Thanks for the details, didn't know the new PWM commit entangles so much the firmware.jdb wrote: ↑Tue Sep 01, 2020 9:46 amThe change won't be reverted, as there are multiple other use-cases that break if the driver doesn't support multiple writers.
- Please upload a sample of garbled audio somewhere downloadable (preferably captured by a sound card line-in port, not a microphone)
- Do you have composite video enabled on any of your devices?
I was looking for an easy and consistent setup where you could replicate 100% the reported sound issue (garbled sound) and choosed the latest LibreELEC 9.2.4 for the Raspberry Pi2B target.
Configuration: playback on either MMAL or OpenMAX acceleration, no de-interlacing and audio settings on lowest (no GPU accel & fixed 44.1kHz sampling)
LibreELEC:~ # uptime
16:14:03 up 29 min, load average: 0.44, 0.68, 0.67
LibreELEC:~ # uname -r
LibreELEC:~ # /opt/vc/bin/vcgencmd version
Apr 15 2020 11:44:24
Copyright (c) 2012 Broadcom
version 82f9bb929ce2186eb1824178c1ae82902ad6275c (clean) (release) (start_x)
LibreELEC:~ # cat /etc/os-release
PRETTY_NAME="LibreELEC (official): 9.2.4"
Choose any DVB-(C/T/S) 1080p stream that contains a proper quality video above 5-6 Mbit/s and you'll get the following audio outputs:
music.wav - 1080p Music Channel
speech.wav - 1080p Documentary Channel
I believe you could also test it by playing a 1080p proper Blu-ray full rip (uncompressed - no loss). Playing some very lossy Internet streams (Youtube & such) works OK with audio_pwm_mode=2. I guess it doesn't overwhelm the vc4 core, but testing such lossy video formats is substandard.
No, I don't have the composite video enabled on any of my devices, just HDMI. Don't know if it matters, but I have the mpeg2 HW decoding engine activated - bought mpeg2 licenses on all of them and enabling it in /boot/config.txt