On Mon, Feb 25, 2013 at 10:26 PM, Dan Dennedy <d...@dennedy.org> wrote: > On Mon, Feb 25, 2013 at 10:20 PM, Dan Dennedy <d...@dennedy.org> wrote: >> 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. >>> [,,,] >>> 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 > > excuse me, I meant > melt -silent libdv:test.dv -consumer blipflash > > using the libdv producer instead of avformat. > >> 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. > > I started to look into this, but like the other isolation problem, now > I am not sure whether to look at audio or video initially!
I created a blipflash DV with frame numbers: melt blipflash -attach dynamictext:#frame# bgcolour=white -consumer libdv:test.dv Then, I generated an image sequence with the libdv producer: melt -silent libdvtest.dv -consumer avformat:test-%04d.jpg progressive=1 It looks fine. Then, using the avformat producer: melt -silent test.dv -consumer avformat:test-%04d.jpg progressive=1 The result shows frame 0 followed by frame 2! Now, applying an in point: melt -silent test.dv in=5 -consumer avformat:test-%04d.jpg progressive=1 test-0001.jpg shows frame# 6 instead of 5. Off-by-one in the video handling of the avformat producer. -- +-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
