[pulseaudio-discuss] review+pull-request: Passthrough support

Dark Shadow shadowofdarkness at gmail.com
Sat Apr 16 12:36:56 PDT 2011

On Sat, Apr 16, 2011 at 9:39 AM, Dark Shadow <shadowofdarkness at gmail.com> wrote:
> On Thu, Apr 14, 2011 at 5:49 AM, Arun Raghavan
> <arun.raghavan at collabora.co.uk> wrote:
>> On Wed, 2011-04-13 at 18:23 +0530, Arun Raghavan wrote:
>> [...]
>>> The changes needed to actually use this in GStreamer are also done, but
>>> not upstream yet. I need to do some rebasing to make this stuff good to
>>> push out, so details on this in a following mail.
>> Okay, this is also pushed and good to test. I'll be pushing this out to
>> master after the next round of gst* releases (which should happen in the
>> next couple of weeks or so). For now, you'll need:
>> * gstreamer from git master
>> * gst-plugins-base from:
>> http://git.collabora.co.uk/?p=user/arun/gst-plugins-base.git;a=shortlog;h=refs/heads/passthrough
>> * gst-plugins-good from:
>> http://git.collabora.co.uk/?p=user/arun/gst-plugins-good.git;a=shortlog;h=refs/heads/passthrough
>> * gst-plugins-bad, gst-plugins-ugly, gst-ffmpeg built against the above
>> would probably also be needed (for non-passthrough playback)
>> With all but the top-most commit to gst-plugins-good, pulsesink will be
>> plugged in passthrough mode when the sink supports the format of the
>> input.
>> The top-most commit on gst-plugins-good introduces a new pulsesinkbin
>> element, which automatically reconfigures based on what formats are
>> available on the sink we're connected to. So if you're playing AC3 in
>> passthrough mode over S/PDIF and switch to analog out, it'll
>> transparently plug in a decoder, and if you switch back to digital out,
>> the decoder will be removed and passthrough mode will be enabled again.
>> pulsesinkbin will be autoplugged if your app (or gst-launch) is using
>> playbin2, but most applications totem/rhythmbox/... override the
>> playbin2 audio sink, so there's some work pending before this just works
>> with players.
>> I'm happy to help if anyone runs into problems while testing.
>> Cheers,
>> Arun
>> p.s.: for those of you who want to test but don't have a
>> gstreamer-from-git setup already, jhbuild[1] or gst-uninstalled[2]
>> should be useful.
> I have been using this branch for awhile (since the first day XBMC
> could use it to passthrough DTS-HD) and will it worked for most that
> time yesterday I updated to the most recent git pull and now
> pulseaudio doesn't even see my Nvidia HDMI at all anymore. It doesn't
> show as a possible sink.
> This is on a XBMC-Live dedicated HTPC that nothing else has changed in
> recent time.
> I can still use HDMI by using straight Alsa so nothing happened to it.

Don't worry, it must of been a random problem after rolling back to
old versions of your passthrough branch then moving up one commit at
at time to try and track the breakage I made it back to the newest
with it working again.

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