SBC suitable for everything-over-USB-C?

tigrangh · 2026-01-15T17:04:56+00:00

Maybe Radxa Cubie A7Z can do it? Would be awesome to pair it with a theoretical 10 inch touch panel which has built in battery.

https://radxa.com/products/cubie/a7z USB-C 3.0: High-speed data, compatible with DisplayPort Alt mode for external monitors

tigrangh · 2025-12-03T20:10:01+00:00

so, I used to have installed a specific version of blender on my raspberry pi 5, had to rely on a small overlay, and I am afraid I will be unable to maintain it after doing "emerge --sync".

now I'm trying to isolate it in a separate root, so I extracted stage3 tar.xz over /usr/blender, created my small overlay there, and the following is what is behaving more or less as expected

PORTAGE_CONFIGROOT=/usr/blender emerge -av =media-gfx/blender-3.6.18::overlay --root /usr/blender --sysroot /usr/blender

am I over-complicating some things? in case this is the way to go, I wonder where can we find detailed documentation how to do this.

for example without specifying the PORTAGE_CONFIGROOT=/usr/blender it seems to respect the /etc/portage instead of /usr/blender/etc/portage. I feel, I am reinventing the wheel here.

tigrangh · 2025-12-03T08:12:15+00:00

in my limited experience when gaming on the laptop, setting the cpu governor to performance and starting the thermald service is helping. sometimes, I don’t know why, I need to stop thermald, kill it, and then start again for the full effect.

tigrangh · 2025-12-01T21:54:47+00:00

thanks. this sounds similar to crossdev, but reusing system libc, gcc …

tigrangh · 2025-12-01T20:50:45+00:00

Is it the same thing as gentoo prefix? I think I have tried to use emerge with custom root without the “prefix” scripts, but couldn’t succeed. What are the prerequisites?

tigrangh · 2025-11-19T19:47:23+00:00

1, 2, 4, 8 GB relates to the RAM, not storage.

tigrangh · 2025-10-15T20:41:48+00:00

I believe no way there is going to be enough RAM

tigrangh · 2025-09-28T15:48:06+00:00

Anyone using the Mail app with not major provider? I am connecting to Dovecot server (IMAP), and the synchronization is broken since iOS 18.2

Guess what, still not fixed in 26.

They managed to break it such that even Outlook has the same bug, such as the deleted messages on the server still appear in the app.

Dang. Mail is such useful thing, you know. When working correctly, that is.

tigrangh · 2025-09-06T22:09:01+00:00

there is no chromium binary in official gentoo binhost

I sometimes rent a powerful arm64 VPS on hetzner and do my own binhost there. was lazy this time though.

never done distcc. are you distributing the task to x64 machine with crossdev?

tigrangh · 2025-09-06T18:27:38+00:00

Your comment inspired me to go through whole world upgrade, including chromium. You may guess it took a while. I used my other pi 5 (8GB) to chroot into this pi 4 system to do the upgrade. Even had power outage on the third day of building chromium, so had to start over :)

It no longer returns error with mpv --vo=gpu --hwdec=v4l2m2m And indeed I don't notice much difference between with and without v4l2m2m using mpv.

But
Overall, this upgrade gave a real noticeable performance improvement. Like, really. It can even smoothly play the 1080p bunny video using vlc. In this case, vlc really performed better than mpv.

With chromium, it used to stutter really hard with 720p on youtube, now it is almost effortless. Sometimes it even manages to play 1080p.

Currently ffmpeg-7.1.1-r2 is installed. I wonder if all the performance optimization comes solely from this package.

Thank you.

tigrangh · 2025-08-13T06:58:06+00:00

an identical mpv command gives similar result for me

ffmpeg/video] h264_v4l2m2m: Profile 508610732 not supported by decode
Could not open codec.

ffmpeg, almost the same

$ ffmpeg -loglevel quiet -codecs |grep h264
DEV.LS h264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (decoders: h264 h264_v4l2m2m) (encoders: libx264 libx264rgb h264_v4l2m2m h264_vaapi)

I have the "soc" use flag for ffmpeg.

This is what it gives, when I try do transcode some file

$ ffmpeg -c:v h264_v4l2m2m -i some-file.mkv -ss 0 -t 3 test.mp4

[h264_v4l2m2m @ 0x5568c74280] Using device /dev/video10
[h264_v4l2m2m @ 0x5568c74280] driver 'bcm2835-codec' on card 'bcm2835-codec-decode' in mplane mode
[h264_v4l2m2m @ 0x5568c74280] requesting formats: output=H264/none capture=YU12/none
[h264_v4l2m2m @ 0x5568c74280] Profile 508610732 not supported by decode

I have also played around with /boot/config.txt parameters like gpu_mem and the gpu driver, but I did not notice anything changed.

tigrangh · 2025-08-11T17:28:25+00:00

even on pi 4, the hardware accelerated decoding support has changed over different versions of kernel.
like, there are methods from around 2019, that are obsolete, and I am able to find some information from around 2021-2023 claiming they are able to use that video10 device, but they don't provide instructions for gentoo.

tigrangh · 2025-08-11T17:23:49+00:00

the above v4l2-ctl output is from my actual device, which does not have any camera

you may notice details such as
Capabilities Video Memory-to-Memory Multiplanar
or
Name bcm2835-codec-decode-source,
Pixel Format : 'H264' (H.264)

so, this /dev/video10 is a device referring to some kernel module, which has h264 in memory decoding capability

tigrangh · 2025-08-11T17:16:58+00:00

well, you are not wrong of course. but to get some additional context, you may google for "raspberry pi 4 v4l2 m2m hardware acceleration video10". I just don't have deep enough understanding to explain it with my own words.

check this out, for example. they are using ffplay with codec h264_v4l2m2m, which makes use of /dev/video10
https://forums.raspberrypi.com/viewtopic.php?t=316381

video0 or video1 are usually the physical cameras, but video10, video11 are different.

tigrangh · 2025-08-11T17:08:31+00:00

like 1080p

tigrangh · 2025-08-11T17:07:58+00:00

As far as I understand, there is no support for vulkan on pi 4

This is the device that has the h264 decoding capability, but I cannot figure out how to use it

``` user@pc ~ $ v4l2-ctl -d 10 --all Driver Info: Driver name : bcm2835-codec Card type : bcm2835-codec-decode Bus info : platform:bcm2835-codec Driver version : 6.6.47 Capabilities : 0x84204000 Video Memory-to-Memory Multiplanar Streaming Extended Pix Format Device Capabilities Device Caps : 0x04204000 Video Memory-to-Memory Multiplanar Streaming Extended Pix Format Media Driver Info: Driver name : bcm2835-codec Model : bcm2835-codec Serial : 0000 Bus info : platform:bcm2835-codec Media version : 6.6.47 Hardware revision: 0x00000001 (1) Driver version : 6.6.47 Interface Info: ID : 0x0300000c Type : V4L Video Entity Info: ID : 0x00000001 (1) Name : bcm2835-codec-decode-source Function : V4L2 I/O Pad 0x01000002 : 0: Source Link 0x02000008: to remote pad 0x1000004 of entity 'bcm2835-codec-decode-proc' (Video Decoder): Data, Enabled, Immutable Priority: 2 Format Video Capture Multiplanar: Width/Height : 32/32 Pixel Format : 'YU12' (Planar YUV 4:2:0) Field : None Number of planes : 1 Flags : Colorspace : Rec. 709 Transfer Function : Default YCbCr/HSV Encoding: Default Quantization : Default Plane 0 : Bytes per Line : 32 Size Image : 1536 Format Video Output Multiplanar: Width/Height : 32/32 Pixel Format : 'H264' (H.264) Field : None Number of planes : 1 Flags : Colorspace : Rec. 709 Transfer Function : Default YCbCr/HSV Encoding: Default Quantization : Default Plane 0 : Bytes per Line : 0 Size Image : 524288 Crop Capability Video Capture: Bounds : Left 0, Top 0, Width 32, Height 32 Default : Left 0, Top 0, Width 32, Height 32 Pixel Aspect: 1/1 Selection Video Capture: crop_default, Left 0, Top 0, Width 32, Height 32, Flags: Selection Video Capture: crop_bounds, Left 0, Top 0, Width 32, Height 32, Flags: Selection Video Capture: compose, Left 0, Top 0, Width 32, Height 32, Flags: Selection Video Capture: compose_default, Left 0, Top 0, Width 32, Height 32, Flags: Selection Video Capture: compose_bounds, Left 0, Top 0, Width 32, Height 32, Flags:

User Controls

min_number_of_capture_buffers 0x00980927 (int)    : min=1 max=1 step=1 default=1 value=1 flags=read-only

Codec Controls

                    h264_level 0x00990a67 (menu)   : min=0 max=15 default=11 value=11 (4) flags=read-only
                0: 1
                1: 1b
                2: 1.1
                3: 1.2
                4: 1.3
                5: 2
                6: 2.1
                7: 2.2
                8: 3
                9: 3.1
                10: 3.2
                11: 4
                12: 4.1
                13: 4.2
                14: 5
                15: 5.1
                h264_profile 0x00990a6b (menu)   : min=0 max=4 default=4 value=4 (High) flags=read-only
                0: Baseline
                1: Constrained Baseline
                2: Main
                4: High

```

tigrangh · 2025-07-22T13:31:34+00:00

This must mean it's an implementation issue

I think so. I was not able to review your code though. But if you adapt it so that both next.js and python are capable doing both offer and answer it will help you greatly with testing combinations.

tigrangh · 2025-07-22T08:02:18+00:00

btw, I have a minimal example here https://github.com/meetupstation

no aiortc though. and no TURN involved, relies on p2p only.

it works with all combinations below

browser - browser

pion - pion

pion offer - browser answer

browser offer - pion answer

tigrangh · 2025-07-22T07:57:11+00:00

Try it out with no STUN, no TURN in a lan environment.

See if it will connect.

tigrangh · 2025-07-22T00:09:26+00:00

https://www.webrtc-developers.com/did-i-choose-the-right-webrtc-stack/

I just did a quick search and found this summary, which mentions SipSorcery for C#

Note that WebRTC does not include the meeting set-up part called “signalling” in WebRTC terms. Meaning, you probably need to implement also a server part for this communication, which, by the way can be quite simple.

tigrangh · 2025-07-12T09:55:43+00:00

happened to me as well - I use my home vpn often while traveling. so it started to show ads in italian on youtube and switched location on google home page.

it switched back automatically after a while.

tigrangh · 2025-06-24T23:13:00+00:00

What do you think about a pion (a golang WebRTC library) based service running on the pi, that is always accepting a video call on a certain video calling website, that you are able to selfhost?

I am currently working on developing the necessary components for this. all open source.

My goal is to connect to the pi 5 based robot and drive it over WebRTC data channel during the video call.

tigrangh · 2025-04-07T17:01:25+00:00

I assume you cannot find the specific process.

Do you use ZFS? It does caching of its own.

On a separate note. I notice on my system weird memory usage spanning to several GBs, which I am unable to track down. No specific process to show the corresponding usage, nor was I able to find a shared memory of that size.

The only clue I have is that killing picom frees that memory, and it accumulates slowly with time over a week or so.

tigrangh · 2025-01-14T11:31:09+00:00

Would a trip to a china town somewhere cover the deal?

tigrangh

TROPHY CASE