Re: [PATCH v7 5/9] media: venus: vdec: add video decoder files

From: Nicolas Dufresne
Date: Fri Mar 24 2017 - 14:21:29 EST


Le vendredi 24 mars 2017 Ã 15:41 +0100, Hans Verkuil a ÃcritÂ:
> > +static const struct venus_format vdec_formats[] = {
> > +ÂÂÂÂÂ{
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂ.pixfmt = V4L2_PIX_FMT_NV12,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂ.num_planes = 1,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂ.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE,
>
> Just curious: is NV12 the only uncompressed format supported by the
> hardware?
> Or just the only one that is implemented here?

The downstream kernel[0], from Qualcomm have:

{
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.name = "UBWC YCbCr Semiplanar 4:2:0",
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.description = "UBWC Y/CbCr 4:2:0",
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.fourcc = V4L2_PIX_FMT_NV12_UBWC,
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.num_planes = 2,
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.get_frame_size = get_frame_size_nv12_ubwc,
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.type = CAPTURE_PORT,
ÂÂÂÂÂÂÂÂ},
ÂÂÂÂÂÂÂÂ{
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.name = "UBWC YCbCr Semiplanar 4:2:0 10bit",
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.description = "UBWC Y/CbCr 4:2:0 10bit",
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.fourcc = V4L2_PIX_FMT_NV12_TP10_UBWC,
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.num_planes = 2,
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.get_frame_size = get_frame_size_nv12_ubwc_10bit,
ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ.type = CAPTURE_PORT,
ÂÂÂÂÂÂÂÂ},

I have no idea what UBWC stands for. The performance in NV12 is more
then decent from my testing. Though, there is no 10bit variant.

regards,
Nicolas

[0] https://android.googlesource.com/kernel/msm/+/android-7.1.0_r0.2/dr
ivers/media/platform/msm/vidc/msm_vdec.c#695

Attachment: signature.asc
Description: This is a digitally signed message part