[patch] Consistent global limits for rate and channels

[twonoise]

Hello.

I've noticed that pcm_plugin.h provides SND_PCM_PLUGIN_RATE_MIN and ...MAX, but these values are not used always. Rather, various local limits used, include a bit unusual ones like 786000 (this one is probably just a typo). In order to make limits consistent across alsa-lib (and -utils), i've make these small patches. Also two more globals introduced for max channels. As well as some minor things fixed.

Are there chances that it can be merged?

I'll share via mailing list if need.

Thanks!

alsa-lib.patch

alsa-utils.patch

[perexg]

Thank you for your idea. Those limits are mostly unrelated to plugin subsystem. I would prefer to create SND_PCM_LIMIT_* constants in pcm.h. The rate 786000 is not a typo. Some new codecs support this sampling rate. Create pull requests to review your changes. Also split unrelated changes to separate PR.

@tiwai FYI

[twonoise]

Thank you for answer @perexg . So i follow this requirement and put at pcm.h the following:

• At PCM_HW_Params group: SND_PCM_LIMIT_HW_RATE_MIN, ...MAX, ...CHANNELS_MAX
• At PCM_SW_Params group: SND_PCM_LIMIT_SW_RATE_MIN, ...MAX, ...CHANNELS_MAX

The latter one (SND_PCM_LIMIT_SW_RATE...) replaces now SND_PCM_PLUGIN_RATE_, make it more consistent globally.

At .c files, for both alsa-lib, and -utils, i've replaced local numeric values, to constants above. Btw, i am not sure, if i precisely correctly used ...HW... vs ...SW... here and there, but, looks like, it is. (Values are same, but I am try to be pedantically correct).

Looks like, alsa-plugins not contains rate or channels constants.

LINEAR_DIV_SHIFT 19 constant is not changed, as limits itself are same; while i've tested lower global rate from 4000 down to 750 Hz, it works as expected for speaker-test, pcm, JACK (jackd), and others.

Btw, my

786000

is from here, it looks a bit unusual compared to like this, so i've thought that former one was just typo; anyway they replaced to globals now.

Here are patches for reference; i'll create PRs soon. Hope it will be correct and useful.
PR(s) not related to LIMITs, i.e. with some small fixes, will be submitted separately.

alsa-lib.patch

alsa-utils.patch