when play music The sound was all rustling

[明镜明]

HI,

the music rate is 24 bits, and the sampling rate is 48K。

take the fpga as codec。

fpga works in master，and provide bit clock (2*32*48k) and  frame sync clock (48k)。

1:  we use mplayer command  to  play  the music ,  in kernel , params_format(params)  get SNDRV_PCM_FORMAT_S16_LE,  treat as  double channle， 48k sample rate， 16bit。

and sound good 。

2：

we use aplay  command  to  play  the music ,  in kernel , params_format(params)  get SNDRV_PCM_FORMAT_S20_3LE,  treat as  double channle， 48k sample rate， 20bit。

and sound badly，The sound was all rustling。

why ？

ssi support  20 WL。

how do i slove ？debug ？

[igorpadykov]

Hi 明镜 明

please check supported formats in sect.28.2.1 Stereo CODEC Features

attached Linux Manual. Try to test and debug using sect.28.5 Unit Test

Best regards
igor
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[明镜明]

imx6q support 2  channels,  48k sample rate,  24bit data format .   

[明镜明]

HI,igorpadykov

      we use aplay  command to play  sound file (24bit, 48k, double channels). 

      after function (snd_pcm_hw_refine_user) processing.   

      we use function params_format(params), then  we get   SNDRV_PCM_FORMAT_S20_3LE

   in  function imx_ssi_hw_params.   

     data bits are converted from 24 to 20 bits。