RMVB - AVS - M2V/MPG Audio Unsyncs

[koberulz]

I have an RMVB file. I wish to end up with an m2v file and an ac3 file.

Step one, create avs file with the following:

DirectShowSource("linktofile.rmvb", fps=29.97, convertfps=true)

Step two, play avs file in MPC. Works fine.

Step three, open avs file in TMPGEnc, cut off the first few seconds, check the rest of it. Works fine.

Step four, set encode settings.

Step five, preview output. Works fine.

Step five, put m2v and ac3 files into Encore, burn disc. Play disc. Audio is one second ahead of video.

Step six, repeat steps three, four and five, encoding to mpg instead of m2v/ac3 to see if the audio is in sync. Audio is still in sync when previewing output in TMPGEnc. Encode.

Step seven, open MPG file. Audio is one second ahead of video.

Step eight, throw hands in air, head to VideoHelp.

It's cutting off the first second or so of audio for some reason, and then lining up the start of the actual sound with the start of the video instead of leaving a second or so of silence. But again, it works fine when playing the avs in MPC, and when previewing the output in TMPGEnc, so it makes absolutely no sense.

[poisondeathray]

Try cutting in the script instead of TMPGEnc

DirectShowSource("linktofile.rmvb", fps=29.97, convertfps=true)
Trim(90,0)

"90" would be ~3 seconds because fps is 29.97 , so adjust it to wherever you want to make the cut, preview the script, etc...



Another method would be to multiplex with a +/- delay if the sync is constant

[El Heggunte]

Another possiblity (just a guess, since we don't have a MediaInfo report about your .RMVB): Variable Bitrate Audio (RealAAC). Give a try to EnsureVBRMP3Sync() According to the documentation:

EnsureVBRMP3Sync (clip)

EnsureVBRMP3Sync will ensure synchronization of video with variable bitrate audio (MP3-AVI's for example) during seeking or trimming. It does so by buffering the audio. The name of the filter is a bit misleading, since it is useful for every stream with variable bitrate audio and not just for MP3.

It will slow seeking down considerably, but is very useful when using Trim for instance. Always use it before trimming.

# Ensures that soundtrack is in sync after trimming
AviSource("movie.avi")
EnsureVBRMP3Sync()
Trim(250,2500)

[koberulz]

Just added the trim, as per the first suggestion, and it works fine.

[Cornucopia]

What I want to know is who the hell is still making these stupid RMVB files?

Scott

[El Heggunte]

^ According to a FFmpeg deviloper (roozhou), RealMedia is alive and well in the Far East countries. And WMV, sadly, still is largely used for pornography. Anyway, here is a list of some "officially-dead" codecs and containers:

ogg

asf

rm(vb)

ms-mpeg4, wmv1, wmv2

wma (all flavors of it)

vorbis

atrac3

musepack

theora

vp3, vp4, vp5, vp6, vp7, vp8

[Cornucopia]

I don't know where you got that "official" list, El Heggunte, but there's nothing official about it.

vp8 = WebM and it's expanding, and usually that means support for the older vp's as well.
asf = wmv container. I don't have a problem with the container on a technical level (it's more full-featured than AVI), it's just the MS-centric-ness that bothers me. But as long as MS is around, wmv (aka asf) will be too, in one form or another. that includes wma. not going away anytime soon.
atrac-3: lots of sony hardware still supports this (like ps3).

IMO, ogg was never ready for prime time, and I couldn't care less about musepak & theora.

I'd much prefer what seems to be happening now: the trend to consolidate and streamline into a few major, well-designed, robust, full-featured, low- to no-cost/license mass codecs (whether they be proprietary or FOSS though that's preferable). Then everybody can share and interact much better with less hassle.

Me, I stopped outputting to RM around 2002.

OP, if you have further troubles, try doing it in 3 stages: Decode RMVB to Intermediate I-frame video format with LPCM/CBR audio, then Edit, then Encode to M2v/Ac3. Takes extra time and HD space, but I bet your sync problems go away for good.

Scott

[El Heggunte]

I don't know where you got that "official" list, El Heggunte, but there's nothing official about it.

Excuse me, but for me it's difficult to believe you DID NOT notice that I was just kidding.

Anyway, ...

vp8 = WebM and it's expanding, and usually that means support for the older vp's as well.

VP8 is the codec, WebM is the container. For the time being, it seems VP8 is suitable for Google Themselves only. FFmpeg has a fast VP8 encoder, but this still needs some serious tweaks and fixes. The "official" vpxenc is slow as hell, not to mention the infamous VfW-port of VP8. I am not aware of any plans for future support of older VPs indide WebM files.

asf = wmv container. I don't have a problem with the container on a technical level (it's more full-featured than AVI), it's just the MS-centric-ness that bothers me. But as long as MS is around, wmv (aka asf) will be too, in one form or another. that includes wma. not going away anytime soon.

OK, ASF supports VFR-video and VSR-audio, but it does not support B-frames at all (the specs do not allow the use of non-monotone timestamps). BTW, the default DMO decoder for WMV shows the annoying "B-frame decoding lag", even when the container is not ASF (or AVI), and even when no VfW-wrapper is being used by DirectShow.

atrac-3: lots of sony hardware still supports this (like ps3).

That's right. Outside of the MiniDisc and PlayStation worlds, almost-nobody listens to ATRAC. Years ago, RealNetworks licensed and implemented a high-bitrate version of ATRAC3 (up to 352kbps). But today, unless you have a functional RealProducer 8.5, you cannot create those "archival quality" RealAudio files. And yes, the codec is locked at the sampling frequency of 44.1kHz (there IS a hack/workaround for that limitation, but it's not worth the effort, IMHO).