ffplay.c

F:图像处理资料264264书籍ffmpeg-0.4.9-pre1VideoStream.rar 一个视频解压缩源代码

                           s->xleft + x, ys, 1, y, 
                           fgcolor);
            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);
    }
    SDL_UpdateRect(screen, s->xleft, s->ytop, s->width, s->height);
}

/* display the current picture, if any */
static void video_display(VideoState *is)
{
    if (is->audio_st && is->show_audio) 
        video_audio_display(is);
    else if (is->video_st)
        video_image_display(is);
}

static Uint32 sdl_refresh_timer_cb(Uint32 interval, void *opaque)
{
    SDL_Event event;
    event.type = FF_REFRESH_EVENT;
    event.user.data1 = opaque;
    SDL_PushEvent(&event);
    return 0; /* 0 means stop timer */
}

/* schedule a video refresh in 'delay' ms */
static void schedule_refresh(VideoState *is, int delay)
{
    SDL_AddTimer(delay, sdl_refresh_timer_cb, is);
}

/* get the current audio clock value */
static double get_audio_clock(VideoState *is)
{
    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)
{
    double delta;
    if (is->paused) {
        delta = 0;
    } else {
        delta = (av_gettime() - is->video_current_pts_time) / 1000000.0;
    }
    return is->video_current_pts + delta;
}

/* 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)
{
    is->seek_pos = pos;
    is->seek_req = 1;
}

/* pause or resume the video */
static void stream_pause(VideoState *is)
{
    is->paused = !is->paused;
    if (is->paused) {
        is->video_current_pts = get_video_clock(is);
    }
}

/* called to display each frame */
static void video_refresh_timer(void *opaque)
{
    VideoState *is = opaque;
    VideoPicture *vp;
    double actual_delay, delay, sync_threshold, ref_clock, diff;


    if (is->video_st) {
        if (is->pictq_size == 0) {
            /* if no picture, need to wait */
            schedule_refresh(is, 1);
        } else {
            /* dequeue the picture */
            vp = &is->pictq[is->pictq_rindex];

            /* update current video pts */
            is->video_current_pts = vp->pts;
            is->video_current_pts_time = av_gettime();

            /* compute nominal delay */
            delay = vp->pts - is->frame_last_pts;
            if (delay <= 0 || delay >= 1.0) {
                /* if incorrect delay, use previous one */
                delay = is->frame_last_delay;
            }
            is->frame_last_delay = delay;
            is->frame_last_pts = vp->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 */
                ref_clock = get_master_clock(is);
                diff = vp->pts - ref_clock;
                
                /* 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 = AV_SYNC_THRESHOLD;
                if (delay > sync_threshold)
                    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;
            /* compute the REAL delay (we need to do that to avoid
               long term errors */
            actual_delay = is->frame_timer - (av_gettime() / 1000000.0);
            if (actual_delay < 0.010) {
                /* XXX: should skip picture */
                actual_delay = 0.010;
            }
            /* launch timer for next picture */
            schedule_refresh(is, (int)(actual_delay * 1000 + 0.5));

#if defined(DEBUG_SYNC)
            printf("video: delay=%0.3f actual_delay=%0.3f pts=%0.3f A-V=%f\n", 
                   delay, actual_delay, vp->pts, -diff);
#endif

            /* display picture */
            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 */

        schedule_refresh(is, 40);

        /* if only audio stream, then display the audio bars (better
           than nothing, just to test the implementation */
        
        /* display picture */
        video_display(is);
    } else {
        schedule_refresh(is, 100);
    }
    if (show_status) {
        static int64_t last_time;
        int64_t cur_time;
        int aqsize, vqsize;
        double av_diff;
        
        cur_time = av_gettime();
        if (!last_time || (cur_time - last_time) >= 500 * 1000) {
            aqsize = 0;
            vqsize = 0;
            if (is->audio_st)
                aqsize = is->audioq.size;
            if (is->video_st)
                vqsize = is->videoq.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 aq=%5dKB vq=%5dKB    \r", 
                   get_master_clock(is), av_diff, aqsize / 1024, vqsize / 1024);
            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(void *opaque)
{
    VideoState *is = opaque;
    VideoPicture *vp;

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

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

#if 0
    /* XXX: use generic function */
    /* XXX: disable overlay if no hardware acceleration or if RGB format */
    switch(is->video_st->codec.pix_fmt) {
    case PIX_FMT_YUV420P:
    case PIX_FMT_YUV422P:
    case PIX_FMT_YUV444P:
    case PIX_FMT_YUV422:
    case PIX_FMT_YUV410P:
    case PIX_FMT_YUV411P:
        is_yuv = 1;
        break;
    default:
        is_yuv = 0;
        break;
    }
#endif
    vp->bmp = SDL_CreateYUVOverlay(is->video_st->codec.width,
                                   is->video_st->codec.height,
                                   SDL_YV12_OVERLAY, 
                                   screen);
    vp->width = is->video_st->codec.width;
    vp->height = is->video_st->codec.height;

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

static int queue_picture(VideoState *is, AVFrame *src_frame, double pts)
{
    VideoPicture *vp;
    int dst_pix_fmt;
    AVPicture pict;
    
    /* wait until we have space to put a new picture */
    SDL_LockMutex(is->pictq_mutex);
    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 || 
        vp->width != is->video_st->codec.width ||
        vp->height != is->video_st->codec.height) {
        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) {
        /* get a pointer on the bitmap */
        SDL_LockYUVOverlay (vp->bmp);

        dst_pix_fmt = PIX_FMT_YUV420P;
        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];
        img_convert(&pict, dst_pix_fmt, 
                    (AVPicture *)src_frame, is->video_st->codec.pix_fmt, 
                    is->video_st->codec.width, is->video_st->codec.height);
        /* update the bitmap content */
        SDL_UnlockYUVOverlay(vp->bmp);

        vp->pts = pts;

        /* now we can update the picture count */
        if (++is->pictq_windex == VIDEO_PICTURE_QUEUE_SIZE)
            is->pictq_windex = 0;
        SDL_LockMutex(is->pictq_mutex);
        is->pictq_size++;
        SDL_UnlockMutex(is->pictq_mutex);
    }
    return 0;
}

/* compute the exact PTS for the picture if it is omitted in the stream */
static int output_picture2(VideoState *is, AVFrame *src_frame, double pts1)
{
    double frame_delay, pts;
    
    pts = pts1;

    /* if B frames are present, and if the current picture is a I
       or P frame, we use the last pts */
    if (is->video_st->codec.has_b_frames && 
        src_frame->pict_type != FF_B_TYPE) {
        /* use last pts */
        pts = is->video_last_P_pts;
        /* get the pts for the next I or P frame if present */
        is->video_last_P_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 = (double)is->video_st->codec.frame_rate_base / 
        (double)is->video_st->codec.frame_rate;
    /* for MPEG2, the frame can be repeated, so we update the
       clock accordingly */
    if (src_frame->repeat_pict) {
        frame_delay += src_frame->repeat_pict * (frame_delay * 0.5);
    }
    is->video_clock += frame_delay;

#if defined(DEBUG_SYNC) && 0
    {
        int ftype;
        if (src_frame->pict_type == FF_B_TYPE)
            ftype = 'B';
        else if (src_frame->pict_type == FF_I_TYPE)
            ftype = 'I';
        else
            ftype = 'P';
        printf("frame_type=%c clock=%0.3f pts=%0.3f\n", 
               ftype, pts, pts1);
    }
#endif
    return queue_picture(is, src_frame, pts);
}

static int video_thread(void *arg)
{
    VideoState *is = arg;
    AVPacket pkt1, *pkt = &pkt1;
    int len1, got_picture;
    AVFrame *frame= avcodec_alloc_frame();
    double pts;

    for(;;) {
        while (is->paused && !is->videoq.abort_request) {
            SDL_Delay(10);
        }
        if (packet_queue_get(&is->videoq, pkt, 1) < 0)
            break;
        /* NOTE: ipts is the PTS of the _first_ picture beginning in
           this packet, if any */
        pts = 0;
        if (pkt->pts != AV_NOPTS_VALUE)
            pts = (double)pkt->pts / AV_TIME_BASE;

        if (is->video_st->codec.codec_id == CODEC_ID_RAWVIDEO) {
            avpicture_fill((AVPicture *)frame, pkt->data, 
                           is->video_st->codec.pix_fmt,
                           is->video_st->codec.width,
                           is->video_st->codec.height);
            frame->pict_type = FF_I_TYPE;
            if (output_picture2(is, frame, pts) < 0)
                goto the_end;
        } else {
            len1 = avcodec_decode_video(&is->video_st->codec, 
                                        frame, &got_picture, 
                                        pkt->data, pkt->size);
//            if (len1 < 0)
//                break;
            if (got_picture) {
                if (output_picture2(is, frame, pts) < 0)
                    goto the_end;
            }
        }
        av_free_packet(pkt);
        if (step) 
            if (cur_stream)
                stream_pause(cur_stream);
    }
 the_end:
    av_free(frame);
    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;