Probs w/ DVD Lab Pro and PCM

[ADigitalMan]

I've had a problem for years that I've yet to solve. Whenever I try to author a project with PCM audio using DVD Lab Pro (my authoring program of choice) it takes an abnormally long amount of time, and the muxed video always stutters.

I usually would resort to TMPGEnc DVD Author, but that supports only one audio track. My current project requires two.

The search function is broken at the moment, so I don't know if this has already been addressed on the forum.

--ADM

[FulciLives]

Are you sure the bitrate is not too high? When the bitrate is too high then a DVD player will stutter on playback.

Remember that a single PCM WAV audio track has a bitrate of 1536kbps which means your video bitrate needs to be no higher than 8000kbps and of course if you have more than one audio track then both have to be considered.

For instance if you have one PCM WAV audio track at 1536kbps and a second 2.0 AC-3 audio track at 256kbps then you better limit the video bitrate to about 7700kbps to be safe.

If both audio tracks are PCM WAV then that's 1536kbps times two or 3072kbps in which case you need to limit the video bitrate to about 6400kbps to be safe.

So yes it is only a guess on my part but this is just a reminder if nothing else to watch your total bitrate which includes the bitrate of the video as well as the bitrate of the audio file(s) ... I think even subtitle streams take up a bit of bitrate but not much as I recall reading.

- John "FulciLives" Coleman

[ADigitalMan]

Bitrate is 6420

[greator]

Your PCM audio must be raw..meaning big file size over 100mb...DVDLab will tell you if the PCM can be use or not..Beside, DVDlab can create PCM audio for you...I dont usually use that much so I cant tell you how..

[FulciLives]

Bitrate is 6420

I assume you mean this is the video bitrate? Is that the AVG of a VBR or was it CBR or what?

Anyways assuming total bitrate is not the problem (meaning it is not too high) then I would look at your PCM WAV audio file. Make sure it is 2 channel (mono or stereo) 16-bit 48k format. Sometimes people make the mistake of it being 44.1k instead of 48k and the DVD standard calls for 48k to be used.

If that is not the problem then maybe there is an issue with the program you use to make your PCM WAV audio file ... I really don't know.

You haven't really given much detail and the answer to most questions tends to be in the details given ...

- John "FulciLives" Coleman

[ADigitalMan]

Found it. Sure enough it was the video bitrate ... one chapter had a CBR of 8000 whereas everything else was 6300. (The two sources had been spliced together via a GOP editor).

I re-encoded the 8000 segment to 6300, re-spliced, re-muxed, and everything came together nicely.

Many thanks!!!