Emulator Issues #10682
Crackling at high audio amplitudes in macOS High Sierra (and maybe earlier)
Any game, tested with Super Mario Galaxy and Super Mario Galaxy 2
Game ID? (right click the game in the game list, properties, info tab)
RMGP01 and SB4P01 respectively (both Europe)
MD5 Hash? (right click the game in the game list, properties, info tab, MD5 Hash: Compute)
4a7379f93369f3335cfdae90cdac2f96 and 3546701f83bc771cada2a9c43dcd4857 respectively
What's the problem? Describe what went wrong.
Whenever loudish music or sound effects play (such as the final bowser battle in Super Mario Galaxy 2,) the sound will crackle moderately loudly (quite noticeable)
What steps will reproduce the problem?
Having Cubeb set as the audio backend, and have an emulated title or software play any audio louder than about -5db (VERY rough estimate, relative to the emulated console, not the host audio)
Is the issue present in the latest development version? For future reference, please also write down the version number of the latest development version.
Yes, 5.0-5991 (latest as of 7:05PM, Sunday, December 3, 2017 Eastern Time)
Is the issue present in the latest stable version?
If the issue isn't present in the latest stable version, which is the first broken version? (You can find the first broken version by bisecting. Windows users can use the tool https://forums.dolphin-emu.org/Thread-green-notice-development-thread-unofficial-dolphin-bisection-tool-for-finding-broken-builds and anyone who is building Dolphin on their own can use git bisect.)
Technically 5.0-3937. I say technically, because that's when Cubeb was merged, and it was optional, as CoreAudio was still available as an audio backend. After going back to that version, and switching between Cubeb and CoreAudio, it became apparent that Cubeb was amplifying the audio quite a bit more than CoreAudio (which likely is causing the crackle) CoreAudio sounds softer, but more detailed and has zero crackling. Whenever Cubeb was made the only audio backend on Dolphin, is when the issue really came out, as the user had no choice but to use Cubeb, which is broken.
If your issue is a graphical issue, please attach screenshots and record a three frame fifolog of the issue if possible. Screenshots showing what it is supposed to look like from either console or older builds of Dolphin will help too. For more information on how to use the fifoplayer, please check here: https://wiki.dolphin-emu.org/index.php?title=FifoPlayer
What are your PC specifications? (CPU, GPU, Operating System, more)
MacPro5,1, Intel Xeon E5645 @ 2.40Ghz, AMD Radeon HD 5570, macOS High Sierra 10.13.0, Darwin Kernel Version 17.0.0: Thu Aug 24 21:48:19 PDT 2017; root:xnu-4570.1.46~2/RELEASE_X86_64 x86_64
Is there anything else that can help developers narrow down the issue? (e.g. logs, screenshots,
configuration files, savefiles, savestates)
The issue is definitely Cubeb, as CoreAudio sounds perfectly fine. Cubeb is either doing something funky to the audio levels, or just amplifying the audio too much.
#2 Updated by newhacker1746 about 2 years ago
PR #5690 corresponds to Dolphin 5.0-4901, which means that 5.0-4899 was the last version with CoreAudio, if anybody wants to have the latest version that has both backends to compare the sound. (Since I found it, I just put it here so that you don't have waste time bisecting it)