[PATCH] aplay: Support setting timestamp

[Jaroslav Kysela]

On 16. 06. 22 12:00, Pavel Hofman wrote:
> Dne 16. 06. 22 v 10:13 Takashi Sakamoto napsal(a):
>>
>> On Thu, Jun 16, 2022 at 08:54:26AM +0200, Pavel Hofman wrote:
>>> To allow enabling timestamp and specify its type, a new option
>>> --tstamp-type=TYPE is added. Recognized values are none (default),
>>> gettimeofday, monotonic, monotonic-raw.
>>>
>>> Signed-off-by: Pavel Hofman <pavel.hofman at ivitera.com>
>>> ---
>>>    aplay/aplay.1 |  4 ++++
>>>    aplay/aplay.c | 32 ++++++++++++++++++++++++++++++++
>>>    2 files changed, 36 insertions(+)
>>    
>> I prefer the idea to work for timestamp feature defined in ALSA PCM
>> interface, while I have a mixed feeling to integrate `aplay` tool, since
>> I have an intension to obsolete the tool with `axfer` tool with more
>> robust design with command argument compatibility (as much as possible).
>>
>> This is not so strong request but would I ask you to work for `axfer` tool
>> instead of `aplay`? Then, it's preferable that the name of command
>> argument is decided with enough care of all of timestamp feature in ALSA
>> PCM interface, since we have two categories of timestamps at least; e.g.
>> system timestamp and audio timestamp. As long as I know, they possibly use
>> different clock sources, thus these two timestamps have different levels
>> of clock id, I think.
>>
>> Of course, it's a loose accord in the community to obsolete `aplay`, and
>> it's easy to decide to continue aplay integration. (I'm not in leading
>> place of the project.) I'll be a bit happy if people take care of axfer
>> tool as well.
> 
> Thanks for your input. I use aplay in my project and needed to have
> tstamps enabled in proc status files for my simple code which calculates
> relative samplerate between capture and playback soundcards (one of them
> having rate adjustable - audio gadget, snd-aloop)
> https://mailman.alsa-project.org/pipermail/alsa-devel/2022-June/201647.html
> . The existing aplay did not have this feature, so I added it and
> submitted the patch. I did not know aplay was planned to be obsoleted,
> it seems to receive a healthy stream of patches.

It would be good to sync both tools (aplay/axfer) for the easy replacement. 
Could you add this code to axfer, too?

> As of the tstamp terminology - what command option would be more
> appropriate instead? Thanks a lot,

I'm fine with the proposed argument.

				Thank you,
					Jaroslav

-- 
Jaroslav Kysela <perex at perex.cz>
Linux Sound Maintainer; ALSA Project; Red Hat, Inc.