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Allwinner VPU support for the Linux kernel
- pedrocr 9y agoWhat kind of hardware is this that makes it usable for encoding/decoding mpeg2/h264/h265? Is this something that should be exposed as a general programming target instead of a set of video specific APIs?
- bri3d 9y agoAs you can see from the documented reverse-engineering of the hardware here: http://linux-sunxi.org/VE_Register_guide http://linux-sunxi.org/VE_Register_guide the device is generally single-function for each codec, with the decoding pipeline implemented in actual hardware. Unless you were able to express your kernel as a data transform used in a common video codec and express your I/O data as pixels, you're unlikely to accelerate a general purpose task this way.
- revelation 9y agoIt's a DSP firmware turned into silicon. If you look at for example the VP8 decoder registers for a Rockchip VPU here: https://patchwork.kernel.org/patch/8118991/ https://patchwork.kernel.org/patch/8118991/ You can see it's quite specific to the primitives the codec needs. If you want general purpose, we now have Vulkan for that. (And this one is reasonably low-level. On some like the Raspberry Pi, you throw bitstream over the wall to a coprocessor which gives you YUV back)
- snaky 9y agoOn Raspberry Pi it's not clear who is coprocessor, actually.
- WhitneyLand 9y agoWhy do more work on mpeg-2? Couldn’t that path just be left without acceleration, being it’s a less complex codec to begin with, usage is not growing, and the data sources are likely smaller to begin with (no 4k for example)?
- bonyt 9y agoIt's still useful for some applications. ATSC digital broadcasts in the U.S., for example, are in MPEG-2, as are the signals provided by many cable companies. I have an HDHomeRun Prime, and purchased the MPEG-2 HW Decoder license[1] for my Raspberry Pi 3 to make things a bit smoother. [1]: http://www.raspberrypi.com/mpeg-2-license-key/ http://www.raspberrypi.com/mpeg-2-license-key/
- djsumdog 9y agoSince they want to do hardware x264, are there any patent issues they'll have to deal with, or will that be included in the cost? I didn't see anything listed on the Kickstarter page.
- mastax 9y agoLooks like Bootlin is located in France. France doesn't recognize software patents (as I understand it), which is why VLC can exist. (Though I noticed on VLC's website that the EC could try to change that: https://www.videolan.org/press/patents.html https://www.videolan.org/press/patents.html)
- gsnedders 9y agoDVDs, too, are almost all MPEG-2.
- Narishma 9y agoIsn't the Raspberry Pi 3 powerful enough to do MPEG-2 decoding in software?
- dsr_ 9y agoNot if you want it to do anything else at the same time, and not if you need de-interlacing of the 1080i streams that half the over-the-air channels use.
- jagger27 9y agoAllwinner would be pretty foolish not to fully fund this endeavour (including stretch goals). They couldn't do it themselves this cheap. They'd make up the costs in new sales faster from FOSS-minded devs in no time flat and they'll have minimal recurring dev costs in the long run. To me this is a no-brainer.
- ZenoArrow 9y ago> "Allwinner would be pretty foolish not to fully fund this endeavour" Why would they fund it? If they saw the potential benefits, they could probably open source their own closed source drivers and avoid this Kickstarter being needed, or at the very least provide documentation to speed this work along.
- amluto 9y agoIf I were Allwinner, I'd be quite nervous about open-sourcing my code. Who knows what patents it infringes?
- joezydeco 9y agoWe have a winner!
- ktta 9y agoI think you've put forward an important point many don't consider when debating why companies won't open source.
- ZenoArrow 9y agoPatents for what? Algorithms? I've heard similar arguments/excuses made before, I'd like to understand if there's any legal precedence for them, or if it's more of a hypothetical risk. Lastly, with the 'supply of documentation' approach, does this (to your knowledge) carry the same legal risks?
- joezydeco 9y ago