On Mon, Mar 2, 2020 at 8:08 PM Volker Rümelin <vr_q...@t-online.de> wrote:
> Patch "audio: change naming scheme of FLOAT_CONV macros" and > patch "audio: consistency changes" should have been a review > for ed2a4a7941 "audio: proper support for float samples in > mixeng", but I was too slow. > > Patch "audio: change mixing engine float range to [-1.f, 1.f]" > definitely needs to be tested by macOS users. I verified > PulseAudio, SDL2 and ALSA (actually libasound) work, but I > don't want to introduce a regression for CoreAudio. I spent > some time on https://developer.apple.com but I couldn't find > the answer if CoreAudio uses the [-1.f, 1.f] range too. The > results from my favorite search engine suggest the answer is > yes. > > @Howard: > I need your help once again. Can you please test if you can > hear (or see) clipping with my patches? Don't forget to set all > volume controls in the guest and on the host to 100% or 0dB to > get a reliable result. Compared to qemu without these patches I > expect the playback volume is a bit louder, but there's still > no clipping. > > Volker Rümelin (5): > qapi/audio: add documentation for AudioFormat > audio: change naming scheme of FLOAT_CONV macros > audio: consistency changes > audio: change mixing engine float range to [-1.f, 1.f] > audio: fix saturation nonlinearity in clip_* functions > > audio/mixeng.c | 26 +++++++++++++------------- > audio/mixeng_template.h | 22 ++++++++++------------ > qapi/audio.json | 14 ++++++++++++++ > 3 files changed, 37 insertions(+), 25 deletions(-) > > -- > 2.16.4 > > Hi, I applied these to Mark's screamer branch to create a new OSX build. Testing was done by playing system sounds, and an MP3/Internet radio with QuickTime/iTunes. With or without 6dB, the max volume is way out of my comfort zone. I hear no real difference in quality compared to a build from the current screamer branch. If any, it might sound a bit better. That means there still is some minimal crackling (clipping?) in the high volume parts of the audio I played with OSX guests, not Mac OS 9.x guests. So as there is no regression, tested by: howard spoelstra <hsp.c...@gmail.com>
