[Kdenlive-devel] Bug#584132: kdenlive: No sound with pulseaudio audio driver

[Dan Dennedy]

2010/6/1 Alberto Villa <avilla at freebsd.org>:
> On Tuesday 01 June 2010 20:12:34 Patrick Matthäi wrote:
>> > When audio playback in the configuration menu is set to
> "automatic" mode,
>> > kdenlive decides to use ALSA over here, but this is redirected to
>> > pulseaudio via asoundrc and doesn't play nicely. It stutters and
> hangs,
>> > so I chose "Pulse" for the audio driver, however, there's no sound
> at
>> > all with this choice.

I think this means he does not have the libsdl1.2debian-pulseaudio or
libsdl1.2debian-all packages installed because that option explicitly
selects the pulse backend to SDL.
With Kino, I used to recommend people use the OSS output method and
ALSA OSS emulation modules (snd_pcm_oss) to bypass PulseAudio. I just
tried it with the libsdl1.2debian-all package installed on Ubuntu
10.04, and it did not work unless I ran melt with padsp :-/

>> @kdenlive devs:
>> What is the status with kdenlive and pulseaudio?

It depends on PulseAudio, ALSA, and SDL versions and how they are
built and with which patches. Of course, this is the case for
anything, but especially so for audio on Linux since the tumultuous
introduction of PulseAudio. I can say that MLT has not not done
*anything* to try to help; the SDL audio output part of the code is
untouched for years. With that said, I do think things with PulseAudio
are much better now than compared with a year ago.

> kdenlive talks to pulseaudio through mlt, which uses sdl. so, unless
> mlt has some special magic, it's all about pulseaudio relationship with
> sdl

exactly. All that we do is set an SDL environment variable to select a
backend, which is not performed when using "Automatic," which I think
simply defaults to ALSA. One can also set an env var to select an oss
device node or alsa pcm.

Oh, and at least one person has reported some good results using
pulseaudio-module-jack.
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