Record and Play 4K@30fps .mp4 with USB Camera

[Derek0902]

Hi,

The USB Camera format is below:

Use V4L2 to record 4K@30fps .mp4 file :

v4l2-ctl --device /dev/video4 --set-fmt-video=width=3840,height=2160,pixelformat=MJPG --stream-mmap --stream-to=./output4K.mp4 --stream-count=300

Use Gstreamer to play .mp4 file :

gst-launch-1.0 filesrc location=/home/root/output4K.mp4 ! jpegdec ! autovideosink

The video only have 8.6 fps:

On my ubuntu PC:

The video play smoothly, but only take 5 sec to finish.

The video time should be 300 frame / 30fps = 10 sec. 

Regards,

Derek Lin

[Bio_TICFSL]

Hello,

It is weird, but the i.mx8 is able to decode mp4 videos but you have to see the usb, is transfer the data ok? which usb are you using 2.0 or 3.0?

Regards

[Derek0902]

Hi @Bio_TICFSL ,

The camera interface is USB 2.0 . 

If I use Gstreamer to stream and display camera preview, the fps  will be lower than 5 and appear computer too slow. Then the CPU usage is over than 100%. Here is my command:

gst-launch-1.0 v4l2src device=/dev/video4 ! image/jpeg,width=3840,height=2160,framerate=30/1 ! jpegdec ! autovideosink

If  camera resolution is modified to 640x360, the fps will be correct.

Regards,

Derek Lin