Stutter playback with OGG files

[dhinaghena]

Hi,

I have a problem when reading some (but a lot) of my OGG audio files from my musical library : I got a stuttered sound on some parts of the audio when playing it with VLC, Audacity, or Clementine.

As I found this issue with several softwares, I suppose the issue comes from my Mac OSX 10.9.5 and not the softwares.
I didn't have this problem with my previous Mac OSX computer.

The stutters are reproductible for each sotware. Their sound aspect are different along the softwares, but they occur at the same time position in the audio, usually at the beginning during some seconds but sometimes for a long time.

The codec of these files are Vorbis Audio (Vorb) but it doesn't seem the issue as others OGG files with the same coding don't give this problem.

I don't find any similar issue reported on the web. Could you give me some help please ?

[G]

Since OGG and FLAC are not natively supported in OS X, when I get the rare important OGG file I will usually convert it to something the system can handle without outside interpretation (WAV, AIFF, AAC, Apple Lossless or even MP3). That might be why there's not much discussion about OGG issues—we don't bother with it for long.

That said, since some of your files do work, there must be some clue with the ones that don't. Are they extra long or a different (or variable) bit rate? When happens if you convert them to AIFF? And back to OGG? When playback stutters, have you checked Activity Monitor to see if the playback app is spiking the CPU?

[dhinaghena]

Thanks for the reply.

Are they extra long or a different (or variable) bit rate?

They are not extra long compared to the others that works (~5-10 min), and they have the same bit rate.

When happens if you convert them to AIFF? And back to OGG?

That may be interesting : when I open a stuttering file with Audacity (I suppose it is converted to aiff or wav when imported) and if I play it, no stuttering is there anymore but the sampling rate (playing velocity) sounds to change on the part where there were stutters.
If I export it to OGG, no stuttering is there anymore but the effect of sampling rate modification is there like when playing with Audacity.

When playback stutters, have you checked Activity Monitor to see if the playback app is spiking the CPU?

I've just check it and the CPU doesn't seem to change when the palyback stutters.

[G]

That may be interesting : when I open a stuttering file with Audacity (I suppose it is converted to aiff or wav when imported) and if I play it, no stuttering is there anymore but the sampling rate (playing velocity) sounds to change on the part where there were stutters.
If I export it to OGG, no stuttering is there anymore but the effect of sampling rate modification is there like when playing with Audacity.

That's a good clue. Apparently, Vorbis audio is always variable bit rate. I wonder if the current translator in VLC, Audacity, etc. (they may share libs) is buggy and having trouble with the changes? That doesn't really help or explain what's going on, though.

You can't re-source the files?

[dhinaghena]

I have a good trail from these news :
- The OGG files with the stuttering issue keep stuttering when played from an Ubuntu
- These OGG files from an old backup don't stutter from my Mac

I've noticed that these stuttering approximately start after having synchronized the statistics of my Clementine audioplayer with the audio files of my musical library.
I suspect that when these statistics were written into the OGG files, something wird happened in the coding and now this issue is there.
I gonna report this story to Clementine.

Thank you for the Help mister G.