Re: [PATCH v11 10/15] media: uapi: Add audio rate controls support

[Hans Verkuil]

Hi Shengjiu,

Some small comments below:

On 22/11/2023 08:23, Shengjiu Wang wrote:
> Add V4L2_CID_M2M_AUDIO_SOURCE_RATE and V4L2_CID_M2M_AUDIO_DEST_RATE
> new IDs for rate control.
> 
> Add V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET and
> V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET for clock drift.
> 
> Signed-off-by: Shengjiu Wang <shengjiu.wang@xxxxxxx>
> ---
>  .../media/v4l/ext-ctrls-audio-m2m.rst         | 20 +++++++++++++++++++
>  drivers/media/v4l2-core/v4l2-ctrls-defs.c     |  6 ++++++
>  include/uapi/linux/v4l2-controls.h            |  5 +++++
>  3 files changed, 31 insertions(+)
> 
> diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst
> index 82d2ecedbfee..a3c06fbb91b9 100644
> --- a/Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst
> +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst
> @@ -19,3 +19,23 @@ Audio M2M Control IDs
>      The Audio M2M class descriptor. Calling
>      :ref:`VIDIOC_QUERYCTRL` for this control will
>      return a description of this control class.
> +
> +.. _v4l2-audio-asrc:
> +
> +``V4L2_CID_M2M_AUDIO_SOURCE_RATE (integer menu)``
> +    Sets the audio source sample rate, unit is Hz
> +
> +``V4L2_CID_M2M_AUDIO_DEST_RATE (integer menu)``
> +    Sets the audio destination sample rate, unit is Hz
> +
> +``V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET (fixed point)``
> +    Sets the offset from the audio source sample rate, unit is Hz.
> +    The offset compensates for any clock drift. The actual source audio sample
> +    rate is the ideal source audio sample rate from
> +    ``V4L2_CID_M2M_AUDIO_SOURCE_RATE`` plus this fixed point offset.
> +
> +``V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET (fixed point)``
> +    Sets the offset from the audio dest sample rate, unit is Hz.

dest -> destination

> +    The offset compensates for any clock drift. The actual dest audio sample

Ditto.

> +    rate is the ideal source audio sample rate from
> +    ``V4L2_CID_M2M_AUDIO_DEST_RATE`` plus this fixed point offset.
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> index 2a85ea3dc92f..4e606d7fd971 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> @@ -1245,6 +1245,8 @@ const char *v4l2_ctrl_get_name(u32 id)
>  
>  	/* Audio M2M controls */
>  	case V4L2_CID_M2M_AUDIO_CLASS:  return "Audio M2M Controls";
> +	case V4L2_CID_M2M_AUDIO_SOURCE_RATE:	return "Audio Source Sample Rate";
> +	case V4L2_CID_M2M_AUDIO_DEST_RATE:	return "Audio Dest Sample Rate";

Dest -> Destination

>  	default:
>  		return NULL;
>  	}
> @@ -1606,6 +1608,10 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
>  	case V4L2_CID_COLORIMETRY_HDR10_MASTERING_DISPLAY:
>  		*type = V4L2_CTRL_TYPE_HDR10_MASTERING_DISPLAY;
>  		break;
> +	case V4L2_CID_M2M_AUDIO_SOURCE_RATE:
> +	case V4L2_CID_M2M_AUDIO_DEST_RATE:
> +		*type = V4L2_CTRL_TYPE_INTEGER_MENU;
> +		break;
>  	default:
>  		*type = V4L2_CTRL_TYPE_INTEGER;
>  		break;
> diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
> index 7d318065a33d..493b59f20a35 100644
> --- a/include/uapi/linux/v4l2-controls.h
> +++ b/include/uapi/linux/v4l2-controls.h
> @@ -3489,6 +3489,11 @@ struct v4l2_ctrl_av1_film_grain {
>  #define V4L2_CID_M2M_AUDIO_CLASS_BASE  (V4L2_CTRL_CLASS_M2M_AUDIO | 0x900)
>  #define V4L2_CID_M2M_AUDIO_CLASS       (V4L2_CTRL_CLASS_M2M_AUDIO | 1)
>  
> +#define V4L2_CID_M2M_AUDIO_SOURCE_RATE	(V4L2_CID_M2M_AUDIO_CLASS_BASE + 0)
> +#define V4L2_CID_M2M_AUDIO_DEST_RATE	(V4L2_CID_M2M_AUDIO_CLASS_BASE + 1)
> +#define V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET	(V4L2_CID_M2M_AUDIO_CLASS_BASE + 2)
> +#define V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET	(V4L2_CID_M2M_AUDIO_CLASS_BASE + 3)
> +
>  /* MPEG-compression definitions kept for backwards compatibility */
>  #ifndef __KERNEL__
>  #define V4L2_CTRL_CLASS_MPEG            V4L2_CTRL_CLASS_CODEC

Regards,

	Hans