git: 903873ce1560 - main - Implement and use new mixer(3) library for FreeBSD.

[Mateusz Piotrowski]

Hi Hans,

On 03/10/2021 21:08, Hans Petter Selasky wrote:
> On 10/3/21 6:03 PM, Mateusz Piotrowski wrote:
>> On 22/09/2021 20:03, Hans Petter Selasky wrote:
>>> The branch main has been updated by hselasky:
>>>
>>> URL: https://cgit.FreeBSD.org/src/commit/?id=903873ce15600fc02a0ea42cbf888cff232b411d
>>>
>>> commit 903873ce15600fc02a0ea42cbf888cff232b411d
>>> Author:     Hans Petter Selasky <hselasky at FreeBSD.org>
>>> AuthorDate: 2021-09-22 13:42:51 +0000
>>> Commit:     Hans Petter Selasky <hselasky at FreeBSD.org>
>>> CommitDate: 2021-09-22 17:43:56 +0000
>>>
>>>      Implement and use new mixer(3) library for FreeBSD.
>>>      Wiki article: https://wiki.freebsd.org/SummerOfCode2021Projects/SoundMixerImprovements
>>>      This project was part of Google Summer of Code 2021.
>>
>> This may be a bit late to discuss but the new mixer has a completely different
>> set of options and command-line arguments. In addition to that,
>> the output of the command is different.
>>
>> Shouldn't we keep supporting the previous way of interacting with mixer?
>> I know that people are scripting mixer and its output in production
>> in order to control soundcards. Are there any good reasons to keep the new
>> mixer(8) as it is now while keeping the old name? Perhaps we could change
>> the name of the new mixer to, e.g., newmixer. Users are going to have to
>> rewrite their scripts for mixer(8) anyway for 14.0.
>>
>
> It depends what level of compatibility you need.
>
> If you have a script parsing mixer output, then it needs to be binary compatible so to speak. That 
> means some new features like "mute" won't work.
Hmm, I agree that mute and volume controls in the new CLI interface are very consistent. However, in 
case of the old CLI interface, the mute functionality could also be added without a problem (at 
least by looking at the manual pages, the "mute" command could look like this: "mixer mute vol"). My 
point is that I feel that the CLI interface should be backwards-compatible in this case.
>
> Would it help to make a port, like "oldmixer", under "audio" ?

That's a good idea. I've committed the "old" mixer to the ports tree: 
https://cgit.freebsd.org/ports/commit/?id=e9a0efe4509b8dbdef0b4e4b5b94abf0aebd78a9.

However, I feel that it is a solution to a problem that could have been avoided. The mixer 
improvements should have been introduced in a way that users do not have to do anything to keep 
their scripts working. At the moment, it does not really matter if a user has to install an 
additional port or patch their scripts. In the end, it's extra work and potential bugs.

On the other hand, from what I understand so far, mixer(8) needed a redesign. Also, usually people 
don't script mixer(8) too heavily so the changes in the interface are going to be only a minor 
annoyance when FreeBSD 14.0 is released. An entry in the release notes and the availability of the 
old mixer in the ports tree should be enough.

Best,

Mateusz Piotrowski