Messages in this thread | | | Subject | Re: [PATCH v2] media: v4l2-ctrl: Add base layer priority id control. | From | Hans Verkuil <> | Date | Tue, 17 Nov 2020 15:53:03 +0100 |
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Nicolas, can you take a look at this with your codec knowledge?
Some other review comments below:
On 15/10/2020 13:05, Dikshita Agarwal wrote: > This control indicates the priority id to be applied > to base layer. > > Signed-off-by: Dikshita Agarwal <dikshita@codeaurora.org> > --- > Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst | 9 +++++++++ > drivers/media/v4l2-core/v4l2-ctrls.c | 1 + > include/uapi/linux/v4l2-controls.h | 1 + > 3 files changed, 11 insertions(+) > > diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst > index 6e9240a..aac1ea3 100644 > --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst > +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst > @@ -4407,3 +4407,12 @@ enum v4l2_mpeg_video_hevc_size_of_length_field - > to the LTR index max LTR count-1. > This is applicable to H264 and HEVC encoder and can be applied using > request api. > + > +``V4L2_CID_MPEG_VIDEO_BASELAYER_PRIORITYID (integer)``
I'd add a_ before the ID, so: V4L2_CID_MPEG_VIDEO_BASELAYER_PRIORITY_ID.
> + Specifies a priority identifier for the NAL unit, > + which will be applied to base layer. > + By default this value is set to 0 for base layer. > + And the next layer will have priority ID assigned as 1,2,3 and so on. > + Video encode can't decide the priority id to be applied to a layer > + so this has to come from client. > + Valid Range: from 0 to 63
I'm slightly rephrasing the text above:
Specifies a priority identifier for the NAL unit, which will be applied to the base layer. By default this value is set to 0 for the base layer, and the next layer will have the priority ID assigned as 1, 2, 3 and so on. The video encoder can't decide the priority id to be applied to a layer, so this has to come from client. Valid Range: from 0 to 63.
For which codecs is this applicable? H264 and HEVC? That should be stated. If you have a reference to the corresponding sections that describe this, then that would be nice to add.
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c > index 046198f..c973058 100644 > --- a/drivers/media/v4l2-core/v4l2-ctrls.c > +++ b/drivers/media/v4l2-core/v4l2-ctrls.c > @@ -952,6 +952,7 @@ const char *v4l2_ctrl_get_name(u32 id) > case V4L2_CID_MPEG_VIDEO_LTR_COUNT: return "LTR Count"; > case V4L2_CID_MPEG_VIDEO_FRAME_LTR_INDEX: return "Mark LTR frame index"; > case V4L2_CID_MPEG_VIDEO_USE_LTR_FRAME: return "Use LTR Frame"; > + case V4L2_CID_MPEG_VIDEO_BASELAYER_PRIORITYID: return "Base Layer Priority ID"; > case V4L2_CID_MPEG_VIDEO_MPEG2_SLICE_PARAMS: return "MPEG-2 Slice Parameters"; > case V4L2_CID_MPEG_VIDEO_MPEG2_QUANTIZATION: return "MPEG-2 Quantization Matrices"; > case V4L2_CID_MPEG_VIDEO_FWHT_PARAMS: return "FWHT Stateless Parameters"; > diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h > index 3801372..433e119 100644 > --- a/include/uapi/linux/v4l2-controls.h > +++ b/include/uapi/linux/v4l2-controls.h > @@ -418,6 +418,7 @@ enum v4l2_mpeg_video_multi_slice_mode { > #define V4L2_CID_MPEG_VIDEO_LTR_COUNT (V4L2_CID_MPEG_BASE+230) > #define V4L2_CID_MPEG_VIDEO_FRAME_LTR_INDEX (V4L2_CID_MPEG_BASE+231) > #define V4L2_CID_MPEG_VIDEO_USE_LTR_FRAME (V4L2_CID_MPEG_BASE+232) > +#define V4L2_CID_MPEG_VIDEO_BASELAYER_PRIORITYID (V4L2_CID_MPEG_BASE+233) > > /* CIDs for the MPEG-2 Part 2 (H.262) codec */ > #define V4L2_CID_MPEG_VIDEO_MPEG2_LEVEL (V4L2_CID_MPEG_BASE+270) >
Regards,
Hans
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