Created attachment 143863 [details]
picture from screen
I want to decode a H264 1280x720 video with v4l2 decoder and present this on
DRM with a dumb buffer.
On screen the Y plane is correct but UV plane have the doubled height. Pitc=
h is
correct. But looks like a line from uv plane is used for 4 lines on y plane
instead of 2. Attached are a picture from the screen. I use the format
describtion from:
https://www.linuxtv.org/downloads/v4l-dvb-apis-new/uapi/v4l=
/pixfmt-nv12mt.html.=20
For dumb buffer configuration the height must aligned to 64 instead of to 3=
2.
If align height to 32 EINVAL is returned from AddFB2. OK, the UV plane have=
the
half height from Y plane and must aligned to 32.
The size from DRM_IOCTL_CREATE_DUMB_BUFFER is to big. IOCTL returned a dumb
buffer size from 1966080.
width =3D 1280 =3D> aligned to 128 width =3D 1280
height =3D 720 =3D> aligned to 64 height =3D 768
Y plane 1280 * 768 =3D 983040
UV plane 1280 * 768 / 2 =3D 491520
Dumb buffer size should be 1474560. Looks like the UV plane have doubled si=
ze
as it should be.
The device is a Odroid-U3 with Exynos4412.
Kernel version is 5.0.5.