diff mbox series

[v5,1/3] media: videodev2: Add flag to unconditionnaly enumerate pixels formats

Message ID 20240722150523.149667-2-benjamin.gaignard@collabora.com
State New
Headers show
Series Enumerate all pixels formats | expand

Commit Message

Benjamin Gaignard July 22, 2024, 3:05 p.m. UTC
When the index field is ORed with V4L2_FMT_FLAG_ENUM_ALL the driver
will ignore any configuration and enumerate all the possible formats.
Drivers which do not support this flag yet always return an EINVAL
error code.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
---
changes in version 5:
- Reset the proposal to follow Hans's advices
- Add new flag to be used with index field.

 .../userspace-api/media/v4l/vidioc-enum-fmt.rst      | 12 +++++++++++-
 .../userspace-api/media/videodev2.h.rst.exceptions   |  1 +
 include/uapi/linux/videodev2.h                       |  3 +++
 3 files changed, 15 insertions(+), 1 deletion(-)

Comments

Benjamin Gaignard July 31, 2024, 6:59 a.m. UTC | #1
Le 30/07/2024 à 09:08, Hans Verkuil a écrit :
> On 22/07/2024 17:05, Benjamin Gaignard wrote:
>> When the index field is ORed with V4L2_FMT_FLAG_ENUM_ALL the driver
>> will ignore any configuration and enumerate all the possible formats.
>> Drivers which do not support this flag yet always return an EINVAL
>> error code.
>>
>> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
>> ---
>> changes in version 5:
>> - Reset the proposal to follow Hans's advices
>> - Add new flag to be used with index field.
>>
>>   .../userspace-api/media/v4l/vidioc-enum-fmt.rst      | 12 +++++++++++-
>>   .../userspace-api/media/videodev2.h.rst.exceptions   |  1 +
>>   include/uapi/linux/videodev2.h                       |  3 +++
>>   3 files changed, 15 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
>> index 3adb3d205531..12e1e65e6a71 100644
>> --- a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
>> +++ b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
>> @@ -85,7 +85,11 @@ the ``mbus_code`` field is handled differently:
>>       * - __u32
>>         - ``index``
>>         - Number of the format in the enumeration, set by the application.
>> -	This is in no way related to the ``pixelformat`` field.
>> +        This is in no way related to the ``pixelformat`` field. When the
> You need to start a new paragraph before 'When'. Otherwise you might read
> that the 'When' sentence is somehow related to the previous sentence.
>
>> +        index is ORed with V4L2_FMT_FLAG_ENUM_ALL the driver will ignore
>> +        any configuration and enumerate all the possible formats. Drivers
> I'd rephrase this a little bit:
>
> the driver will enumerate all the possible formats, ignoring any limitations
> from the current configuration.
>
> And after that I would like to see an example of a use-case.
>
>> +        which do not support this flag yet always return an ``EINVAL``
>> +        error code.
>>       * - __u32
>>         - ``type``
>>         - Type of the data stream, set by the application. Only these types
>> @@ -234,6 +238,12 @@ the ``mbus_code`` field is handled differently:
>>   	valid. The buffer consists of ``height`` lines, each having ``width``
>>   	Data Units of data and the offset (in bytes) between the beginning of
>>   	each two consecutive lines is ``bytesperline``.
>> +    * - ``V4L2_FMT_FLAG_ENUM_ALL``
> I am not really happy with this name since the prefix is identical to that
> of other V4L2_FMT_FLAG_ defines. How about: V4L2_FMTDESC_FLAG_ENUM_ALL?
> Or V4L2_FMT_IDX_ENUM_ALL?

I will use V4L2_FMTDESC_FLAG_ENUM_ALL in the next version.

Regards,
Benjamin

>
>> +      - 0x80000000
>> +      - When the applications ORs ``index`` with ``V4L2_FMT_FLAG_ENUM_ALL`` flag
>> +        the driver enumerates all the possible pixel formats without taking care
>> +        of any already set configuration. Drivers which do not support this flag
>> +        yet always return ``EINVAL``.
>>   
>>   Return Value
>>   ============
>> diff --git a/Documentation/userspace-api/media/videodev2.h.rst.exceptions b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
>> index bdc628e8c1d6..8dc10a500fc6 100644
>> --- a/Documentation/userspace-api/media/videodev2.h.rst.exceptions
>> +++ b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
>> @@ -216,6 +216,7 @@ replace define V4L2_FMT_FLAG_CSC_YCBCR_ENC fmtdesc-flags
>>   replace define V4L2_FMT_FLAG_CSC_HSV_ENC fmtdesc-flags
>>   replace define V4L2_FMT_FLAG_CSC_QUANTIZATION fmtdesc-flags
>>   replace define V4L2_FMT_FLAG_META_LINE_BASED fmtdesc-flags
>> +replace define V4L2_FMT_FLAG_ENUM_ALL fmtdesc-flags
>>   
>>   # V4L2 timecode types
>>   replace define V4L2_TC_TYPE_24FPS timecode-type
>> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
>> index 4e91362da6da..3d11f91273a1 100644
>> --- a/include/uapi/linux/videodev2.h
>> +++ b/include/uapi/linux/videodev2.h
>> @@ -904,6 +904,9 @@ struct v4l2_fmtdesc {
>>   #define V4L2_FMT_FLAG_CSC_QUANTIZATION		0x0100
>>   #define V4L2_FMT_FLAG_META_LINE_BASED		0x0200
>>   
>> +/*  Format description flag, to be ORed with the index */
>> +#define V4L2_FMT_FLAG_ENUM_ALL			0x80000000
>> +
>>   	/* Frame Size and frame rate enumeration */
>>   /*
>>    *	F R A M E   S I Z E   E N U M E R A T I O N
> Regards,
>
> 	Hans
>
diff mbox series

Patch

diff --git a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
index 3adb3d205531..12e1e65e6a71 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-enum-fmt.rst
@@ -85,7 +85,11 @@  the ``mbus_code`` field is handled differently:
     * - __u32
       - ``index``
       - Number of the format in the enumeration, set by the application.
-	This is in no way related to the ``pixelformat`` field.
+        This is in no way related to the ``pixelformat`` field. When the
+        index is ORed with V4L2_FMT_FLAG_ENUM_ALL the driver will ignore
+        any configuration and enumerate all the possible formats. Drivers
+        which do not support this flag yet always return an ``EINVAL``
+        error code.
     * - __u32
       - ``type``
       - Type of the data stream, set by the application. Only these types
@@ -234,6 +238,12 @@  the ``mbus_code`` field is handled differently:
 	valid. The buffer consists of ``height`` lines, each having ``width``
 	Data Units of data and the offset (in bytes) between the beginning of
 	each two consecutive lines is ``bytesperline``.
+    * - ``V4L2_FMT_FLAG_ENUM_ALL``
+      - 0x80000000
+      - When the applications ORs ``index`` with ``V4L2_FMT_FLAG_ENUM_ALL`` flag
+        the driver enumerates all the possible pixel formats without taking care
+        of any already set configuration. Drivers which do not support this flag
+        yet always return ``EINVAL``.
 
 Return Value
 ============
diff --git a/Documentation/userspace-api/media/videodev2.h.rst.exceptions b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
index bdc628e8c1d6..8dc10a500fc6 100644
--- a/Documentation/userspace-api/media/videodev2.h.rst.exceptions
+++ b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
@@ -216,6 +216,7 @@  replace define V4L2_FMT_FLAG_CSC_YCBCR_ENC fmtdesc-flags
 replace define V4L2_FMT_FLAG_CSC_HSV_ENC fmtdesc-flags
 replace define V4L2_FMT_FLAG_CSC_QUANTIZATION fmtdesc-flags
 replace define V4L2_FMT_FLAG_META_LINE_BASED fmtdesc-flags
+replace define V4L2_FMT_FLAG_ENUM_ALL fmtdesc-flags
 
 # V4L2 timecode types
 replace define V4L2_TC_TYPE_24FPS timecode-type
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 4e91362da6da..3d11f91273a1 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -904,6 +904,9 @@  struct v4l2_fmtdesc {
 #define V4L2_FMT_FLAG_CSC_QUANTIZATION		0x0100
 #define V4L2_FMT_FLAG_META_LINE_BASED		0x0200
 
+/*  Format description flag, to be ORed with the index */
+#define V4L2_FMT_FLAG_ENUM_ALL			0x80000000
+
 	/* Frame Size and frame rate enumeration */
 /*
  *	F R A M E   S I Z E   E N U M E R A T I O N