Replacing DVD audio with CDDA

[galneon]

I recently bought the official DVD of a concert for which I already have the corresponding live album. The only audio stream offered on the DVD is stereo 224 Kbps 48 KHz AC-3 which I'm not very pleased with. I wouldn't mind putting in the time to replace the audio (concert footage only--screw the menu audio) with LPCM.

It's obvious from the size of the DVD9 that the concert is on that the 2 1/2 hours long LPCM track would not fit on proper media, but I don't intend to burn any discs, much less physically spin them, so an over-sized ISO is not a problem for me.

That's one possibility, but would it be more practical for me to just rip the video stream, hack it together with the LPCM stream, encode and just go without the (worthless) menu content?

Am I right in thinking the latter approach might make more sense than authoring a new DVD if I genuinely don't care about the menus or putting it on optical media? The combined length of the CDs and the main concert track of the DVD are the same, so I don't think I'll have to worry about reconciling the differences pertaining to synchronicity based on, say, different lengths of time between songs.

Any advice would be appreciated. I don't need a detailed step-by-step, but tool suggestion would be helpful. I work in DAWs a lot, but admittedly am naive to video editing.

[filler56789]

If I were you, I would (after decrypting and extracting the VIDEO_TS folder to the HDD, of course):

1) demux the concert video to a single M2V file with PGCdemux;

2) convert the Audio CDs to a single WAV file, and then convert the WAV to LPCM with:

wav2lpcm - Copyright (C) 2005 Dave Chapman
Latest version available from http://dvd-audio.sourceforge.net/

USAGE: wav2lpcm input.wav > output.lpcm

3) mux the old video and the new audio to an MPG file with mplex.

[galneon]

Ahh, exactly what I was hoping to see :) Thank you!

[Ghitulescu]

Remember that the CD is sampled at 44100Hz and this is not allowed for DVD, whose minimum sampling rate is 48000. A sampling conversion is required, and this might cost you quality, depending on how it's done.

Secondly - the sound on CD is like that of the DVD taken from the master copy tapes. While there is no incentive or necessity to resample the audio for CD (the absolute pitch is kept), it may be very well needed to do so for DVD, in particular for PAL issues (it's popularly called PALspeedup). So not only you have to resample the audio but also to speed it up by 4% (with or without pitch change).

Your call. :)

[galneon]

Right, I'm not worried about converting this back into a working DVD at this point. It would be too large anyway. I'll keep the audio at 44.1 KHz. Am I correct in thinking I don't have to worry about 50 Hz PAL issues if my DVD is NTSC? Thanks for your input.

I actually noticed there is a few minutes of time difference between the total length of the CDs and the primary video stream of the DVD, so it looks like I will be doing quite a bit of splicing in Reaper... I intend to start with the DVD audio stream converted to 44.1 KHz wave and carefully overwrite most of it with the CD audio so that I have interludes of DVD audio (converted to mesh as close to seamlessly as possible with the CD waves). I'll ultimately end up with x264/FLAC 2.0 unless I have serious sync issues or loss of quality compared to the original AC-3.

[TheSkiller]

Am I correct in thinking I don't have to worry about 50 Hz PAL issues if my DVD is NTSC?There will be no speed-up. But there may be other issues. ;)
Even if it was a PAL DVD it does not imply the video is speed-up, it all depends on how it was recorded. If you're unlucky the original recording is PAL and hence your NTSC DVD is a normconversion.


The only audio stream offered on the DVD is stereo 224 Kbps 48 KHz AC-3 which I'm not very pleased with.May I ask why? Sure, it's not audiophile quality looking at the compression but it should sound quite alright unless something unfortunate happened to it (not related to compression).

[galneon]

It was recorded in the US and I'm not sure if it was even released in Europe... Certainly not elsewhere. Most likely it was recorded NTSC.

Something unfortunate likely did happen to it. The DVD version was delayed for around a year amid undisclosed "audio issues" of which the CD version evidently didn't suffer. It doesn't sound awful, though notably worse than the CD version with regard to mixing as well as compression artifacts (cymbals...). I don't think the extent of the LPF effect, in particular, can be attributed solely to compression, but in any case, given that I have the much nicer CDDA at my disposal and generally don't listen to any music that is lossy, it seems like a worthy use of my time. The DVD will otherwise be neglected.

[manono]

...it seems like a worthy use of my time.
That remains to be seen. I wish you all the luck but this is going to be a really big and time-consuming job for you.

I actually noticed there is a few minutes of time difference between the total length of the CDs and the primary video stream of the DVD, so it looks like I will be doing quite a bit of splicing in Reaper...
Splicing and stretching and matching up wave-forms.

[Ghitulescu]

I'll keep the audio at 44.1 KHz. Am I correct in thinking I don't have to worry about 50 Hz PAL issues if my DVD is NTSC?
Remember that the CD is sampled at 44100Hz and this is not allowed for DVD, whose minimum sampling rate is 48000.
Which part you did not understand? :)

[Stereodude]

I wish you luck with your tedious task. I've actually done the opposite. That is buy a DVD of a concert instead of the CD because the CD was 80 minutes (or less) and the DVD had many more songs. The few I've done that for had 48kHz LPCM stereo audio on the DVD though.

FWIW, unless the DVD authoring company was completely incompetent 224kbit 2.0 AC3 audio should sound pretty good though.

[galneon]

Which part you did not understand? :)

I see you conveniently snipped the first sentence from what you quoted. I'll refresh your memory with the full quote:

Right, I'm not worried about converting this back into a working DVD at this point. It would be too large anyway. I'll keep the audio at 44.1 KHz. Am I correct in thinking I don't have to worry about 50 Hz PAL issues if my DVD is NTSC?

What part of "I'm not worried about converting this back into a working DVD at this point" did you not understand? :) The "my DVD" I'm referring to in the third sentence refers to the source I possess. Didn't my mention of x264 later in the same post make it clear I'm no longer considering sticking with DVD format?

Anyway, thanks to all for the information, including Ghitulescu :P It's a scary task but I should be able to tell if it's worth finishing shortly after I begin.