On Monday, September 22, 2025 4:36 PM Svyatoslav Ryhel wrote:
> пн, 22 вер. 2025 р. о 10:27 Mikko Perttunen <[email protected]> пише:
> >
> > On Monday, September 22, 2025 3:30 PM Svyatoslav Ryhel wrote:
> > > пн, 22 вер. 2025 р. о 09:23 Mikko Perttunen <[email protected]> пише:
> > > >
> > > > On Monday, September 22, 2025 2:13 PM Svyatoslav Ryhel wrote:
> > > > > пн, 22 вер. 2025 р. о 07:44 Mikko Perttunen <[email protected]>
> > > > > пише:
> > > > > >
> > > > > > On Saturday, September 6, 2025 10:53 PM Svyatoslav Ryhel wrote:
> > > > > > > Simplify format align calculations by slightly modifying
> > > > > > > supported formats
> > > > > > > structure.
> > > > > > >
> > > > > > > Signed-off-by: Svyatoslav Ryhel <[email protected]>
> > > > > > > ---
> > > > > > > drivers/staging/media/tegra-video/tegra20.c | 41
> > > > > > > ++++++++-------------
> > > > > > > 1 file changed, 16 insertions(+), 25 deletions(-)
> > > > > > >
> > > > > > > diff --git a/drivers/staging/media/tegra-video/tegra20.c
> > > > > > > b/drivers/staging/media/tegra-video/tegra20.c
> > > > > > > index 6e0b3b728623..781c4e8ec856 100644
> > > > > > > --- a/drivers/staging/media/tegra-video/tegra20.c
> > > > > > > +++ b/drivers/staging/media/tegra-video/tegra20.c
> > > > > > > @@ -280,20 +280,8 @@ static void tegra20_fmt_align(struct
> > > > > > > v4l2_pix_format *pix, unsigned int bpp)
> > > > > > > pix->width = clamp(pix->width, TEGRA20_MIN_WIDTH,
> > > > > > > TEGRA20_MAX_WIDTH);
> > > > > > > pix->height = clamp(pix->height, TEGRA20_MIN_HEIGHT,
> > > > > > > TEGRA20_MAX_HEIGHT);
> > > > > > >
> > > > > > > - switch (pix->pixelformat) {
> > > > > > > - case V4L2_PIX_FMT_UYVY:
> > > > > > > - case V4L2_PIX_FMT_VYUY:
> > > > > > > - case V4L2_PIX_FMT_YUYV:
> > > > > > > - case V4L2_PIX_FMT_YVYU:
> > > > > > > - pix->bytesperline = roundup(pix->width, 2) * 2;
> > > > > > > - pix->sizeimage = roundup(pix->width, 2) * 2 *
> > > > > > > pix->height;
> > > > > > > - break;
> > > > > > > - case V4L2_PIX_FMT_YUV420:
> > > > > > > - case V4L2_PIX_FMT_YVU420:
> > > > > > > - pix->bytesperline = roundup(pix->width, 8);
> > > > > > > - pix->sizeimage = roundup(pix->width, 8) *
> > > > > > > pix->height * 3 / 2;
> > > > > > > - break;
> > > > > > > - }
> > > > > > > + pix->bytesperline = DIV_ROUND_UP(pix->width * bpp, 8);
> > > > > >
> > > > > > Assuming the bpp is coming from the format table below, this
> > > > > > changes the value of bytesperline for planar formats. With this
> > > > > > it'll be (width * 12) / 8 i.e. width * 3/2, which doesn't sound
> > > > > > right.
> > > > > >
> > > > >
> > > > > Downstream uses soc_mbus_bytes_per_line for this calculation which was
> > > > > deprecated some time ago, here is a fragment
> > > > >
> > > > > s32 soc_mbus_bytes_per_line(u32 width, const struct soc_mbus_pixelfmt
> > > > > *mf)
> > > > > {
> > > > > if (mf->fourcc == V4L2_PIX_FMT_JPEG)
> > > > > return 0;
> > > > >
> > > > > if (mf->layout != SOC_MBUS_LAYOUT_PACKED)
> > > > > return width * mf->bits_per_sample / 8;
> > > > >
> > > > > switch (mf->packing) {
> > > > > case SOC_MBUS_PACKING_NONE:
> > > > > return width * mf->bits_per_sample / 8;
> > > > > case SOC_MBUS_PACKING_2X8_PADHI:
> > > > > case SOC_MBUS_PACKING_2X8_PADLO:
> > > > > case SOC_MBUS_PACKING_EXTEND16:
> > > > > return width * 2;
> > > > > case SOC_MBUS_PACKING_1_5X8:
> > > > > return width * 3 / 2;
> > > > > case SOC_MBUS_PACKING_VARIABLE:
> > > > > return 0;
> > > > > }
> > > > > return -EINVAL;
> > > > > }
> > > > >
> > > > > V4L2_PIX_FMT_YUV420 and V4L2_PIX_FMT_YVU420 are classified as
> > > > > SOC_MBUS_PACKING_1_5X8 hence we get width * 3/2
> > > >
> > > > Googling this brings up the entry
> > > >
> > > > {
> > > > .code = V4L2_MBUS_FMT_YUYV8_1_5X8,
> > > > .fmt = {
> > > > .fourcc = V4L2_PIX_FMT_YUV420,
> > > > .name = "YUYV 4:2:0",
> > > > .bits_per_sample = 8,
> > > > .packing =
> > > > SOC_MBUS_PACKING_1_5X8,
> > > > .order = SOC_MBUS_ORDER_LE,
> > > > .layout = SOC_MBUS_LAYOUT_PACKED,
> > > > },
> > > > }
> > > >
> > > > which matches that you're describing. It doesn't make sense to me,
> > > > since it at the same time specifies PIX_FMT_YUV420 (which is planar
> > > > with 3 planes, as documented by include/uapi/linux/videodev2.h), and
> > > > LAYOUT_PACKED
> > > >
> > > > /**
> > > > * enum soc_mbus_layout - planes layout in memory
> > > > * @SOC_MBUS_LAYOUT_PACKED: color components packed
> > > > * @SOC_MBUS_LAYOUT_PLANAR_2Y_U_V: YUV components stored in 3
> > > > planes (4:2:2)
> > > > * @SOC_MBUS_LAYOUT_PLANAR_2Y_C: YUV components stored in a luma
> > > > and a
> > > > * chroma plane (C plane is half
> > > > the size
> > > > * of Y plane)
> > > > * @SOC_MBUS_LAYOUT_PLANAR_Y_C: YUV components stored in a luma
> > > > and a
> > > > * chroma plane (C plane is the
> > > > same size
> > > > * as Y plane)
> > > > */
> > > > enum soc_mbus_layout {
> > > > SOC_MBUS_LAYOUT_PACKED = 0,
> > > > SOC_MBUS_LAYOUT_PLANAR_2Y_U_V,
> > > > SOC_MBUS_LAYOUT_PLANAR_2Y_C,
> > > > SOC_MBUS_LAYOUT_PLANAR_Y_C,
> > > > };
> > > >
> > > > i.e. non-planar. The code in the driver is handling it as three planes
> > > > as well, with addresses
> > > > VB0_BASE_ADDRESS/VB0_BASE_ADDRESS_U/VB0_BASE_ADDRESS_V. Since the
> > > > planes are separate, there should be no need to have more than 'width'
> > > > samples per line.
> > > >
> > >
> > > I did not invent this, I have just simplified this calculation from
> > > downstream, output values remain same. I have no cameras which can
> > > output V4L2_PIX_FMT_YUV420 or V4L2_PIX_FMT_YVU420 so I cannot test if
> > > this works either. Other YUV and RAW formats were tested on real HW
> > > and work perfectly fine.
> >
> > My understanding from the code was, that the MEDIA_BUS_FMT_ formats listed
> > in the video format table refer to the input formats from the camera, and
> > the V4L2_PIX_FMT_ formats to output formats from VI. Hence VI could input
> > UYVY8_2X8 and write to memory in YUV420. The code dealing with
> > V4L2_PIX_FMT_ values seems to be related to the output to memory. Is it
> > possible to test this (your camera -> VI converts to YUV420) or am I
> > mistaken?
> >
>
> Camera I am testing with has no YUV420 options available and from what
> I can tell there is no way to force VI to output in YUV420 unless
> camera supports it. Any format manipulations should requite hooking up
> ISP, or am I missing smth?
>From a quick look at the spec it looks to me like for YUV422 packed input
>formats specifically, VI should be able to convert to YUV420. If that were not
>the case, e.g. 'TEGRA20_VIDEO_FMT(YUV422_8, 16, UYVY8_2X8, 12, YUV420),' would
>not make sense anyway as it's talking about both YUV422 packed input data and
>then also YUV420.
>
> > It's certainly possible that the current code is functional -- if
> > bytesperline is set to a too large value and that information flows to
> > userspace, it could still read the buffer. It would just waste memory.
> >
> > >
> > > > >
> > > > > > > + pix->sizeimage = pix->bytesperline * pix->height;
> > > > > > > }
> > > > > > >
> > > > > > > /*
> > > > > > > @@ -576,20 +564,23 @@ static const struct tegra_vi_ops
> > > > > > > tegra20_vi_ops = {
> > > > > > > .vi_stop_streaming = tegra20_vi_stop_streaming,
> > > > > > > };
> > > > > > >
> > > > > > > -#define TEGRA20_VIDEO_FMT(MBUS_CODE, BPP, FOURCC) \
> > > > > > > -{ \
> > > > > > > - .code = MEDIA_BUS_FMT_##MBUS_CODE, \
> > > > > > > - .bpp = BPP, \
> > > > > > > - .fourcc = V4L2_PIX_FMT_##FOURCC, \
> > > > > > > +#define TEGRA20_VIDEO_FMT(DATA_TYPE, BIT_WIDTH, MBUS_CODE, BPP,
> > > > > > > FOURCC) \
> > > > > > > +{
> > > > > > > \
> > > > > > > + .img_dt = TEGRA_IMAGE_DT_##DATA_TYPE,
> > > > > > > \
> > > > > > > + .bit_width = BIT_WIDTH,
> > > > > > > \
> > > > > > > + .code = MEDIA_BUS_FMT_##MBUS_CODE,
> > > > > > > \
> > > > > > > + .bpp = BPP,
> > > > > > > \
> > > > > > > + .fourcc = V4L2_PIX_FMT_##FOURCC,
> > > > > > > \
> > > > > > > }
> > > > > > >
> > > > > > > static const struct tegra_video_format tegra20_video_formats[] =
> > > > > > > {
> > > > > > > - TEGRA20_VIDEO_FMT(UYVY8_2X8, 2, UYVY),
> > > > > > > - TEGRA20_VIDEO_FMT(VYUY8_2X8, 2, VYUY),
> > > > > > > - TEGRA20_VIDEO_FMT(YUYV8_2X8, 2, YUYV),
> > > > > > > - TEGRA20_VIDEO_FMT(YVYU8_2X8, 2, YVYU),
> > > > > > > - TEGRA20_VIDEO_FMT(UYVY8_2X8, 1, YUV420),
> > > > > > > - TEGRA20_VIDEO_FMT(UYVY8_2X8, 1, YVU420),
> > > > > > > + /* YUV422 */
> > > > > > > + TEGRA20_VIDEO_FMT(YUV422_8, 16, UYVY8_2X8, 16, UYVY),
> > > > > > > + TEGRA20_VIDEO_FMT(YUV422_8, 16, VYUY8_2X8, 16, VYUY),
> > > > > > > + TEGRA20_VIDEO_FMT(YUV422_8, 16, YUYV8_2X8, 16, YUYV),
> > > > > > > + TEGRA20_VIDEO_FMT(YUV422_8, 16, YVYU8_2X8, 16, YVYU),
> > > > > > > + TEGRA20_VIDEO_FMT(YUV422_8, 16, UYVY8_2X8, 12, YUV420),
> > > > > > > + TEGRA20_VIDEO_FMT(YUV422_8, 16, UYVY8_2X8, 12, YVU420),
> > > > > > > };
> > > > > > >
> > > > > > > const struct tegra_vi_soc tegra20_vi_soc = {
> > > > > > >
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> > > > > >
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> >
