Audio chops at the beginning of mp3 play.

[Trapper]

I'm sure this topic has already been posted but my searches aren't returning any threads pertaining to it. I guess I am not using the proper search words or something. I've searched substantially.

I have vlc 0.9.9a on ubuntu 9.04, both 32 bit & 64 bit. Every mp3 audio file I play has several chops in the sound at the very beginning of the music. It's driving me crazy and I cannot figure out how to alter settings so this behavior stops. It doesn't happen in audacious, rhythmbox, gnome mplayer, mplayer, etc. With vlc being my preferred player, I'd really like to fix this problem. Any ideas?

[Trapper]

I installed ubuntu's pulse audio plugin but when I use that for audio output it had even more chop than alsa does. Just for kicks I assigned UNIX OSS as the audio output. End of choppy mp3 starts. This probably isn't the correct resolve but it did at least end the choppiness.

[Arite]

Are you using a custom .asoundrc/asound.conf? What are VLC's message when it skips/becomes choppy? Go to "View >> Messages" and set the "Verbosity Level" to 2.

Arite.

[Trapper]

Are you using a custom .asoundrc/asound.conf?

No.

What are VLC's message when it skips/becomes choppy? Go to "View >> Messages" and set the "Verbosity Level" to 2.

I did a debug in OSS, Pulse and Alsa. OSS plays okay. Pulse and alsa both have several skips/chops right at the start of play. It does this with any mp3. I combined the outputs into one file and posted it here:

http://ledduk.net/bonnie/messages.txt

Just for the record, I am using 0.9.9a and "Messages" is found under "Tools". I find no "View" in the app.

[Arite]

Just for the record, I am using 0.9.9a and "Messages" is found under "Tools". I find no "View" in the app.

Oh sorry - yes I meant "Tools".

In the messages, the skipping occurs here (this exert from the ALSA messages):

Code: Select all

main warning: output date isn't PTS date, requesting resampling (66010) main warning: buffer is 66009 late, triggering upsampling main warning: output date isn't PTS date, requesting resampling (49313) main warning: timing screwed, stopping resampling main warning: buffer is 115323 late, triggering upsampling main debug: audio output is starving (24318), playing silence alsa debug: recovered from buffer underrun main warning: output date isn't PTS date, requesting resampling (62783) main warning: audio drift is too big (174478), dropping buffer main warning: audio drift is too big (148355), dropping buffer main warning: audio drift is too big (122233), dropping buffer

You could try increasing the file cache by going to:
Tools >> Preferences >> (Select "All" for "Show settings") >> Input / Codecs >> Access modules >> File

And raise the "Caching value in ms" etc.

I'm not sure why it is happening for just ALSA/Pulse though (if that works, that is).

Arite.

[Trapper]

You could try increasing the file cache by going to:
Tools >> Preferences >> (Select "All" for "Show settings") >> Input / Codecs >> Access modules >> File
And raise the "Caching value in ms" etc.

Thanks Arite. The caching value was initially set at 300 ms. For alsa I eventually ended up around 1500 ms before the skips stopped. With pulseaudio it was significantly higher. I ended up with a setting of 2500 ms. I could probably fine tune that down a bit but I am going to leave it there seeing that doesn't seem to currently present any problems and all mp3 tested now play well. I note the progress bar moving along a bit before sound actually starts during playback and understand why that is.

I appreciate your help!

[Arite]

OK - glad it worked .

Cheers, Arite.

[Michele]

With pulseaudio I have exactly the same problem with every file I play. A friend of mine has it too.
Is it a VLC Bug or a system problem?