Audio pitch correction

[MacEachaidh]

I much prefer PAL-formatted DVDs to NTSC ones (can't stand the shudder in pans and tracks), but the raising of the audio pitch caused by the 4% speed-up drives me nuts as well.

WinDVD has a feature that supposedly corrects the audio pitch in real time as the disc plays. Unfortunately, it simply doesn't work. But the idea has appeal.

It'd be really nice if this could be implemented in VLC -- presumably as an optional feature to be toggled on or off, to accommodate those (few) PAL DVDs that have already been pitch-corrected in the mastering.

[Jean-Baptiste Kempf]

VLC does it already... USe VLC 1.0.2!

[Mozzza]

VLC does it already... USe VLC 1.0.2!

I'm using 1.1.4 but I can't find any option to correct the pitch, unless I'm just blind.

[MacEachaidh]

No, I can't find any option either, which is why I asked. Does that mean the feature was implemented, but was then removed?

Enquiring minds want to know!!

[Jean-Baptiste Kempf]

No, you can deactivate auto-pitch correction in preferences and you can play at 96%

[MacEachaidh]

Really? Thanks for the reply, but I really can't find the setting for this. Any hints, please?

(BTW, I'm using VLC 1.1.4.)

[VLC_help]

Tools -> Preferences, Audio section and option called Enable Time-Stretching audio. (Save and restart VLC after changes)

[MacEachaidh]

Thanks, but how do you specify for it to adjust by a certain amount?

If I have a DVD encoded in PAL but I want it to play the audio at correct pitch, how do I specify that?

I'd looked in the Knowledgebase Wiki before I posted here, but as far as I can see this feature isn't documented or even mentioned at all.

[Jean-Baptiste Kempf]

play it at 0.96x speed or 1.04x for the contrary.

[MacEachaidh]

I don't know what you mean. I can't see anywhere to specify the speed. It's either on or off, and that's it.

[MacEachaidh]

j_b, VLC_Help, thanks for your responses.

I don't want to sound like I'm complaining, but clearly I don't know what you're referring to, so making general and inspecific responses isn't helping anyone.

Yes, there's an "Enable time-stretching" option under preferences -- I'd already found that -- but it's a simple tick-box to toggle it on or off. I can't see any option to alter the speed of the audio response, and there's nothing in the documentation or Wiki that even mentions "time-stretching", so it seems like the feature is completely undocumented. I've tried playing PAL DVDs that haven't been pitch-corrected on VLC with this option enabled, and with it not enabled, and it makes no difference to the pitch of the sound.

So simply saying "yes you can do it" doesn't resolve the issue, does it? *If* you know yourselves, won't you please tell me how?

[VLC_help]

There is a speed icon in GUI (1.00x), you can click it if you want to change playback speed.

[MacEachaidh]

Sorry, but WHERE??!!!!!

Isn't it obvious fro my posts that I can't find any such thing??!

I appreciate the answers, really, but to be blunt, cryptic half-answers that don't actually address my question really don't help much at all. so you're wasting your time as well as mine (and anyone else's who wants to know how to do this.)

If you've taken the time to answer, couldn't you at least give me a full answer?!

PLEASE ?!

[Jean-Baptiste Kempf]

http://www.recipester.org/Recipe:Adjust ... r_35017844
or
Click on the speed icon in GUI

[MacEachaidh]

Thank you very much, j-b. Now I understand. I'm not a dummy, but I;m also not a coder, and I didn't appreciate what you were meaning by reference to the "GUI" (especially after the conversation up to that point was about settings in the Preferences).

A few points to note, if I may:
1) This only works acceptably for me if I actually enable "Time-Stretching", not disable as suggested earlier in the thread.
2) This facility of slowing the playback speed appears to be cumulative, for some bizarre reason. If I set the speed at 0.96, the pitch is fine for the first few minutes, but from then the pitch gets progressively lower and lower as the movie progresses. Not what it's supposed to do, I imagine, but it's happening for me. Should I lodge a bug report?
3) It would be really useful to have a preset facility to automatically pitch-correct when a PAL-encoded file is detected. Is this worth writing an enhancement request for?

Thanks again for your replies, j-b and VLC_Help.

[VLC_help]

2. Did you use VLC 1.1.5? That has some timing bugs under Win32, so it might cause strange issues.
3. VLC cannot identify native PAL and converted NTSC -> PAL so it wouldn't really work. And you can create shortcut for VLC that sets the speed to certain value.

[MacEachaidh]

Hi VLC_Help,
No, I'm using 1.1.4, because of the audio stuttering bug in 1.1.5.

I'm not using discs that have been converted from NTSC->PAL; I have either PAL-coded discs from R4 and R2, or NTSC-coded discs from R1.

Anyway, it was just a thought. I think it would be a useful feature. The speed shift as it currently stands is a bit unwieldy, and it also doesn't seem to work reliably.

[roger jonsson]

On the Mac I pre-set the PAL correction to 0.96 in "Tools/Preference" selecting "all", then in "input/codecs" i set "playback speed" to 0.96 (by printing it with the keyboard). Then save and restart the movie.
I do it this way, because there is no speed button with 0.96 on the VLC window in the Mac version. I tried this with my PC and it seems stable over time on the PC as well.

For the pitch to go down correctly with the speed "Enable time streching audio" should be disabled (un-ticked). Then Save.
This is true for most PAL-DVD:s. Don't forget to save and restart the movie.
Unfortunately idiots at some movie companies added time stretching already to some DVD:s and then there is not much you can do. It is clearly audible especially on music where especially long bass notes are garbled. Personally I play those videos at x1 speed, because lowering the speed and then adding another layer of timestretch to not lower the pitch (it was already lowered) sounds plain awful.

When it comes to non interlaced NTSC DVD:s (23.976 fps),VLC after 1.0.5 is giving me terrible frequent jerking. VLC 1.0.5 works fine. (I filed a bug report on this.) Playing interlaced NTSC DVD:s I find that Deinterlacing with Yadif or Yadif2 restores the interlacing pretty well.

[VLC_help]

Some DVD playback fixes are incoming (and better deinterlace filters also).