Re: Audio/video out of sync in DV firewire capture

On Apr 5, 11:44 pm, "nappy" <s...@xxxxxxxx> wrote:
hm.. sounds like your callback is not interpreting theaudiodata from the
stream correctly. Could be you are only getting every other sample. Sounds
like some version of that ..

<krishnendu.bag...@xxxxxxxxx> wrote in message

news:1175774983.027685.290240@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx



I am trying to captureDVdata from a Firewire card usingDirectShow
SDK. The firewire card is getting input from a camcorder. I am
capturing bothaudioandvideodata in a callback routine frame by
frame and writting the rawaudiodata (in PCM format) to a
simple .wav
file. What I observe after the capture/recording is over is, if I
have
recorded for 15 seconds, the .wav file actually consists of nearly
7/8
seconds ofaudio. Theaudiois more or less understandable, but just
thataudioframes are getting compacted together, meaning the pitch
is
high. Has any one observed it before? Any clue as to how it happens?
Any remedy?- Hide quoted text -

- Show quoted text -



The audio is almost twice faster than the
actual. Like if I utter say "A" for 2 seconds while recording, when I
run the file, it plays "A" for one scond. As if most of the cases
it's
just ommiting the silence.

The WAVEFORMATEX settings are absolutely perfect and reassured.
Stereo, 16 bits per sample, 48000 Hz. I have cross checked with
graphedit pin property. The average difference between
IMediaSample::GetTime()'s start and end time is 33 milliseconds and
the data size is 6400. That's also correct as per the equation
2X16X48000/16/8X.033=6336 (which is close to 6400).


Any further clue?





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