audio sync problems

[webwonk]

Hi gang. I've lurked, searched and experimented for a while now; and have not yet been able to ensure audio-video sync with my rips. Here's what I use: DVD Decrypter 3.1.6.0; DVD2AVI 1.76; VFAPI 1.05; BeSweet 1.4 and AVIMUX-GUI 1.14. I've tried converting individual Chapter VOB's AC3 to get each VOB's audio delay using BeSweet's VOBInput auto av delay detection/correction - then I use SoundForge 6.0 to string together the WAV files and mux with AVIMUX. I frameserve this to either Helix Producer or Sorenson MX. The audio might start out in sync but in movies like Fellowship of the Ring; it desyncs. Can anyone suggest a better method? I've recently began experimenting with AVISynth 2.5.2, but still cannot get audio/video to sync consistantly. Thanks in Advance.

[Awatef]

When you rip, no stream processing

in dvd2avi, load all VOBs, choose demux for audio

note the delay, then convert the ac3 to wav with the AZID program like that:

azid -c normal -a filename.ac3 filename.wav

Then convert this to MP3 using RazorLame (GUI for Lame)

Encode your video WITHOUT SOUND.

Take the soundless AVI and the mp3 and mux them using VirtualDubMod. Be sure to enter the right delay. All other settings on default (video on direct stream copy of course)

In case of Lord of the Rings Extended edition, I ripped every DVD on one separate CD, no sync problems.

[webwonk]

Thanks for your reply Awatef. Actually, I should have been more specific. I want to keep the audio as PCM WAV. There isn't any way to import an MP3 stream into Sorenson Squeeze, and I don't want to incur a quality hit by doing so in Helix Producer.

Also, I'm unsure about not selecting No stream processing. I don't want anything (usually) except the 2channel AC3, nor subtitles.

When I've split to chapter VOBs, I notice that each one has its own delay. I would think this would help keep it in sync throughout the duration of the movie. If I just demux to one AC3 with one reported delay, isn't that just an average? And isn't it bound to eventually be out of sync? I dunno. The whole thing is so confusing. I've figure out how to do most of what I needed from Doom9 - but foolproof, accurate, consistant A/V sync seems to be elusive. Help help help.

Web

[Awatef]

The delay reported is no average, ripping every VOB alone is only useful when the VOBs are independant (kinda opening in one VOB, episode in a second VOB, and closing in a third one, you see that they are in different places in SmartRipper, or when the VOBs are on 2 different DVDs). Most DVDs don't have independant VOBs, so it doesn't make any sense to rip every VOB alone.
So don't worry, rip your movie normally, and load all VOBs at once in DVD2AVI and choose demux in the audio tab (select the right audio track of course).

Second, it makes absolutely no sense to keep WAV in your AVI, because it takes way too much bitrate (1536k!!). Keep the WAV format while processing (noise reduction or whatsoever), then encode as MP3 in the final step, just before you mux with your soundless AVI in direct stream copy mode. MP3 with a bitrate of 192k or higher should sound very good even for audiophiles, the higher the better of course.

[webwonk]

Thanks Awatef! What you write makes perfect sense. It never occurred to me that by using DVD Decrypter in File mode was in anyway a "truer" form of the movie.

As to encoding to MP3, well you're right that WAV files are huge, but it is only for importing the now-muxed VFAPI and WAV file (via AVIMux-GUI 1.11x) into Sorenson's Squeeze MX (I've been adding video to Flash. I know, I know - Sorenson's Spark Pro is terrible compared to RV9 with EHQ=80, etc. - but this is a "one-off")

Another problem might be the frame-chopping (2 before, 3 after) that DVD2AVI 1.76 is known for.

Oh well, back to the "lab" for me. And thanks again Awatef. You have shown me the way.

Web