Why can't TMPGEnc DVD Author and DVDLab handle MP2 audio?

[MrMungus]

It appears that if I author a DVD with TMPGEnc DVD Author or DVDLab using MPEG-2 files that have MP2 audio, both programs create VOBs with audio sync issues (whether I do or do not convert the audio to LPCM). But if I use Ulead DVD MovieFactory, I get VOBs with perfect audio sync.

Also, what other programs can author using MPEG-2 files with MP2 audio?

[mazinz]

its not that they cant handle mp2 audio (they can), but rather it is the muxing process done in the program itself when authoring your dvd. Ulead handles the muxing quite well in most cases, which is why your clips are insync after using it.

[MrMungus]

its not that they cant handle mp2 audio (they can), but rather it is the muxing process done in the program itself when authoring your dvd. Ulead handles the muxing quite well in most cases, which is why your clips are insync after using it.

Bummer. I was hoping to use the MPEG-2 files encoded by the PVR-250 as a source for DVD's in Author. I'm also trying to figure out how to capture to ACM or LPCM audio using the PVR-250...no luck yet...

Also, what other programs CAN use files with MP2 audio?

[NightWing]

How much of a sync shift are you getting?

Use Tmpge Author and have done a lot of shows to HM-DVD with no problems on playback.

Planing on try DVD-Lab to finish making a HM-DVD Battlestar Galatica with transision video when I can ever find the time but the audio on the short test runs did well.

[MrMungus]

How much of a sync shift are you getting?

Use Tmpge Author and have done a lot of shows to HM-DVD with no problems on playback.

Planing on try DVD-Lab to finish making a HM-DVD Battlestar Galatica with transision video when I can ever find the time but the audio on the short test runs did well.

Five to ten seconds and it's consistient -- not only do Author and DVD lab consistiently create files with audio sync problems but MovieFactory can consistiently create files without audio sync problems.

I see you're having success, but how are you capturing your video? What hardware and audio format/bitrate?

[NightWing]

Lets see.

Video Capture Card: DC10+ With driver only from Studio 8.
OS: Windows 98se with Direct X9.
MB: K7S5A with 2.2ghz Athlon and 512mb ram.
DVD Software: Nero 5.514?
CAPTURE SW: AVI_IO.
SOUND: On MB sound card.

I uses to use a Asus Terminator but wanted a faster cpu.

Avi_Io is set up to reset after 5 frames { for the 71 minute bug }.
Audio is set to PCM 44.1khz 16 bit Stereo.
Video is set for 2600 on the rate. At 640x480 resolution. 29.970fps. It stores its recording in the native DC10+ MJPEG format.

Will have the exact figure when Monster House is finished recording this morning.

I have never had a problem with AVI_IO not keeping thing in sync which I asume is translated through Tmpge compresson and then through Tmpge Author.


Hope that helped.

PS: I know it really 29.970005fps or something like that but thats all that AVI_IO can be set to is 29.970fps.

[MrMungus]

Lets see.

I have never had a problem with AVI_IO not keeping thing in sync which I asume is translated through Tmpge compresson and then through Tmpge Author.


Hope that helped.

PS: I know it really 29.970005fps or something like that but thats all that AVI_IO can be set to is 29.970fps.

The capture is not the problem. The captured MPEG-2 files I'm getting from the PVR-250 are perfectly synched. It's during the authoring process that they're getting screwed up. I was hoping you were going to tell me you're using a PVR-250 also (with good results).

Ah well. I'm trying now to change the audio frequency to 44khz vs. 48khz so we'll see how that goes.

[andkiich]

That's weird. I've done over 50 DVD's with a mix of AC3 and MP2 audio files in DVD-Lab and have had zero sync issues. If you want PM me later and I'll look up my audio encoding options in TMPGEN Plus. Maybe there are some encoding options that are making TMPGEN DVD Author and DVD-Lab be slightly off.

[NightWing]

Hum...

Unless Ulead is correcting any strange thing in the video from the PVR-250. I also have a TV card with software compressor into mpeg. If I get a chance will let it capture a few minutes of video at DVD level and see if TA messes up. May be a bit before I can run that test.

One test I love to run on any other capture system is to capture a bit of tv news from Fox or CNN news. Esp with the scrolling banner and a talking head. Good to check the stablity of the capture.

[mazinz]

sync issues as yours are very well known when it comes to making dvds. their are two options to fix that problem.

1. get a time base corrector
2. get a sync inserter.

the sync inserter runs about 45-50$, while a good tbc can go upwards towards 1000. The sync inserter just makes sure your video signal is strong by adding in numbers for each frame. So lets say you have a dropout in your pic, well our capture cards see this, later when remuxing it is little errors like this that is causing your sync issue. The sync inserter makes sure that doesn't happen. So when your pc card sees that glitch it no longer reads it as a dropout (so no padding frames are used) and it sees it as a regular strong signal instead.

99% of homedeck dvd reocrders use these (and some form of a tbc) to correct video problems)

[bottle-necked]

I have seen many sync issues and what might be causing your problem is simple audio offset. Creating the vob files is making the problem show up, but in my experiences, the original files were at fault not the author program.

Correcting simple offset is easy using a program like VirtualDub(MPEG) once the amount needed has been established. Just process the audio using your needed offset amount (Interleaving, Audio Skew Correction, + or -ms) and save to Wav. Convert the wav file to MP2 with TMPGEnc, then take the streams to author.

Good luck.

[bugster]

The capture is not the problem. The captured MPEG-2 files I'm getting from the PVR-250 are perfectly synched.

That means nothing.

In a mpeg program stream there exists presentation timestamps(PTS). These, as you may expect, are used to keep the audio & video in sync. In the MPEG encoding process (TV card or whatever), audio and video may start at a different PTS or some frames may be lost during the recording. You will not notice this when playing back the recording, as the PTS info present in the MPEG2 PS will mean that video and audio will be presented at the correct time, even with frames missing. Audio and video will still be "in sync", as the player knows exactly, when to present the A/V chunks.

Now in order to do a DVD we have to seperate the elementary streams from the program stream and re-multiplex to create the VOB files.

During demuxing we generate elementary streams, that have no timing information. Now - when you re-mux these streams, a missing or corrupted A/V block will lead to de-synchronization of audio and video.....

So if you capture direct to mpeg-2, and it is in sync, you have no guarantee of maintaining that sync when you author a DVD.

[MrMungus]

That's weird. I've done over 50 DVD's with a mix of AC3 and MP2 audio files in DVD-Lab and have had zero sync issues. If you want PM me later and I'll look up my audio encoding options in TMPGEN Plus. Maybe there are some encoding options that are making TMPGEN DVD Author and DVD-Lab be slightly off.

Well, there aren't many options in Author other than setting the audio format and bitrate.

[MrMungus]

Hum...

Unless Ulead is correcting any strange thing in the video from the PVR-250. I also have a TV card with software compressor into mpeg. If I get a chance will let it capture a few minutes of video at DVD level and see if TA messes up. May be a bit before I can run that test.

One test I love to run on any other capture system is to capture a bit of tv news from Fox or CNN news. Esp with the scrolling banner and a talking head. Good to check the stablity of the capture.

Yeah, I did a test this morning encoding 30 minutes of TV to MPEG-2 then authoring it to DVD using Author and the audio was synched. What I changed this time was changing the audio format on capture from 48khz audio sampling to 44khz sampling. Maybe that was the issue. I'm going to try the test again tonight with a longer clip.

Still, I wish I could capture directly to LPCM. Maybe I'll ditch the PVR-250 in favor of using a Firewire/software MPEG encoding process when the new 3GHz computer arrives this week.

[MrMungus]

sync issues as yours are very well known when it comes to making dvds. their are two options to fix that problem.

1. get a time base corrector
2. get a sync inserter.

the sync inserter runs about 45-50$, while a good tbc can go upwards towards 1000. The sync inserter just makes sure your video signal is strong by adding in numbers for each frame. So lets say you have a dropout in your pic, well our capture cards see this, later when remuxing it is little errors like this that is causing your sync issue. The sync inserter makes sure that doesn't happen. So when your pc card sees that glitch it no longer reads it as a dropout (so no padding frames are used) and it sees it as a regular strong signal instead.

99% of homedeck dvd reocrders use these (and some form of a tbc) to correct video problems)

Hmm...I didn't think the problem was the original file since it is synched on playback, but reading this I'm wondering if it is (especially since, like I said in my last post, I was able to capture and convert to DVD some video that was taken directly off a tuner). The tape I've been trying to use to convert does have some serious issues so maybe it's creating files that are borderline (even though I'm using TBC on it) such that some DVD authoring programs can correct it and others cannot. Thanks! I'll look into those options. Do you know of any cheap sync testers?

[MrMungus]

So if you capture direct to mpeg-2, and it is in sync, you have no guarantee of maintaining that sync when you author a DVD.

Ah ha!

So...what programs can I use to check my MPEG files for such things?

[bugster]

So if you capture direct to mpeg-2, and it is in sync, you have no guarantee of maintaining that sync when you author a DVD.

Ah ha!

So...what programs can I use to check my MPEG files for such things?

Probably the simplest way is to simply de-multiplex the source mpeg into elementary streams, then re-multiplex them back into a system stream. Then check if this new mpeg still has sync. You can use TmpGenc mpeg tools to do this.

[MrMungus]

So if you capture direct to mpeg-2, and it is in sync, you have no guarantee of maintaining that sync when you author a DVD.

Ah ha!

So...what programs can I use to check my MPEG files for such things?

Probably the simplest way is to simply de-multiplex the source mpeg into elementary streams, then re-multiplex them back into a system stream. Then check if this new mpeg still has sync. You can use TmpGenc mpeg tools to do this.

Based on your "bad MPEG-2 file" theory, I did a test and found that if I encode an MPEG-2 file from a live source such as the TV that I can create a DVD with perfect sync. So what I think is happening is that the tape I'm trying to encode is so out of wack that a "good" MPEG-2 file (good enough for authoring) can't be created.

So, I'm assuming that for some bad sources, I need more time-base correction than I can currently get from the JVC VCR I'm using (as LordSmurf says, JVC TBC isn't always enough).

I'm also wondering if more expensive MPEG-2 capture cards are better able to compensate for "bad" video input.

Thanks everybody!