Static in audio with VLC under Mac OS X

[PC+Mac]

Hey everyone, I've been hearing small amounts of static in the playback of my divx files in VLC that is non-existent in Quicktime or Mplayer. This happens even when the output volume of VLC is lower than in Quicktime or mplayer. I've poked around VLC's settings but to no avail. Does anyone have the same problem or even better, have a solution?

VLC 0.8.0-test1, Mac OS X 10.3 Panther on 1Ghz Powerbook. Btw, the static was present in VLC 0.7.2 as well.

[PC+Mac]

K, I've narrowed it down to some changes between 0.5.3 and 0.6.0. In 0.5.3, the audio is great; as good or nearly as good as Quicktime, mplayer, etc. without static when the volume isn't too high.

Looking through the change log:

Mac OS X port:
* ...
* New audio resampler. Should make VLC much faster.
* ...

I think this is the reason for the poor audio quality and why VLC seems to bring out audio flaws that are absent when the file is played in other players.

Now, I could use 0.5.3, but there have been many optimisations, improvements, extra codec support etc that I'll be missing. Most noticably the more accurate seeking and auto alphabetic arrangement of playlist items with other like OpenGL, etc.

Would it be possible to at least have an option to use the old audio resampler in 0.8.0? I mean, macs are getting faster after all, OS X is improving and so is VLC. I'd like to get the full original sound from files I'm playing.

Anyway, thanks for the program. You can't beat free, but I just hope that this ONLY VLC problem of mine can be resolved. Too bad I had to post this on the weekend. :/

[Guest]

I agree, noise is the sole reason I don't have vlc installed. It's simply not useable on my iBook G4 with Mac OS X v10.3.5. Dvd playback is great and noise free, but 90% of the time I watch lots of anime encoded in Divx/Xvid with mp3 audio and the resulting noise on these clips is simply too annoying.

I know you developers are under no obligation to fix this and probably have better things to do in your free time, but if you could put an option at least to use the old audio sampler (if indeed it is the new audio sampler since 0.6 causing these issues) in newer builds, I'm sure the mac community will be greatful.

[PC+Mac]

Yep... that more or less describes my situation. Anime watching is spoiled by the noise in the audio. I'm guessing that DVD audio is well, a perfect and 'clean' source while most anime is recorded from television and so contains some residual noise as it is digitised from an analogue signal. Unless you're watching DVD-ripped anime of course.

I'm just making an educated guess and I do hope that the developers (*hint* *hint* "The DJ") can investigate the cause. I concluded on the resampler because the static seems to be present only in the Mac versions and so should be a result of a mac only change. Of all the changes in the log for the Mac version, the resampler seems to be the best candidate as it deals with the audio. The resampler seems to bring out the flaws in the audio.

I agree, the mac and VLC using community would greatly appreciate this. I know at least 3 people would. And there are many more silent ones out there. What's annoying is that this seems to be a problem of ONLY the Mac port. It doens't seem to be a problem inherent to the core of VLC. It plays perfectly fine in the Windows version of VLC. Perhaps the new resampler (I'm assuming it's the resampler) was a quick-fix for performance gains, but right now, I think it seems unnecessary. Again, for the sake of the owners of slower macs, at least make it an option.

[The DJ]

and just the fact that i answer most posts on this forums doesn't mean a thing about what i do. There are many people on the project who code more (much more) on vlc than i do.

[PC+Mac]

and just the fact that i answer most posts on this forums doesn't mean a thing about what i do. There are many people on the project who code more (much more) on vlc than i do.

Perhaps there are many people on the project who code more than you do, but I was under the impression that there would be specific teams for the core, linux, windows and Mac versions. And I specifically referred to you as in your sig is:

Videolan - VLC media player
Derk-Jan Hartman
Developer of the MacOS X port of vlc

So I thought you would at least know something about the problem that seems to affect ONLY the Mac version.

And is this your reply to the 'bug'?

As stated many times before on this forum, we currently have noone who can work on VLCs OSX audio support, when we find someone who CAN fix it, it will be fixed.

Next to that, it's not said that this is caused by the resampler. Actually, i think it would be very unlikely and probably caused by a change in the audio output.

So your saying that the static is NOT caused by the resampler? Then it's all up to you guys now. But I just wanna know, have u been aware of the problem since 0.6.0? So you're also saying that the static has persisted since 0.6.0 upto 0.8.0b because there's no one available that can work on the audio? And I'm guessing that the change in the audio output is out of the hands of us end users huh? I've tried tinkering with virtually every audio setting trying to get 0.7.2 to sound as good as 0.5.3.

Believe me, I appreciate the amount of time and effort you programmers have to put into this project. I'm not asking you to fix it immediately, though that would be nice. What I would like to know is, whether this bug is being looked into and whether you guys intend on fixing it. If the answer is no, I'll stop going to VLC's website and trying the latest betas and final releases in false hopes of hearing crystal clear audio from my video files and start giving feedback to the people behind mplayer instead.

[The DJ]

Yes we have been aware of many trouble in the osx audio core of VLC for a long time. No we don't plan to fix it, we don't know how. if someone who knows how audio on the mac actually works comes along, then it will be fixed.

Also be aware that this particular audio bug is only on a very small range of iBooks as it appears. The change that probably caused your problem fixed loads of problems for other users (and i mean LOADS). However it is still far from perfect, and since apparently no on who works with coding audio on the mac seems to be using VLC or something, i see no fix in the foreseeable future.

DJ

[Guest]

Too bad, too bad.

The problem existed on my PowerBook G4 550MHz and now on my PB G4
1,25GHz and G5.

[PC+Mac]

Well, needless to say, I'm very disappointed it won't be fixed in the foreseeable future. At least you guys are aware of the problem. Maybe in 6 months time, maybe with Tiger, maybe after 1, even 2 years, it will be fixed or there will be other better alternatives. For now, I’ll just use my PC or QuickTime for Mac to play my files. The only thing I don’t like about QuickTime now is the absence of a play list feature so watching short clips or having an anime marathon is a pain. Wait... so I guess I'll just use MPlayer.

Hmm... perhaps the team may not know how to fix this OS X audio bug, but the funny thing is that it was working fine before, in 0.5.3. There was a version where you guys got it right. It’s not like it was broken since 0.0.1 alpha or whatever. I thought you guys could just look and compare 0.5.3 code and 0.6.0 code. But, I’m not a programmer. At times like these, I wish I had taken up computer science though.

And this particular audio bug does not only happen on a very small range of iBooks as far as I am concerned. I’m using a Titanium Powerbook G4, another poster was using the an aluminum one, another with an iBook G4, and according to the person above, his/her titanium and aluminum PowerBooks and his G5. But I will say that the static is not as bad when I output sound from my Powerbook via an external Creative Sound Blaster MP3+/ Digital Music sound card. But it is still there and can be heard with good speakers.

Well, for all those users who have benefited from the change, I say lucky them. I don’t have any issues with 0.5.3 though so I don’t see any changes that had to be made concerning audio. As I’ve said earlier, I would like to use the new versions because of some other small improvements like codec support, play list alphabetical arranging, better video support, etc.

Anyway, thanks for your response. I’ve sat in silence since 0.6.0 waiting for newer versions to be released in hopes that I would once again hear crystal clear audio from new VLC builds. Yeah, I believe that’s more than a year. So finally I just had to ask. Sorry for the long post everyone. Just wanted to give my 2cents. Looks like I dropped too many pennies.

Oh, and for everyone trying to watch anime or some other divx/xvid file with mp3 audio that gives static, let me suggest Quicktime with the divx and FFusion codec installed or mplayer. Both give perfect sound but have some flaws in other areas. I’ll just use VLC for whatever those 2 can’t play.

[The DJ]

what part of: The change that probably caused your problem fixed loads of problems for other users (and i mean LOADS).

didn't you understand?

[PC+Mac]

what part of: The change that probably caused your problem fixed loads of problems for other users (and i mean LOADS).

didn't you understand?

Hey, what's with the attitude? I hate to say this, but your posts have lacked politeness in many instances. And to answer your "question" my answer is, NOTHING. I understand it perfectly and completely. I am extremely curious as to why you said that. Really. Perhaps if you actually read my post and understood it.

Did you catch this in my post?

Well, for all those users who have benefited from the change, I say lucky them. I don’t have any issues with 0.5.3 though so I don’t see any changes that had to be made concerning audio.

And I meant I PERSONALLY didn't have any issues.

And hey, you seem to have found out the cause of the problem since you say that that particular change fixed problems for others. If you can't fix it, I accept it. Don't have to try and find an excuse to try and insult me just cause I pointed out some bug. Again, I really have NO IDEA how I made u think I didn't understand the benefits of the change to others. Sheesh. If you can't be helpful, don't try and act all high and mighty.

[Peter Parker]

Uh, whats wrong with you, The DJ?

You are not all mighty (as we can hear on the VLC audio in OS X!). Try to be
more polite, and cut the bullshit. Now you know about a BIGbug in VLC, fix it if you can.

[The DJ]

I apoligise. If you read these forums, you might understand that answering questions can be a very tedious and frustrating job. And with the large amount of posts and few amount of people who answer, I usually don't take the time to read long postings in full. Spending more than 2 minutes on somebodies question/post is too much. I already spent more than 4 hours a day on videolan, and the forum takes up about 1 of those. which is more than i would LIKE to spent on forums. However if I don't answer, people start mailing ME, or PM'ing, or storming into the IRC channel, pissed that noone is looking at what they post.

I should learn not to answer at 2AM anymore. That usually breaks my nerves.

[The DJ]

BTW. some engineer that works a lot with CoreAudio says he knows how to solve many of our problems in this area and says he is working on it.

Won't say it will be fixed, cause we have had others look at it before, but I trust this guy a bit more than previous persons.

No ETA.

[The DJ]

Uh, whats wrong with you, The DJ?

You are not all mighty (as we can hear on the VLC audio in OS X!). Try to be more polite, and cut the bullshit. Now you know about a BIG bug in VLC, fix it if you can.

I'm definetly not all mighty, and nowhere did it say I was. I also didn't say i was the author of the audio plugin ergo responsible for creating a bug. And as to that latter i repeat the following

Yes we have been aware of many trouble in the osx audio core of VLC for a long time. No we don't plan to fix it, we don't know how. if someone who knows how audio on the mac actually works comes along, then it will be fixed.

Also be aware that this particular audio bug is only on a very small range of iBooks as it appears. The change that probably caused your problem fixed loads of problems for other users (and i mean LOADS). However it is still far from perfect, and since apparently no on who works with coding audio on the mac seems to be using VLC or something, i see no fix in the foreseeable future.

knowing about a bug, and knowing how to fix them are two different things. In essence our entire design for the audio output is broken. We use CoreAudio in a way that it simply doesn't work. That one change that was spoken about is only like a fractional small piece of that entire broken piece of code. It improved things, but the whole module still needs rewriting....

DJ

[PC+Mac]

Hey there, just in case this hasn't been noticed yet, the avi files that I've been playing whose audio contains static, use the mp3 format at 48000 Hz sample rate.
But when I use Divx Doctor II to decompress the audio, the static is gone. However, I don't think it's the decompression but the change in the sample rate. The decompressed file had a sample rate of 44100 Hz.

I think it's the sample rate because when I use my SoundBlaster MP3+ / digital music as the output (which shows up with 48000 Hz in Mac OS X's Audio MIDI setup), the static is virtually gone, with perhaps a little there. Using the integrated sound on my Powerbook though (which shows up with 44100 Hz in Mac OS X's Audio MIDI setup) gives static in VLC's playback.

Which brings me to again point the finger at the New audio resampler. Is this audio resampler respnsible for downsampling sample rates? I've tried putting 44100, 48000 and several other values into the Audio output frequency in VLC, but does nothing to solve the problem.

Anyway, just letting you people know. Hopefully it will be of use in solving (if you even are) this tiny bug.

[PC+Mac]

Btw, The DJ, is it possible to have an option to use the old resampler? Like letting it have a checkbox or something in the preferences?

It doesn't seem to downsample 48000Hz audio properly for playback on 44100Hz audio devices.