i.MX ProcessorsのトピックAbout IMX8QM Decode With Gstreamer

About IMX8QM Decode With Gstreamer

xu_liu — Tue, 21 Jan 2020 08:32:25 GMT

I want to test the VPU decode on the IMX8QM board with Gstreamer plugin.

I use these two gst command the video can display right

gst-launch-1.0 v4l2src device=/dev/video3 io-mode=dmabuf num-buffers=1000 ! video/x-raw,format=NV12,width=1280,height=720 ! autovideosink

gst-launch-1.0 v4l2src device=/dev/video3 io-mode=dmabuf num-buffers=100 ! video/x-raw,format=NV12,width=1280,height=720 ! v4l2h264enc output-io-mode=dmabuf-import ! h264parse ! flvmux streamable=true ! filesink location=/tmp/test_8.flv

But when I add the decode part with Gstreamer command

gst-launch-1.0 v4l2src device=/dev/video3 io-mode=dmabuf num-buffers=300 ! video/x-raw,format=NV12,width=1280,height=720 ! v4l2h264enc output-io-mode=dmabuf-import ! h264parse ! v4l2h264dec capture-io-mode=dmabuf ! autovideosink

the board can't decode the video right and show follow errors

WARNING: from element /GstPipeline:pipeline0/GstAutoVideoSink:autovideosink0/GstWaylandSink:autovideosink0-actual-sink-wayland: A lot of buffers are being dropped.
Additional debug info:
../../../../git/libs/gst/base/gstbasesink.c(2902): gst_base_sink_is_too_late (): /GstPipeline:pipeline0/GstAutoVideoSink:autovideosink0/GstWaylandSink:autovideosink0-actual-sink-wayland:
There may be a timestamping problem, or this computer is too slow.
WARNING: from element /GstPipeline:pipeline0/GstAutoVideoSink:autovideosink0/GstWaylandSink:autovideosink0-actual-sink-wayland: A lot of buffers are being dropped.
Additional debug info:
../../../../git/libs/gst/base/gstbasesink.c(2902): gst_base_sink_is_too_late (): /GstPipeline:pipeline0/GstAutoVideoSink:autovideosink0/GstWaylandSink:autovideosink0-actual-sink-wayland:
There may be a timestamping problem, or this computer is too slow.
Got EOS from element "pipeline0".
Execution ended after 0:00:07.801222625
Setting pipeline to PAUSED ...
Setting pipeline to READY ...
[19864.238975] ds960_mipi 8-0030: ds960_s_stream: set stream 3 off, now running 1
[19864.246286] ds960_mipi 8-0030: ds960_s_stream: stream off
Setting pipeline to NULL ...[19864.257093] [VPU Decoder] error: v4l2_ioctl_reqbufs() can't request (0) buffer : -16

Total showed frames (5), playing for (0:00:07.801577750), fps (0.641).
Freeing pipeline ...

If you have some advice about this question, please share it with me.

Thank you

Re: About IMX8QM Decode With Gstreamer

igorpadykov — Thu, 23 Jan 2020 05:00:33 GMT

Hi Xu

as transcoding example one can try:

gst-launch-1.0 v4l2src ! video/x-raw,format=NV12,width=640,height=480 ! v4l2h264enc ! h264parse ! v4l2h264dec ! queue ! waylandsink enable-tile=true sync=false

Best regards
igor
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Re: About IMX8QM Decode With Gstreamer

xu_liu — Mon, 03 Feb 2020 09:37:21 GMT

Thank you for your answer.

I have tried your method, but it still dosen't work. The display device shows as follow picture

The command I use is

gst-launch-1.0 v4l2src device=/dev/video3 ! video/x-raw,format=NV12,width=1280,height=720 ! v4l2h264enc ! h264parse ! v4l2h264dec ! queue ! waylandsink enable-tile=true sync=false

When I end the command, the board give the same fault. This time the number of fps is right.

Execution ended after 0:06:46.804658625
Setting pipeline to PAUSED ...
Setting pipeline to READY ...
[ 1997.621501] [VPU Decoder] error: v4l2_ioctl_reqbufs() can't request (0) buffer : -16
[ 1997.643927] ds960_mipi 8-0030: ds960_s_stream: set stream 3 off, now running 1
[ 1997.651220] ds960_mipi 8-0030: ds960_s_stream: stream off
Setting pipeline to NULL ...
Total showed frames (17468), playing for (0:06:46.804939250), fps (42.939).
Freeing pipeline ...

Can you figure out anther solution? Thank you!

Re: About IMX8QM Decode With Gstreamer

xu_liu — Wed, 05 Feb 2020 07:08:12 GMT

Do you any idea about this question? Waiting your reply. ^-^

Re: About IMX8QM Decode With Gstreamer

igorpadykov — Wed, 05 Feb 2020 08:15:46 GMT

please check that latest silicon revision used in the case,

it is described in Table 2. i.MX 8QuadMax Orderable part numbers

i.MX 8QuadMax Automotive and Infotainment Applications Processors

Test on i,MX8QM MEK board with Demo Images from

i.MX Software and Development Tools | NXP

Best regards
igor