camera capture size is wrong

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX1
1

hi

i would like to make low video file.
so i scaled underflow…

videotestsrc encoding size is good
but v4l2src encoding size is wrong…

is it right size?

/*capute videotestsrc scale to 640x480 */
gst-launch-1.0 videotestsrc num-buffers=100 ! ‘video/x-raw, format=(string)I420, width=(int)1280, height=(int)720’ ! nvvidconv ! ‘video/x-raw(memory:NVMM), width=(int)640, height=(int)480, format=(string)I420’ ! omxh264enc ! ‘video/x-h264, stream-format=(string)byte-stream’ ! h264parse ! qtmux ! filesink location=videotestsrc_640x480.mp4

/*capute videotestsrc scale to 320x240 */
gst-launch-1.0 videotestsrc num-buffers=100 ! ‘video/x-raw, format=(string)I420, width=(int)1280, height=(int)720’ ! nvvidconv ! ‘video/x-raw(memory:NVMM), width=(int)320, height=(int)240, format=(string)I420’ ! omxh264enc ! ‘video/x-h264, stream-format=(string)byte-stream’ ! h264parse ! qtmux ! filesink location=videotestsrc_320x240.mp4

/*capute v4l2src scale to 640x480 */
gst-launch-1.0 v4l2src device=/dev/video0 num-buffers=100 ! ‘video/x-raw,format=UYVY,width=1280,height=720’ ! nvvidconv ! ‘video/x-raw(memory:NVMM), width=(int)640, height=(int)480, format=(string)I420’ ! omxh264enc ! ‘video/x-h264, stream-format=(string)byte-stream’ ! h264parse ! qtmux ! filesink location=v4l2_640x480.mp4

/*capute v4l2src scale to 320x240 */
gst-launch-1.0 v4l2src device=/dev/video0 num-buffers=100 ! ‘video/x-raw,format=UYVY,width=1280,height=720’ ! nvvidconv ! ‘video/x-raw(memory:NVMM), width=(int)320, height=(int)240, format=(string)I420’ ! omxh264enc ! ‘video/x-h264, stream-format=(string)byte-stream’ ! h264parse ! qtmux ! filesink location=v4l2_320x240.mp4


-rw-r–r-- 1 root root----1629324 Mar 27 12:01 v4l2_320x240.mp4<-------------------1.6M
-rw-r–r-- 1 root root----1779584 Mar 27 12:01 v4l2_640x480.mp4<-------------------1.7M
-rw-r–r-- 1 root root-----383803 Mar 27 12:00 videotestsrc_320x240.mp4<-----------375K
-rw-r–r-- 1 root root----1605905 Mar 27 12:00 videotestsrc_640x480.mp4<-----------1.6M

2

Hi walterkim,
It is normal, the camera frame is always more complex than the video test source, leading to higher bitrate.

Please refer to user guide on encoder parameters of setting bitrate

3

Thank you for you reply

default bitrate is 4000000.

so i change bitrate 1000000 to 320x240 resolution

i checked reduce image size.

thank you

gst-launch-1.0
v4l2src device=/dev/video0 num-buffers=100 ! ‘video/x-raw,format=UYVY,width=1280,height=720’ !
nvvidconv ! ‘video/x-raw(memory:NVMM), width=(int)320, height=(int)240, format=(string)I420’ !
omxh264enc bitrate=1000000 ! ‘video/x-h264, stream-format=(string)byte-stream’ ! h264parse ! qtmux ! filesink location=v4l2_320x240.mp4

-rw-r–r-- 1 root root 415K Mar 27 16:16 v4l2_320x240.mp4