4k editing - no fun without using vaapi

[karl]

I've been using avidemux for years to cut 1080p videos from my cameras coarsely in the compressed domain - and I was very happy with avidemux for this, in general (just missing a "fullscreen view" feature).

Now that cameras deliver wonderful 4k (or 2160p) videos, I would of course like to continue using avidemux. And the good news is that this is generally possible. But... even on a core i7 CPU, it's not fun, as seeking back and forth is just too slow, and even normal speed replay stutters.

I've compiled the latest git head and tried every combination of output device and "HW acceleration" possible, but it seems that full hardware acceleration as available from the Intel CPI is never really used (maybe just for output/buffering/scaling).

In contrast, the (also ffmpeg-based) player http://mpv.io/ (that actually uses vaapi with --vo=vaapi --hwdec=vaapi) is not only able to replay the 4k video files smoothly with very little CPU usage, you can also seek to any position in the video (using mpv's on-screen mouse GUI) without noticable delay - just as it would be perfect for a NLE like avidemux.

Is there a chance to make use of vaapi (both for decoding and display) from avidemux?

[pchristy]

Are you using Intel or AMD graphics? If its Intel, I believe you can use VDPAU via the open-source drivers. If its AMD, I believe that the latest open-source drivers also support VDPAU. I'm in a similar position with my (rather underpowered) laptop. Unfortunately AMD dropped support for the GFX chips just after I bought it (Grrr!) and the chipset isn't supported by the open-source drivers. Although I can play HD video via a VAAPI-modified MPlayer, using Avidemux on it - even for ordinary HD - is very slow.

On my desktop machine, with VDPAU and an NVidia Gfx card, no problem. Avidemux supports - at least partly - VDPAU. VAAPI seems to be slowly vanishing through lack of support, which is a nuisance, because I need it.....!

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Pete

[karl]

Are you using Intel or AMD graphics? If its Intel, I believe you can use VDPAU via the open-source drivers.

I use Intel graphics - but I've never heard of a VDPAU driver for Intel CPUs, what driver are you referring to?

VAAPI seems to be slowly vanishing through lack of support, which is a nuisance, because I need it.....!

From what I experience, quite the opposite is true: There's perfect vaapi support for Intel GPUs, both for decoding and encoding H.264, and mpv supports vaapi great!

Actually, there's a lua script being written right at this time which allows mpv to mark ranges and extract parts of the video, I might have to resort to using this for 4k videos.

[mean]

Could you share a short sample of your 4k video ?
5 or 10 secs would be enough

[Jan Gruuthuse]

Not very clear yet: some linux flavours have libvdpau-va-gl or mesa-dri with intel support.

[karl]

Could you share a short sample of your 4k video ? 5 or 10 secs would be enough

Sure, if you can recommend some upload service where I can put it...?
(Tried filebin.net, but they seem to have technical issues at the moment.)

[Jan Gruuthuse]

You could use a Dropbox Basic account (2 GB free)

[pchristy]

I use Intel graphics - but I've never heard of a VDPAU driver for Intel CPUs, what driver are you referring to?

According to this link:

https://wiki.archlinux.org/index.php/VDPAU

Intel GMA 4500 series and newer GPUs are supported by the libvdpau-va-gl package together with the libva-intel-driver.  I think mesa is also involved.

Its not something I've tried as my chipset (AMD) isn't supported by the open source drivers, but it is something I stumbled across during my research. If you Google for "Intel vdpau", you'll get quite a lot of hits, but you will need to sift through them.

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Pete

[karl]

I just realized there is an easier solution than me uploading a 4k sample to some file sharing site: dpreview.com has published a review of the Panasonic LX100 camera I use which also contains a link to a downloadable 10 second sample 4k file right from the camera: http://movies.dpreview.com.s3.amazonaws.com/panasonic_dmclx100/P9630089.MP4.