On Thu, May 26, 2016 at 3:53 AM, Daniel Vetter <daniel at ffwll.ch> wrote:
> On Wed, May 25, 2016 at 07:55:23PM +0000, Yang, Eric wrote:
>> Hi Thierry Reding,
>>
>> enum hdmi_picture_aspect {
>> > HDMI_PICTURE_ASPECT_NONE,
>> > HDMI_PICTURE_ASPECT_4_3,
>> > HDMI_PICTURE_ASPECT_16_9,
>> > + HDMI_PICTURE_ASPECT_64_27,
>> > + HDMI_PICTURE_ASPECT_256_135,
>> > HDMI_PICTURE_ASPECT_RESERVED,
>> > };
>>
>> These are defined since CEA861F defines them in section 4.1.
>> However, it is not indicated in AVI InfoFrame definition for picture aspect
>> ratio (M1,M0), and we should indicate (M1,M0) = (0,0) for "No Data" when
>> sending VICs corresponding to these new aspect ratios.
>>
>> If (M1,M0) = (0,0) "No Data" is indicated, then If M=0 (M1=0, M0=0) and
>> VIC=0, a Sink shall assume the Picture is formatted according to the
>> Preferred Picture Aspect Ratio.
>>
>> The defition:
>>
>> Preferred Picture Aspect Ratio-In a Dual-Aspect Ratio DTV, the preferred
>> aspect ratio of a given Video Format Timing (e.g., 720x480p) is the aspect
>> ratio of the first such timing listed in the EDID data structure (see
>> Section 4.1). This would be the Picture Aspect Ratio that would be displayed
>> if a DTV were to receive a Video Format Timing with no accompanying Picture
>> Aspect Ratio information (i.e., no AVI sent from Source).
>>
>> Alternatively, since our code does not actively use
>> HDMI_PICTURE_ASPECT_64_27, HDMI_PICTURE_ASPECT_256_135, we can unify them as
>> HDMI_PICTURE_ASPECT_NONE, and send (M1,M0) = (0,0) to avoid confusion.
>
> There's already drm core patches to add all this stuff for the new aspect
> ratios:
>
> https://patchwork.freedesktop.org/series/4896/
Patches 1-4 from that series are:
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
>
> Would be great if you can review them. Patch 5 of that series (for
> i915.ko) needs to be polished a bit, but the other bits all look fine to
> me at a quick glance.
>
> Thanks, Daniel
>
>>
>>
>>
>> -----Original Message-----
>> From: Thierry Reding <thierry.reding at gmail.com>
>> Sent: Friday, May 13, 2016 11:28:39 AM
>> To: Yang, Eric
>> Cc: dri-devel at lists.freedesktop.org; linux-fbdev at vger.kernel.org;
>> tomi.valkeinen at ti.com; plagnioj at jcrosoft.com
>> Subject: Re: [PATCH] drm: expand cea861 mode timing table
>>
>> On Thu, May 12, 2016 at 03:37:33PM -0400, Eric Yang wrote:
>> [...]
>> > diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h index
>> > e974420..edbb4fc 100644
>> > --- a/include/linux/hdmi.h
>> > +++ b/include/linux/hdmi.h
>> > @@ -78,6 +78,8 @@ enum hdmi_picture_aspect {
>> > HDMI_PICTURE_ASPECT_NONE,
>> > HDMI_PICTURE_ASPECT_4_3,
>> > HDMI_PICTURE_ASPECT_16_9,
>> > + HDMI_PICTURE_ASPECT_64_27,
>> > + HDMI_PICTURE_ASPECT_256_135,
>> > HDMI_PICTURE_ASPECT_RESERVED,
>> > };
>>
>> Where did you get these from? I'm asking because I sent this patch last year
>> (or at least I wrote it and we discussed it on IRC, since I can't find an
>> email archive link to it), and back at the time the picture aspect ratio was
>> the big question mark. My recollection is that CEA-861-F introduces these
>> new picture aspect ratios in the mode tables but never specifies their
>> values. As a matter of fact, the AVI infoframe where these values are used
>> only has space for 4 values (none, 4:3, 16:9 and reserved).
>>
>> Would you mind pointing me at the specification for these values?
>>
>> Thanks,
>> Thierry
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
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