[vlc] Fast switching between audio tracks?

[Chris Angelico]

I have a few video files with multiple audio tracks, which I can cycle
through using the 'b' key. But when I do, there's a significant gap in
the music. Is there a way to reduce that? I tried cutting the file
caching buffer, which helped some, but there's still about a
quarter-second of silence before the next track starts playing.

The files are under my control, so solutions involving changing the
encoding are viable. I have 16GB of RAM in this computer and am happy
to let VLC have the lion's share of it if this can be sorted out.

Any ideas would be appreciated!

Chris Angelico

[Jean-Baptiste Kempf]

Post by Chris Angelico
I have a few video files with multiple audio tracks, which I can cycle
through using the 'b' key. But when I do, there's a significant gap in
the music. Is there a way to reduce that? I tried cutting the file
caching buffer, which helped some, but there's still about a
quarter-second of silence before the next track starts playing.

You should try VLC 2.2.0 where we improved that.

Else, you should report this bug with samples on our bugtracker.

With my kindest regards,

[Chris Angelico]

Post by Jean-Baptiste Kempf

Post by Chris Angelico
I have a few video files with multiple audio tracks, which I can cycle
through using the 'b' key. But when I do, there's a significant gap in
the music. Is there a way to reduce that? I tried cutting the file
caching buffer, which helped some, but there's still about a
quarter-second of silence before the next track starts playing.

You should try VLC 2.2.0 where we improved that.
Else, you should report this bug with samples on our bugtracker.

Thanks, I'd pretty much given up hope of a response to that :) I
mainly use 2.0.3 (on Debian Wheezy), but gave 2.2.0 (on Debian Jessie)
a shot; sadly, the sound simply cut out when I hit b (the OSD said the
name of the next audio track, but it didn't play). Will have to track
down what's going on there.

ChrisA

[Jean-Baptiste Kempf]

Post by Chris Angelico
Thanks, I'd pretty much given up hope of a response to that :) I
mainly use 2.0.3 (on Debian Wheezy), but gave 2.2.0 (on Debian Jessie)
a shot; sadly, the sound simply cut out when I hit b (the OSD said the
name of the next audio track, but it didn't play). Will have to track
down what's going on there.

Pulse or Alsa?

With my kindest regards,

[Chris Angelico]

Post by Jean-Baptiste Kempf

Post by Chris Angelico
Thanks, I'd pretty much given up hope of a response to that :) I
mainly use 2.0.3 (on Debian Wheezy), but gave 2.2.0 (on Debian Jessie)
a shot; sadly, the sound simply cut out when I hit b (the OSD said the
name of the next audio track, but it didn't play). Will have to track
down what's going on there.

Pulse or Alsa?

Heh, seems that computer still has Pulse installed. That might be it.
On my main system (Wheezy) I use Alsa.

ChrisA

[Chris Angelico]

Post by Jean-Baptiste Kempf

Post by Chris Angelico
Thanks, I'd pretty much given up hope of a response to that :) I
mainly use 2.0.3 (on Debian Wheezy), but gave 2.2.0 (on Debian Jessie)
a shot; sadly, the sound simply cut out when I hit b (the OSD said the
name of the next audio track, but it didn't play). Will have to track
down what's going on there.

Pulse or Alsa?

While the list is still alive, I'll keep discussing here, but will
shift to someplace else when the time comes.

With an early January build of VLC from git, using ALSA, I get the
same result: switch audio tracks, audio disappears and doesn't come
back. The exact same file on the exact same computer, played with
2.0.3, switches correctly (but with the aforementioned gap).

***@sikorsky:~/vlc$ ./vlc --version
VLC media player 3.0.0-git Vetinari (revision 2.2.0-git-1924-g2703bba)
VLC version 3.0.0-git Vetinari (2.2.0-git-1924-g2703bba)
Compiled by rosuav on sikorsky.kepl.com.au (Jan 2 2015 01:22:56)
Compiler: gcc version 4.7.2 (Debian 4.7.2-5)

ChrisA

[Jean-Baptiste Kempf]

Post by Chris Angelico

Post by Jean-Baptiste Kempf

Post by Chris Angelico
Thanks, I'd pretty much given up hope of a response to that :) I
mainly use 2.0.3 (on Debian Wheezy), but gave 2.2.0 (on Debian Jessie)
a shot; sadly, the sound simply cut out when I hit b (the OSD said the
name of the next audio track, but it didn't play). Will have to track
down what's going on there.

Pulse or Alsa?

While the list is still alive, I'll keep discussing here, but will
shift to someplace else when the time comes.
With an early January build of VLC from git, using ALSA, I get the
same result: switch audio tracks, audio disappears and doesn't come
back. The exact same file on the exact same computer, played with
2.0.3, switches correctly (but with the aforementioned gap).
VLC media player 3.0.0-git Vetinari (revision 2.2.0-git-1924-g2703bba)
VLC version 3.0.0-git Vetinari (2.2.0-git-1924-g2703bba)
Compiled by rosuav on sikorsky.kepl.com.au (Jan 2 2015 01:22:56)
Compiler: gcc version 4.7.2 (Debian 4.7.2-5)

More logs are needed.

With my kindest regards,

[Chris Angelico]

Post by Jean-Baptiste Kempf
More logs are needed.

Not sure what logs you're looking for; but the console shows many
lines like this, if and only if I press 'b' *twice*:

[00007f3f90103288] core decoder error: Could not convert timestamp 214341776107
[00007f3f90103288] core decoder error: Could not convert timestamp 214341802229
[00007f3f90103288] core decoder error: Could not convert timestamp 214341828351
[00007f3f90103288] core decoder error: Could not convert timestamp 214341854474
[00007f3f90103288] core decoder error: Could not convert timestamp 214341881107

Large number of those, with different timestamps. Does that help at all?

ChrisA