Hello,
it seems like the latest OSMC kernel (4.4.13-5) limits the alsa audio to 48khz.
I can’t remember from what version i upgraded my system from (4.4.8-X i think) but i’m positive that my 96khz/24bits audio file was playing at 96khz/16bits (the bit depth was converted to 16).
Right now, when i play a 96khz/24bits file with aplay i get the following dowsampling message :
Playing WAVE ‘01 Immigrant Song feat. Karen O.wav’ : Signed 24 bit Little Endian in 3bytes, Rate 96000 Hz, Stereo
Plug PCM: Rate conversion PCM (48000, sformat=S16_LE)
Converter: linear-interpolation
Protocol version: 10002
Its setup is:
stream : PLAYBACK
access : RW_INTERLEAVED
format : S24_3LE
subformat : STD
channels : 2
rate : 96000
exact rate : 96000 (96000/1)
msbits : 24
buffer_size : 32768
period_size : 8192
period_time : 85333
tstamp_mode : NONE
period_step : 1
avail_min : 8192
period_event : 0
start_threshold : 32768
stop_threshold : 32768
silence_threshold: 0
silence_size : 0
boundary : 1073741824
Slave: Hardware PCM card 0 ‘bcm2835 ALSA’ device 0 subdevice 0
Its setup is:
stream : PLAYBACK
access : MMAP_INTERLEAVED
format : S16_LE
subformat : STD
channels : 2
rate : 48000
exact rate : 48000 (48000/1)
msbits : 16
buffer_size : 16384
period_size : 4096
period_time : 85333
tstamp_mode : NONE
period_step : 1
avail_min : 4096
period_event : 0
start_threshold : 16384
stop_threshold : 16384
silence_threshold: 0
silence_size : 0
boundary : 1073741824
appl_ptr : 0
hw_ptr : 0
Thoughts?
Was the frequency limit reverted to the original value of 48khz on purpose?
Thanks
EDIT: i confirm that in the previous build (kernel 4.4.8-3-osmc) it was not limited to 48khz. i’ve just performed two fresh installs: one with the new 4.4.13.5-osmc kernel and one with the previous 4.4.8-3-osmc kernel.
With the new one i get the same results as above. With the previous one it plays as 96khz/16bits as shown below:
Playing WAVE ‘01 Immigrant Song feat. Karen O.wav’ : Signed 24 bit Little Endian in 3bytes, Rate 96000 Hz, Stereo
Plug PCM: Linear conversion PCM (S16_LE)
Its setup is:
stream : PLAYBACK
access : RW_INTERLEAVED
format : S24_3LE
subformat : STD
channels : 2
rate : 96000
exact rate : 96000 (96000/1)
msbits : 24
buffer_size : 16384
period_size : 4096
period_time : 42666
tstamp_mode : NONE
period_step : 1
avail_min : 4096
period_event : 0
start_threshold : 16384
stop_threshold : 16384
silence_threshold: 0
silence_size : 0
boundary : 1073741824
Slave: Hardware PCM card 0 ‘bcm2835 ALSA’ device 0 subdevice 0
Its setup is:
stream : PLAYBACK
access : MMAP_INTERLEAVED
format : S16_LE
subformat : STD
channels : 2
rate : 96000
exact rate : 96000 (96000/1)
msbits : 16
buffer_size : 16384
period_size : 4096
period_time : 42666
tstamp_mode : NONE
period_step : 1
avail_min : 4096
period_event : 0
start_threshold : 16384
stop_threshold : 16384
silence_threshold: 0
silence_size : 0
boundary : 1073741824
appl_ptr : 0
hw_ptr : 0
Etienne