Development Thread Testing of Audio Latency Fix branch

[degasus]

Hi,

I've created a WIP branch to reduce the currently very high audio latency with LLE and AX-HLe (it has no effect on zelda ucode games with hle). As this changes interact both with the audio backend and with the OS+drivers, it should be tested on as much systems as possible.

Please focus on:
- Does all available audio backends still work fine?
- Are there any new audio stuttering?
- Did the audio latency improve?
- Are any games broken which works fine on master?

Builds are here:
Win64: http://dl.dolphin-emu.org/wips/degasus-dolphin-latencyFix-4.0-859-x64.7z
OSX: http://dl.dolphin-emu.org/wips/degasus-dolphin-latencyFix-4.0-859.dmg
Src: https://github.com/degasus/dolphin/tree/latencyFix

Known issues:
- Stuttering on slowdowns is wrose. Lower latency results in shorter but more frequent stutters, so they sound worse. This can't be resolved without bigger latency.
- Small pitch shift while syncing. Does anyone notice this as it's limited to 0.6% -- 0.15 semi-tone? The higher the pitch, the faster we can correct the latency.

New features:
- Audio resampling controller: The resampling rate is controlled by the mixer fifo utilization to get a latency of 40 ms which is also the timing variance of our throttler.
- Audio resampling based on framelimiter: On configuring the framelimiter, this branch also configure the resampler to avoid stuttering. It's impossible to do this based on real slowdowns without a huge audio latency, but so you'll be able to get smooth audio on limiting the speed yourself. Check out the hotkeys to change the framelimiter UPDATE: This is disabled on the OpenAL backend as our OpenAL backend itself stretches the time on slowdowns.

[DJBarry004]

Will test right now.

EDIT: Tried with DSound under HLE and there was no sutter, even if speed is under 100% (Luigi´s Mansion). Tried again with LLE (same backend) (Mario Kart DD): the stutter seems to be gone, but now it sounds like a distorted/cutted echo. Speed more or less near half.

[JMC47]

Luigi's Mansion is Zelda ucode, it will not be affected on HLE.

Check the actual audio latency as well. Audio latency should be lower on this build on AX-HLE games and LLE on every game.

[DJBarry004]

Can you tell me which games use AX-HLE? Indeed, latency was lower.

EDIT: Does SMG uses AX-HLE? I don´t know a lot about audio ucode things, as you can see.

[degasus]

DJBarry004: you can easy check zelda HLE, as it's the only dsp emulation which doesn't stutter on slowdowns. Both LLE + AX-HLE stutter as hell on slowdowns, both on master and on this branch. But if you want, you can test LLE with a very low framelimiter

[DJBarry004]

(02-12-2014, 08:31 AM)degasus Wrote: DJBarry004: you can easy check zelda HLE, as it's the only dsp emulation which doesn't stutter on slowdowns. Both LLE + AX-HLE stutter as hell on slowdowns, both on master and on this branch. But if you want, you can test LLE with a very low framelimiter

You mean that I can test with any FPS limit under full speed (like 40 instead of 60, 30 instead of 50)?

I did notice a performance improvement, BTW. Dunno how it happened since the branch is related to audio, but whatever.

The thing is that, when testing MK-DD under LLE, I set Virtual XFB on. As I reported, when under full speed the sound (instead of stuttering) was like a continuously breaking echo sound. That thing dissapeared a bit with XFB on (for ex.: the VPS go to 50 and near 60 instead of 30 near 40). Again, maybe this doesn´t have anything to do but I think that it would be interesting if I told you this.

[delroth]

Can I ban you from this forum or should I wait for one more stupid post?

[Qaazavaca Qaanic]

Still 100-300 ms of latency in MKDD menu. (Zelda LLE, DAudio) (verified using Audacity recording, microphone)
Any suggestions for games that have a very clean sound effect easy to distinguish from BGM?

SSBB (LLE, XAudio2) has around 157 milliseconds or less of latency (from button sound to first sound from Dolphin). Is there any good way to record the stereo mix and the microphone simultaneously?

[NaturalViolence]

delroth Wrote:Can I ban you from this forum or should I wait for one more stupid post?

What did he do wrong this time? Better yet what rules did he break?

[neobrain]

(02-12-2014, 10:35 AM)NaturalViolence Wrote:

delroth Wrote:Can I ban you from this forum or should I wait for one more stupid post?

What did he do wrong this time? Better yet what rules did he break?

Just because there are no written rules applying to this case doesn't mean we are in any way obliged to let everyone use our forum software, you know.