linux-kernel - Re: [Patch v4 12/12] Documention: v4l: Documentation for HEVC CIDs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-id: <b26d966f-5acd-5d1e-0cb6-0232f84c2b31@samsung.com>
Date:   Fri, 07 Apr 2017 12:26:31 +0200
From:   Sylwester Nawrocki <s.nawrocki@...sung.com>
To:     Smitha T Murthy <smitha.t@...sung.com>
Cc:     linux-arm-kernel@...ts.infradead.org, linux-media@...r.kernel.org,
        linux-kernel@...r.kernel.org, kyungmin.park@...sung.com,
        kamil@...as.org, jtp.park@...sung.com, a.hajda@...sung.com,
        mchehab@...nel.org, pankaj.dubey@...sung.com, krzk@...nel.org,
        m.szyprowski@...sung.com
Subject: Re: [Patch v4 12/12] Documention: v4l: Documentation for HEVC CIDs

On 04/07/2017 12:03 PM, Smitha T Murthy wrote:
>>> +``V4L2_CID_MPEG_VIDEO_HEVC_LF``
>>> +    Indicates loop filtering. Control ID 0 indicates loop filtering
>>> +    is enabled and when set to 1 indicates no filter.
 >>
>> "Setting this control to 0 enables loop filtering, setting this control
>> to 1 disables loop filtering." ?
>>
>> Couldn't the meaning be inverted, so setting the control to 0 disables
>> the loop filtering?
>>
>>>From register point of view, this control value needs be 0 to enable
> loop filtering.

OK, this is true for our specific hardware/firmware implementation.

In general, for this user space interface I would rather define that
boolean control so value 1 enables LF and value 0 disables LF.
The driver could simply negate the value when writing registers.

BTW we might need to specify type of the control here as Hans suggested
commenting on other control.

--
Regards,
Sylwester