v4l2src with NV12: failed to map video frame

[Frédéric Sureau]

Hi !

I am trying to use a v4l2 capture device using v4l2src element.
The device supports YUY2 and NV12 formats, I can get some frames using 
v4l2-ctl this way:

v4l2-ctl --device=/dev/v4l/by-path/platform-v4l2cap\@ipu1-video-index4 
--set-edid edid=hdmi,pad=0 -i2
v4l2-ctl --device=/dev/v4l/by-path/platform-v4l2cap\@ipu1-video-index4 
--set-dv-bt-timings index=4 -i2
v4l2-ctl --device=/dev/v4l/by-path/platform-v4l2cap\@ipu1-video-index4 
--set-fmt-video=width=1280,height=720,pixelformat=NV12,field=none,bytesperline=1920

v4l2-ctl --device=/dev/v4l/by-path/platform-v4l2cap\@ipu1-video-index4 
--stream-mmap --stream-to=/data/test.raw --stream-count=120

mplayer -idle -fixed-vo -demuxer rawvideo -rawvideo 
fps=15:w=1280:h=720:format=nv12 test.raw


However, when I use GStreamer, it works fine with YUY2 format, but not 
with NV12.
Here is what I get:

# gst-launch-1.0 -evvv v4l2src 
device=/dev/v4l/by-path/platform-v4l2cap\@ipu1-video-index4 ! 
"video/x-raw,format=NV12,width=1280,height=720,framerate=50/1" ! fakesink

Setting pipeline to PAUSED ...

Pipeline is live and does not need PREROLL ...

Setting pipeline to PLAYING ...

/GstPipeline:pipeline0/GstV4l2Src:v4l2src0.GstPad:src: caps = 
"video/x-raw\,\ format\=\(string\)NV12\,\ framerate\=\(fraction\)50/1\,\ 
width\=\(int\)1280\,\ height\=\(int\)720\,\ 
interlace-mode\=\(string\)progressive\,\ 
pixel-aspect-ratio\=\(fraction\)1/1"

New clock: GstSystemClock

/GstPipeline:pipeline0/GstCapsFilter:capsfilter0.GstPad:src: caps = 
"video/x-raw\,\ format\=\(string\)NV12\,\ framerate\=\(fraction\)50/1\,\ 
width\=\(int\)1280\,\ height\=\(int\)720\,\ 
interlace-mode\=\(string\)progressive\,\ 
pixel-aspect-ratio\=\(fraction\)1/1"

/GstPipeline:pipeline0/GstFakeSink:fakesink0.GstPad:sink: caps = 
"video/x-raw\,\ format\=\(string\)NV12\,\ framerate\=\(fraction\)50/1\,\ 
width\=\(int\)1280\,\ height\=\(int\)720\,\ 
interlace-mode\=\(string\)progressive\,\ 
pixel-aspect-ratio\=\(fraction\)1/1"

/GstPipeline:pipeline0/GstCapsFilter:capsfilter0.GstPad:sink: caps = 
"video/x-raw\,\ format\=\(string\)NV12\,\ framerate\=\(fraction\)50/1\,\ 
width\=\(int\)1280\,\ height\=\(int\)720\,\ 
interlace-mode\=\(string\)progressive\,\ 
pixel-aspect-ratio\=\(fraction\)1/1"

0:00:00.302709667  1867  0x15779b0 ERROR                default 
/home/fred/Projets/vodabox3/poky/build/tmp/work/cortexa9hf-vfp-neon-mx6qdl-poky-linux-gnueabi/gstreamer1.0-plugins-base/git-r0/git/gst-libs/gst/video/video-frame.c:147:gst_video_frame_map_id: 
failed to map video frame plane 1

0:00:00.303003000  1867  0x15779b0 ERROR                   v4l2 
/home/fred/Projets/vodabox3/poky/build/tmp/work/cortexa9hf-vfp-neon-poky-linux-gnueabi/gstreamer1.0-plugins-good/git-r0/git/sys/v4l2/gstv4l2bufferpool.c:159:gst_v4l2_buffer_pool_copy_buffer:<v4l2src0:pool:src> 
could not map buffer

0:00:00.303208333  1867  0x15779b0 ERROR                   v4l2 
/home/fred/Projets/vodabox3/poky/build/tmp/work/cortexa9hf-vfp-neon-poky-linux-gnueabi/gstreamer1.0-plugins-good/git-r0/git/sys/v4l2/gstv4l2bufferpool.c:1805:gst_v4l2_buffer_pool_process:<v4l2src0:pool:src> 
failed to copy buffer

ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Internal 
data flow error.

Additional debug info:

/home/fred/Projets/vodabox3/poky/build/tmp/work/cortexa9hf-vfp-neon-poky-linux-gnueabi/gstreamer1.0/git-r0/git/libs/gst/base/gstbasesrc.c(2943): 
gst_base_src_loop (): /GstPipeline:pipeline0/GstV4l2Src:v4l2src0:

streaming task paused, reason error (-5)

EOS on shutdown enabled -- waiting for EOS after Error

Waiting for EOS...

^Chandling interrupt.

Interrupt: Stopping pipeline ...

Interrupt while waiting for EOS - stopping pipeline...

Execution ended after 0:00:01.943978000

Setting pipeline to PAUSED ...

Setting pipeline to READY ...

Setting pipeline to NULL ...

Freeing pipeline ...


Any idea ?

Thanks
Fred