Re: Opus 1.3-rc
Reply #28 – 2018-06-08 23:03:11
I would imagine we are talking very small differences in sound quality to where when casually listening I would not expect to hear any obvious differences between v1.2.1 and v1.3RC at bit rates of 32-48kbps (give or take). Here we don't imagine things but actually test it. 1.3RC is significantly better than 1.2.1 at least for speech at low bitrates. Not only 1.3RC is much better than 1.2.1 but also bitrates are less bloated on speech samples. P.S. 1.3RC has new advanced speech detector based on algorithms of artificial intelligence, RNN. I did notice a tiny difference in file size between v1.3RC and v1.2.1 on the sample (i.e. 24-Greensleeves-Korean-male-speech.441) you linked to... v1.2.1 (@ 16kbps) =19.5 KB (19,974 bytes) v1.3RC (@ 16kbps) = 19.2 KB (19,682 bytes) but other than that, I can't say I notice any obvious difference between the two when listening to those two Opus speech files, at least based on my Klipsch Pro-Media speakers for the PC. if there is a difference it's got to be minimal especially given that low of a bit rate as I set it to 16kbps and v1.3RC shows 17kbps and v1.2.1 shows 18kbps in Foobar2000. so your saying Opus v1.3's greatest advantage over v1.2.1 is definitely speech? ; if that's true, I would not expect to hear any obvious difference between v1.3 and v1.2.1 if that speech file you linked to is a good test for the encoders. but who knows, maybe there could be differences in other random speech files(?). but I just noticed that there is some volume change between the WAV file and the Opus files and I know what the WAV sounds like so it's easy for me to detect the WAV vs Opus files on that alone when ABXing. like in the WAV file, the left speaker is louder where as with the Opus v1.2.1 and v1.3RC those sound the same in that regard in that the left speaker has less volume and is quieter. like I can adjust volume (on the speaker itself) so it's nice and even on both speakers with the Opus files but when I play back the WAV file the left speaker is noticeably louder. but just strictly playing the v1.2.1 and v1.3RC and listening, back and fourth, I can't say I feel confident enough to say one sounds noticeably better than the other as they seem pretty much the same to me. but trying to overlook the volume change, I am pretty sure I could ABX those 16kbps Opus speech files from the WAV. but in terms of just doing a straight compare of v1.2.1 and v1.3RC, I don't feel confident enough to say I hear any clear difference between the two files.