Re: [PATCH v2 11/11] alsaaudio: reintroduce default recording settings

[Philippe Mathieu-Daudé]

On 21/1/23 10:47, Volker Rümelin wrote:
> Audio recording with ALSA default settings currently doesn't
> work. The debug log shows updates every 0.75s and 1.5s.
>
> audio: Elapsed since last alsa run (running): 0.743030
> audio: Elapsed since last alsa run (running): 1.486048
> audio: Elapsed since last alsa run (running): 0.743008
> audio: Elapsed since last alsa run (running): 1.485878
> audio: Elapsed since last alsa run (running): 1.486040
> audio: Elapsed since last alsa run (running): 1.485886
>
> The time between updates should be in the 10ms range. Audio
> recording with ALSA has the same timing contraints as playback.
> Reintroduce the default recording settings and use the same
> default settings for recording as for playback.
>
> The term "reintroduce" is correct because commit a93f328177
> ("alsaaudio: port to -audiodev config") removed the default
> settings for recording.
>
> Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
> ---
>   audio/alsaaudio.c | 10 ++++------
>   1 file changed, 4 insertions(+), 6 deletions(-)

> -    /*
> -     * OptsVisitor sets unspecified optional fields to zero, but do not depend
> -     * on it...
> -     */
>       if (!dev->u.alsa.in->has_period_length) {
> -        dev->u.alsa.in->period_length = 0;
> +        /* 256 frames assuming 44100Hz */
> +        dev->u.alsa.in->period_length = 5805;
>       }
>       if (!dev->u.alsa.in->has_buffer_length) {
> -        dev->u.alsa.in->buffer_length = 0;
> +        /* 4096 frames assuming 44100Hz */
> +        dev->u.alsa.in->buffer_length = 92880;
>       }

Please use DIV_ROUND_UP(). Maybe worth adding definitions?