0 bytes AC3 file after transcoding

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Hi,

I am trying to transcode a WAV file to AC3 with Besweet/Belight but everytime I recieve a 0 bytes AC3 file.

I have two folders: one is BeSweetv1.5b31 and the second is BeLight-0.22beta9. Do I understand right that I actually need only the second one as it includes all files from BeSweetv1.5b31 + BeLight.exe ?

Thanks.

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I checked the log and it showed that VOBinput.dll and libvorbis.dll were not installed.

I've located and installed both .DLLs (it was quite a hassle to find libvorbis.dll) into the Belight floder but the result is still the same. The log shows all DLLs are present.

The AC3 file I receive after the transcoding has 0 bytes. Your advice would be appreciated. Thanks.

[guns1inger]

I would use ffmpeggui. I know it works.

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guns1inger,

Thank you. I'll try it right now but what's confusing to me is that I've read so many times: Bewsweet is the best audio tool around.

I was attracted by the Besweet feature (SoundTouch) that allows to change audio fps, which could possibly fix my asynch problems with AVI to NTSC DVD.

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Hi,

Yes, ffmpeggui created AC3 in a blink of an eye but the file still gives the same progressive asynch problem. I have four AVI to NTSC conversions unfinished just because of the problem. I browsed the forum and Doom9 but cannot find any ideas why it is happening.

Hopefully I'll find the way how to make Besweet working somehow.

[guns1inger]

audio doesn't have a fps. Audio has length. Any good audio editor can alter the length through time stretching - audition sound forge, goldwave etc. All you need to do is make the audio match the length of the video, then encode. Assuming that is all your problem is.

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I probably put it in a wrong way. What I meant that Besweet has the feature (Advanced settings) where you insert the rate of the original and of the resulting video file.

I believed (though it could be just my mistake) that this might positively affect my problem.

As for the lenngth, the running time of the video and the audio is the same. That's why I thought that it might the feature in Besweet would work.

I am not sure that just time stretching could work as it is progressive: it is perfectly synchronized at the beginning and then the audio lacks more and more behind the video.

In "The Night Porter" at the end of the movie, I hear the shots and the folks fall down half a minute later.....

[guns1inger]

If the video and audio running time is the same then besweet isn't going to help you. The fps feature of besweet is just a silly way of saying 'timestretch' to make it a video tool. Again, audio has no framerate, so changing the 'framerate' in besweet changes the running time (length).

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Thank you. I know you are right. I was just trying something new as I have no idea why it's happening and what to do with it.

I muxed audio and vdieo from PAL DVD to NTSC DVD conversion with no problem but AVI to NTSC DVD does not go.

[guns1inger]

If the avi was PAL to begin with (25 fps) then the process is exactly the same. If it was not 25 fps to begin with then you are aren't doing PAL to NTSC, and may need to adjust the process accordingly.

[redwudz]

How did you obtain the WAV file? If you converted it from VBR MP3, that would explain the sync problem. Other than that, if the original video or audio was corrupted or missing frames, you can have sync problems.

I've converted a lot of MP3 audio to AC3 with ffmpeggui and never had a sync problem with a good file to start with. The ffmpeggui program should work OK, it's just that some of the other AC3 converters may have a little higher compatibility with the AC3 specification. And they may have somewhat better quality, but all that would depend on the quality of your source audio file.

I think the bigger problem your sync loss. I would sort out the cause of that before anything else. If you are doing framerate conversions from PAL<>NTSC, that can also mess up the sync.

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The first AVI is PAL and I did the way through Procoder: to 25 > 29.97 with pulldown.

The second one is 23.97 and if you remeber I've done it to 23.97 (2-3 pulldown).

The audio when trying to mux in both is just the same: lacking behind.

I browsed Internet and found that Direct X cann affect synch. I ireinstalled it anew but nothing has changed.

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Gspot shows the original audio (the first file - PAL) as:

0x0055(MP3, ISO) MPEG-1 Layer 3
32000Hz 58 kb/s (1 chnl)

"If you converted it from VBR MP3, that would explain the sync problem." - What would you suggest in the situation?

[guns1inger]

Post the screenshot - this doesn't say if it is VBR or CBR

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Here it is:

[LloydAZ]

Gspot shows the original audio (the first file - PAL) as:

0x0055(MP3, ISO) MPEG-1 Layer 3
32000Hz 58 kb/s (1 chnl)

"If you converted it from VBR MP3, that would explain the sync problem." - What would you suggest in the situation?

I've had a similar problem with BeSweet/BeLight when the audio is not either 41000Hz or 48000Hz. Try running it through dBpowerAMP and convert it to 48000Hz then run it through BeSweet/Belight and see if that does the trick.

I've also had some problems with 1 Channel audio as well. To fix that problem I would open it in Goldwave and save it back as a stereo WAV file. It's been a while since I've done that, but I believe that Goldwave will also let you save it off at 48000Hz as well.

I hope this does the trick for you.

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LloydAZ,

Thank you very much. I will give it a try.

The movie (The Night Porter) is an old one. I changed the audio (from French to English) and all the stuff could cause the mess.

The second one also is not straightforward. It is HD recording converted to AVI.

Well, those are just my guesses about hardships...

[redwudz]

The 'Night' one does show MP3 VBR. If you saved it out as a WAV in VirtualDub with full audio processing, that should have kept it in sync. If you wanted to add the other channel so you would have 'joint stereo', IE, both channels the same, most audio editors can 'clone' the working track and transfer it to a new track. Not real stereo, but at least the sound would come out of both speakers.

I don't usually do PAL<>NTSC conversions, so I'm no help there.

Sync basics: If the sync error is the same throughout the video, then the start time is wrong and you need to add a 'offset' positive or negative to correct it. If the sync error changes throughout the video, then either the video or audio are likely different lengths and you have to change one or the other to correct it. VBR will give you that problem if you don't process it properly to WAV. Throw in framerate changes and that complicates things.

That's the simple part. Fixing it can be difficult. If you have any corruption of the video file, then you can end up with both types of sync error at once. Really tough to fix.

But I would assume simple sync error. Check the lengths of the audio and video and see if anything shows. If you have a simple offset problem, VD Mod can correct that by adding audio 'skew'.

There is a simple method for all this that handles the framerate conversions fairly well, along with the VBR.
You can save out the WAV as before, then add (mux) it back in with VD Mod. Then drop the newly muxed AVI file into ConvertXToDVD. It can usually handle VBR, but I would rather not take the chance. This has saved me a lot of time and energy. If you are starting with a 700MB Xvid, the quality is quite good. A higher quality Xvid of maybe 1.5GB or bigger may benefit more from a longer or more complex method.

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Thank you for your input.

"If you saved it out as a WAV in VirtualDub with full audio processing, that should have kept it in sync." - Both "yes" and "no".

VirtualDub could not handdle it. It gave error message all the way though usually works fine.

I saved MP# to WAV with ImTOO MPEGencoder and checked the WAV with GSpot.

The running times, audio and video, are the same. I tripple checked it.

"the sync error is the same throughout the video" - No, it is not. It is progressive: at the beginning everything is perfectly well and later on the audio is ahead of the video. But it depends on how I create the audio: if through WAV the audio is ahead of video. If from MP3, the audio is lacking behind.

[machf]

Try converting the audio from the original .AVI file to a .WAV file using a program that can extract the audio from video files, like RiverPast Audio Converter, CoolEdit, etc, (you can make it two-channel "stereo" at the same time), then use that .WAV file as the audio source. If the source AVI audio is VBR MP3 and VirtualDub can't decode it to save it as a .WAV file, usually doing that will solve the problem.
And if the original AVI source of that audio was at 25fps and you want to add it to a video at 24fps, you have to stretch the audio by a factor of 25/24, or about 4.17% longer.

[guns1inger]

If the file is OK to begin with, Virtualdubmod should have given you one warning, right at the beginning, with an offer to re-write the header. If you say no at this point, game over. If you say yes, then save out the wav as uncompressed PCM, you should be OK. If you get further error messages then one of two things is happening. Either you didn't answer yes at the beginning, in which case go back and start again, or the file is corrupt.

Now before you tell me the file can't be corrupt because you can play it back, let me tell you that playback is irrelevant. There is a certain level of error correction and compensation built-in to allow playback to continue past minor corruption. Some players are more robust than others in this respect. However the process for encoding is not so forgiving, and problems that might not adversely effect playback, or whose affect is very slight, can stop encoding happening correctly.

Personally, I suspect that you are not extracting the audio correctly to begin with.

There is an alternate approach, that may save you some trouble. ConvertXtoDVD produces 192kbps 2.0 AC3 audio output. What you could do is let it convert the file (as PAL), demux just the AC3 audio, an use that in your project. ConvertXtoDVD is usually immune to VBR MP3 issues. Use can use a tool like Rejig to extract the audio. And as you don't need the video compnent, you can use the demo version of ConvertXtoDVD as the watermark isn't an issue.

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Guys,

Thank you very much!

It is overwhelming for my level of understanding the stuff. Not to waste your time, please allow me some time to analyze the info and to try the practical steps.

I will sure post the results.

Again, thank you very much for your time!

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Hello everybody,

I made my homework with the audio based on the advices.

Frist, I tried to save the audio as uncompressed WAV in VDM. It gave the error message about VBR but when I clicked "yes", there was another error message that there wa no decpmpressor though as GSpot shows all required codecs are installed.

I saved decompressed WAV through ImTOOEncoder (please see the log screenshot)




After that I converted the WAV to AC3 with ImTOOEncoder. The synch problem was still there.

After that, I used GoldWave and pretty easily synchronized the beginning and the end of the movie by increasing the audio length. I was surprised to find out that the middle part of the movie was still a complete mess. There is still strong asynchronization there.

In GoldWave, I worked for two evenings with Effects > Time Warp > Similiraty. I encoded numerous copies with various settings from the WAV that matches the beginning and the end of the movie but I still have strong asynchronization in the middle part of the movie.

I did not try Effects > Time Warp > Rate as I do not understand how to use it. Tha same about FFT.[/img]

[guns1inger]

Install the correct LAME MP3 codecs and virtualdub should use them happily. I have had only one instance where a VBR MP3 basically screwed up regardless of tools used. From freebie ffmpeggui through to Sound Forge and Vegas. In the end it simply wasn't worth the effort to try to fix it. VBR MP3 is an abomination that saves a few MB of size, and is useful only for playback. As if MP3 wasn't bad enough . . . . .

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guns1inger, thanks.

Do I understnad you right that if I am able to save the audio as WAV with virtualdubmod, I will avoid the asynch problems?

[guns1inger]

You have a better chance. Until I got my Divx player, that was the process I used. I'm also suspicious of the ImToo Encoder, but one step at a time.

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I have a player that plays all AVIs and Divx - Philips but I do not like the picture it produces comparing to my Panasonic; the aspect ratio it generates. If zoomed the picture is ugly.

Besides, if everything goes more or less fine, it is fun to work with the files.