pulseaudio assume surround21 is four channels since buffer time is half of stereo
why alsa lib surround21 did not specity any channel ? http://git.alsa-project.org/?p=alsa-lib.git;a=commitdiff;h=48f1b308cc66152eb6db66742dd0d08d888cda8d;hp=5c4cd46810cef8850b037fca9e38ffd43b0bff22 2.1 speaker set is different from 5.1 speaker set 070| 0.000) D: [pulseaudio] alsa-util.c: Trying front:0 with SND_PCM_NO_AUTO_FORMAT ... ( 0.071| 0.000) D: [pulseaudio] alsa-util.c: Managed to open front:0 ( 0.071| 0.000) D: [pulseaudio] alsa-util.c: Maximum hw buffer size is 371 ms ( 0.071| 0.000) D: [pulseaudio] alsa-util.c: Set buffer size first (to 3528 samples), period size second (to 441 samples). ( 0.071| 0.000) D: [pulseaudio] alsa-mixer.c: Profile output:analog-stereo+input:analog-stereo supported. ( 0.071| 0.000) D: [pulseaudio] alsa-mixer.c: Skipping profile output:analog-stereo+input:iec958-stereo - will not be able to open input:iec958-stereo ( 0.071| 0.000) D: [pulseaudio] alsa-mixer.c: Looking at profile output:analog-surround-21 ( 0.071| 0.000) D: [pulseaudio] alsa-mixer.c: Checking for playback on Analog Surround 2.1 (analog-surround-21) ( 0.071| 0.000) D: [pulseaudio] alsa-util.c: Trying surround21:0 with SND_PCM_NO_AUTO_FORMAT ... ( 0.072| 0.000) D: [pulseaudio] alsa-util.c: Managed to open surround21:0 ( 0.072| 0.000) D: [pulseaudio] alsa-util.c: Maximum hw buffer size is 185 ms ( 0.094| 0.021) D: [pulseaudio] alsa-util.c: Set buffer size first (to 3528 samples), period size second (to 441 samples). ( 0.094| 0.000) D: [pulseaudio] alsa-mixer.c: Profile output:analog-surround-21 supported. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to alsa-lib in Ubuntu. https://bugs.launchpad.net/bugs/1286021 Title: 2.1 surround support (userspace) Status in “alsa-lib” package in Ubuntu: Fix Committed Status in “pulseaudio” package in Ubuntu: In Progress Bug description: 2.1 surround should work as seamlessly as other surround options, such as 4.0, 5.1 and 7.1 work today. Alsa-lib and pulseaudio patches for 14.04 can be tested here: https://launchpad.net/~diwic/+archive/surround21 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/alsa-lib/+bug/1286021/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp