Audio Delay & B-Frames: A Nasty Discovery

[JohnMK]

Apparently B-frame use, either in XviD or DivX, will insert an additional delay into the video. If you just trust the AC3 delay reported by your ripper, DVD2AVI, or another program, your audio will play 42ms too soon, typically. This is a very small slice of time, as such few people may notice it, but it's large enough to cause anal-retentive types to reencode all their movies. :eek:

Hmmm, take this with a grain of salt. I'm still doing some investigation. Apparently there are differing opinions on this issue. -h says the Divx 5 DS Filter compensates for the delay, then he goes on to say that there's still a 1-frame delay (1/24 ~ roughly 40ms). So I don't have any clue what's going on now.

[ChristianHJW]

Originally posted by JohnMK This is a very small slice of time, as such few people may notice it, but it's large enough to cause anal-retentive types to reencode all their movies. :eek: [/B]

No need to reencode. Simply remux the, and change the delay in Vdub, unless you are using OGM.

Note that Virtualdub, since ver. 1.4.10, can compensate the delay caused by inserted 'dummy frames' ( a result of a 'hack' that was necessary, as VfW cant handle b-frames correctly ) for DivX5, if used in DivX VOP mode.

However, Suiryc has integrated the same for Xvid now into latest 1.4.12.1 ver. of VirtualdubMod ...

[JohnMK]

is VOP mode default?