ffplay.c

            cb[0] = ALPHA_BLEND(a1 >> 2, cb[0], u1, 1);
            cr[0] = ALPHA_BLEND(a1 >> 2, cr[0], v1, 1);
            cb++;
            cr++;
            p += -wrap3 + BPP;
            lum += -wrap + 1;
        }
        p += wrap3 + (wrap3 - dstw * BPP);
        lum += wrap + (wrap - dstw - dstx);
        cb += dst->linesize[1] - width2 - skip2;
        cr += dst->linesize[2] - width2 - skip2;
    }
    /* handle odd height */
    if (h) {
        lum += dstx;
        cb += skip2;
        cr += skip2;

        if (dstx & 1) {
            YUVA_IN(y, u, v, a, p, pal);
            lum[0] = ALPHA_BLEND(a, lum[0], y, 0);
            cb[0] = ALPHA_BLEND(a >> 2, cb[0], u, 0);
            cr[0] = ALPHA_BLEND(a >> 2, cr[0], v, 0);
            cb++;
            cr++;
            lum++;
            p += BPP;
        }
        for (w = dstw - (dstx & 1); w >= 2; w -= 2) {
            YUVA_IN(y, u, v, a, p, pal);
            u1 = u;
            v1 = v;
            a1 = a;
            lum[0] = ALPHA_BLEND(a, lum[0], y, 0);

            YUVA_IN(y, u, v, a, p + BPP, pal);
            u1 += u;
            v1 += v;
            a1 += a;
            lum[1] = ALPHA_BLEND(a, lum[1], y, 0);
            cb[0] = ALPHA_BLEND(a1 >> 2, cb[0], u, 1);
            cr[0] = ALPHA_BLEND(a1 >> 2, cr[0], v, 1);
            cb++;
            cr++;
            p += 2 * BPP;
            lum += 2;
        }
        if (w) {
            YUVA_IN(y, u, v, a, p, pal);
            lum[0] = ALPHA_BLEND(a, lum[0], y, 0);
            cb[0] = ALPHA_BLEND(a >> 2, cb[0], u, 0);
            cr[0] = ALPHA_BLEND(a >> 2, cr[0], v, 0);
        }
    }
}

static void free_picture(Frame *vp)
{
     if (vp->bmp) {
         SDL_FreeYUVOverlay(vp->bmp);
         vp->bmp = NULL;
     }
}

static void calculate_display_rect(SDL_Rect *rect,
                                   int scr_xleft, int scr_ytop, int scr_width, int scr_height,
                                   int pic_width, int pic_height, AVRational pic_sar)
{
    float aspect_ratio;
    int width, height, x, y;

    if (pic_sar.num == 0)
        aspect_ratio = 0;
    else
        aspect_ratio = av_q2d(pic_sar);

    if (aspect_ratio <= 0.0)
        aspect_ratio = 1.0;
    aspect_ratio *= (float)pic_width / (float)pic_height;

    /* XXX: we suppose the screen has a 1.0 pixel ratio */
    height = scr_height;
    width = ((int)rint(height * aspect_ratio)) & ~1;
    if (width > scr_width) {
        width = scr_width;
        height = ((int)rint(width / aspect_ratio)) & ~1;
    }
    x = (scr_width - width) / 2;
    y = (scr_height - height) / 2;
    rect->x = scr_xleft + x;
    rect->y = scr_ytop  + y;
    rect->w = FFMAX(width,  1);
    rect->h = FFMAX(height, 1);
}

static void video_image_display(VideoState *is)
{
    Frame *vp;
    Frame *sp;
    AVPicture pict;
    SDL_Rect rect;
    int i;

    vp = frame_queue_peek(&is->pictq);
    if (vp->bmp) {
        if (is->subtitle_st) {
            if (frame_queue_nb_remaining(&is->subpq) > 0) {
                sp = frame_queue_peek(&is->subpq);

                if (vp->pts >= sp->pts + ((float) sp->sub.start_display_time / 1000)) {
                    SDL_LockYUVOverlay (vp->bmp);

                    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];

                    for (i = 0; i < sp->sub.num_rects; i++)
                        blend_subrect(&pict, sp->sub.rects[i],
                                      vp->bmp->w, vp->bmp->h);

                    SDL_UnlockYUVOverlay (vp->bmp);
                }
            }
        }

        calculate_display_rect(&rect, is->xleft, is->ytop, is->width, is->height, vp->width, vp->height, vp->sar);

        SDL_DisplayYUVOverlay(vp->bmp, &rect);

        if (rect.x != is->last_display_rect.x || rect.y != is->last_display_rect.y || rect.w != is->last_display_rect.w || rect.h != is->last_display_rect.h || is->force_refresh) {
            int bgcolor = SDL_MapRGB(screen->format, 0x00, 0x00, 0x00);
            fill_border(is->xleft, is->ytop, is->width, is->height, rect.x, rect.y, rect.w, rect.h, bgcolor, 1);
            is->last_display_rect = rect;
        }
    }
}

static inline int compute_mod(int a, int b)
{
    return a < 0 ? a%b + b : a%b;
}

static void video_audio_display(VideoState *s)
{
    int i, i_start, x, y1, y, ys, delay, n, nb_display_channels;
    int ch, channels, h, h2, bgcolor, fgcolor;
    int64_t time_diff;
    int rdft_bits, nb_freq;

    for (rdft_bits = 1; (1 << rdft_bits) < 2 * s->height; rdft_bits++)
        ;
    nb_freq = 1 << (rdft_bits - 1);

    /* compute display index : center on currently output samples */
    channels = s->audio_tgt.channels;
    nb_display_channels = channels;
    if (!s->paused) {
        int data_used= s->show_mode == SHOW_MODE_WAVES ? s->width : (2*nb_freq);
        n = 2 * channels;
        delay = s->audio_write_buf_size;
        delay /= n;

        /* to be more precise, we take into account the time spent since
           the last buffer computation */
        if (audio_callback_time) {
            time_diff = av_gettime_relative() - audio_callback_time;
            delay -= (time_diff * s->audio_tgt.freq) / 1000000;
        }

        delay += 2 * data_used;
        if (delay < data_used)
            delay = data_used;

        i_start= x = compute_mod(s->sample_array_index - delay * channels, SAMPLE_ARRAY_SIZE);
        if (s->show_mode == SHOW_MODE_WAVES) {
            h = INT_MIN;
            for (i = 0; i < 1000; i += channels) {
                int idx = (SAMPLE_ARRAY_SIZE + x - i) % SAMPLE_ARRAY_SIZE;
                int a = s->sample_array[idx];
                int b = s->sample_array[(idx + 4 * channels) % SAMPLE_ARRAY_SIZE];
                int c = s->sample_array[(idx + 5 * channels) % SAMPLE_ARRAY_SIZE];
                int d = s->sample_array[(idx + 9 * channels) % SAMPLE_ARRAY_SIZE];
                int score = a - d;
                if (h < score && (b ^ c) < 0) {
                    h = score;
                    i_start = idx;
                }
            }
        }

        s->last_i_start = i_start;
    } else {
        i_start = s->last_i_start;
    }

    bgcolor = SDL_MapRGB(screen->format, 0x00, 0x00, 0x00);
    if (s->show_mode == SHOW_MODE_WAVES) {
        fill_rectangle(screen,
                       s->xleft, s->ytop, s->width, s->height,
                       bgcolor, 0);

        fgcolor = SDL_MapRGB(screen->format, 0xff, 0xff, 0xff);

        /* total height for one channel */
        h = s->height / nb_display_channels;
        /* graph height / 2 */
        h2 = (h * 9) / 20;
        for (ch = 0; ch < nb_display_channels; ch++) {
            i = i_start + ch;
            y1 = s->ytop + ch * h + (h / 2); /* position of center line */
            for (x = 0; x < s->width; x++) {
                y = (s->sample_array[i] * h2) >> 15;
                if (y < 0) {
                    y = -y;
                    ys = y1 - y;
                } else {
                    ys = y1;
                }
                fill_rectangle(screen,
                               s->xleft + x, ys, 1, y,
                               fgcolor, 0);
                i += channels;
                if (i >= SAMPLE_ARRAY_SIZE)
                    i -= SAMPLE_ARRAY_SIZE;
            }
        }

        fgcolor = SDL_MapRGB(screen->format, 0x00, 0x00, 0xff);

        for (ch = 1; ch < nb_display_channels; ch++) {
            y = s->ytop + ch * h;
            fill_rectangle(screen,
                           s->xleft, y, s->width, 1,
                           fgcolor, 0);
        }
        SDL_UpdateRect(screen, s->xleft, s->ytop, s->width, s->height);
    } else {
        nb_display_channels= FFMIN(nb_display_channels, 2);
        if (rdft_bits != s->rdft_bits) {
            av_rdft_end(s->rdft);
            av_free(s->rdft_data);
            s->rdft = av_rdft_init(rdft_bits, DFT_R2C);
            s->rdft_bits = rdft_bits;
            s->rdft_data = av_malloc_array(nb_freq, 4 *sizeof(*s->rdft_data));
        }
        if (!s->rdft || !s->rdft_data){
            av_log(NULL, AV_LOG_ERROR, "Failed to allocate buffers for RDFT, switching to waves display\n");
            s->show_mode = SHOW_MODE_WAVES;
        } else {
            FFTSample *data[2];
            for (ch = 0; ch < nb_display_channels; ch++) {
                data[ch] = s->rdft_data + 2 * nb_freq * ch;
                i = i_start + ch;
                for (x = 0; x < 2 * nb_freq; x++) {
                    double w = (x-nb_freq) * (1.0 / nb_freq);
                    data[ch][x] = s->sample_array[i] * (1.0 - w * w);
                    i += channels;
                    if (i >= SAMPLE_ARRAY_SIZE)
                        i -= SAMPLE_ARRAY_SIZE;
                }
                av_rdft_calc(s->rdft, data[ch]);
            }
            /* Least efficient way to do this, we should of course
             * directly access it but it is more than fast enough. */
            for (y = 0; y < s->height; y++) {
                double w = 1 / sqrt(nb_freq);
                int a = sqrt(w * sqrt(data[0][2 * y + 0] * data[0][2 * y + 0] + data[0][2 * y + 1] * data[0][2 * y + 1]));
                int b = (nb_display_channels == 2 ) ? sqrt(w * sqrt(data[1][2 * y + 0] * data[1][2 * y + 0]
                       + data[1][2 * y + 1] * data[1][2 * y + 1])) : a;
                a = FFMIN(a, 255);
                b = FFMIN(b, 255);
                fgcolor = SDL_MapRGB(screen->format, a, b, (a + b) / 2);

                fill_rectangle(screen,
                            s->xpos, s->height-y, 1, 1,
                            fgcolor, 0);
            }
        }
        SDL_UpdateRect(screen, s->xpos, s->ytop, 1, s->height);
        if (!s->paused)
            s->xpos++;
        if (s->xpos >= s->width)
            s->xpos= s->xleft;
    }
}

static void stream_close(VideoState *is)
{
    /* XXX: use a special url_shutdown call to abort parse cleanly */
    is->abort_request = 1;
    SDL_WaitThread(is->read_tid, NULL);
    packet_queue_destroy(&is->videoq);
    packet_queue_destroy(&is->audioq);
    packet_queue_destroy(&is->subtitleq);

    /* free all pictures */
    frame_queue_destory(&is->pictq);
    frame_queue_destory(&is->sampq);
    frame_queue_destory(&is->subpq);
    SDL_DestroyCond(is->continue_read_thread);
#if !CONFIG_AVFILTER
    sws_freeContext(is->img_convert_ctx);
#endif
    av_free(is);
}

static void do_exit(VideoState *is)
{
    if (is) {
        stream_close(is);
    }
    av_lockmgr_register(NULL);
    uninit_opts();
#if CONFIG_AVFILTER
    av_freep(&vfilters_list);
#endif
    avformat_network_deinit();
    if (show_status)
        printf("\n");
    SDL_Quit();
    av_log(NULL, AV_LOG_QUIET, "%s", "");
    exit(0);
}

static void sigterm_handler(int sig)
{
    exit(123);
}

static void set_default_window_size(int width, int height, AVRational sar)
{
    SDL_Rect rect;
    calculate_display_rect(&rect, 0, 0, INT_MAX, height, width, height, sar);
    default_width  = rect.w;
    default_height = rect.h;
}

static int video_open(VideoState *is, int force_set_video_mode, Frame *vp)
{
    int flags = SDL_HWSURFACE | SDL_ASYNCBLIT | SDL_HWACCEL;
    int w,h;

    if (is_full_screen) flags |= SDL_FULLSCREEN;
    else                flags |= SDL_RESIZABLE;

    if (vp && vp->width)
        set_default_window_size(vp->width, vp->height, vp->sar);

    if (is_full_screen && fs_screen_width) {
        w = fs_screen_width;
        h = fs_screen_height;
    } else if (!is_full_screen && screen_width) {
        w = screen_width;
        h = screen_height;
    } else {
        w = default_width;
        h = default_height;
    }
    w = FFMIN(16383, w);
    if (screen && is->width == screen->w && screen->w == w
       && is->height== screen->h && screen->h == h && !force_set_video_mode)
        return 0;
    screen = SDL_SetVideoMode(w, h, 0, flags);
    if (!screen) {
        av_log(NULL, AV_LOG_FATAL, "SDL: could not set video mode - exiting\n");
        do_exit(is);
    }
    if (!window_title)
        window_title = input_filename;
    SDL_WM_SetCaption(window_title, window_title);

    is->width  = screen->w;
    is->height = screen->h;

    return 0;
}

/* display the current picture, if any */
static void video_display(VideoState *is)
{
    if (!screen)
        video_open(is, 0, NULL);
    if (is->audio_st && is->show_mode != SHOW_MODE_VIDEO)
        video_audio_display(is);
    else if (is->video_st)
        video_image_display(is);
}

static double get_clock(Clock *c)
{
    if (*c->queue_serial != c->serial)
        return NAN;
    if (c->paused) {
        return c->pts;
    } else {
        double time = av_gettime_relative() / 1000000.0;
        return c->pts_drift + time - (time - c->last_updated) * (1.0 - c->speed);
    }
}

static void set_clock_at(Clock *c, double pts, int serial, double time)
{
    c->pts = pts;
    c->last_updated = time;
    c->pts_drift = c->pts - time;
    c->serial = serial;
}

static void set_clock(Clock *c, double pts, int serial)
{
    double time = av_gettime_relative() / 1000000.0;
    set_clock_at(c, pts, serial, time);
}

static void set_clock_speed(Clock *c, double speed)
{
    set_clock(c, get_clock(c), c->serial);
    c->speed = speed;
}

static void init_clock(Clock *c, int *queue_serial)
{
    c->speed = 1.0;
    c->paused = 0;
    c->queue_serial = queue_serial;
    set_clock(c, NAN, -1);
}

static void sync_clock_to_slave(Clock *c, Clock *slave)
{
    double clock = get_clock(c);
    double slave_clock = get_clock(slave);
    if (!isnan(slave_clock) && (isnan(clock) || fabs(clock - slave_clock) > AV_NOSYNC_THRESHOLD))
        set_clock(c, slave_clock, slave->serial);
}

static int get_master_sync_type(VideoState *is) {
    if (is->av_sync_type == AV_SYNC_VIDEO_MASTER) {
        if (is->video_st)
            return AV_SYNC_VIDEO_MASTER;
        else
            return AV_SYNC_AUDIO_MASTER;
    } else if (is->av_sync_type == AV_SYNC_AUDIO_MASTER) {
        if (is->audio_st)
            return AV_SYNC_AUDIO_MASTER;
        else
            return AV_SYNC_EXTERNAL_CLOCK;
    } else {
        return AV_SYNC_EXTERNAL_CLOCK;
    }
}

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

    switch (get_master_sync_type(is)) {
        case AV_SYNC_VIDEO_MASTER:
            val = get_clock(&is->vidclk);
            break;
        case AV_SYNC_AUDIO_MASTER:
            val = get_clock(&is->audclk);
            break;
        default:
            val = get_clock(&is->extclk);
            break;
    }
    return val;
}

static void check_external_clock_speed(VideoState *is) {
   if (is->video_stream >= 0 && is->videoq.nb_packets <= MIN_FRAMES / 2 ||
       is->audio_stream >= 0 && is->audioq.nb_packets <= MIN_FRAMES / 2) {
       set_clock_speed(&is->extclk, FFMAX(EXTERNAL_CLOCK_SPEED_MIN, is->extclk.speed - EXTERNAL_CLOCK_SPEED_STEP));
   } else if ((is->video_stream < 0 || is->videoq.nb_packets > MIN_FRAMES * 2) &&
              (is->audio_stream < 0 || is->audioq.nb_packets > MIN_FRAMES * 2)) {
       set_clock_speed(&is->extclk, FFMIN(EXTERNAL_CLOCK_SPEED_MAX, is->extclk.speed + EXTERNAL_CLOCK_SPEED_STEP));
   } else {
       double speed = is->extclk.speed;
       if (speed != 1.0)
           set_clock_speed(&is->extclk, speed + EXTERNAL_CLOCK_SPEED_STEP * (1.0 - speed) / fabs(1.0 - speed));
   }
}

/* 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;
        SDL_CondSignal(is->continue_read_thread);
    }
}

/* pause or resume the video */
static void stream_toggle_pause(VideoState *is)
{
    if (is->paused) {
        is->frame_timer += av_gettime_relative() / 1000000.0 - is->vidclk.last_updated;
        if (is->read_pause_return != AVERROR(ENOSYS)) {
            is->vidclk.paused = 0;
        }
        set_clock(&is->vidclk, get_clock(&is->vidclk), is->vidclk.serial);
    }
    set_clock(&is->extclk, get_clock(&is->extclk), is->extclk.serial);
    is->paused = is->audclk.paused = is->vidclk.paused = is->extclk.paused = !is->paused;
}

static void toggle_pause(VideoState *is)
{
    stream_toggle_pause(is);
    is->step = 0;
}

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

static double compute_target_delay(double delay, VideoState *is)
{
    double sync_threshold, diff = 0;

    /* update delay to follow master synchronisation source */
    if (get_master_sync_type(is) != AV_SYNC_VIDEO_MASTER) {
        /* if video is slave, we try to correct big delays by
           duplicating or deleting a frame */
        diff = get_clock(&is->vidclk) - 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_MIN, FFMIN(AV_SYNC_THRESHOLD_MAX, delay));
        if (!isnan(diff) && fabs(diff) < is->max_frame_duration) {
            if (diff <= -sync_threshold)
                delay = FFMAX(0, delay + diff);
            else if (diff >= sync_threshold && delay > AV_SYNC_FRAMEDUP_THRESHOLD)
                delay = delay + diff;
            else if (diff >= sync_threshold)
                delay = 2 * delay;
        }
    }

    av_log(NULL, AV_LOG_TRACE, "video: delay=%0.3f A-V=%f\n",
            delay, -diff);

    return delay;
}

static double vp_duration(VideoState *is, Frame *vp, Frame *nextvp) {
    if (vp->serial == nextvp->serial) {
        double duration = nextvp->pts - vp->pts;
        if (isnan(duration) || duration <= 0 || duration > is->max_frame_duration)
            return vp->duration;
        else
            return duration;
    } else {
        return 0.0;
    }
}

static void update_video_pts(VideoState *is, double pts, int64_t pos, int serial) {
    /* update current video pts */
    set_clock(&is->vidclk, pts, serial);
    sync_clock_to_slave(&is->extclk, &is->vidclk);
}

/* called to display each frame */
static void video_refresh(void *opaque, double *remaining_time)
{
    VideoState *is = opaque;
    double time;

    Frame *sp, *sp2;

    if (!is->paused && get_master_sync_type(is) == AV_SYNC_EXTERNAL_CLOCK && is->realtime)
        check_external_clock_speed(is);

    if (!display_disable && is->show_mode != SHOW_MODE_VIDEO && is->audio_st) {
        time = av_gettime_relative() / 1000000.0;
        if (is->force_refresh || is->last_vis_time + rdftspeed < time) {
            video_display(is);
            is->last_vis_time = time;
        }
        *remaining_time = FFMIN(*remaining_time, is->last_vis_time + rdftspeed - time);
    }

    if (is->video_st) {
        int redisplay = 0;
        if (is->force_refresh)
            redisplay = frame_queue_prev(&is->pictq);
retry:
        if (frame_queue_nb_remaining(&is->pictq) == 0) {
            // nothing to do, no picture to display in the queue
        } else {
            double last_duration, duration, delay;
            Frame *vp, *lastvp;

            /* dequeue the picture */
            lastvp = frame_queue_peek_last(&is->pictq);
            vp = frame_queue_peek(&is->pictq);

            if (vp->serial != is->videoq.serial) {
                frame_queue_next(&is->pictq);
                redisplay = 0;
                goto retry;
            }

            if (lastvp->serial != vp->serial && !redisplay)
                is->frame_timer = av_gettime_relative() / 1000000.0;

            if (is->paused)
                goto display;

            /* compute nominal last_duration */
            last_duration = vp_duration(is, lastvp, vp);
            if (redisplay)
                delay = 0.0;
            else
                delay = compute_target_delay(last_duration, is);

            time= av_gettime_relative()/1000000.0;
            if (time < is->frame_timer + delay && !redisplay) {
                *remaining_time = FFMIN(is->frame_timer + delay - time, *remaining_time);
                return;
            }

            is->frame_timer += delay;
            if (delay > 0 && time - is->frame_timer > AV_SYNC_THRESHOLD_MAX)
                is->frame_timer = time;

            SDL_LockMutex(is->pictq.mutex);
            if (!redisplay && !isnan(vp->pts))
                update_video_pts(is, vp->pts, vp->pos, vp->serial);
            SDL_UnlockMutex(is->pictq.mutex);

            if (frame_queue_nb_remaining(&is->pictq) > 1) {
                Frame *nextvp = frame_queue_peek_next(&is->pictq);
                duration = vp_duration(is, vp, nextvp);
                if(!is->step && (redisplay || framedrop>0 || (framedrop && get_master_sync_type(is) != AV_SYNC_VIDEO_MASTER)) && time > is->frame_timer + duration){
                    if (!redisplay)
                        is->frame_drops_late++;
                    frame_queue_next(&is->pictq);
                    redisplay = 0;
                    goto retry;
                }
            }

            if (is->subtitle_st) {
                    while (frame_queue_nb_remaining(&is->subpq) > 0) {
                        sp = frame_queue_peek(&is->subpq);

                        if (frame_queue_nb_remaining(&is->subpq) > 1)
                            sp2 = frame_queue_peek_next(&is->subpq);
                        else
                            sp2 = NULL;

                        if (sp->serial != is->subtitleq.serial
                                || (is->vidclk.pts > (sp->pts + ((float) sp->sub.end_display_time / 1000)))
                                || (sp2 && is->vidclk.pts > (sp2->pts + ((float) sp2->sub.start_display_time / 1000))))
                        {
                            frame_queue_next(&is->subpq);
                        } else {
                            break;
                        }
                    }
            }

display:
            /* display picture */
            if (!display_disable && is->show_mode == SHOW_MODE_VIDEO)
                video_display(is);

            frame_queue_next(&is->pictq);

            if (is->step && !is->paused)
                stream_toggle_pause(is);
        }
    }
    is->force_refresh = 0;
    if (show_status) {
        static int64_t last_time;
        int64_t cur_time;
        int aqsize, vqsize, sqsize;
        double av_diff;

        cur_time = av_gettime_relative();
        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_clock(&is->audclk) - get_clock(&is->vidclk);
            else if (is->video_st)
                av_diff = get_master_clock(is) - get_clock(&is->vidclk);
            else if (is->audio_st)
                av_diff = get_master_clock(is) - get_clock(&is->audclk);
            av_log(NULL, AV_LOG_INFO,
                   "%7.2f %s:%7.3f fd=%4d aq=%5dKB vq=%5dKB sq=%5dB f=%"PRId64"/%"PRId64"   \r",
                   get_master_clock(is),
                   (is->audio_st && is->video_st) ? "A-V" : (is->video_st ? "M-V" : (is->audio_st ? "M-A" : "   ")),
                   av_diff,
                   is->frame_drops_early + is->frame_drops_late,
                   aqsize / 1024,
                   vqsize / 1024,
                   sqsize,
                   is->video_st ? is->video_st->codec->pts_correction_num_faulty_dts : 0,
                   is->video_st ? is->video_st->codec->pts_correction_num_faulty_pts : 0);
            fflush(stdout);
            last_time = cur_time;
        }
    }
}

/* allocate a picture (needs to do that in main thread to avoid
   potential locking problems */
static void alloc_picture(VideoState *is)
{
    Frame *vp;
    int64_t bufferdiff;

    vp = &is->pictq.queue[is->pictq.windex];

    free_picture(vp);

    video_open(is, 0, vp);

    vp->bmp = SDL_CreateYUVOverlay(vp->width, vp->height,
                                   SDL_YV12_OVERLAY,
                                   screen);
    bufferdiff = vp->bmp ? FFMAX(vp->bmp->pixels[0], vp->bmp->pixels[1]) - FFMIN(vp->bmp->pixels[0], vp->bmp->pixels[1]) : 0;
    if (!vp->bmp || vp->bmp->pitches[0] < vp->width || bufferdiff < (int64_t)vp->height * vp->bmp->pitches[0]) {
        /* SDL allocates a buffer smaller than requested if the video
         * overlay hardware is unable to support the requested size. */
        av_log(NULL, AV_LOG_FATAL,
               "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(is);
    }

    SDL_LockMutex(is->pictq.mutex);
    vp->allocated = 1;
    SDL_CondSignal(is->pictq.cond);
    SDL_UnlockMutex(is->pictq.mutex);
}

static void duplicate_right_border_pixels(SDL_Overlay *bmp) {
    int i, width, height;
    Uint8 *p, *maxp;
    for (i = 0; i < 3; i++) {
        width  = bmp->w;
        height = bmp->h;
        if (i > 0) {
            width  >>= 1;
            height >>= 1;
        }
        if (bmp->pitches[i] > width) {
            maxp = bmp->pixels[i] + bmp->pitches[i] * height - 1;
            for (p = bmp->pixels[i] + width - 1; p < maxp; p += bmp->pitches[i])
                *(p+1) = *p;
        }
    }
}

static int queue_picture(VideoState *is, AVFrame *src_frame, double pts, double duration, int64_t pos, int serial)
{
    Frame *vp;

#if defined(DEBUG_SYNC) && 0
    printf("frame_type=%c pts=%0.3f\n",
           av_get_picture_type_char(src_frame->pict_type), pts);
#endif

    if (!(vp = frame_queue_peek_writable(&is->pictq)))
        return -1;

    vp->sar = src_frame->sample_aspect_ratio;

    /* alloc or resize hardware picture buffer */
    if (!vp->bmp || vp->reallocate || !vp->allocated ||
        vp->width  != src_frame->width ||
        vp->height != src_frame->height) {
        SDL_Event event;

        vp->allocated  = 0;
        vp->reallocate = 0;
        vp->width = src_frame->width;
        vp->height = src_frame->height;

        /* 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);
        }
        /* if the queue is aborted, we have to pop the pending ALLOC event or wait for the allocation to complete */
        if (is->videoq.abort_request && SDL_PeepEvents(&event, 1, SDL_GETEVENT, SDL_EVENTMASK(FF_ALLOC_EVENT)) != 1) {
            while (!vp->allocated && !is->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 = { { 0 } };

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

        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
        // FIXME use direct rendering
        av_picture_copy(&pict, (AVPicture *)src_frame,
                        src_frame->format, vp->width, vp->height);
#else
        av_opt_get_int(sws_opts, "sws_flags", 0, &sws_flags);
        is->img_convert_ctx = sws_getCachedContext(is->img_convert_ctx,
            vp->width, vp->height, src_frame->format, vp->width, vp->height,
            AV_PIX_FMT_YUV420P, sws_flags, NULL, NULL, NULL);
        if (!is->img_convert_ctx) {
            av_log(NULL, AV_LOG_FATAL, "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
        /* workaround SDL PITCH_WORKAROUND */
        duplicate_right_border_pixels(vp->bmp);
        /* update the bitmap content */
        SDL_UnlockYUVOverlay(vp->bmp);

        vp->pts = pts;
        vp->duration = duration;
        vp->pos = pos;
        vp->serial = serial;

        /* now we can update the picture count */
        frame_queue_push(&is->pictq);
    }
    return 0;
}

static int get_video_frame(VideoState *is, AVFrame *frame)
{
    int got_picture;

    if ((got_picture = decoder_decode_frame(&is->viddec, frame, NULL)) < 0)
        return -1;

    if (got_picture) {
        double dpts = NAN;

        if (frame->pts != AV_NOPTS_VALUE)
            dpts = av_q2d(is->video_st->time_base) * frame->pts;

        frame->sample_aspect_ratio = av_guess_sample_aspect_ratio(is->ic, is->video_st, frame);

        if (framedrop>0 || (framedrop && get_master_sync_type(is) != AV_SYNC_VIDEO_MASTER)) {
            if (frame->pts != AV_NOPTS_VALUE) {
                double diff = dpts - get_master_clock(is);
                if (!isnan(diff) && fabs(diff) < AV_NOSYNC_THRESHOLD &&
                    diff - is->frame_last_filter_delay < 0 &&
                    is->viddec.pkt_serial == is->vidclk.serial &&
                    is->videoq.nb_packets) {
                    is->frame_drops_early++;
                    av_frame_unref(frame);
                    got_picture = 0;
                }
            }
        }
    }

    return got_picture;
}

#if CONFIG_AVFILTER
static int configure_filtergraph(AVFilterGraph *graph, const char *filtergraph,
                                 AVFilterContext *source_ctx, AVFilterContext *sink_ctx)
{
    int ret, i;
    int nb_filters = graph->nb_filters;
    AVFilterInOut *outputs = NULL, *inputs = NULL;

    if (filtergraph) {
        outputs = avfilter_inout_alloc();
        inputs  = avfilter_inout_alloc();
        if (!outputs || !inputs) {
            ret = AVERROR(ENOMEM);
            goto fail;
        }

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

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

        if ((ret = avfilter_graph_parse_ptr(graph, filtergraph, &inputs, &outputs, NULL)) < 0)
            goto fail;
    } else {
        if ((ret = avfilter_link(source_ctx, 0, sink_ctx, 0)) < 0)
            goto fail;
    }

    /* Reorder the filters to ensure that inputs of the custom filters are merged first */
    for (i = 0; i < graph->nb_filters - nb_filters; i++)
        FFSWAP(AVFilterContext*, graph->filters[i], graph->filters[i + nb_filters]);

    ret = avfilter_graph_config(graph, NULL);
fail:
    avfilter_inout_free(&outputs);
    avfilter_inout_free(&inputs);
    return ret;
}

static int configure_video_filters(AVFilterGraph *graph, VideoState *is, const char *vfilters, AVFrame *frame)
{
    static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE };
    char sws_flags_str[128];
    char buffersrc_args[256];
    int ret;
    AVFilterContext *filt_src = NULL, *filt_out = NULL, *last_filter = NULL;
    AVCodecContext *codec = is->video_st->codec;
    AVRational fr = av_guess_frame_rate(is->ic, is->video_st, NULL);

    av_opt_get_int(sws_opts, "sws_flags", 0, &sws_flags);
    snprintf(sws_flags_str, sizeof(sws_flags_str), "flags=%"PRId64, sws_flags);
    graph->scale_sws_opts = av_strdup(sws_flags_str);

    snprintf(buffersrc_args, sizeof(buffersrc_args),
             "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
             frame->width, frame->height, frame->format,
             is->video_st->time_base.num, is->video_st->time_base.den,
             codec->sample_aspect_ratio.num, FFMAX(codec->sample_aspect_ratio.den, 1));
    if (fr.num && fr.den)
        av_strlcatf(buffersrc_args, sizeof(buffersrc_args), ":frame_rate=%d/%d", fr.num, fr.den);

    if ((ret = avfilter_graph_create_filter(&filt_src,
                                            avfilter_get_by_name("buffer"),
                                            "ffplay_buffer", buffersrc_args, NULL,
                                            graph)) < 0)
        goto fail;

    ret = avfilter_graph_create_filter(&filt_out,
                                       avfilter_get_by_name("buffersink"),
                                       "ffplay_buffersink", NULL, NULL, graph);
    if (ret < 0)
        goto fail;

    if ((ret = av_opt_set_int_list(filt_out, "pix_fmts", pix_fmts,  AV_PIX_FMT_NONE, AV_OPT_SEARCH_CHILDREN)) < 0)
        goto fail;

    last_filter = filt_out;

/* Note: this macro adds a filter before the lastly added filter, so the
 * processing order of the filters is in reverse */
#define INSERT_FILT(name, arg) do {                                         \
    AVFilterContext *filt_ctx;                                              \
                                                                            \