[SOLVED] 24 bit Output to HDMI downsamples to 16 bit

[jcucurull]

Yes 16-bit but in the kernel hdmi.c source file there is code for 24/192
https://github.com/raspberrypi/linux/blo...deo/hdmi.c

I'm not sure whether this code is whats being used to support the Pi HDMI ports but there is no question that Pi HDMI audio has been problematic for many years. Hopefully there will be some relief in Bookworm.

I'd like to see it work reliably up to 24/192, multichannel LPCM up to 7.1 and for passthrough Dolby AC3 and DTS bitstream. I think this is sort of whats expected from modern HDMI audio.

That would be very good.

Using the command you mentioned, I see that the HDMI currently only supports 16 bits:

Code:

*** Scanning for playback devices ***
Card 0, ID `b1', name `bcm2835 HDMI 1'
  Device 0, ID `bcm2835 HDMI 1', name `bcm2835 HDMI 1', 4 subdevices (4 available)
    1..8 channels, sampling rate 8000..192000 Hz
    Sample formats: U8, S16_LE
    Buffer size range from 80 to 131072
    Period size range from 80 to 131072

      Subdevice 0, name `subdevice #0'
      Subdevice 1, name `subdevice #1'
      Subdevice 2, name `subdevice #2'
      Subdevice 3, name `subdevice #3'
  Device 1, ID `bcm2835 HDMI 1', name `bcm2835 HDMI 1', 1 subdevices (1 available)
    2 channels, sampling rate 44100..48000 Hz
    Sample formats: S16_LE
    Buffer size range from 444 to 32768
    Period size range from 444 to 32768

      Subdevice 0, name `subdevice #0'

Best,
Jordi