Re: exhale - Open Source USAC encoder
Reply #296 – 2020-07-06 17:34:36
I see. Well, FDK produces way higher bitrate than target 64 kbps. Aslo Apple CVBR is kindy tricky to test. I don't know if You remeber we have seen and You have posted about it too that Apple CVBR produces higher bitrate during first 5 seconds and then in order to keep bitrate it can go deep down (eig is a good sample to see how quality/bitrate varies drastically ). I was careful enough to test the whole samples. FDK is a bit higher than 64 kbps, and FHG is a bit lower. Comparing each against any 64 kbps contender is not a problem in my opinion; but comparing each other may be more questionable.On the other hand, exhale hits target bitrate without issues and doesn't do tricks behind. So it's a good achivement for exhale to be on par with HE-AAC encoders with such bitrate behavior. It's exactly my point. SBR has a positive effect on overall quality when bitrate starvation occurs; but SBR also lead to artefacts on its own. So keeping a similar quality without SBR is a very good thing. OPUS has a different encoding technique than SBR which also bring serious issues. It was very clear by testing classical music but sound quality but much less with louder music.
Wavpack Hybrid: one encoder, one encoding for all scenarios WavPack -c4.5hx6 (44100Hz & 48000Hz) ≈ 390 kbps + correction file WavPack -c4hx6 (96000Hz) ≈ 768 kbps + correction file WavPack -h (SACD & DSD) ≈ 2400 kbps at 2.8224 MHz