ffmpeg import from DVD - glitchy audio (SOLVED)

I am an occasional user of Audacity. I just recently wanted to extract audio from a DVD. After a little research I discovered that ffmpeg with audacity will do this. So I upgraded to Audacity 2.0 and downloaded FFmpeg_v0.6.2_for_Audacity_on_Windows. Got it working, or so I thought. :slight_smile: I imported audio from the VOB files, noticing that during the import the progress bar would start over several times, before eventually finishing the import. But then the waveform was there and it seemed to play back. But I found that after about eleven minutes the imported waveform was glitchy. It would start repeating short sections and making short medium-pitched (for lack of a better word) “honking” sounds. These are not playback issues but waveform importing issues. Overall this results in an approximately 22 minute VOB imported as an approximately 24 minute waveform. With frequent short glitches starting to appear typically around the ten to twelve minute mark. I tried it with several different VOB files. I also tried it by importing directly from the disc, and with decrypted files copied to my hard drive. The glitches are very consistent. I haven’t done any testing to confirm, apart from listening with my ears, but it seems that it glitches in approximately the same way at approximately the same place for any particular VOB, every time I try it.

Any advice? I’d love to get this working.

DVDs can have several different audio tracks depending on how much room they had available during encoding. Are you trying to open the PCM track or the Dolby AC3? AC3 in a theatrical release is going to try to open into 6 audio channels.

You claim to have decrypted the disk. It also sounds like maybe you haven’t.


When importing I’m presented with three different audio tracks to import. Two of them are six-channel tracks (DTS and Dolby). One of them is a two-channel track. I’m importing the two-channel stereo track. And it sounds great… up until around the eleven minute mark. On any of the VOBs on the disc. By decrypted, I mean I used DVD Decrypter to copy the files onto my hard drive. The results are the same with importing from the disc and importing from the hard drive.

So what format is the two channel track in? What happens if you convert/downmix the 6-channel AC3 to 2-channel WAV in HeadAC3he ?


The disk plays as a straight movie, right?
What happens if you try an different disk?

Here is what it says in the “Select stream(s) to import” dialog: Index[80] Codec[ac3], Language[], Bitrate[1], Channels[2], Duration[526]
The stereo audio on the DVD is labelled as Dolby Digital Stereo.

I haven’t yet tried to downmix.

Do the VOB files play correctly in other applications (for example in VLC)?

There are a few “DVD audio extractor” programs avalilable, but I haven’t tried them.

I generally use my video editor (Corel Video Studio). I can import the audio and video from (non-encrypted) DVDs to a single MPEG-2 file. Then, there’s an option to create a sound file.

[u]SUPER[/u] (FREE!!!) should be able to create an audio-only file from the (non-encrypted) VOB, either as a “stream” in the original format, or converted to another audio format. I use SUPER whenever I run across a “difficult” audio/video format. If you download SUPER, make sure you follow the confusing links and download SUPERsetup.exe… There are ads for other software on that website.

[u]VOB 2 MPG[/u] (FREE!!!) can combine the group of (non-encrypted) VOB files into one big MPEG-2 file without transcoding. Then you can use SUPER, a video editor, an audio extraction tool, or possibly Audacity, to extract/convert the audio.

If all else fails, connect the RCA audio line-outputs from your DVD player to the line-input on your soundcard, and make an “analog” recording. :wink:

Do the VOB files play correctly in other applications (for example in VLC)?

That’s what I want to know. This smacks strongly of a damaged disk. Koz

Or a copyright protected disk that has foiled the ripping software.

Thank you all for taking the time to try to help with this. As it turns out, the VOB files do not play correctly in VLC. They glitch in the same way. I didn’t realize I was just dealing with a difficult disc. Other discs produce better importing results. So instead of being able to import this audio directly, I have to play the disc and use audacity to record the live Windows stereo mix. More of a pain, but at least now I can proceed. Thanks again.

Topic marked as solved.