[pulseaudio-discuss] xine 5.1 channel downmix / gmplayer pulse output

[Nikolaus Filus]

Hi,

Pierre Ossman wrote:
> Nikolaus Filus wrote:
>> Hello,
>>
>> recently I switched to pulseaudio on ubuntu feisty. I got almost everything
>> working (again) except 2 things:
>>
>> 1. xine is working great, but if I play an AC3 5.1 file, I hear only 2 of five
>> channels (1 front and 1 silent back channel). For alsa xine has a downmix
>> option, but it doesn't work for pulse output.
>> Should that be corrected in xine's pulse output plugin or is there a builtin
>> channel downmix in pulseaudio? Mplayer does it as expected, but I couldn't
>> figure out, where is it done.
>>
> 
> It all depends on what backends you use. The basic problem is probably
> that xine is not giving you the same channels you have specified in your
> sink. I would suggest using pacmd and checking the channel maps while
> xine is playing.

1 sink(s) available.
  * index: 0
        name: <alsa_output.pci_8086_24c5_alsa_playback_0>
        driver: <modules/module-alsa-sink.c>
        volume: <0: 100% 1: 100%>
        latency: <55827 usec>
        monitor_source: <0>
        sample spec: <s16le 2ch 44100Hz>
        channel map: <front-left,front-right>
        owner module: <0>
        description: <ALSA PCM on hw:0 (Intel 82801DB-ICH4)>

1 sink input(s) available.
    index: 62
        name: <audio stream>
        driver: <pulsecore/protocol-native.c>
        state: RUNNING
        sink: <0> 'alsa_output.pci_8086_24c5_alsa_playback_0'
        volume: <0: 100% 1: 100% 2: 100% 3: 100% 4: 100% 5: 100%>
        latency: <845546 usec>
        sample spec: <s16le 6ch 48000Hz>
        channel map: <front-left,side-left,front-center,front-right,side-right,lfe>
        resample method: src-sinc-fastest
        owner module: <4>
        client: <22> 'xine'
[A-Kraze]_Seirei_no_Moribito_-_05_[FBB9B5F9].mkv
1 sink input(s) available.
    index: 63
        name: <audio stream>
        driver: <pulsecore/protocol-native.c>
        state: RUNNING
        sink: <0> 'alsa_output.pci_8086_24c5_alsa_playback_0'
        volume: <0: 100% 1: 100%>
        latency: <461179 usec>
        sample spec: <s16le 2ch 48000Hz>
        channel map: <front-left,front-right>
        resample method: src-sinc-fastest
        owner module: <4>
        client: <26> 'MPlayer'


Ok, so now I confirmed the channel maps are different. But where can I downmix
5.1 to 2? Where can I read more about possible setups?
- configure sink for 5.1 (my notebook can't do that, but this would be nice-to-know)
- downmix channels
- select n channels and pass to sink

>> 2. mplayer works fine, but gmplayer freezes after few played samples and waits
>> for some event. I get a lot of
>> futex(0x8bb0af0, FUTEX_WAKE, 1)         = 0
>> in strace output.
>> Sometimes there is a window showing up: "AO: [pulse] Failed to get sink input
>> info: Timeout"
> 
> No idea. I've only tested mplayer directly. Have you checked that it
> doesn't call mplayer with some odd parameters?

gmplayer is only a link to mplayer, which automatically selects -gui and chooses
it's configuration from gui.conf instead of mplayer.conf. I started from a clean
a clean configuration, so there are no user options involved.
On IRC I got the hint to select softvol for mplayer, where the problem doesn't
occur. So may mplayer in gui mode do something on the mixer, what can make it fail?


Thanks.

Nikolaus