ap->initial_pause = 1; /* we force a pause when starting an RTSP
                              stream */

    err = av_open_input_file(&ic, is->filename, is->iformat, 0, ap);
    if (err < 0) {
        print_error(is->filename, err);
        ret = -1;
        goto fail;
    }
    is->ic = ic;
#ifdef CONFIG_NETWORK
    use_play = (ic->iformat == &rtsp_demux);
#else
    use_play = 0;
#endif

    if(genpts)
        ic->flags |= AVFMT_FLAG_GENPTS;

    if (!use_play) {
        err = av_find_stream_info(ic);
        if (err < 0) {
            fprintf(stderr, "%s: could not find codec parameters\n", is->filename);
            ret = -1;
            goto fail;
        }
        ic->pb.eof_reached= 0; //FIXME hack, ffplay maybe shouldnt use url_feof() to test for the end
    }

    /* if seeking requested, we execute it */
    if (start_time != AV_NOPTS_VALUE) {
        int64_t timestamp;

        timestamp = start_time;
        /* add the stream start time */
        if (ic->start_time != AV_NOPTS_VALUE)
            timestamp += ic->start_time;
        ret = av_seek_frame(ic, -1, timestamp, AVSEEK_FLAG_BACKWARD);
        if (ret < 0) {
            fprintf(stderr, "%s: could not seek to position %0.3f\n",
                    is->filename, (double)timestamp / AV_TIME_BASE);
        }
    }

    /* now we can begin to play (RTSP stream only) */
    av_read_play(ic);

    if (use_play) {
        err = av_find_stream_info(ic);
        if (err < 0) {
            fprintf(stderr, "%s: could not find codec parameters\n", is->filename);
            ret = -1;
            goto fail;
        }
    }

    for(i = 0; i < ic->nb_streams; i++) {
        AVCodecContext *enc = ic->streams[i]->codec;
        switch(enc->codec_type) {
        case CODEC_TYPE_AUDIO:
            if (audio_index < 0 && !audio_disable)
                audio_index = i;
            break;
        case CODEC_TYPE_VIDEO:
            if (video_index < 0 && !video_disable)
                video_index = i;
            break;
        default:
            break;
        }
    }
    if (show_status) {
        dump_format(ic, 0, is->filename, 0);
        dump_stream_info(ic);
    }

    /* open the streams */
    if (audio_index >= 0) {
        stream_component_open(is, audio_index);
    }

    if (video_index >= 0) {
        stream_component_open(is, video_index);
    } else {
        if (!display_disable)
            is->show_audio = 1;
    }

    if (is->video_stream < 0 && is->audio_stream < 0) {
        fprintf(stderr, "%s: could not open codecs\n", is->filename);
        ret = -1;
        goto fail;
    }

    for(;;) {
        if (is->abort_request)
            break;
#ifdef CONFIG_NETWORK
        if (is->paused != is->last_paused) {
            is->last_paused = is->paused;
            if (is->paused)
                av_read_pause(ic);
            else
                av_read_play(ic);
        }
        if (is->paused && ic->iformat == &rtsp_demux) {
            /* wait 10 ms to avoid trying to get another packet */
            /* XXX: horrible */
            SDL_Delay(10);
            continue;
        }
#endif
        if (is->seek_req) {
            /* XXX: must lock decoder threads */
            SDL_LockMutex(is->video_decoder_mutex);
            SDL_LockMutex(is->audio_decoder_mutex);
            SDL_LockMutex(is->subtitle_decoder_mutex);
            ret = av_seek_frame(is->ic, -1, is->seek_pos, 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);
                }
                if (is->subtitle_stream >= 0) {
                    packet_queue_flush(&is->subtitleq);
                }
                if (is->video_stream >= 0) {
                    packet_queue_flush(&is->videoq);
                    avcodec_flush_buffers(ic->streams[video_index]->codec);
                }
            }
            SDL_UnlockMutex(is->subtitle_decoder_mutex);
            SDL_UnlockMutex(is->audio_decoder_mutex);
            SDL_UnlockMutex(is->video_decoder_mutex);
            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;
    pstrcpy(is->filename, sizeof(is->filename), filename);
    is->iformat = iformat;
    if (screen) {
        is->width = screen->w;
        is->height = screen->h;
    }
    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();

    is->subtitle_decoder_mutex = SDL_CreateMutex();
    is->audio_decoder_mutex = SDL_CreateMutex();
    is->video_decoder_mutex = SDL_CreateMutex();

    /* 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);
    SDL_DestroyMutex(is->subtitle_decoder_mutex);
    SDL_DestroyMutex(is->audio_decoder_mutex);
    SDL_DestroyMutex(is->video_decoder_mutex);
}

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);
}


void toggle_full_screen(void)
{
    int w, h, flags;
    is_full_screen = !is_full_screen;
    if (!fs_screen_width) {
        /* use default SDL method */
        SDL_WM_ToggleFullScreen(screen);
    } else {
        /* use the recorded resolution */
        flags = SDL_HWSURFACE|SDL_ASYNCBLIT|SDL_HWACCEL;
        if (is_full_screen) {
            w = fs_screen_width;
            h = fs_screen_height;
            flags |= SDL_FULLSCREEN;
        } else {
            w = screen_width;
            h = screen_height;
            flags |= SDL_RESIZABLE;
        }
        screen = SDL_SetVideoMode(w, h, 0, flags);
        cur_stream->width = w;
        cur_stream->height = h;
    }
}

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

void step_to_next_frame(void)
{
    if (cur_stream) {
        if (cur_stream->paused)
            cur_stream->paused=0;
        cur_stream->video_current_pts = get_video_clock(cur_stream);
    }
    step = 1;
}

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

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

/* handle an event sent by the GUI */
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, CODE