Nano PI Duo2

[alexlansovich]

Will this work on Nano PI Duo2 on Linux NanoPi-Duo2 3.4.39-h3 Ubuntu 20.04.6 LTS ?
My kernel dont have /dev/media0 device.

[avafinger]

There is a good chance it will work. fswebcam only uses v4l2 io calls.
/dev/media0 is required to set up v4l2 calls for kernel 4.x and above.
I think you need to build it from the source.

[alexlansovich]

Can i update 3.4 to 4.x? Because on https://wiki.friendlyelec.com/wiki/index.php/NanoPi_Duo2 write that
The Linux-4.14 based ROM currently doesn't support hardware-encoding. If you use a H3 boards with Linux-3.4 based ROM you can use the ffmpeg utility to hardware-encode stream data and this can greatly release CPU's resources and speed up encoding:

ffmpeg -t 30 -f v4l2 -channel 0 -video_size 1280x720 -i /dev/video0 -pix_fmt nv12 -r 30
-b:v 64k -c:v cedrus264 test.mp4

Also question - can i rotate cam in linux 3.4, because v4l2 says - error 25.

pi@NanoPi-Duo2:~$ v4l2-ctl --all --device /dev/video0
Driver Info:
Driver name : sunxi-vfe
Card type : sunxi-vfe
Bus info : sunxi_vfe sunxi_vfe.0
Driver version : 1.0.0
Capabilities : 0x05000001
Video Capture
Read/Write
Streaming
Video input : 0 (: ok)
Format Video Capture:
Width/Height : 640/480
Pixel Format : '
Field : None
Bytes per Line : 0
Size Image : 0
Colorspace : Default
Transfer Function : Default (maps to Rec. 709)
YCbCr/HSV Encoding: Default (maps to ITU-R 601)
Quantization : Default (maps to Full Range)
Streaming Parameters Video Capture:
Capabilities : timeperframe
Frames per second: 30.000 (30/1)
Read buffers : 0
error 25 getting ctrl White Balance, Automatic
error 25 getting ctrl Exposure
error 25 getting ctrl Horizontal Flip
error 25 getting ctrl Vertical Flip
error 25 getting ctrl Color Effects

[avafinger]

I don't think kernel 3.4.x is fully v4l2 compliant. If i remember correctly, sunxi-vfe is in charge when you grab frames, switching VFLIP and HFLIP is done by editing the script.fex file (decompiled from script.bin) and changing what you need to 1:

vip_dev0_vflip = 0
vip_dev0_hflip = 0

There are plenty of information on the net on how to do that, but if you have the BSP (kernel 3.4.x) search for *.hex and change the correct fex file there and build the script.bin from there.

the encoder works on 3.4.x, and with poor results if > 720p.
There is a port for a newer kernel you can find it here: https://github.com/uboborov/sunxi-cedar-mainline

I would build fswebcam from the source (fix any compiling error) and give it a try.
If does not work, move on to one of the kernel used in sunxi-cedar-mailine.

[alexlansovich]

Avafinger - i see your ffmpeg with cedrus driver, but i need a ffmpeg library to use another application(baresip).
Have you https://github.com/avafinger/ffmpeg_cedrus264_H3 for the new ffmpeg - for example, version 4.
Or you can help with another working repo, which is have segfault after second usage.

[avafinger]

What kernel version do you have?

[alexlansovich]

Linux NanoPi-Duo2 3.4.39-h3 #34 SMP PREEMPT Tue Dec 18 15:20:42 CST 2018 armv7l armv7l armv7l GNU/Linux
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 18.04.6 LTS
Release: 18.04
Codename: bionic

[avafinger]

I see, i haven't tried with ffmpeg version 4, maybe it was not available then.
I don't know anyone else trying that but i haven't really followed the development on this platform.
Did you try to check the Armbian forum?

[alexlansovich]

Yes. i have found https://github.com/twdragon/FFmpeg and this is working.
But after using second usage of encoder - program is segfaults. (program is the sip client, that using ffmpeg encoder)
-- example --
Thread 1 "baresip" received signal SIGSEGV, Segmentation fault.
0xb33dc6ea in memlist_del (mem=0xb1b71780) at libavcodec/arm/sunxi/ve.c:116

[avafinger]

Segfault is on libavcodec/arm/sunxi/ve.c:116 , maybe ion mem it was not released.
Try valgrind on the first time and see what it reports, or ping the author but i see he stated: "not tested"...

[alexlansovich]

i try ping author - have some answers, but without line of error. Now waiting reply to the new request.
Thanks for the additional information.

[alexlansovich]

Do you know C and can debug this problem? I can give you ssh and all what is need.

[avafinger]

You need more than just knowing c and debugging., unfortunately.
The error is here:
https://github.com/twdragon/FFmpeg/blob/afd516bd9c62c5c03b22230d9d087f7682f39997/libavcodec/arm/sunxi/ve.c#L116

My guess, It tries to read-protected memory.
What's the size of the RAM on your board?
The version 3.3.x work or not?

[alexlansovich]

DDR3 RAM: 512M
What your repo i can test for my linux?

[avafinger]

Try this one and see what you get:

https://github.com/avafinger/ffmpeg-3.3.4_cedrus264

[alexlansovich]

I have test this. FFmpeg is working standalone, but if compile baresip - i get error.
I create issue on your repo. ok?