Re: [Patch v4 10/12] [media] v4l2: Add v4l2 control IDs for HEVC encoder

Sylwester Nawrocki
2017-04-07T09:26:00Z

On 04/07/2017 10:31 AM, Smitha T Murthy wrote:
> On Thu, 2017-04-06 at 15:14 +0200, Sylwester Nawrocki wrote:
>> On 04/06/2017 08:11 AM, Smitha T Murthy wrote:
>>> @@ -775,6 +832,47 @@ const char *v4l2_ctrl_get_name(u32 id)
>>> case V4L2_CID_MPEG_VIDEO_VPX_P_FRAME_QP: return "VPX P-Frame QP Value";
>>> case V4L2_CID_MPEG_VIDEO_VPX_PROFILE: return "VPX Profile";
>>>
>>> + /* HEVC controls */
>> [...]
>>> + case V4L2_CID_MPEG_VIDEO_HEVC_LF_SLICE_BOUNDARY: return "HEVC LF Across Slice Boundary or Not";
>> Please make sure the names are no longer than 31 characters to avoid
>> truncation during control enumeration in user space.
>> Data structures like struct v4l2_queryctrl, struct v4l2_query_ext_ctrl
>> have only 32 bytes long array dedicated for the control name.
>
> I will try to make the names less than 31 characters long without losing
> the context. But there are many control names in this file which are
> longer than 31 characters like
> V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER_QP,
> V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_REF_PERIOD etc so I assumed it was
> alright to have such long names. But I will shorten them as per your
> suggestion.

Apologies if it wasn't clean enough but my comment referred to the
length of the character string being returned (e.g. "HEVC LF Across
Slice Boundary or Not") and not to the name of the enum.

--
Regards,
Sylwester