Dear all,
i am in the need to play some audio, captured from a very similar si476x radio chip, and played with main cs42888 codec or hdmi.
My board is very similar to sabreauto.
While piping arecord | aplay from si476x -> cs42888 works fine, piping si476x -> hdmi-imx-soc have issues.
Likely, hdmi is too fast, and after some seconds i get a buffer underrun and hear a small cut.
Looking the 2 pcm stream details (si476x capture device and hdmi playing device), i see
Hardware PCM card 1 'imx-hdmi-soc' device 0 subdevice 0
Its setup is:
stream : PLAYBACK
access : RW_INTERLEAVED
format : S16_LE
subformat : STD
channels : 2
rate : 44100
exact rate : 44100 (44100/1)
msbits : 16
buffer_size : 6144
period_size : 768
period_time : 17414
tstamp_mode : NONE
period_step : 1
avail_min : 768
period_event : 0
start_threshold : 2147483647
stop_threshold : 6144
silence_threshold: 0
silence_size : 0
boundary : 1610612736
appl_ptr : 0
hw_ptr : 0
Hardware PCM card 2 'imx-audio-si4745' device 0 subdevice 0
Its setup is:
stream : CAPTURE
access : RW_INTERLEAVED
format : S16_LE
subformat : STD
channels : 2
rate : 44100
exact rate : 44100 (44100/1)
msbits : 16
buffer_size : 2048
period_size : 1024
period_time : 23219
tstamp_mode : NONE
period_step : 1
avail_min : 1024
period_event : 0
start_threshold : 2147483647
stop_threshold : 2048
silence_threshold: 0
silence_size : 0
boundary : 1073741824
appl_ptr : 0
hw_ptr : 0
Starting ...
As you can see, the 2 pcm devices have different period size.
This should means, as seen, that player is faster.
One thing i suspect is the fact the fm chip is clocked by 32768 Khz ext ref clock, while hdmi should be clocked from something derived from 24Mhz. Could this be an issue ?
thanks
Best regards
angelo
