[Milhouse]

I'll need more details.
Does it occur with passthrough/non-passthrough?
While playing normally or during pause/seeking?
What make/model of receiver/TV?
Does the receiver indicate any sync loss when the chirp happens?
Does it occur with all files? Anything in common with files that chirp? (i.e. sampling rate, coded, number of channels)
Does reverting to an earlier firmware (start_x.elf/fixup_x.dat) solve the problem? Can you identify the firmware version that introduced the problem.

Here's a 100MB sample mkv on dropbox, it's the opening titles from Blade Runner Directors Cut, 1080p/DD5.1. Audio starts at 13 seconds, however chirping is usually evident as the green tree is being traced line by line.

A second 100MB sample mkv (dropbox) - the opening titles from Blade Runner Final Cut, 5 audio streams: default TrueHD, DD5.1 and 3x DD2.0 - is even worse, though I'm not sure if the multitude of audio streams (including TrueHD) is a complicating issue. If you play it then cycle to the DD5.1 audio, stop it and restart playback with the DD5.1 audio, you should hear chirping from the outset.

Note that the chirping isn't continuous, but it is frequent, and sound quality is much worse as a result. I'd say many films are now unwatchable (or maybe that should be "unlistenable").

Let me know if/when you download these samples so that I can delete them!

Going back through my builds, the problem starts with the following build:

Code:

-rw-rw-r-- 1 neil neil 106260480 Nov 20 03:14 OpenELEC.tv/target/OpenELEC_Gotham-RPi.arm-devel-20131120031424-r16398.tar

The build log is here: pastebin - it's not very large, so may not be complete (if a build fails and is restarted to completion, I'm only keeping the log for the successful part of the build). There is a new bcm2385 firmware in this build, but not sure if it is the only change. It's also possible I did a mkpkg_bcm2835-driver of the next firmware to create this build so take any hashes in the log with a pinch of salt. Lucky if I can remember what I had yesterday for lunch let alone what went into this build...

The build prior (created Nov 20 02:51:51) is fine, playing both samples without a problem.

Firmware details for this "bad" 03:14 build:

Code:

rpi512:~ # vcgencmd version
Nov 12 2013 23:39:45
Copyright (c) 2012 Broadcom
version 4aee5454c7955e7bc0bbb152ca4c0e26e75376e1 (clean) (release)
rpi512:~ # uname -a
Linux rpi512 3.12.0 #1 PREEMPT Wed Nov 20 03:03:17 GMT 2013 armv6l GNU/Linux
rpi512:~ # lsb_release
OpenELEC_Gotham (unofficial) - Version: devel-20131120031424-r16398

and the firmware details for the "good" 02:51 build:

Code:

rpi512:~ # vcgencmd version
Nov  7 2013 16:45:47
Copyright (c) 2012 Broadcom
version 8573b0747a17baf22e97e08254737a13d80430dd (clean) (release)
rpi512:~ # uname -a
Linux rpi512 3.12.0 #1 PREEMPT Wed Nov 20 01:48:14 GMT 2013 armv6l GNU/Linux
rpi512:~ # lsb_release
OpenELEC_Gotham (unofficial) - Version: devel-20131120025151-r16388

Here are my audio settings for reference:

and I also have Volume Amplification set to 30db.