i.MX Processors中的主题 audio lost and reverse when playback beep audio

audio lost and reverse when playback beep audio

yunyangsihai — Sun, 28 Apr 2019 13:52:57 GMT

Dear community:

platform：iMX6 DualLite + Linux BSP4.1.15

1. We can hear pop noise when playback beep audio. beep device configured as below in asound.conf

aplay -v -D beep beep1.wav

2. we found the audio lost 1~2 waveform in the beginning when capture the audio by hardware connecting to the amplifier as above configuration.

3. we could acquire complete waveform whe configure beep device as plughw like this.

4. add 20ms null data to the beginning of the beep file, then we could acquire complete waveform. but the waveform reversed . upper is original beep file, below is beep file adding 20ms null data

why dmix lost some audio? and the audio be reversed?

Thanks a lot for any tips .

Re: audio lost and reverse when playback beep audio

igorpadykov — Mon, 29 Apr 2019 05:18:04 GMT

Hi yang

one can try to decrease pop using volume control or codec stby signal as

described on

iMX6Q+SGTL5000 have pop noise in suspend/resume and shutdown processes

try with latest NXP Linux L4.14.98, link
https://source.codeaurora.org/external/imx/linux-imx/tree/?h=imx_4.14.98_2.0.0_ga

Best regards
igor
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