From: Takashi Sakamoto Date: Sun, 27 Jan 2019 05:39:18 +0000 (+0900) Subject: axfer: fulfill section for backward compatibitity for chmap option X-Git-Tag: v1.1.9~24 X-Git-Url: https://git.alsa-project.org/?a=commitdiff_plain;h=b6142611c68a380644ce34f885e2d67da084b538;p=alsa-utils.git axfer: fulfill section for backward compatibitity for chmap option At present, axfer losts backward compatibility to aplay in a point of 'chmap' option. This commit filfills a section to describe lose of backward compatibility of chmap option. Signed-off-by: Takashi Sakamoto Signed-off-by: Takashi Iwai --- diff --git a/axfer/axfer-transfer.1 b/axfer/axfer-transfer.1 index 02e5b4c..1fdfc91 100644 --- a/axfer/axfer-transfer.1 +++ b/axfer/axfer-transfer.1 @@ -872,6 +872,15 @@ according to pushed enter key. However, this feature requires an additional input handling in main loop and leave bothersome operation to maintain PCM substream. +.TP +.I \-m, \-\-chmap=CH1,CH2,... +ALSA PCM core and control core doesn't support this feature, therefore +remapping should be done in userspace. This brings overhead to align audio +data frames, especially for mmap operation. Furthermore, as of alsa-lib v1.1.8, +some plugins don't support this feature expectedly, thus this option is a lack +of transparent operation. At present, this option is not supported yet not to +confuse users. + .TP .I SIGTSTP, SIGCONT This performs suspend/resume of PCM substream. In aplay(1) implementation,