On Mon, Feb 25, 2013 at 8:45 PM, Brian Matherly <pez4br...@yahoo.com> wrote: > Dan, > > I added a new module: avsync. It has one producer and one consumer. The > producer generates a stream with a classic blip/flash pattern. The consumer > attempts to detect the blip/flash and calculate the audio/video sync. The > consumer will report the caluclated lipsync in milliseconds. A positive > number indicates that audio leads video. A negative number indicates that > audio lags video. > > The module can test itself: > > melt -silent -profile atsc_720p_30 blipflash -consumer blipflash > avsync = 0.00 > > Obviously, 0 is perfect sync. > > It is interesting to round-trip the pattern through some various encodings: > > melt -profile atsc_720p_30 blipflash -consumer avformat:test.avi > melt -silent test.avi -consumer blipflash > avsync = -23.02 > > melt -profile atsc_720p_30 blipflash -consumer avformat:test.mpg > melt -silent test.mpg -consumer blipflash > avsync = -10.02 > > melt -profile atsc_720p_30 blipflash -consumer avformat:test.mkv > melt -silent test.mkv -consumer blipflash > avsync = 0.00 > > melt -profile atsc_720p_30 blipflash -consumer avformat:test.mov acodec=ac3 > melt -silent test.mov -consumer blipflash > avsync = -5.33 > > melt blipflash -consumer libdv:test.dv > melt -silent test.dv -consumer blipflash > avsync = -40.00 >
It is interesting to note that melt blipflash -consumer libdv:test.dv gives 0.00, which lends itself to a possible off-by-one error in the avformat producer since this is PAL, which is 40ms per frame. -- +-DRD-+ ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_feb _______________________________________________ Mlt-devel mailing list Mlt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mlt-devel
