ffplay.c

    double pts;
    int hw_buf_size, bytes_per_sec;
    pts = is->audio_clock;
    hw_buf_size = audio_write_get_buf_size(is);
    bytes_per_sec = 0;
    if (is->audio_st) {
        bytes_per_sec = is->audio_st->codec->sample_rate *
            2 * is->audio_st->codec->channels;
    }
    if (bytes_per_sec)
        pts -= (double)hw_buf_size / bytes_per_sec;
    return pts;
}

/* get the current video clock value */
static double get_video_clock(VideoState *is)
{
    if (is->paused) {
        return is->video_current_pts;
    } else {
        return is->video_current_pts_drift + av_gettime() / 1000000.0;
    }
}

/* get the current external clock value */
static double get_external_clock(VideoState *is)
{
    int64_t ti;
    ti = av_gettime();
    return is->external_clock + ((ti - is->external_clock_time) * 1e-6);
}

/* get the current master clock value */
static double get_master_clock(VideoState *is)
{
    double val;

    if (is->av_sync_type == AV_SYNC_VIDEO_MASTER) {
        if (is->video_st)
            val = get_video_clock(is);
        else
            val = get_audio_clock(is);
    } else if (is->av_sync_type == AV_SYNC_AUDIO_MASTER) {
        if (is->audio_st)
            val = get_audio_clock(is);
        else
            val = get_video_clock(is);
    } else {
        val = get_external_clock(is);
    }
    return val;
}

/* seek in the stream */
static void stream_seek(VideoState *is, int64_t pos, int64_t rel, int seek_by_bytes)
{
    if (!is->seek_req) {
        is->seek_pos = pos;
        is->seek_rel = rel;
        is->seek_flags &= ~AVSEEK_FLAG_BYTE;
        if (seek_by_bytes)
            is->seek_flags |= AVSEEK_FLAG_BYTE;
        is->seek_req = 1;
    }
}

/* pause or resume the video */
static void stream_pause(VideoState *is)
{
    if (is->paused) {
        is->frame_timer += av_gettime() / 1000000.0 + is->video_current_pts_drift - is->video_current_pts;
        if(is->read_pause_return != AVERROR(ENOSYS)){
            is->video_current_pts = is->video_current_pts_drift + av_gettime() / 1000000.0;
        }
        is->video_current_pts_drift = is->video_current_pts - av_gettime() / 1000000.0;
    }
    is->paused = !is->paused;
}

static double compute_target_time(double frame_current_pts, VideoState *is)
{
    double delay, sync_threshold, diff;

    /* compute nominal delay */
    delay = frame_current_pts - is->frame_last_pts;
    if (delay <= 0 || delay >= 10.0) {
        /* if incorrect delay, use previous one */
        delay = is->frame_last_delay;
    } else {
        is->frame_last_delay = delay;
    }
    is->frame_last_pts = frame_current_pts;

    /* update delay to follow master synchronisation source */
    if (((is->av_sync_type == AV_SYNC_AUDIO_MASTER && is->audio_st) ||
         is->av_sync_type == AV_SYNC_EXTERNAL_CLOCK)) {
        /* if video is slave, we try to correct big delays by
           duplicating or deleting a frame */
        diff = get_video_clock(is) - get_master_clock(is);

        /* skip or repeat frame. We take into account the
           delay to compute the threshold. I still don't know
           if it is the best guess */
        sync_threshold = FFMAX(AV_SYNC_THRESHOLD, delay);
        if (fabs(diff) < AV_NOSYNC_THRESHOLD) {
            if (diff <= -sync_threshold)
                delay = 0;
            else if (diff >= sync_threshold)
                delay = 2 * delay;
        }
    }
    is->frame_timer += delay;
#if defined(DEBUG_SYNC)
    printf("video: delay=%0.3f actual_delay=%0.3f pts=%0.3f A-V=%f\n",
            delay, actual_delay, frame_current_pts, -diff);
#endif

    return is->frame_timer;
}

/* called to display each frame */
static void video_refresh_timer(void *opaque)
{
    VideoState *is = opaque;
    VideoPicture *vp;

    SubPicture *sp, *sp2;

    if (is->video_st) {
retry:
        if (is->pictq_size == 0) {
            //nothing to do, no picture to display in the que
        } else {
            double time= av_gettime()/1000000.0;
            double next_target;
            /* dequeue the picture */
            vp = &is->pictq[is->pictq_rindex];

            if(time < vp->target_clock)
                return;
            /* update current video pts */
            is->video_current_pts = vp->pts;
            is->video_current_pts_drift = is->video_current_pts - time;
            is->video_current_pos = vp->pos;
            if(is->pictq_size > 1){
                VideoPicture *nextvp= &is->pictq[(is->pictq_rindex+1)%VIDEO_PICTURE_QUEUE_SIZE];
                assert(nextvp->target_clock >= vp->target_clock);
                next_target= nextvp->target_clock;
            }else{
                next_target= vp->target_clock + is->video_clock - vp->pts; //FIXME pass durations cleanly
            }
            if(framedrop && time > next_target){
                is->skip_frames *= 1.0 + FRAME_SKIP_FACTOR;
                if(is->pictq_size > 1 || time > next_target + 0.5){
                    /* update queue size and signal for next picture */
                    if (++is->pictq_rindex == VIDEO_PICTURE_QUEUE_SIZE)
                        is->pictq_rindex = 0;

                    SDL_LockMutex(is->pictq_mutex);
                    is->pictq_size--;
                    SDL_CondSignal(is->pictq_cond);
                    SDL_UnlockMutex(is->pictq_mutex);
                    goto retry;
                }
            }

            if(is->subtitle_st) {
                if (is->subtitle_stream_changed) {
                    SDL_LockMutex(is->subpq_mutex);

                    while (is->subpq_size) {
                        free_subpicture(&is->subpq[is->subpq_rindex]);

                        /* update queue size and signal for next picture */
                        if (++is->subpq_rindex == SUBPICTURE_QUEUE_SIZE)
                            is->subpq_rindex = 0;

                        is->subpq_size--;
                    }
                    is->subtitle_stream_changed = 0;

                    SDL_CondSignal(is->subpq_cond);
                    SDL_UnlockMutex(is->subpq_mutex);
                } else {
                    if (is->subpq_size > 0) {
                        sp = &is->subpq[is->subpq_rindex];

                        if (is->subpq_size > 1)
                            sp2 = &is->subpq[(is->subpq_rindex + 1) % SUBPICTURE_QUEUE_SIZE];
                        else
                            sp2 = NULL;

                        if ((is->video_current_pts > (sp->pts + ((float) sp->sub.end_display_time / 1000)))
                                || (sp2 && is->video_current_pts > (sp2->pts + ((float) sp2->sub.start_display_time / 1000))))
                        {
                            free_subpicture(sp);

                            /* update queue size and signal for next picture */
                            if (++is->subpq_rindex == SUBPICTURE_QUEUE_SIZE)
                                is->subpq_rindex = 0;

                            SDL_LockMutex(is->subpq_mutex);
                            is->subpq_size--;
                            SDL_CondSignal(is->subpq_cond);
                            SDL_UnlockMutex(is->subpq_mutex);
                        }
                    }
                }
            }

            /* display picture */
            if (!display_disable)
                video_display(is);

            /* update queue size and signal for next picture */
            if (++is->pictq_rindex == VIDEO_PICTURE_QUEUE_SIZE)
                is->pictq_rindex = 0;

            SDL_LockMutex(is->pictq_mutex);
            is->pictq_size--;
            SDL_CondSignal(is->pictq_cond);
            SDL_UnlockMutex(is->pictq_mutex);
        }
    } else if (is->audio_st) {
        /* draw the next audio frame */

        /* if only audio stream, then display the audio bars (better
           than nothing, just to test the implementation */

        /* display picture */
        if (!display_disable)
            video_display(is);
    }
    if (show_status) {
        static int64_t last_time;
        int64_t cur_time;
        int aqsize, vqsize, sqsize;
        double av_diff;

        cur_time = av_gettime();
        if (!last_time || (cur_time - last_time) >= 30000) {
            aqsize = 0;
            vqsize = 0;
            sqsize = 0;
            if (is->audio_st)
                aqsize = is->audioq.size;
            if (is->video_st)
                vqsize = is->videoq.size;
            if (is->subtitle_st)
                sqsize = is->subtitleq.size;
            av_diff = 0;
            if (is->audio_st && is->video_st)
                av_diff = get_audio_clock(is) - get_video_clock(is);
            printf("%7.2f A-V:%7.3f s:%3.1f aq=%5dKB vq=%5dKB sq=%5dB f=%"PRId64"/%"PRId64"   \r",
                   get_master_clock(is), av_diff, FFMAX(is->skip_frames-1, 0), aqsize / 1024, vqsize / 1024, sqsize, is->pts_ctx.num_faulty_dts, is->pts_ctx.num_faulty_pts);
            fflush(stdout);
            last_time = cur_time;
        }
    }
}

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);
    SDL_WaitThread(is->refresh_tid, NULL);

    /* free all pictures */
    for(i=0;i<VIDEO_PICTURE_QUEUE_SIZE; i++) {
        vp = &is->pictq[i];
#if CONFIG_AVFILTER
        if (vp->picref) {
            avfilter_unref_buffer(vp->picref);
            vp->picref = NULL;
        }
#endif
        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);
#if !CONFIG_AVFILTER
    if (is->img_convert_ctx)
        sws_freeContext(is->img_convert_ctx);
#endif
    av_free(is);
}

static void do_exit(void)
{
    if (cur_stream) {
        stream_close(cur_stream);
        cur_stream = NULL;
    }
    uninit_opts();
#if CONFIG_AVFILTER
    avfilter_uninit();
#endif
    if (show_status)
        printf("\n");
    SDL_Quit();
    av_log(NULL, AV_LOG_QUIET, "");
    exit(0);
}

/* allocate a picture (needs to do that in main thread to avoid
   potential locking problems */
static void alloc_picture(void *opaque)
{
    VideoState *is = opaque;
    VideoPicture *vp;

    vp = &is->pictq[is->pictq_windex];

    if (vp->bmp)
        SDL_FreeYUVOverlay(vp->bmp);

#if CONFIG_AVFILTER
    if (vp->picref)
        avfilter_unref_buffer(vp->picref);
    vp->picref = NULL;

    vp->width   = is->out_video_filter->inputs[0]->w;
    vp->height  = is->out_video_filter->inputs[0]->h;
    vp->pix_fmt = is->out_video_filter->inputs[0]->format;
#else
    vp->width   = is->video_st->codec->width;
    vp->height  = is->video_st->codec->height;
    vp->pix_fmt = is->video_st->codec->pix_fmt;
#endif

    vp->bmp = SDL_CreateYUVOverlay(vp->width, vp->height,
                                   SDL_YV12_OVERLAY,
                                   screen);
    if (!vp->bmp || vp->bmp->pitches[0] < vp->width) {
        /* SDL allocates a buffer smaller than requested if the video
         * overlay hardware is unable to support the requested size. */
        fprintf(stderr, "Error: the video system does not support an image\n"
                        "size of %dx%d pixels. Try using -lowres or -vf \"scale=w:h\"\n"
                        "to reduce the image size.\n", vp->width, vp->height );
        do_exit();
    }

    SDL_LockMutex(is->pictq_mutex);
    vp->allocated = 1;
    SDL_CondSignal(is->pictq_cond);
    SDL_UnlockMutex(is->pictq_mutex);
}

/**
 *
 * @param pts the dts of the pkt / pts of the frame and guessed if not known
 */
static int queue_picture(VideoState *is, AVFrame *src_frame, double pts, int64_t pos)
{
    VideoPicture *vp;
    int dst_pix_fmt;
#if CONFIG_AVFILTER
    AVPicture pict_src;
#endif
    /* wait until we have space to put a new picture */
    SDL_LockMutex(is->pictq_mutex);

    if(is->pictq_size>=VIDEO_PICTURE_QUEUE_SIZE && !is->refresh)
        is->skip_frames= FFMAX(1.0 - FRAME_SKIP_FACTOR, is->skip_frames * (1.0-FRAME_SKIP_FACTOR));

    while (is->pictq_size >= VIDEO_PICTURE_QUEUE_SIZE &&
           !is->videoq.abort_request) {
        SDL_CondWait(is->pictq_cond, is->pictq_mutex);
    }
    SDL_UnlockMutex(is->pictq_mutex);

    if (is->videoq.abort_request)
        return -1;

    vp = &is->pictq[is->pictq_windex];

    /* alloc or resize hardware picture buffer */
    if (!vp->bmp ||
#if CONFIG_AVFILTER
        vp->width  != is->out_video_filter->inputs[0]->w ||
        vp->height != is->out_video_filter->inputs[0]->h) {
#else
        vp->width != is->video_st->codec->width ||
        vp->height != is->video_st->codec->height) {
#endif
        SDL_Event event;

        vp->allocated = 0;

        /* the allocation must be done in the main thread to avoid
           locking problems */
        event.type = FF_ALLOC_EVENT;
        event.user.data1 = is;
        SDL_PushEvent(&event);

        /* wait until the picture is allocated */
        SDL_LockMutex(is->pictq_mutex);
        while (!vp->allocated && !is->videoq.abort_request) {
            SDL_CondWait(is->pictq_cond, is->pictq_mutex);
        }
        SDL_UnlockMutex(is->pictq_mutex);

        if (is->videoq.abort_request)
            return -1;
    }

    /* if the frame is not skipped, then display it */
    if (vp->bmp) {
        AVPicture pict;
#if CONFIG_AVFILTER
        if(vp->picref)
            avfilter_unref_buffer(vp->picref);
        vp->picref = src_frame->opaque;
#endif

        /* get a pointer on the bitmap */
        SDL_LockYUVOverlay (vp->bmp);

        dst_pix_fmt = PIX_FMT_YUV420P;
        memset(&pict,0,sizeof(AVPicture));
        pict.data[0] = vp->bmp->pixels[0];
        pict.data[1] = vp->bmp->pixels[2];
        pict.data[2] = vp->bmp->pixels[1];

        pict.linesize[0] = vp->bmp->pitches[0];
        pict.linesize[1] = vp->bmp->pitches[2];
        pict.linesize[2] = vp->bmp->pitches[1];

#if CONFIG_AVFILTER
        pict_src.data[0] = src_frame->data[0];
        pict_src.data[1] = src_frame->data[1];
        pict_src.data[2] = src_frame->data[2];

        pict_src.linesize[0] = src_frame->linesize[0];
        pict_src.linesize[1] = src_frame->linesize[1];
        pict_src.linesize[2] = src_frame->linesize[2];

        //FIXME use direct rendering
        av_picture_copy(&pict, &pict_src,
                        vp->pix_fmt, vp->width, vp->height);
#else
        sws_flags = av_get_int(sws_opts, "sws_flags", NULL);
        is->img_convert_ctx = sws_getCachedContext(is->img_convert_ctx,
            vp->width, vp->height, vp->pix_fmt, vp->width, vp->height,
            dst_pix_fmt, sws_flags, NULL, NULL, NULL);
        if (is->img_convert_ctx == NULL) {
            fprintf(stderr, "Cannot initialize the conversion context\n");
            exit(1);
        }
        sws_scale(is->img_convert_ctx, src_frame->data, src_frame->linesize,
                  0, vp->height, pict.data, pict.linesize);
#endif
        /* update the bitmap content */
        SDL_UnlockYUVOverlay(vp->bmp);

        vp->pts = pts;
        vp->pos = pos;

        /* now we can update the picture count */
        if (++is->pictq_windex == VIDEO_PICTURE_QUEUE_SIZE)
            is->pictq_windex = 0;
        SDL_LockMutex(is->pictq_mutex);
        vp->target_clock= compute_target_time(vp->pts, is);

        is->pictq_size++;
        SDL_UnlockMutex(is->pictq_mutex);
    }
    return 0;
}

/**
 * compute the exact PTS for the picture if it is omitted in the stream
 * @param pts1 the dts of the pkt / pts of the frame
 */
static int output_picture2(VideoState *is, AVFrame *src_frame, double pts1, int64_t pos)
{
    double frame_delay, pts;

    pts = pts1;

    if (pts != 0) {
        /* update video clock with pts, if present */
        is->video_clock = pts;
    } else {
        pts = is->video_clock;
    }
    /* update video clock for next frame */
    frame_delay = av_q2d(is->video_st->codec->time_base);
    /* for MPEG2, the frame can be repeated, so we update the
       clock accordingly */
    frame_delay += src_frame->repeat_pict * (frame_delay * 0.5);
    is->video_clock += frame_delay;

#if defined(DEBUG_SYNC) && 0
    printf("frame_type=%c clock=%0.3f pts=%0.3f\n",
           av_get_pict_type_char(src_frame->pict_type), pts, pts1);
#endif
    return queue_picture(is, src_frame, pts, pos);
}

static int get_video_frame(VideoState *is, AVFrame *frame, int64_t *pts, AVPacket *pkt)
{
    int len1, got_picture, i;

    if (packet_queue_get(&is->videoq, pkt, 1) < 0)
        return -1;

    if (pkt->data == flush_pkt.data) {
        avcodec_flush_buffers(is->video_st->codec);

        SDL_LockMutex(is->pictq_mutex);
        //Make sure there are no long delay timers (ideally we should just flush the que but thats harder)
        for (i = 0; i < VIDEO_PICTURE_QUEUE_SIZE; i++) {
            is->pictq[i].target_clock= 0;
        }
        while (is->pictq_size && !is->videoq.abort_request) {
            SDL_CondWait(is->pictq_cond, is->pictq_mutex);
        }
        is->video_current_pos = -1;
        SDL_UnlockMutex(is->pictq_mutex);

        init_pts_correction(&is->pts_ctx);
        is->frame_last_pts = AV_NOPTS_VALUE;
        is->frame_last_delay = 0;
        is->frame_timer = (double)av_gettime() / 1000000.0;
        is->skip_frames = 1;
        is->skip_frames_index = 0;
        return 0;
    }

    len1 = avcodec_decode_video2(is->video_st->codec,
                                 frame, &got_picture,
                                 pkt);

    if (got_picture) {
        if (decoder_reorder_pts == -1) {
            *pts = guess_correct_pts(&is->pts_ctx, frame->pkt_pts, frame->pkt_dts);
        } else if (decoder_reorder_pts) {
            *pts = frame->pkt_pts;
        } else {
            *pts = frame->pkt_dts;
        }

        if (*pts == AV_NOPTS_VALUE) {
            *pts = 0;
        }

        is->skip_frames_index += 1;
        if(is->skip_frames_index >= is->skip_frames){
            is->skip_frames_index -= FFMAX(is->skip_frames, 1.0);
            return 1;
        }

    }
    return 0;
}

#if CONFIG_AVFILTER
typedef struct {
    VideoState *is;
    AVFrame *frame;
    int use_dr1;
} FilterPriv;

static int input_get_buffer(AVCodecContext *codec, AVFrame *pic)
{
    AVFilterContext *ctx = codec->opaque;
    AVFilterBufferRef  *ref;
    int perms = AV_PERM_WRITE;
    int i, w, h, stride[4];
    unsigned edge;

    if (codec->codec->capabilities & CODEC_CAP_NEG_LINESIZES)
        perms |= AV_PERM_NEG_LINESIZES;

    if(pic->buffer_hints & FF_BUFFER_HINTS_VALID) {
        if(pic->buffer_hints & FF_BUFFER_HINTS_READABLE) perms |= AV_PERM_READ;
        if(pic->buffer_hints & FF_BUFFER_HINTS_PRESERVE) perms |= AV_PERM_PRESERVE;
        if(pic->buffer_hints & FF_BUFFER_HINTS_REUSABLE) perms |= AV_PERM_REUSE2;
    }
    if(pic->reference) perms |= AV_PERM_READ | AV_PERM_PRESERVE;

    w = codec->width;
    h = codec->height;
    avcodec_align_dimensions2(codec, &w, &h, stride);
    edge = codec->flags & CODEC_FLAG_EMU_EDGE ? 0 : avcodec_get_edge_width();
    w += edge << 1;
    h += edge << 1;

    if(!(ref = avfilter_get_video_buffer(ctx->outputs[0], perms, w, h)))
        return -1;

    ref->video->w = codec->width;
    ref->video->h = codec->height;
    for(i = 0; i < 4; i ++) {
        unsigned hshift = (i == 1 || i == 2) ? av_pix_fmt_descriptors[ref->format].log2_chroma_w : 0;
        unsigned vshift = (i == 1 || i == 2) ? av_pix_fmt_descriptors[ref->format].log2_chroma_h : 0;

        if (ref->data[i]) {
            ref->data[i]    += (edge >> hshift) + ((edge * ref->linesize[i]) >> vshift);
        }
        pic->data[i]     = ref->data[i];
        pic->linesize[i] = ref->linesize[i];
    }
    pic->opaque = ref;
    pic->age    = INT_MAX;
    pic->type   = FF_BUFFER_TYPE_USER;
    pic->reordered_opaque = codec->reordered_opaque;
    if(codec->pkt) pic->pkt_pts = codec->pkt->pts;
    else           pic->pkt_pts = AV_NOPTS_VALUE;
    return 0;
}

static void input_release_buffer(AVCodecContext *codec, AVFrame *pic)
{
    memset(pic->data, 0, sizeof(pic->data));
    avfilter_unref_buffer(pic->opaque);
}

static int input_reget_buffer(AVCodecContext *codec, AVFrame *pic)
{
    AVFilterBufferRef *ref = pic->opaque;

    if (pic->data[0] == NULL) {
        pic->buffer_hints |= FF_BUFFER_HINTS_READABLE;
        return codec->get_buffer(codec, pic);
    }

    if ((codec->width != ref->video->w) || (codec->height != ref->video->h) ||
        (codec->pix_fmt != ref->format)) {
        av_log(codec, AV_LOG_ERROR, "Picture properties changed.\n");
        return -1;
    }

    pic->reordered_opaque = codec->reordered_opaque;
    if(codec->pkt) pic->pkt_pts = codec->pkt->pts;
    else           pic->pkt_pts = AV_NOPTS_VALUE;
    return 0;
}

static int input_init(AVFilterContext *ctx, const char *args, void *opaque)
{
    FilterPriv *priv = ctx->priv;
    AVCodecContext *codec;
    if(!opaque) return -1;

    priv->is = opaque;
    codec    = priv->is->video_st->codec;
    codec->opaque = ctx;
    if(codec->codec->capabilities & CODEC_CAP_DR1) {
        priv->use_dr1 = 1;
        codec->get_buffer     = input_get_buffer;
        codec->release_buffer = input_release_buffer;
        codec->reget_buffer   = input_reget_buffer;
        codec->thread_safe_callbacks = 1;
    }

    priv->frame = avcodec_alloc_frame();

    return 0;
}

static void input_uninit(AVFilterContext *ctx)
{
    FilterPriv *priv = ctx->priv;
    av_free(priv->frame);
}

static int input_request_frame(AVFilterLink *link)
{
    FilterPriv *priv = link->src->priv;
    AVFilterBufferRef *picref;
    int64_t pts = 0;
    AVPacket pkt;
    int ret;

    while (!(ret = get_video_frame(priv->is, priv->frame, &pts, &pkt)))
        av_free_packet(&pkt);
    if (ret < 0)
        return -1;

    if(priv->use_dr1) {
        picref = avfilter_ref_buffer(priv->frame->opaque, ~0);
    } else {
        picref = avfilter_get_video_buffer(link, AV_PERM_WRITE, link->w, link->h);
        av_image_copy(picref->data, picref->linesize,
                      priv->frame->data, priv->frame->linesize,
                      picref->format, link->w, link->h);
    }
    av_free_packet(&pkt);

    picref->pts = pts;
    picref->pos = pkt.pos;
    picref->video->pixel_aspect = priv->is->video_st->codec->sample_aspect_ratio;
    avfilter_start_frame(link, picref);
    avfilter_draw_slice(link, 0, link->h, 1);
    avfilter_end_frame(link);

    return 0;
}

static int input_query_formats(AVFilterContext *ctx)
{
    FilterPriv *priv = ctx->priv;
    enum PixelFormat pix_fmts[] = {
        priv->is->video_st->codec->pix_fmt, PIX_FMT_NONE
    };

    avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts));
    return 0;
}

static int input_config_props(AVFilterLink *link)
{
    FilterPriv *priv  = link->src->priv;
    AVCodecContext *c = priv->is->video_st->codec;

    link->w = c->width;
    link->h = c->height;
    link->time_base = priv->is->video_st->time_base;

    return 0;
}

static AVFilter input_filter =
{
    .name      = "ffplay_input",

    .priv_size = sizeof(FilterPriv),

    .init      = input_init,
    .uninit    = input_uninit,

    .query_formats = input_query_formats,

    .inputs    = (AVFilterPad[]) {{ .name = NULL }},
    .outputs   = (AVFilterPad[]) {{ .name = "default",
                                    .type = AVMEDIA_TYPE_VIDEO,
                                    .request_frame = input_request_frame,
                                    .config_props  = input_config_props, },
                                  { .name = NULL }},
};

static int configure_video_filters(AVFilterGraph *graph, VideoState *is, const char *vfilters)
{
    char sws_flags_str[128];
    int ret;
    FFSinkContext ffsink_ctx = { .pix_fmt = PIX_FMT_YUV420P };
    AVFilterContext *filt_src = NULL, *filt_out = NULL;
    snprintf(sws_flags_str, sizeof(sws_flags_str), "flags=%d", sws_flags);
    graph->scale_sws_opts = av_strdup(sws_flags_str);

    if ((ret = avfilter_graph_create_filter(&filt_src, &input_filter, "src",
                                            NULL, is, graph)) < 0)
        goto the_end;
    if ((ret = avfilter_graph_create_filter(&filt_out, &ffsink, "out",
                                            NULL, &ffsink_ctx, graph)) < 0)
        goto the_end;

    if(vfilters) {
        AVFilterInOut *outputs = av_malloc(sizeof(AVFilterInOut));
        AVFilterInOut *inputs  = av_malloc(sizeof(AVFilterInOut));

        outputs->name    = av_strdup("in");
        outputs->filter_ctx = filt_src;
        outputs->pad_idx = 0;
        outputs->next    = NULL;

        inputs->name    = av_strdup("out");
        inputs->filter_ctx = filt_out;
        inputs->pad_idx = 0;
        inputs->next    = NULL;

        if ((ret = avfilter_graph_parse(graph, vfilters, inputs, outputs, NULL)) < 0)
            goto the_end;
        av_freep(&vfilters);
    } else {
        if ((ret = avfilter_link(filt_src, 0, filt_out, 0)) < 0)
            goto the_end;
    }

    if ((ret = avfilter_graph_config(graph, NULL)) < 0)
        goto the_end;

    is->out_video_filter = filt_out;
the_end:
    return ret;
}

#endif  /* CONFIG_AVFILTER */

static int video_thread(void *arg)
{
    VideoState *is = arg;
    AVFrame *frame= avcodec_alloc_frame();
    int64_t pts_int;
    double pts;
    int ret;

#if CONFIG_AVFILTER
    AVFilterGraph *graph = avfilter_graph_alloc();
    AVFilterContext *filt_out = NULL;
    int64_t pos;

    if ((ret = configure_video_filters(graph, is, vfilters)) < 0)
        goto the_end;
    filt_out = is->out_video_filter;
#endif

    for(;;) {
#if !CONFIG_AVFILTER
        AVPacket pkt;
#else
        AVFilterBufferRef *picref;
        AVRational tb;
#endif
        while (is->paused && !is->videoq.abort_request)
            SDL_Delay(10);
#if CONFIG_AVFILTER
        ret = get_filtered_video_frame(filt_out, frame, &picref, &tb);
        if (picref) {
            pts_int = picref->pts;
            pos     = picref->pos;
            frame->opaque = picref;
        }

        if (av_cmp_q(tb, is->video_st->time_base)) {
            av_unused int64_t pts1 = pts_int;
            pts_int = av_rescale_q(pts_int, tb, is->video_st->time_base);
            av_dlog(NULL, "video_thread(): "
                    "tb:%d/%d pts:%"PRId64" -> tb:%d/%d pts:%"PRId64"\n",
                    tb.num, tb.den, pts1,
                    is->video_st->time_base.num, is->video_st->time_base.den, pts_int);
        }
#else
        ret = get_video_frame(is, frame, &pts_int, &pkt);
#endif

        if (ret < 0) goto the_end;

        if (!ret)
            continue;

        pts = pts_int*av_q2d(is->video_st->time_base);

#if CONFIG_AVFILTER
        ret = output_picture2(is, frame, pts, pos);
#else
        ret = output_picture2(is, frame, pts,  pkt.pos);
        av_free_packet(&pkt);
#endif
        if (ret < 0)
            goto the_end;

        if (step)
            if (cur_stream)
                stream_pause(cur_stream);
    }
 the_end:
#if CONFIG_AVFILTER
    avfilter_graph_free(&graph);
#endif
    av_free(frame);
    return 0;
}

static int subtitle_thread(void *arg)
{
    VideoState *is = arg;
    SubPicture *sp;
    AVPacket pkt1, *pkt = &pkt1;
    int len1, got_subtitle;
    double pts;
    int i, j;
    int r, g, b, y, u, v, a;

    for(;;) {
        while (is->paused && !is->subtitleq.abort_request) {
            SDL_Delay(10);
        }
        if (packet_queue_get(&is->subtitleq, pkt, 1) < 0)
            break;

        if(pkt->data == flush_pkt.data){
            avcodec_flush_buffers(is->subtitle_st->codec);
            continue;
        }
        SDL_LockMutex(is->subpq_mutex);
        while (is->subpq_size >= SUBPICTURE_QUEUE_SIZE &&
               !is->subtitleq.abort_request) {
            SDL_CondWait(is->subpq_cond, is->subpq_mutex);
        }
        SDL_UnlockMutex(is->subpq_mutex);

        if (is->subtitleq.abort_request)
            goto the_end;

        sp = &is->subpq[is->subpq_windex];

       /* NOTE: ipts is the PTS of the _first_ picture beginning in
           this packet, if any */
        pts = 0;
        if (pkt->pts != AV_NOPTS_VALUE)
            pts = av_q2d(is->subtitle_st->time_base)*pkt->pts;

        len1 = avcodec_decode_subtitle2(is->subtitle_st->codec,
                                    &sp->sub, &got_subtitle,
                                    pkt);
//            if (len1 < 0)
//                break;
        if (got_subtitle && sp->sub.format == 0) {
            sp->pts = pts;

            for (i = 0; i < sp->sub.num_rects; i++)
            {
                for (j = 0; j < sp->sub.rects[i]->nb_colors; j++)
                {
                    RGBA_IN(r, g, b, a, (uint32_t*)sp->sub.rects[i]->pict.data[1] + j);
                    y = RGB_TO_Y_CCIR(r, g, b);
                    u = RGB_TO_U_CCIR(r, g, b, 0);
                    v = RGB_TO_V_CCIR(r, g, b, 0);
                    YUVA_OUT((uint32_t*)sp->sub.rects[i]->pict.data[1] + j, y, u, v, a);
                }
            }

            /* now we can update the picture count */
            if (++is->subpq_windex == SUBPICTURE_QUEUE_SIZE)
                is->subpq_windex = 0;
            SDL_LockMutex(is->subpq_mutex);
            is->subpq_size++;
            SDL_UnlockMutex(is->subpq_mutex);
        }
        av_free_packet(pkt);
//        if (step)
//            if (cur_stream)
//                stream_pause(cur_stream);
    }
 the_end:
    return 0;
}

/* copy samples for viewing in editor window */
static void update_sample_display(VideoState *is, short *samples, int samples_size)
{
    int size, len, channels;

    channels = is->audio_st->codec->channels;

    size = samples_size / sizeof(short);
    while (size > 0) {
        len = SAMPLE_ARRAY_SIZE - is->sample_array_index;
        if (len > size)
            len = size;
        memcpy(is->sample_array + is->sample_array_index, samples, len * sizeof(short));
        samples += len;
        is->sample_array_index += len;
        if (is->sample_array_index >= SAMPLE_ARRAY_SIZE)
            is->sample_array_index = 0;
        size -= len;
    }
}

/* return the new audio buffer size (samples can be added or deleted
   to get better sync if video or external master clock) */
static int synchronize_audio(VideoState *is, short *samples,
                             int samples_size1, double pts)
{
    int n, samples_size;
    double ref_clock;

    n = 2 * is->audio_st->codec->channels;
    samples_size = samples_size1;

    /* if not master, then we try to remove or add samples to correct the clock */
    if (((is->av_sync_type == AV_SYNC_VIDEO_MASTER && is->video_st) ||
         is->av_sync_type == AV_SYNC_EXTERNAL_CLOCK)) {
        double diff, avg_diff;
        int wanted_size, min_size, max_size, nb_samples;

        ref_clock = get_master_clock(is);
        diff = get_audio_clock(is) - ref_clock;

        if (diff < AV_NOSYNC_THRESHOLD) {
            is->audio_diff_cum = diff + is->audio_diff_avg_coef * is->audio_diff_cum;
            if (is->audio_diff_avg_count < AUDIO_DIFF_AVG_NB) {
                /* not enough measures to have a correct estimate */
                is->audio_diff_avg_count++;
            } else {
                /* estimate the A-V difference */
                avg_diff = is->audio_diff_cum * (1.0 - is->audio_diff_avg_coef);

                if (fabs(avg_diff) >= is->audio_diff_threshold) {