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FFmpeg's VP9 Decoder Faster Than Google's
An anonymous reader writes "A VP9 video decoder written for FFmpeg, FFvp9, now holds the title of being the world's fastest VP9 video decoder. FFvp9 is faster than Google's de facto VP9 decoder found in libvpx, but this doesn't come as too much of a surprise given that FFmpeg also produced a faster VP8 video decoder than Google a few years back with both single and multi-threaded performance."
I'm not an expert, but I'd say that when decoding video, frame drops caused by CPU overload sort of tend to be more noticable than a few decoding artifacts. At least that's how I always perceived it.
Ezekiel 23:20
The output is equivalent to what libvpx produces (as measured by MD5 on each output frame) on all files in the VP9 conformance suite.
Stop pulling examples out of your ass.
My understanding is that there is no room for decode artifacts in this - you either do it right, or it's not a proper decoder. This is a proper decoder, so will produce identical output to the google standard one. I believe there are test streams with md5s for the test frames, and this decoder passes the tests.
So, it's free, and it's correct, and it's fast. I think you have pre-conceived prejudices which are in this case wrong ;-)
From my perspective, faster is good for low power devices, so if this helps spread decent video codecs to more devices, that's a win.
100 years ago, nothing supports H.264 in hardware either, yet here it is. I know, lets waste money making hardware for codecs that are not standards yet!
A decoder is indeed normally specified with bit level output requirements. Two different decoders thus generate exactly the same decoded bitstream. Some hardware decoders do generate 'wrong' output, but it is either that or 3-4 times as much battery drain. It is also not so important when watching a fullHD movie on a 320x480 screen wether all 18 bits of output are right.
This is false. Decoding for modern video formats is strictly defined, and all decoders must produce bit-perfect output. You can add as many filters as you want after that, but that's a postprocessing step in the video player and has nothing to do with the decoder. Things like in-loop filters are strictly defined as part of the decoding process and must be there for the decoder to be considered correct.
I haven't seen dropped frames in video in longer than that... on my desktop. My AMD E-350 based netbook, on the other hand... when it runs into something incompatible and can't do hardware decoding, it gets bad.
Besides, even if you have a decently powerful laptop, each second your CPU spends in higher performance states costs you battery runtime. Faster code gives you less heat and longer battery life for free.
Just how slow am I talking about? As per the link, often about 50 times slower than x264.
This may be OK for google, which encodes a video once and then sends it to many many customers (youtube), the bandwidth savings pay for the increased CPU cost.
But for most users, that's just not acceptable. Until they get the speed up to a reasonable, we'll keep using what works: x264 or vp8
TODO: 753) write sig.
Most users never encode a single video in their life. (Except for cameras on devices, and who is doing 4k video on thier phone these days?)
And if encoding takes 50x longer, that's 50x the resources Google needs to keep up with the work flow.
So you have it totally backwards.
Not to mention that we are talking about 4k-targetted codecs, so you should be comparing to H.265, not H.264. The additional computations for encoding H.265/VP9 are to reduce bandwidth requirements. If you don't care about bandwidth, feel free to generate a 5GB H.264 video.