i.MX Processors中的主题 Re: [MultiMedia-Audio Output] Need an answer to confirm this discussion

[MultiMedia-Audio Output] Need an answer to confirm this discussion

tongchunyang — Mon, 25 Nov 2013 02:53:45 GMT

Hi All

Good Morning.

Now I have a question need to be confirmed. The question's details just like bellow:

1, Decided to using I2S output port AUDMUX4/ESAI to output the PCM data.

2, The understanding of the audio file codec is imaged bellow.

Description:

Just like image shows above, there are many audio files with different sample rate from USB device. By the soft side, these different rates are converted to the fixed rate, and then decode the file to RAW data and

push into SSI&ESAI. Finally to the ASRC converted to another fixed sample rate(48Kbps) to output.

Questions:

1, Is the understanding above correct?

2, If the understanding above is correct. Is there maybe some sound output dely and original sample rate should be changed error occurred?

3, Is the LRCK frequency of the I2S' output is fixed with 48KHz(because of the sample rate is 48Kbps), can this value be changed anymore?

Best Regards

Re: [MultiMedia-Audio Output] Need an answer to confirm this discussion

YixingKong — Fri, 21 Feb 2014 07:13:19 GMT

Tong

We are sorry for getting back to you so late. Are you still stuck with the issue? If you have somehow to resolved the issue, can we close the discussion? If you still need help, please feel free to reply with an update to this discussion.

Thanks,
Yixing

Re: [MultiMedia-Audio Output] Need an answer to confirm this discussion

tongchunyang — Sun, 23 Feb 2014 23:55:02 GMT

Hi Yixing

Thanks for your reply.

I still need to know about this issue, and please help me.

Best wishes

TongChunyang

Re: [MultiMedia-Audio Output] Need an answer to confirm this discussion

YixingKong — Mon, 24 Feb 2014 03:18:10 GMT

Chunyang

I will branch your question into an internal group and assign an engineer to work on it. If you do not see anything back in 5 days, please reply here again.

Regards,

Yixing

Re: [MultiMedia-Audio Output] Need an answer to confirm this discussion

tongchunyang — Mon, 24 Feb 2014 03:39:03 GMT

Hi Yixing

Thanks for help action.

And waiting for good news

Re: [MultiMedia-Audio Output] Need an answer to confirm this discussion

karina_valencia — Fri, 28 Feb 2014 21:42:55 GMT

Re: [MultiMedia-Audio Output] Need an answer to confirm this discussion

AdrianAlonso Feb 28, 2014 2:01 PM (in response to imxcommunityscout)

Hi Tong,

Audio clock configuration is perform on "decode" stage from your diagram, here the linux driver for audio card

will trigger a callback that will configure ESAI to work at a certain sample frequency (depends on the tag info passed by the audio file).

when ASRC is enabled it will re sample if needed. (board file pass a data struct with the native supported sample rates that a codec

can support).

The LRCK frequency can be changed but depends on the actual codec for example iMX6Q Sabre Auto board uses codec cs48888,

tha datashet say that for a given master clock freq, the codec can support a set of frequencies; 48k is the default config, but it could

also support 96k, 192k.

Regards

Adrian

/message/384560?et=watches.email.thread

Re: [MultiMedia-Audio Output] Need an answer to confirm this discussion

tongchunyang — Sun, 02 Mar 2014 23:59:23 GMT

Hi Karina

Thanks for your helpful answer.

And I will learn with your answer.

Best Wishes

TongChunyang