It's a wild combination of many things, from what I know about it (I might be wrong!):
Mesa / OpenGL / Panfrost (GPU) is different from hardware video decoding (VPU).
Non-blob VPU hardware decoding is still being implemented in the kernel (hantro driver) and also needs libva-v4l2-request (the whole vaapi-/libva-/etc.-concept is a somewhat messy one). Work is being done on this, experimental patches are at https://forum.pine64.org/showthread.php?tid=9171.
To add to this, not all codecs are yet supported (vp8/vp9(?) is still unsupported, iirc).
And then chromium probably actually needs to be built with va-api support; for reasons™ the ChromiumOS changes for this are not included in mainline Chromium.
(And if I recall correctly, there was also some ChromiumOS-specific libva-v4l2-request-thing that wasn't just easily portable or something along that line, but I can't find this right now, so take this with a few grains of salt).
There's https://aur.archlinux.org/packages/chromium-vaapi/ with at least the Chromium-patches included, but that's for x86_64 only. I've been building caidao (ungoogled-chromium) with the va-api patches for a while now for x86_64 and aarch64 (https://forum.pine64.org/showthread.php?tid=9452), but this, of course, isn't enough (yet) to get hardware video decoding without blobs on Manjaro, unfortunately, for the other reasons above.
Mesa / OpenGL / Panfrost (GPU) is different from hardware video decoding (VPU).
Non-blob VPU hardware decoding is still being implemented in the kernel (hantro driver) and also needs libva-v4l2-request (the whole vaapi-/libva-/etc.-concept is a somewhat messy one). Work is being done on this, experimental patches are at https://forum.pine64.org/showthread.php?tid=9171.
To add to this, not all codecs are yet supported (vp8/vp9(?) is still unsupported, iirc).
And then chromium probably actually needs to be built with va-api support; for reasons™ the ChromiumOS changes for this are not included in mainline Chromium.
(And if I recall correctly, there was also some ChromiumOS-specific libva-v4l2-request-thing that wasn't just easily portable or something along that line, but I can't find this right now, so take this with a few grains of salt).
There's https://aur.archlinux.org/packages/chromium-vaapi/ with at least the Chromium-patches included, but that's for x86_64 only. I've been building caidao (ungoogled-chromium) with the va-api patches for a while now for x86_64 and aarch64 (https://forum.pine64.org/showthread.php?tid=9452), but this, of course, isn't enough (yet) to get hardware video decoding without blobs on Manjaro, unfortunately, for the other reasons above.