I was able to include the Advance Audio Kernel in the upcoming Moode 2.7 update by implementing a Kernel select feature on System config :-) Screenshots attached.
There are two kernels, Standard and Advanced. The standard kernel is a mainline Raspbian kernel which in this case is 4.4.23. The advanced kernel is based on 4.4.23 and custom built by the inmates to make 4.4.23-sc1. This kernel provide important audio capabilities as listed below. These capabilities are not available in mainline kernels.
The following are enabled via <params> supplied to the dtoverlay in config.txt
- 352.8k and 384k sample rates for es9023, pcm512x, pcm514x
- Integer bit clock divider for es9023 codec for less jitter on 48K and 96K sample rate
- DSD128 via 352.8k sample rate (either DoP or DSD -> PCM on-the-fly)
- Bypass pcm512x, pcm514x oversampling filter via 384k sample rate
And by chip type / overlay.
PCM512X, PCM514X
- 384K is automatically enabled, no param needed
ES9018
- simple-bclk-64fs
- Descr: Use a "fixed" 64fs bclk_ratio for 2 channel, 32/24/16 bit audio
MMAP (Memory Mapped I/O for I2S interface)
Memory mapped I/O is available for the I2S interface providing the Player application enables it. Currently MPD does not enable MMAP. Other players for example Squeezelite do enable MMAP.
The other new feature shown in the screen shots is improved handling of chip options for the Burr Brown family of chips including PCM514x, PCM512x and TAS5756.
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