moon1234
22nd February 2003, 12:47
Ok, I am ready to pull my hair out with this one. I have a bunch of these really great DIVX episodes. Some with AC3 audio and some with MP3 audio. Yes you guessed it, DVD backups and some TV shows for later viewing.
I have been converting most of these to SVCD's. My biggest problem is audio sync. The DIVX files are in perfect sync. When I convert to SVCDs using DVD2AVI the audio is almost perfectly in sync. My wife can't notice any difference, but I sure can. Especially in lip sync. If the audio is off by more than 40ms, it drives me bananas. Also gunshots, etc either seem just a tad to early or a tad too late.
I have used VDubs file information for the DIVX files to get the audio skew that was used when multiplexing the DIVX files, but this value is not even close to what seems right when muxing with BBmpeg.
For example, One of my stargate eps from season 5 shows an audio skew of .08 in VDub (80ms). So I think great I will set my video preload in BBMPEG to 180 and my Audio1 Preload to 260. But after multiplexing the audio is too late.
I then find myself searching the episode for a high action/fast lip movement scene to see how bad it is. I then drop or increase the audio skew in BBmpeg by 20 at a time and then recheck the same scene. This gets to be very tedious, but I can usually get almost perfect audio sync through the whole file.
If there any program that will give me the TRUE audio preload skew or am I stuck using the check/remux/check method? The only thing that I can think of that that the overall number of samples is being changed during the conversion from AC3 or MP3 to MP2 in Besweet. I don't do a sample rate convert so I assumed that I would have the same number of samples.
Can Anyone give me a concrete answer, maybe with a technical explanation of what is happening. Or better yet, show me how to find or compute the correct skew.
Thanks,
Moon1234
I have been converting most of these to SVCD's. My biggest problem is audio sync. The DIVX files are in perfect sync. When I convert to SVCDs using DVD2AVI the audio is almost perfectly in sync. My wife can't notice any difference, but I sure can. Especially in lip sync. If the audio is off by more than 40ms, it drives me bananas. Also gunshots, etc either seem just a tad to early or a tad too late.
I have used VDubs file information for the DIVX files to get the audio skew that was used when multiplexing the DIVX files, but this value is not even close to what seems right when muxing with BBmpeg.
For example, One of my stargate eps from season 5 shows an audio skew of .08 in VDub (80ms). So I think great I will set my video preload in BBMPEG to 180 and my Audio1 Preload to 260. But after multiplexing the audio is too late.
I then find myself searching the episode for a high action/fast lip movement scene to see how bad it is. I then drop or increase the audio skew in BBmpeg by 20 at a time and then recheck the same scene. This gets to be very tedious, but I can usually get almost perfect audio sync through the whole file.
If there any program that will give me the TRUE audio preload skew or am I stuck using the check/remux/check method? The only thing that I can think of that that the overall number of samples is being changed during the conversion from AC3 or MP3 to MP2 in Besweet. I don't do a sample rate convert so I assumed that I would have the same number of samples.
Can Anyone give me a concrete answer, maybe with a technical explanation of what is happening. Or better yet, show me how to find or compute the correct skew.
Thanks,
Moon1234