Hi,
Dominique Simon schrieb:
I'd say it's suggested. At least it is part of my H.264 patches.
What does the sync early patch do?
Vanilla VDR waits for an I frame before it passes video (and audio) data on to output devices. Further more, audio data is still not passed on from that time, because VDR takes some time to decide which audio track shall get selected.
The sync early patch addresses these issues. Audio and video packets are passed on a soon as they make up a valid frame. The result is that you can already hear the audio track before the video appears on screen. This is because video decoding can only start with an I frame. Any frames before the I frame won't appear on screen.
But passing these frames to the output device has the benefit that PTS' (presentation time stamp) for these frames are passed on to the output device which needs this information to synchronize audio and video. As a result, audio and video will be in sync already when the first image appears on screen.
That's why the patch got called "sync early".
Bye.