On Tue, Oct 17, 2023 at 9:37 PM Hans Verkuil <hverkuil@xxxxxxxxx> wrote: > > On 17/10/2023 15:11, Shengjiu Wang wrote: > > On Mon, Oct 16, 2023 at 9:16 PM Hans Verkuil <hverkuil@xxxxxxxxx> wrote: > >> > >> Hi Shengjiu, > >> > >> On 13/10/2023 10:31, Shengjiu Wang wrote: > >>> Fixed point controls are used by the user to configure > >>> the audio sample rate to driver. > >>> > >>> Add V4L2_CID_ASRC_SOURCE_RATE and V4L2_CID_ASRC_DEST_RATE > >>> new IDs for ASRC rate control. > >>> > >>> Signed-off-by: Shengjiu Wang <shengjiu.wang@xxxxxxx> > >>> --- > >>> .../userspace-api/media/v4l/common.rst | 1 + > >>> .../media/v4l/ext-ctrls-fixed-point.rst | 36 +++++++++++++++++++ > >>> .../media/v4l/vidioc-g-ext-ctrls.rst | 4 +++ > >>> .../media/v4l/vidioc-queryctrl.rst | 7 ++++ > >>> .../media/videodev2.h.rst.exceptions | 1 + > >>> drivers/media/v4l2-core/v4l2-ctrls-core.c | 5 +++ > >>> drivers/media/v4l2-core/v4l2-ctrls-defs.c | 4 +++ > >>> include/media/v4l2-ctrls.h | 2 ++ > >>> include/uapi/linux/v4l2-controls.h | 13 +++++++ > >>> include/uapi/linux/videodev2.h | 3 ++ > >>> 10 files changed, 76 insertions(+) > >>> create mode 100644 Documentation/userspace-api/media/v4l/ext-ctrls-fixed-point.rst > >>> > >>> diff --git a/Documentation/userspace-api/media/v4l/common.rst b/Documentation/userspace-api/media/v4l/common.rst > >>> index ea0435182e44..35707edffb13 100644 > >>> --- a/Documentation/userspace-api/media/v4l/common.rst > >>> +++ b/Documentation/userspace-api/media/v4l/common.rst > >>> @@ -52,6 +52,7 @@ applicable to all devices. > >>> ext-ctrls-fm-rx > >>> ext-ctrls-detect > >>> ext-ctrls-colorimetry > >>> + ext-ctrls-fixed-point > >> > >> Rename this to ext-ctrls-audio-m2m. > >> > >>> fourcc > >>> format > >>> planar-apis > >>> diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-fixed-point.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-fixed-point.rst > >>> new file mode 100644 > >>> index 000000000000..2ef6e250580c > >>> --- /dev/null > >>> +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-fixed-point.rst > >>> @@ -0,0 +1,36 @@ > >>> +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later > >>> + > >>> +.. _fixed-point-controls: > >>> + > >>> +*************************** > >>> +Fixed Point Control Reference > >> > >> This is for audio controls. "Fixed Point" is just the type, and it doesn't make > >> sense to group fixed point controls. But it does make sense to group the audio > >> controls. > >> > >> V4L2 controls can be grouped into classes. Basically it is a way to put controls > >> into categories, and for each category there is also a control that gives a > >> description of the class (see 2.15.15 in > >> https://linuxtv.org/downloads/v4l-dvb-apis-new/driver-api/v4l2-controls.html#introduction) > >> > >> If you use e.g. 'v4l2-ctl -l' to list all the controls, then you will see that > >> they are grouped based on what class of control they are. > >> > >> So I think it would be a good idea to create a new control class for M2M audio controls, > >> instead of just adding them to the catch-all 'User Controls' class. > >> > >> Search e.g. for V4L2_CTRL_CLASS_COLORIMETRY and V4L2_CID_COLORIMETRY_CLASS to see how > >> it is done. > >> > >> M2M_AUDIO would probably be a good name for the class. > >> > >>> +*************************** > >>> + > >>> +These controls are intended to support an asynchronous sample > >>> +rate converter. > >> > >> Add ' (ASRC).' at the end to indicate the common abbreviation for > >> that. > >> > >>> + > >>> +.. _v4l2-audio-asrc: > >>> + > >>> +``V4L2_CID_ASRC_SOURCE_RATE`` > >>> + sets the resampler source rate. > >>> + > >>> +``V4L2_CID_ASRC_DEST_RATE`` > >>> + sets the resampler destination rate. > >> > >> Document the unit (Hz) for these two controls. > >> > >>> + > >>> +.. c:type:: v4l2_ctrl_fixed_point > >>> + > >>> +.. cssclass:: longtable > >>> + > >>> +.. tabularcolumns:: |p{1.5cm}|p{5.8cm}|p{10.0cm}| > >>> + > >>> +.. flat-table:: struct v4l2_ctrl_fixed_point > >>> + :header-rows: 0 > >>> + :stub-columns: 0 > >>> + :widths: 1 1 2 > >>> + > >>> + * - __u32 > >> > >> Hmm, shouldn't this be __s32? > >> > >>> + - ``integer`` > >>> + - integer part of fixed point value. > >>> + * - __s32 > >> > >> and this __u32? > >> > >> You want to be able to use this generic type as a signed value. > >> > >>> + - ``fractional`` > >>> + - fractional part of fixed point value, which is Q31. > >>> diff --git a/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst b/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst > >>> index f9f73530a6be..1811dabf5c74 100644 > >>> --- a/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst > >>> +++ b/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst > >>> @@ -295,6 +295,10 @@ still cause this situation. > >>> - ``p_av1_film_grain`` > >>> - A pointer to a struct :c:type:`v4l2_ctrl_av1_film_grain`. Valid if this control is > >>> of type ``V4L2_CTRL_TYPE_AV1_FILM_GRAIN``. > >>> + * - struct :c:type:`v4l2_ctrl_fixed_point` * > >>> + - ``p_fixed_point`` > >>> + - A pointer to a struct :c:type:`v4l2_ctrl_fixed_point`. Valid if this control is > >>> + of type ``V4L2_CTRL_TYPE_FIXED_POINT``. > >>> * - void * > >>> - ``ptr`` > >>> - A pointer to a compound type which can be an N-dimensional array > >>> diff --git a/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst b/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst > >>> index 4d38acafe8e1..9285f4f39eed 100644 > >>> --- a/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst > >>> +++ b/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst > >>> @@ -549,6 +549,13 @@ See also the examples in :ref:`control`. > >>> - n/a > >>> - A struct :c:type:`v4l2_ctrl_av1_film_grain`, containing AV1 Film Grain > >>> parameters for stateless video decoders. > >>> + * - ``V4L2_CTRL_TYPE_FIXED_POINT`` > >>> + - n/a > >>> + - n/a > >>> + - n/a > >>> + - A struct :c:type:`v4l2_ctrl_fixed_point`, containing parameter which has > >>> + integer part and fractional part, i.e. audio sample rate. > >>> + > >>> > >>> .. raw:: latex > >>> > >>> diff --git a/Documentation/userspace-api/media/videodev2.h.rst.exceptions b/Documentation/userspace-api/media/videodev2.h.rst.exceptions > >>> index e61152bb80d1..2faa5a2015eb 100644 > >>> --- a/Documentation/userspace-api/media/videodev2.h.rst.exceptions > >>> +++ b/Documentation/userspace-api/media/videodev2.h.rst.exceptions > >>> @@ -167,6 +167,7 @@ replace symbol V4L2_CTRL_TYPE_AV1_SEQUENCE :c:type:`v4l2_ctrl_type` > >>> replace symbol V4L2_CTRL_TYPE_AV1_TILE_GROUP_ENTRY :c:type:`v4l2_ctrl_type` > >>> replace symbol V4L2_CTRL_TYPE_AV1_FRAME :c:type:`v4l2_ctrl_type` > >>> replace symbol V4L2_CTRL_TYPE_AV1_FILM_GRAIN :c:type:`v4l2_ctrl_type` > >>> +replace symbol V4L2_CTRL_TYPE_FIXED_POINT :c:type:`v4l2_ctrl_type` > >>> > >>> # V4L2 capability defines > >>> replace define V4L2_CAP_VIDEO_CAPTURE device-capabilities > >>> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-core.c b/drivers/media/v4l2-core/v4l2-ctrls-core.c > >>> index a662fb60f73f..7a616ac91059 100644 > >>> --- a/drivers/media/v4l2-core/v4l2-ctrls-core.c > >>> +++ b/drivers/media/v4l2-core/v4l2-ctrls-core.c > >>> @@ -1168,6 +1168,8 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx, > >>> if (!area->width || !area->height) > >>> return -EINVAL; > >>> break; > >>> + case V4L2_CTRL_TYPE_FIXED_POINT: > >>> + break; > >> > >> Hmm, this would need this patch 'v4l2-ctrls: add support for V4L2_CTRL_WHICH_MIN/MAX_VAL': > >> > >> https://patchwork.linuxtv.org/project/linux-media/patch/20231010022136.1504015-7-yunkec@xxxxxxxxxx/ > >> > >> since min and max values are perfectly fine for a fixed point value. > >> > >> Even a step value (currently not supported in that patch) would make sense. > >> > >> But I wonder if we couldn't simplify this: instead of creating a v4l2_ctrl_fixed_point, > >> why not represent the fixed point value as a Q31.32. Then the standard > >> minimum/maximum/step values can be used, and it acts like a regular V4L2_TYPE_INTEGER64. > >> > >> Except that both userspace and drivers need to multiply it with 2^-32 to get the actual > >> value. > >> > >> So in enum v4l2_ctrl_type add: > >> > >> V4L2_CTRL_TYPE_FIXED_POINT = 10, > >> > >> (10, because it is no longer a compound type). > > > > Seems we don't need V4L2_CTRL_TYPE_FIXED_POINT, just use V4L2_TYPE_INTEGER64? > > > > The reason I use the 'integer' and 'fractional' is that I want > > 'integer' to be the normal sample > > rate, for example 48kHz. The 'fractional' is the difference with > > normal sample rate. > > > > For example, the rate = 47998.12345. so integer = 48000, fractional= -1.87655. > > > > So if we use s64 for rate, then in driver need to convert the rate to > > the closed normal > > sample rate + fractional. > > That wasn't what the documentation said :-) > > So this is really two controls: one for the 'normal sample rate' (whatever 'normal' > means in this context) and the offset to the actual sample rate. > > Presumably the 'normal' sample rate is set once, while the offset changes > regularly. > > But why do you need the 'normal' sample rate? With audio resampling I assume > you resample from one rate to another, so why do you need a third 'normal' > rate? > 'Normal' rate is used to select the prefilter table. Best regards Wang Shengjiu > Regards, > > Hans > > > > > best regards > > wang shengjiu > > > >> > >>> > >>> default: > >>> return -EINVAL; > >>> @@ -1868,6 +1870,9 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl, > >>> case V4L2_CTRL_TYPE_AREA: > >>> elem_size = sizeof(struct v4l2_area); > >>> break; > >>> + case V4L2_CTRL_TYPE_FIXED_POINT: > >>> + elem_size = sizeof(struct v4l2_ctrl_fixed_point); > >>> + break; > >>> default: > >>> if (type < V4L2_CTRL_COMPOUND_TYPES) > >>> elem_size = sizeof(s32); > >>> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c > >>> index 8696eb1cdd61..d8f232df6b6a 100644 > >>> --- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c > >>> +++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c > >>> @@ -1602,6 +1602,10 @@ 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_ASRC_SOURCE_RATE: > >>> + case V4L2_CID_ASRC_DEST_RATE: > >>> + *type = V4L2_CTRL_TYPE_FIXED_POINT; > >>> + break; > >>> default: > >>> *type = V4L2_CTRL_TYPE_INTEGER; > >>> break; > >>> diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h > >>> index 59679a42b3e7..645e4cccafc7 100644 > >>> --- a/include/media/v4l2-ctrls.h > >>> +++ b/include/media/v4l2-ctrls.h > >>> @@ -56,6 +56,7 @@ struct video_device; > >>> * @p_av1_tile_group_entry: Pointer to an AV1 tile group entry structure. > >>> * @p_av1_frame: Pointer to an AV1 frame structure. > >>> * @p_av1_film_grain: Pointer to an AV1 film grain structure. > >>> + * @p_fixed_point: Pointer to a struct v4l2_ctrl_fixed_point. > >>> * @p: Pointer to a compound value. > >>> * @p_const: Pointer to a constant compound value. > >>> */ > >>> @@ -89,6 +90,7 @@ union v4l2_ctrl_ptr { > >>> struct v4l2_ctrl_av1_tile_group_entry *p_av1_tile_group_entry; > >>> struct v4l2_ctrl_av1_frame *p_av1_frame; > >>> struct v4l2_ctrl_av1_film_grain *p_av1_film_grain; > >>> + struct v4l2_ctrl_fixed_point *p_fixed_point; > >>> void *p; > >>> const void *p_const; > >>> }; > >>> diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h > >>> index c3604a0a3e30..91096259e3ea 100644 > >>> --- a/include/uapi/linux/v4l2-controls.h > >>> +++ b/include/uapi/linux/v4l2-controls.h > >>> @@ -112,6 +112,8 @@ enum v4l2_colorfx { > >>> > >>> /* last CID + 1 */ > >>> #define V4L2_CID_LASTP1 (V4L2_CID_BASE+44) > >>> +#define V4L2_CID_ASRC_SOURCE_RATE (V4L2_CID_BASE + 45) > >>> +#define V4L2_CID_ASRC_DEST_RATE (V4L2_CID_BASE + 46) > >> > >> This patch needs to be split in three parts: > >> > >> 1) Add the new M2M_AUDIO control class, > >> 2) Add the new V4L2_CTRL_TYPE_FIXED_POINT type, > >> 3) Add the new controls. > >> > >> These are all independent changes, so separating them makes it easier to > >> review. > >> > >>> > >>> /* USER-class private control IDs */ > >>> > >>> @@ -3488,4 +3490,15 @@ struct v4l2_ctrl_av1_film_grain { > >>> #define V4L2_CID_MPEG_MFC51_BASE V4L2_CID_CODEC_MFC51_BASE > >>> #endif > >>> > >>> +/** > >>> + * struct v4l2_ctrl_fixed_point - fixed point parameter. > >>> + * > >>> + * @rate_integer: integer part of fixed point value. > >>> + * @rate_fractional: fractional part of fixed point value > >>> + */ > >>> +struct v4l2_ctrl_fixed_point { > >>> + __u32 integer; > >> > >> __s32? > >> > >>> + __u32 fractional; > >>> +}; > >>> + > >>> #endif > >>> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h > >>> index 2ac7b989394c..3ef32c09c2fa 100644 > >>> --- a/include/uapi/linux/videodev2.h > >>> +++ b/include/uapi/linux/videodev2.h > >>> @@ -1888,6 +1888,7 @@ struct v4l2_ext_control { > >>> struct v4l2_ctrl_av1_tile_group_entry __user *p_av1_tile_group_entry; > >>> struct v4l2_ctrl_av1_frame __user *p_av1_frame; > >>> struct v4l2_ctrl_av1_film_grain __user *p_av1_film_grain; > >>> + struct v4l2_ctrl_fixed_point __user *p_fixed_point; > >>> void __user *ptr; > >>> }; > >>> } __attribute__ ((packed)); > >>> @@ -1966,6 +1967,8 @@ enum v4l2_ctrl_type { > >>> V4L2_CTRL_TYPE_AV1_TILE_GROUP_ENTRY = 0x281, > >>> V4L2_CTRL_TYPE_AV1_FRAME = 0x282, > >>> V4L2_CTRL_TYPE_AV1_FILM_GRAIN = 0x283, > >>> + > >>> + V4L2_CTRL_TYPE_FIXED_POINT = 0x290, > >>> }; > >>> > >>> /* Used in the VIDIOC_QUERYCTRL ioctl for querying controls */ > >> > >> Regards, > >> > >> Hans >
