From 4e268aae55c483ec6c743f741f17a8a0f9250f1e Mon Sep 17 00:00:00 2001 From: Marton Balint Date: Sat, 8 Oct 2011 21:38:53 +0200 Subject: [PATCH] ffplay: calculate target clock dynamically, make code more readable Since target clock is based on the current A-V delay, it is better calculate it when we actually need it rather than when we put a picture in the picture queue. The patch also makes a code a bit more readable by renaming some delay variables to duration, and converting compute_target_time to a delay calculating function which does not modify the state. Factoring out the iteration of the pictq to standalone function is also done in this patch. Signed-off-by: Marton Balint --- ffplay.c | 97 +++++++++++++++++++++++++++++++++------------------------------- 1 file changed, 50 insertions(+), 47 deletions(-) diff --git a/ffplay.c b/ffplay.c index 2bf5d27acf..efdbe58bbd 100644 --- a/ffplay.c +++ b/ffplay.c @@ -98,9 +98,9 @@ typedef struct PacketQueue { typedef struct VideoPicture { double pts; ///paused = !is->paused; } -static double compute_target_time(double frame_current_pts, VideoState *is) +static double compute_target_delay(double delay, 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; + double sync_threshold, diff; /* update delay to follow master synchronisation source */ if (((is->av_sync_type == AV_SYNC_AUDIO_MASTER && is->audio_st) || @@ -1103,12 +1093,22 @@ static double compute_target_time(double frame_current_pts, VideoState *is) delay = 2 * delay; } } - is->frame_timer += delay; - av_dlog(NULL, "video: delay=%0.3f pts=%0.3f A-V=%f\n", - delay, frame_current_pts, -diff); + av_dlog(NULL, "video: delay=%0.3f A-V=%f\n", + delay, -diff); - return is->frame_timer; + return delay; +} + +static void pictq_next_picture(VideoState *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); } /* called to display each frame */ @@ -1125,34 +1125,45 @@ retry: //nothing to do, no picture to display in the que } else { double time= av_gettime()/1000000.0; - double next_target; + double last_duration, duration, delay; /* dequeue the picture */ vp = &is->pictq[is->pictq_rindex]; - if(time < vp->target_clock) + if (vp->skip) { + pictq_next_picture(is); + goto retry; + } + + /* compute nominal last_duration */ + last_duration = vp->pts - is->frame_last_pts; + if (last_duration > 0 && last_duration < 10.0) { + /* if duration of the last frame was sane, update last_duration in video state */ + is->frame_last_duration = last_duration; + } + delay = compute_target_delay(is->frame_last_duration, is); + + if(time < is->frame_timer + delay) return; + + is->frame_last_pts = vp->pts; + is->frame_timer += delay; + /* 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 + vp->duration; + + if(is->pictq_size > 1) { + VideoPicture *nextvp= &is->pictq[(is->pictq_rindex+1)%VIDEO_PICTURE_QUEUE_SIZE]; + duration = nextvp->pts - vp->pts; // More accurate this way, 1/time_base is often not reflecting FPS + } else { + duration = vp->duration; } - if((framedrop>0 || (framedrop && is->audio_st)) && time > next_target){ + + if((framedrop>0 || (framedrop && is->audio_st)) && time > is->frame_timer + duration){ is->skip_frames *= 1.0 + FRAME_SKIP_FACTOR; if(is->pictq_size > 1){ - /* 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); + pictq_next_picture(is); goto retry; } } @@ -1205,14 +1216,7 @@ retry: 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); + pictq_next_picture(is); } } else if (is->audio_st) { /* draw the next audio frame */ @@ -1425,13 +1429,12 @@ static int queue_picture(VideoState *is, AVFrame *src_frame, double pts1, int64_ vp->pts = pts; vp->pos = pos; + vp->skip = 0; /* 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); } @@ -1451,7 +1454,7 @@ static int get_video_frame(VideoState *is, AVFrame *frame, int64_t *pts, AVPacke 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; + is->pictq[i].skip = 1; } while (is->pictq_size && !is->videoq.abort_request) { SDL_CondWait(is->pictq_cond, is->pictq_mutex); @@ -1460,7 +1463,7 @@ static int get_video_frame(VideoState *is, AVFrame *frame, int64_t *pts, AVPacke SDL_UnlockMutex(is->pictq_mutex); is->frame_last_pts = AV_NOPTS_VALUE; - is->frame_last_delay = 0; + is->frame_last_duration = 0; is->frame_timer = (double)av_gettime() / 1000000.0; is->skip_frames = 1; is->skip_frames_index = 0; -- 2.11.0