On 10/20/19 7:35 AM, Laurent Pinchart wrote:
> Hi Adam,
>
> On Sat, Oct 19, 2019 at 11:14:03AM -0500, Adam Ford wrote:
>> On Fri, Oct 18, 2019 at 4:17 PM Sakari Ailus <sakari.ailus@xxxxxx> wrote:
>>> On Fri, Oct 18, 2019 at 04:10:23PM -0500, Adam Ford wrote:
>>>> On Fri, Oct 18, 2019 at 4:00 PM Sakari Ailus <sakari.ailus@xxxxxx> wrote:
>>>>> On Fri, Oct 18, 2019 at 02:38:57PM -0500, Adam Ford wrote:
>>>>>> I have a DM3730 with a parallel mt9p031 sensor attached. I am trying
>>>>>> to troubleshoot some issues with streaming video with G-streamer, but
>>>>>> I I think the issue is in how the ISP driver reports the video info.
>>>>>>
>>>>>> I have the pipeline to grab from the resizer:
>>>>>>
>>>>>> media-ctl -v -V '"mt9p031 1-0048":0 [SGRBG8 1280x720
>>>>>> (664,541)/1280x720], "OMAP3 ISP CCDC":2 [SGRBG8 1280x720], "OMAP3 ISP
>>>>>> preview":1 [UYVY 1280x720], "OMAP3 ISP resizer":1 [UYVY 480x272]'
>>>>>>
>>>>>> This make /dev/video6 the output of the resizer and shows the format
>>>>>> and resolution of the output of the resizer as:
>>>>>>
>>>>>> Setting up format UYVY8_1X16 480x272 on pad OMAP3 ISP resizer/1
>>>>>> Format set: UYVY8_1X16 480x272
>>>>>>
>>>>>> I used 480x272 because it's the resolution of my LCD, and I was hoping
>>>>>> the resizer would be able to scale this so the ARM would not need to
>>>>>> do the work, and it appears to not have any issues with this
>>>>>> resolution.
>>>>>>
>>>>>> However, if I query the video format, I don't get UYVY:
>>>>>>
>>>>>> # v4l2-ctl -d6 --list-formats-ext
>>>>>> ioctl: VIDIOC_ENUM_FMT
>>>>>> Type: Video Capture
>>>>>>
>>>>>> [0]: 'RGB3' (RGB3, emulated)
>>>>>> [1]: 'BGR3' (BGR3, emulated)
>>>>>> [2]: 'YU12' (YU12, emulated)
>>>>>> [3]: 'YV12' (YV12, emulated)
>>>>>>
>>>>>> This becomes an issue when I attempt to stream video from my camera to
>>>>>> anything, include fake sink:
>>>>>>
>>>>>> gst-launch-1.0 -v v4l2src device=/dev/video6 ! fakesink
>>>>>> Tried to capture in RGB3, but device returned format UYVY
>>>>>>
>>>>>> So for some reason, when queried, it reports different values than
>>>>>> UYVY, but when attempting to set the video capture to the listed
>>>>>> formats, it returns an error.
>>>>>>
>>>>>> gst-launch-1.0 -v v4l2src device=/dev/video6 ! video/x-raw,
>>>>>> format=UYVY ! fakesink
>>>>>
>>>>> I don't have any experience on v4l2src recently but I can comment on the
>>>>> omap3isp driver.
>>>>>
>>>>> In general, the format the omap3isp may produce on a given video node
>>>>> depends on the format of data which the block associated with the video
>>>>> node is fed with.
>>>>>
>>>>> For instance, in case of the raw Bayer formats, the pixel order does not
>>>>> change, and thus the pixel order remains all the way from the sensor to the
>>>>> video node.
>>>>
>>>> From what I can tell, it looks like the output of the resizer is only
>>>> capable of two formats,
>>>> from ispresizer.c:
>>>>
>>>> /* resizer pixel formats */
>>>> static const unsigned int resizer_formats[] = {
>>>> MEDIA_BUS_FMT_UYVY8_1X16,
>>>> MEDIA_BUS_FMT_YUYV8_1X16,
>>>> };
>>>>
>>>> Also:
>>>>
>>>> * resizer_try_format - Handle try format by pad subdev method
>>>> * @res : ISP resizer device
>>>> * @cfg: V4L2 subdev pad configuration
>>>> * @pad : pad num
>>>> * @fmt : pointer to v4l2 format structure
>>>> * @which : wanted subdev format
>>>>
>>>> switch (pad) {
>>>> case RESZ_PAD_SINK:
>>>> if (fmt->code != MEDIA_BUS_FMT_YUYV8_1X16 &&
>>>> fmt->code != MEDIA_BUS_FMT_UYVY8_1X16)
>>>> fmt->code = MEDIA_BUS_FMT_YUYV8_1X16;
>>>>
>>>> So it looks to me like if we're trying to do anything other than
>>>> either of those,we set it to MEDIA_BUS_FMT_YUYV8_1X16
>>>>
>>>> Am I missing something?
>>>
>>> I guess for this particular video node there's no need for V4L2 extensions
>>> to implement ENUM_FMT. Ideally the other nodes would support ENUM_FMT that
>>> could provide meaningful information as well.
>>
>> I applied a variation of the patch in question, and I was able to both
>> successfully use g-streamer-1.0 and I was able to see UYVY appear in
>> the list. in fact, G-Streamer-1.0 was faster than FFPEG with less
>> lag.
>>
>> ioctl: VIDIOC_ENUM_FMT
>> Type: Video Capture
>>
>> [0]: 'UYVY' (UYVY 4:2:2)
>> [1]: 'RGB3' (RGB3, emulated)
>> [2]: 'BGR3' (BGR3, emulated)
>> [3]: 'YU12' (YU12, emulated)
>> [4]: 'YV12' (YV12, emulated)
>>
>> I don't know enough about VL2. It looks like all the V4L stuff is in
>> the common isp files and not unique to the preview output, resizer
>> output or the CCDC output. I don't have a CSI camera, so I cannot
>> test anything.
>>
>> I checked all the video outputs, and they are all showing the same
>> information. I realize the patch I found won't be accepted upstream
>> as-is, but it would be nice to have some mechanism in place that can
>> determine which output node is being used and somehow return the
>> correct data for each node.
>>
>> I would like to do something to help improve this driver and/or make
>> it more compatible with some of the V4L tools (like G-Streamer), so if
>> someone has a recommendation on how we could move forward, I'm willing
>> work on it.
>
> While I'm not totally opposed to implementing VIDIOC_ENUM_FMT for the
> resizer video node, I'm not sure it would be the best solution to your
> problem. Sure, it will fix an existing issue, but we already know that
> it won't scale, as the other video nodes can't be supported the same
> way.
>
> So far, our position was mostly that userspace should grow support for
> MC-based devices where VIDIOC_ENUM_FMT isn't implemented. Maybe I'm
Well, I disagree: implementing G/S/TRY_FMT without ENUM_FMT is out-of-spec.
The v4l2-compliance utility would flunk any driver that tries that.
Unfortunately, v4l2-compliance didn't exist (or was in its infancy) when
omap3isp was written.
I didn't even know that ENUM_FMT wasn't implemented for the omap3 ISP.
It makes no sense either: the driver is smart enough to validate the
pixelformat, but not smart enough to be able to enumerate the list of
valid formats for the current pipeline configuration?
I suspect that omap3isp can use some TLC, and this would be one of the
things that need addressing.
Regards,
Hans
> relaxing my standards because I'm growing older and wiser (or possibly
> just older and lazier :-)), but we need a better solution than this in
> any case. Compared to the last time I made this statement, we now have
> one possible solution in view in the form of libcamera ([1]). The
> project is still young, doesn't support the OMAP3 ISP, and isn't
> integrated with GStreamer, but fixing all that is on our roadmap.
>
> What I would like to know is whether libcamera would fit your use cases,
> or if you have needs that would require a different solution.
>
> [1] https://www.libcamera.org/
>
>>>>> This also means that there is no way to provide an enumeration of supported
>>>>> formats without knowing the media bus format. There have been proposals to
>>>>> support ENUM_FMT in such cases by providing the source media bus format,
>>>>> but those proposals haven't materialised into patches.
>>>>>
>>>>> So for now, the format needs to be simply set using S_FMT.
>>>>>
>>>>>>
>>>>>> Setting pipeline to PAUSED ...
>>>>>> Pipeline is live and does not need PREROLL ...
>>>>>> Setting pipeline to PLAYING ...
>>>>>> New clock: GstSystemClock
>>>>>> ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0:
>>>>>> Internal data stream error.
>>>>>> Additional debug info:
>>>>>> gstbasesrc.c(3055): gst_base_src_loop ():
>>>>>> /GstPipeline:pipeline0/GstV4l2Src:v4l2src0:
>>>>>> streaming stopped, reason not-negotiated (-4)
>>>>>>
>>>>>> This leads me to believe that v4l2 is trying to set the format to
>>>>>> something it does not think it is able to negotiate, and it's being
>>>>>> rejected.
>>>>>>
>>>>>> I can even explicitly set the output video format to UYVY with:
>>>>>>
>>>>>> v4l2-ctl -d /dev/video6
>>>>>> --set-fmt-video=width=480,height=272,pixelformat=UYVY --verbose
>>>>>>
>>>>>> VIDIOC_QUERYCAP: ok
>>>>>> VIDIOC_G_FMT: ok
>>>>>> VIDIOC_S_FMT: ok
>>>>>> Format Video Capture:
>>>>>> Width/Height : 480/272
>>>>>> Pixel Format : 'UYVY'
>>>>>> Field : None
>>>>>> Bytes per Line : 960
>>>>>> Size Image : 261120
>>>>>> Colorspace : JPEG
>>>>>> Transfer Function : Default (maps to sRGB)
>>>>>> YCbCr/HSV Encoding: Default (maps to ITU-R 601)
>>>>>> Quantization : Default (maps to Full Range)
>>>>>> Flags :
>>>>>> #
>>>>>>
>>>>>> This shows me the UYVY format, but upon a follow-up query, it does not
>>>>>> appear to retain the pixel format of UYVY.
>>>>>>
>>>>>> v4l2-ctl -d /dev/video6 --list-formats-ext
>>>>>> ioctl: VIDIOC_ENUM_FMT
>>>>>> Type: Video Capture
>>>>>>
>>>>>> [0]: 'RGB3' (RGB3, emulated)
>>>>>> [1]: 'BGR3' (BGR3, emulated)
>>>>>> [2]: 'YU12' (YU12, emulated)
>>>>>> [3]: 'YV12' (YV12, emulated)
>>>>>> #
>>>>>>
>>>>>> If I use ffmpeg to stream video, I the video codec there recognizes it
>>>>>> as uyvy and I can convert it to RGB to display on my LCD, but it has
>>>>>> limited framerate, and it seems to me like this should be do-able in
>>>>>> G-Streamer with v4l2src.
>>>>>>
>>>>>> # ffmpeg -an -re -i /dev/video6 -f v4l2 -vcodec rawvideo -pix_fmt bgra
>>>>>> -f fbdev /dev/fb0
>>>>>>
>>>>>> Input #0, video4linux2,v4l2, from '/dev/video6':
>>>>>> Duration: N/A, start: 908.826490, bitrate: N/A
>>>>>> Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422,
>>>>>> 480x272, 17.42 tbr, 1000k tbn, 1000k tbc
>>>>>> Stream mapping:
>>>>>> Stream #0:0 -> #0:0 (rawvideo (native) -> rawvideo (native))
>>>>>> Press [q] to stop, [?] for help
>>>>>> Output #0, fbdev, to '/dev/fb0':
>>>>>> Metadata:
>>>>>> encoder : Lavf57.83.100
>>>>>> Stream #0:0: Video: rawvideo (BGRA / 0x41524742), bgra, 480x272,
>>>>>> q=2-31, 72765 kb/s, 17.42 fps, 17.42 tbn, 17.42 tbc
>>>>>> Metadata:
>>>>>> encoder : Lavc57.107.100 rawvideo
>>>>>>
>>>>>>
>>>>>> This shows me the information is available in some ways from v4l2, but
>>>>>> I wonder if there is a missing IOCTL for VIDIOC_ENUM_FMT for the isp
>>>>>> driver somewhere. Shouldn't VIDIOC_ENUM_FMT return UYVY?
>>>>>>
>>>>>> I noticed vpbe_display.c has a function that appears to correspond to
>>>>>> this. There is a patch at [1] for an older kernel. Is this something
>>>>>> worth pursuing?
>>>>>>
>>>>>> [1] - https://stackoverflow.com/questions/20693155/gstreamer-failed-to-enumerate-video-formats-and-inappropriate-ioctl-for-device
>
