yakima
23rd June 2004, 11:06
hi,
i am transcoding from avi to mp4, using besweet 1.5b26 for the audio. one big problem (as numerous posts on related matters show) are sync issues with slight or not so slight delays in the source avi. actually it seems one gets good results if one uses the difference between audio length and video length as audio delay (edit - cause i guess i should qualify this - this of course doesn't apply to all avis!). so i figure at least some avis have the audio end exactly when the video ends (edit: should be due to vdub cutting audio off at the end, so if the audio is delayed this shows up in the diff length b/w audio & video).
now to the audio encoding matter per se, i have two related questions with regard to feeding avis to besweet:
(1) if the audio is ac3, it seems besweet is handling the initial audio delay as a crc error, and starts the first frame at 00:00:032, no matter what the actual delay was -- in this case it seems it also knows there is an audio delay and prints out: "a/v delay found: 0ms". at least there are some avis with ac3 where no such msg. is printed. could someone tell me if i am correct?
(2) what is the "a/v delay found" msg. intended to indicate in general (including mp3 avis? it seems to always find 0 ms ...
any help/ideas would be very much appreciated!
i am transcoding from avi to mp4, using besweet 1.5b26 for the audio. one big problem (as numerous posts on related matters show) are sync issues with slight or not so slight delays in the source avi. actually it seems one gets good results if one uses the difference between audio length and video length as audio delay (edit - cause i guess i should qualify this - this of course doesn't apply to all avis!). so i figure at least some avis have the audio end exactly when the video ends (edit: should be due to vdub cutting audio off at the end, so if the audio is delayed this shows up in the diff length b/w audio & video).
now to the audio encoding matter per se, i have two related questions with regard to feeding avis to besweet:
(1) if the audio is ac3, it seems besweet is handling the initial audio delay as a crc error, and starts the first frame at 00:00:032, no matter what the actual delay was -- in this case it seems it also knows there is an audio delay and prints out: "a/v delay found: 0ms". at least there are some avis with ac3 where no such msg. is printed. could someone tell me if i am correct?
(2) what is the "a/v delay found" msg. intended to indicate in general (including mp3 avis? it seems to always find 0 ms ...
any help/ideas would be very much appreciated!