Re: [PATCH 0/2] media: v4l: Add Broadcom sand format to the list of V4L formats

From: Nicolas Dufresne <nicolas@ndufresne.ca>
To: John Cox <jc@kynesim.co.uk>, linux-media@vger.kernel.org
Cc: hverkuil-cisco@xs4all.nl
Subject: Re: [PATCH 0/2] media: v4l: Add Broadcom sand format to the list of V4L formats
Date: Thu, 09 Feb 2023 12:56:18 -0500	[thread overview]
Message-ID: <44531f980f771272a8a663c2b2d68dce3bf47456.camel@ndufresne.ca> (raw)
In-Reply-To: <20230127153415.83126-1-jc@kynesim.co.uk>

Le vendredi 27 janvier 2023 à 15:34 +0000, John Cox a écrit :
> This is in preparation for attempting to upstream the Rpi H265 decoder
> as these formats are the only ones the hardware can decode to. They are
> a column format rather than a tile format but I've added them to the
> list of tiled formats as that seems the closest match.
> 
> V4L2_PIX_FMT_NV12_C128 matches DRM format NV12 with modifier
> DRM_FORMAT_MOD_BROADCOM_SAND128_COL_HEIGHT(ch) and
> V4L2_PIX_FMT_P030_C128 matches DRM format P030 with the same modifier.

Cause pixel format matching is hard, P030 matches GStreamer NV12_10LE32, format
also found on Xilinx ZynMP CODECs (but without any modifiers so far).

This is just for curiosity, was there any software implementation of these
formats made available publicly ? or have they only been tested in conjunction
with an importing HW ?

> 
> John Cox (2):
>   media: v4l: Add Broadcom sand formats to videodev2.h
>   media: v4l: Add documentation for Broadcom sand formats
> 
>  .../media/v4l/pixfmt-yuv-planar.rst           | 192 ++++++++++++++++++
>  include/uapi/linux/videodev2.h                |   2 +
>  2 files changed, 194 insertions(+)
> 