Hi, If you were to design a video codec for a very low-end decoder, what would it look like?
My target is MIPS 100MHz, and it should decode 320x240x30 in full speed in software, with headroom for audio too. Seems all the codec research in last 20 years has been more quality with more overhead, nobody looking into "improve quality without more overhead". Currently I'm thinking it would have to be a variant of vector quantization, like Cinepak. The target bitrates however are ~250 kbps or lower, where Cinepak targeted 1200 or higher. Are there any tricks that would improve quality with only encoder-side effort? What is the current top-of-the-line interframe prediction, that is still fast to decode? The platform is fast enough to play back mpeg1, and xvid simple profile L3 barely. Cinepak should also work, but I'd like the quality to be higher than these three. The last relevant VQ paper I found was https://arxiv.org/abs/1710.05311 which used a genetic algorithm to seed the codebook generation, improving PSNR by a few db over previous approaches. I've implemented that (for a single grayscale frame), but it looks too bad at reasonable bitrates. The modern approaches, DCT, FFT, wavelets and such transforms, are all likely too slow to decode. Not sure if this would be better off on other MLs, didn't seem to apply to ffmpeg-user really. - Lauri _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
