Audio plays but TMPGEnc dosn't "recognise" it

[ggaimbot]

hello,
i was trying to make a movie and than when i put it in the DVD player there was no audio at all...i was confused by this so i played it on my computer and i herd all the audio and everything, i figured that maybe there was a problem when i was using TMPGEnc so i re did it, but the thing is when i 1st started how it asks for the video file and the audio file, you can just press on add video file and click on the AVI and it loads both the video and the audio. when i did this it only loaded the video, so i tried to add the audio manualy and the program said that there was either no audio or it was in a format that it didn't understand...but its avi...and it works every other time.i think the avi might have gotten corrupted because i do remember putting it on dvd a while ago and it had audio. the thing is...i can play it in winamp or whatever and it sounds fine...is there something that i can to to make TMPGEnc recognise it?

[guns1inger]

open it in avicodec or g-spot and look at the audio, or try to open it in virtualdubmod and see if you get a warning. Dollars to donuts it is VBR mp3 audio.

[ggaimbot]

Audio : 389 MB, 448 Kbps, 48000 Hz, 5 channels, 0x2000 = AC3 DVM, Supported
thats what the audio is.

UPDATE: ok well i opened it up just fine in that program with no errors...but i didn't get any sound from the video through that program, im not sure if that program is supposed to play audio or not.

[mats.hogberg]

Ah - TMPGEnc doesn't read AC3. Decode to wav first (load AVI in GoldWave, save wav), then use wav as audio source for TMPGEnc. Or maybe the AC3 ACM codec helps TMPGEnc too (Yes, it's advertized to.)?

/Mats

[guns1inger]

tmpgenc won't be able to use AC3, but this is not an issue.

Encode just the video in tmpgenc. Use virtualdubmod to demux the AC3 audio.

Bring the two together when you author.

[PuzZLeR]

tmpgenc won't be able to use AC3, but this is not an issue.

Bring the two together when you author.

Can I ask for an example of bringing the two together when you author? Thanks in advance.

[guns1inger]

I use DVD Lab pro for authoring. I chose the video and audio streams required for a given movie when setting up the disc. DLP does all the muxing etc for me. That is how most authoring tools work.

Which authoring tool do you use ?

[bobkart]

I have a similar problem with a DivX+AC3 (AVI) file that I am trying to author to DVD. TMPGEnc would not recognize the audio portion (5.1 channel). So I used AVI-MUX GUI to separate the AC3 data, then rendered just the video portion to MPEG2 (with TMPGEnc), and authored the MPEG2 plus the demuxed AC3 to DVD, but the result was out of sync by a second or so (audio late) by the end of the video (about 72 minutes). I tried again by rendering both the video and the AC3 at the same time (again with TMPGEnc, it recognized the audio when it was fed in separately for some reason), this caused the 5.1 channel audio to be downconverted to stereo, but I was more curious as to whether it would cure the sync problem, and it didn't, same sync problem going that route. Is TMPGEnc the problem or can it be made to work without resorting to another authoring tool? By the way the original video was apparently made by VirtualDubMod (according to MediaInfo).

[guns1inger]

If the audio is out by a constant amount the whole way through then it is ismply a matter of correcting the delay. Many authoring tools allow you to fix this during authoring. If your doesn't, there are programs like DelayCut to alter the audio file before authoring.

[bobkart]

It starts in sync and gets more out of sync as it plays.

I checked the original and the audio synchronization is fine.

[mats.hogberg]

Different frame rate in the AVI and your encoder setting?

/Mats

[bobkart]

If so it would have to be very slight to account for just a second or so after 72+ minutes.

Hold on, checking . . .

Aha, source is 23.976 fps, TMPGEnc reports the output as "3:2 pulldown playback, 23.976 fps (internally 23.97 fps)"

So there seems to be a 0.006 fps discrepancy. But I don't quite understand the "internally" part.

[bobkart]

Well I tried encoding to 29.97 fps instead, combining during authoring with extracted AC3 from original file, same problem.

I guess the nonstandard framerate of the DivX is the problem (23.976 fps).

So I need to either drop a video frame every 166.667 seconds or resample the audio to make it 0.025% longer.

Time to work on that audio resampler I had plans for!

[guns1inger]

23.976 is not non-standard. It is in fact the correct framerate for most NTSC movies.

"3:2 pulldown playback, 23.976 fps (internally 23.97 fps)"

Should read "internally 29.97 fps", which is what pulldown is for.

[bobkart]

Whoops, yeah just checked again, you'r right, "internally 29.97 fps".

So if everything is fine I guess I don't understand where the audio sync problem is coming from. Is TMPGEnc just blowing it and creating an MPEG2 file that ends up a second or so too short by the end?

[guns1inger]

It could be a small corruption in the original files. Something isn't enough to cause playback problems, but is an issue for encoding.

Just for giggles, try encoding it in something like DivxtoDVD to see what it creates. DivxtoDVD does not use pulldown (that was introduced in ConvertXtoDVD), so it will create a lot of additional frames to get to 29.97 fps, and pans and zooms will be jerky, but will it stay in sync ?

[bobkart]

Okay thanks for that idea guns1nger, I'll give it a try soon, my video PC is busy with some HDV footage at the moment though, so it won't be tonight.

[bobkart]

Well ConvertXtoDVD gets it wrong too. I checked again and it plays right in VLC.

Curiouser and curiouser.

[guns1inger]

Time for a g-spot screenshot of the avi, methinks.

[bobkart]

http://bobkart.gt3times.com/jpeg/G-Spot-1.JPG

[guns1inger]

What are you authoring with ? I can seem to find a reference to an authoring tool in this post to date. Everything else seems to be in order. The audio looks fine, encoding the video as 23.976 with pulldown is good, so that leaves the authoring as a possible problem.

[bobkart]

Authoring with TDA. I guess I did leave that out.