[SOLVED] WMV to MPEG4/AVI/anything else has increasing audio desynch.

[Eilonwy05]

Hi there! I've got a number of WMV files, each encoded with (according to G-Spot) WMP v9 (VC-1 Simple/Main) video, and WMA v2 stereo 2-pass CBR audio.

I've tried easily a dozen or more conversion tools, freeware, trials, commercial, based on ffmpeg, based on mencoder, you name it -- every one of them, when converting the file to another format, gives me desynchronized audio, beginning with a slight discrepancy initially, but by the end of the video it often has increased to 3 to 5 seconds off.

I've scoured the web looking for anyone with a similar problem, and found nothing; there were many, many issues with VBR audio, but apparently although what I've got is a form of CBR, the 2-pass issue may be causing problems for me. I read that the concept for 2-Pass CBR WMA is to optimize the encoding, and I can understand the need for it, but I'm wondering if it might be the source of the desynch issue.

I would greatly appreciate any information or suggestions on how to convert these WMV files and retain the audio and video synch. My ultimate goal is to convert these to PSP-compatible h.264 AVC MPEG4 with AAC audio, but if I needed to convert to an intermediate format to do so, I'd be fine with that too.

Thank you for all the years of help you've given me without a need for me to post a question -- this may be my first post in the forum, but I've certainly learned a lot from this community up until now!

[mgh]

i would suggest 'repairing' the files first with asfbin and a gui for it like cut assistant.

[Eilonwy05]

Downloaded asfbinwin and used it to 'repair' the video, got an output file that seemed to be identical, same filesize to the byte. Converted the output to MPEG4-AVC with AAC audio, and got the exact same desynch issue. The audio always seems to play early by the same increasing amount, every time I encode, so the problem is exactly reproduceable.

Does anyone have any more detailed info on 2-pass CBR WMA? From my other research, I really do suspect this to be the culprit; I just don't know how exactly it figures into things, since it's apparently not used much.

Any further advice is appreciated.

[Midzuki]

https://forum.videohelp.com/topic346029.html#1814650

[Eilonwy05]

https://forum.videohelp.com/topic346029.html#1814650

I don't know *how* I didn't think of doing that -- but it's a very clever idea. Extract the WMA, export to WAV, and re-encode. My only question is how to re-mux the video and audio, since my preferred application for conversion to PSP only accepts an already mux'ed video file, not a separate audio and video stream. Can I copy the WAV file as an audio stream directly into the WMV file?

I'm reluctant to switch to another conversion application just for some of my videos, as everything else I convert with XviD4PSP comes out fine.

Any ideas?

[Midzuki]

Normally I mux the sync-ed .WAV and the original WMV into an intermediate .MKV.

[Eilonwy05]

MKV sounds fair for a temporary file to do the conversion. Any particular tools you'd suggest for creating an MKV? I've never made one, only viewed.

Thanks again for the help with this -- you're the first person who's actually had any decent input on the situation for me!

[Midzuki]

Both MKVtoolnix and AVI-Mux GUI can create MKVs.

Thanks again for the help with this -- you're the first person who's actually had
any decent input on the situation for me!

Probably because we're just happening to consume the same type of Hi-Def p0rn

[DarrellS]

I use Virtualdub with the WMV plugin. You may need to install DivX 3.11 for the hacked wma codec or use ffdshow with WMV9 to decode all WMV formats.

If files use WMV9 professional (5.1) audio then you will need to convert it to something else before adding with Virtualdub since Virtualdub does not support WMV9 professional audio.

[Eilonwy05]

Well, after a bit of a convoluted path, I ended up with an MKV that loaded into XviD4PSP just fine, I ran the conversion to PSP format, and IT WORKS!!

Audio and video are in sync, and no intermediate loss of quality due to re-encoding. Couldn't ask for much of a better result.

@Midzuki: Neither Mkvtoolnix nor AVI-Mux GUI would let me use the WMV/ASF files for input -- mkvmergegui told me it encountered data it couldn't process in the h.264 stream as soon as I told it to mux, and AVI-Mux GUI flat-out refused to open any wmv or asf file.

@DarrellS: I ended up using VirtualDub & the WMV plugin to output to an AVI, but when I loaded the AVI into XviD4PSP I got a single frame from AVISynth notifying me of a System Exception. So I opened the AVI with VirtualDubMod, and copied the streams into an MKV, which parsed just fine. Not sure why I got the error with an AVI container, since I could play the file just fine...

Anyway, a huge *thank you* to everyone for the help, I now have a working method to convert these videos. It's been one long headache until now, and it's quite a relief having a solution.

[Midzuki]

Well, after a bit of a convoluted path, I ended up with an MKV
that loaded into XviD4PSP just fine, I ran the conversion to PSP format,
and IT WORKS!!

@Midzuki: Neither Mkvtoolnix nor AVI-Mux GUI would let me use the WMV/ASF files for input -- mkvmergegui told me it encountered data it couldn't process in the h.264 stream as soon as I told it to mux, and AVI-Mux GUI flat-out refused to open any wmv or asf file.

Yeah, I simply had forgotten such an "irrelevant" detail... Apologies ^.^;;
GDSMux (part of the Haali Media Splitter package) and Gabest's "matroskamuxer.ax" are
what I use for putting WMV3 and VC-1 into a Matroska container. Again, sorry for having made
you depend on VirtualDubMod.

[FulciLives]

I downloaded a MKV that was a 1080p WMV with VC-1 video and 5.1 WMA audio and I was able to load it into XviD4PSP and convert the 5.1 WMA into a 2 channel Stereo Dolby Pro Logic II Surround Sound PCM WAV audio file.

At that point you can then do whatever you want with the PCM WAV audio file. In my case I used GoldWave to convert it to a 9.2 WMA 192kbps Stereo file as I wanted to mux it back in with the WMV video file. Why? I wanted to play it back on a PS3 and the PS3 liked the 9.2 WMA 192kbps Stereo file but I got no audio at all using the original file with the 5.1 WMA audio.

Not sure though with 5.1 WMA how to decode it and keep it as 6 channels *shrugs*

- John "FulciLives" Coleman

[Midzuki]

Fulcilives wrote:

Not sure though with 5.1 WMA how to decode it and keep it as 6 channels

I suppose/hope Avisynth's DirectShowSource ++ the SoundOut plugin can do that.

[DarrellS]

Not sure though with 5.1 WMA how to decode it and keep it as 6 channels *shrugs*

You could try dBpowerAMP convertor with dBpoweramp-Codec-WMA9Pro and dBpoweramp-Codec-WMA10Pro for 9.2.