I can't find anywhere in my datasheet how can I tell what kind of audio I am currently receiving.
I must know the difference when receiving PCM or any compressed audio, because my device should handle those differently.
You need to examine the Audio infoframe
Sometimes Audio infoframe report all zeros - "refer to stream header". Actually most of the laptops will transmit such an infoframe.
So I need an indication from the stream. I am sure that ADV7623 has such an information. For example I2S can serialize zeros if the stream is compressed (reg 0x03, HDMI map)
I need this information to be exposed to me.
The only thing the 7623 does is capture the audio infoframe. If the frame says 'refer to stream header' then the sink needs to decode the stream header.
It sounds reasonable.
The fact is - i am running the stream with Dolby Digital from my laptop via my system (with ADV7623) and the sink is playing the audio. Infoframe is "refer to stream header".
Playing with reg 0x03 I can see the audio is muted and unmuted on sink accordingly.
This is not the case when audio is uncompressed. The register values doesn't matter and audio is always unmuted.
But to make the discussion shorter - you are saying there is no way I can detect compressed audio content if not using the infoframes?
And btw, how does this reg 0x03 works ?
There's noway for the 7623 to know what the audio format is if the info frame says 'refer to stream header'.
DIS_I2S_ZERO_COMPR controls the I2S output depending on compression. Also MUTE_AUDIO can force an audio mute. I'm not sure what you are writing to 0x03
Check out the various control fiedls listed inthe hardware guide section 188.8.131.52
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