VCU, gstreamer using GRAY8 pixel format

[so-lli1]

Hello,

I am currently working on an video streaming application using the XCZU7EV device on an ZCU104 Eval. Board.

In order to test the encoder with my future video properties, I used the following minimalistic gstreamer pipeline. It works fine.

gst-launch-1.0 videotestsrc ! video/x-raw,width=640,height=512,framerate=60/1 ! omxh264enc ! video/x-h264, alignment=au ! fakesink

However, when I want to use GRAY8 as video format, the command fails.

gst-launch-1.0 videotestsrc ! video/x-raw,format=GRAY8,width=640,height=512,framerate=60/1 ! omxh264enc ! video/x-h264, alignment=au ! fakesink

Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...
ERROR: from element /GstPipeline:pipeline0/GstVideoTestSrc:videotestsrc0: Internal data stream error.
Additional debug info:
../../../../git/libs/gst/base/gstbasesrc.c(3055): gst_base_src_loop (): /GstPipeline:pipeline0/GstVideoTestSrc:videotestsrc0:
streaming stopped, reason not-negotiated (-4)
ERROR: pipeline doesn't want to preroll.
Setting pipeline to NULL ...
Freeing pipeline ...

According to PG252, Table 78, GRAY8 should be supported.

gst-inspect-1.0 omxh264enc also lists the pixel format as supported.

I hope somebody can point me in the right direction.
Thanks.

[florentw]

Hi @so-lli1 

Can you check if the videotestsrc has the support for GRAY8? What is your source?

[so-lli1]

Hi @florentw,

as far as I can tell, it should be supported. The following shows the output of gst-inspect-1.0 videotestsrc running on the embedded device.

Furthermore, the following pipeline works. That's why I suspect it is linked to omxh264enc.

gst-launch-1.0 videotestsrc ! video/x-raw,format=GRAY8,width=640,height=512,framerate=60/1 ! fakesink

Thank you.

[florentw]

HI @so-lli1 

What if you try to specify different other format (on your initial command, you are not specifying the format)?

[so-lli1]

Hi @florentw 

I need GRAY8 for the final product, also GRAY8 seems to work fine when the omxh64enc is not in the pipeline (see above post).

[so-lli1]

I would still be interested in an answer. Any news?

[watari]

Hi @so-lli1 

Did you make sure debug log file ?

You might be able to find the route cause in this log file.

Best regards,

[aoifem · Accepted solution]

Hi @so-lli1 

I'm attaching the link to your other post which contains the workaround for this. Can you mark this as an 'accepted solution' so the community can find the answer faster? 

https://forums.xilinx.com/t5/Video-and-Audio/VCU-encoding-framerate-very-low/m-p/1133100