Re: [PATCH v7] media: imx: add mem2mem device

[Tim Harvey <tharvey@gateworks.com>]

On Thu, Jan 17, 2019 at 7:50 AM Philipp Zabel <p.zabel@pengutronix.de> wrote:
>
> Add a single imx-media mem2mem video device that uses the IPU IC PP
> (image converter post processing) task for scaling and colorspace
> conversion.
> On i.MX6Q/DL SoCs with two IPUs currently only the first IPU is used.
>
> The hardware only supports writing to destination buffers up to
> 1024x1024 pixels in a single pass, arbitrary sizes can be achieved
> by rendering multiple tiles per frame.
>
> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> [slongerbeam@gmail.com: use ipu_image_convert_adjust(), fix
>  device_run() error handling, add missing media-device header,
>  unregister and remove the mem2mem device in error paths in
>  imx_media_probe_complete() and in imx_media_remove()]
> Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
> ---
> Changes since v6 [1]:
>  - Change driver name in querycap to imx-media-csc-scaler
>  - Drop V4L2_SEL_TGT_COMPOSE_PADDED from vidioc_g_selection
>  - Simplify error handling in ipu_csc_scaler_init_controls
>
> [1] https://patchwork.linuxtv.org/patch/53757/
> ---

Hi Philipp,

Thanks for this driver - this is providing support that I need to
overcome direct CSI->IC limitations.

Can you give me some examples on how your using this? I'm testing this
on top of linux-media and trying the following gstreamer pipelines
(gstreamer recent master) and running into trouble but it could very
likely be me doing something wrong in my pipelines:

# upscale
gst-launch-1.0 videotestsrc ! video/x-raw,width=320,height=240 !
v4l2convert output-io-mode=dmabuf-import !
video/x-raw,width=640,height=480 ! kmssink
^^^ fails with
ERROR: from element
/GstPipeline:pipeline0/GstAutoVideoSink:autovideosink0/GstKMSSink:autovideosink0-actual-sink-kms:
GStreamer encountered a general resource error.
Additional debug info:
gstkmssink.c(1529): gst_kms_sink_show_frame ():
/GstPipeline:pipeline0/GstAutoVideoSink:autovideosink0/GstKMSSink:autovideosink0-actual-sink-kms:
drmModeSetPlane failed: No space left on device (-28)
perhaps this is something strange with kmssink or is a buffer size not
being set properly in the mem2mem scaler?

# downscale
gst-launch-1.0 videotestsrc ! video/x-raw,width=640,height=480 !
v4l2convert output-io-mode=dmabuf-import !
video/x-raw,width=320,height=280 ! kmssink
(gst-launch-1.0:15493): GStreamer-CRITICAL **: 18:06:49.029:
gst_buffer_resize_range: assertion 'bufmax >= bufoffs + offset + size'
failed
ERROR: from element
/GstPipeline:pipeline0/GstVideoTestSrc:videotestsrc0: Internal data
stream error.
Additional debug info:
gstbasesrc.c(3064): gst_base_src_loop ():
/GstPipeline:pipeline0/GstVideoTestSrc:videotestsrc0:
streaming stopped, reason error (-5)
ERROR: pipeline doesn't want to preroll.
Setting pipeline to NULL ...
Freeing pipeline ...

# downscale using videotstsrc defaults
gst-launch-1.0 videotestsrc ! v4l2convert output-io-mode=dmabuf-import
! video/x-raw,width=100,height=200 ! kmssink
^^^ works

# rotation
gst-launch-1.0 videotestsrc ! v4l2convert output-io-mode=dmabuf-import
extra-controls=cid,rotate=90 ! kmssink
^^^ shows no rotation in displayed video but kernel debugging shows
ipu_csc_scaler_s_ctrl getting called with V4L2_CID_ROTATE,
ctrl->val=90 and ipu_degrees_to_rot_mode sets rot_mode=IPU_ROT_BIT_90
and returns no error. I also see that
ipu_image_convert_adjust gets called with rot_mode=IPU_ROT_BIT_90

I'm also not sure how to specify hflip/vflip... I don't think
extra-controls parses 'hflip', 'vflip' as ipu_csc_scaler_s_ctrl gets
called with V4L2_CID_HFLIP/V4L2_CID_VFLIP but ctrl->val is always 0.

Thanks,

Tim