Non-Standard DVD (PAL/NTSC "Combination")

[greedy]

I recently purchased an R2 DVD (PAL) and would like to create a "non-standard" backup.

The following is a list of what I would like to change/keep:


Framerate: Change to 29.97i (25p > 23.976p > 29.97i)
Audio: Slow down the audio (reverse 4% speed increase)
Resolution: Keep PAL resolution (720x576)
Region: Remove region coding (Region 0?)

So, the result will be a region free DVD with NTSC framerate, corrected audio, and PAL resolution. Will all of this be possible?

Thanks in advance for any feedback.

(I wasn't sure what sub-forum to post this in, so I apologize if this isn't the best place.)

[Matthew]

Will all of this be possible?

Without any patching the video stream resolution details, I suspect DVDLab is your best bet...many authoring apps would reject your video as non-spec. Haven't tried this myself though.

IMO non-spec backups=bad...if this is a copy for long term use it could come back to bite you in the backside.

[greedy]

Thanks for the reply, Matthew. :)

The backup is just an experiment and I will always have the original disc. Basically, I would like to have the best of both worlds (PAL resolution + correct playback speed).

Also, I have some questions regarding the slowdown in framerate.

I was planning on using AssumeFPS(23.976) with Avisynth to slowdown the framerate and then correct the audio pitch using an application like BeSweet.

From what I've read, the above method should work, but I was also wondering about simply changing the header information on the DVD. Using "DVDPatcher" for instance, would it not be possible to change the framerate to playback at 23.976 instead of 25 (allowing the player/tv to apply 3:2 pulldown)? If so, would patching the header this way also slow down the audio to compensate for the decreased framerate or would the audio remain 4% faster and cause sync issues?

Lastly, if I used the first method, could Avisynth's "sync_audio" parameter act as a substitute for seperately processing the audio with BeSweet?

"The AssumeFPS filter changes the frame rate without changing the frame count (causing the video to play faster or slower). It only sets the framerate-parameter. If sync_audio (which is false by default) is true, it also changes the audio sample rate to match the duration of the video, the pitch of the resulting audio gets shifted." - Avisynth (http://www.avisynth.org/FPS)

Thanks again, I really appreciate the feedback!

[Matthew]

I was planning on using AssumeFPS(23.976) with Avisynth to slowdown the framerate and then correct the audio pitch using an application like BeSweet.

You don't need to use re-encode the video as you are not changing the resolution or frame count. So no need for avisynth (btw I don't know about audio processing in avisynth anyway).

Film->PAL audio is not necessarily pitch corrected - to be honest I'm not sure how often it is or isn't - so the pitch may be more accurate if you just slow down the audio without correction. Pitch correction can also cause artifacts, etc.

From what I've read, the above method should work, but I was also wondering about simply changing the header information on the DVD. Using "DVDPatcher" for instance, would it not be possible to change the framerate to playback at 23.976 instead of 25 (allowing the player/tv to apply 3:2 pulldown)? If so, would patching the header this way also slow down the audio to compensate for the decreased framerate or would the audio remain 4% faster and cause sync issues?

You are going to have to reauthor. The appropriate method would be to use Pulldown|DGPulldown to change the fps of the m2v to 23.976 and add flags to get to 29.97. You can of course go direct from 25 to 29.97 using DGPulldown, and avoid re-encoding the audio, but the length of the film will be off as with the original DVD.

Audio has no framerate, so once the length of the film is changed, a re-encode is necessary. No way to avoid that.

And as an aside, you can change the length of the film, and keep the resolution, and remain standards compliant by changing the fps to 23.976 and using DGPulldown to get to 25 fps. This results in relatively jerky (and interlaced) video, hence the use of the 4 percent speedup on retail DVDs, but it may not be a huge problem for you.

[Mug Funky]

This results in relatively jerky (and interlaced) video, hence the use of the 4 percent speedup on retail DVDs, but it may not be a huge problem for you.

i wouldn't say it results in interlaced video. on a CRT TV everything's interlaced, and with a DVD player worth it's salt (and with progressive out), it will read the flags from the stream and bump the rate to 50fps, pure progressive. either way, there's no problem at all.