HW Accelerated video on aarch64

trademark91 · n00b Joined: 03 Dec 2020 Posts: 26 Location: USA

Hello Gentoo on Arm users!

I've been building a gentoo install on my 8gb raspberry pi CM4 on a cm4 to pi4 adapter board, and its been going great. I'm trying to use this to build a handheld machine to carry with me and use as a remote console for my machines at home, using the moonlight streaming system. This has built and runs properly, however, I am really struggling with hw accelerated h265 video decoding. I've followed the instructions here: https://github.com/moonlight-stream/moonlight-docs/wiki/Installing-Moonlight-Qt-on-Raspberry-Pi-4 and I'm able to watch software decoded h.265, but when it streams anything more than a desktop, i drop to about 5 frames per second and its not really useable. From what I've read, this is possible on 64 bit ARM devices now, and functions properly in raspbian using a patched ffmpeg, which is what Sakaki did in the gentoo-on-rpi-64 system, however, the ebuild used fails to compile using the neon CPU flag due to it not wanting to use thumb2, despite that CPU_FLAG being set:

Here is my /etc/portage/package.use/ffmpeg:

Hu · Administrator Joined: 06 Mar 2007 Posts: 21817

cpu_flags_arm_thumb2 is masked in the base profile, and unmasked in the armv7a profile. Are you expecting that the flag is available for you to enable, or are you asking for ways to proceed while keeping the flag disabled?

trademark91 · n00b Joined: 03 Dec 2020 Posts: 26 Location: USA

I was expecting to be able to enable the flag, as it should be supported by my system:

pingtoo · Posted: Sat Jul 29, 2023 9:42 pm Post subject:

NeddySeagoon · Posted: Sat Jul 29, 2023 9:43 pm Post subject:

trademark91,

thumb2 and other extensions do not exist on 64 bit ARM.

Post your dmesg and /boot/.config.txt please.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

trademark91 · n00b Joined: 03 Dec 2020 Posts: 26 Location: USA

Hey NeddySeagoon,

Thanks for helping, here is my config.txt:

https://pastebin.com/KdNhFLu5

Here is the dmesg output:

https://pastebin.com/apynn5Sp

Do you want me to try doing anything first before running dmesg to grab useful output?

NeddySeagoon · Posted: Sun Jul 30, 2023 11:02 am Post subject:

trademark91,

trademark91 · n00b Joined: 03 Dec 2020 Posts: 26 Location: USA

NeddySeagoon,

Thanks for clarifying. I'm using both v3d and vc4 as the VIDEO_CARD.

I've attached dmesg using both the kms and fkms dtoverlay to make it easier to troubleshoot.

Here is the one using the open source kms driver:

https://pastebin.com/GExMfnP0

And here is is after a reboot using the fkms driver:

I've read that dtoverlay=rpivid-vl2 no longer needs to be specified in the config.txt, but i've tried with both here just in case its helpful.

with dtoverlay=rpivid-v4l2 and hdmi_enable_4kp60=1
https://pastebin.com/tGXVNi9W

with those two commented as they were with the open source kms:
https://pastebin.com/JV7GieEp

NeddySeagoon · Posted: Mon Jul 31, 2023 4:33 pm Post subject:

trademark91,

I don't see anything useful on the video decode side there.

trademark91 · n00b Joined: 03 Dec 2020 Posts: 26 Location: USA

NeddySeagoon,

Sorry for the delayed reply, I was trying to get it working on my own before I reached out for more help. I've been unable to get the patched ffmpeg from either sakaki's or your genpi64 repo to build on my system due to the neon/thumb2 error I was seeing earlier, which is to be expected given the feedback you provided. I was able to get ffmpeg built from the gentoo overlay however.

It looks like hardware acceleration is supported here on the system: