I2S bits per sample

Han
Posts: 2
Joined: Mon Oct 31, 2016 5:42 am

I2S bits per sample

Postby Han » Mon Oct 31, 2016 5:23 pm

Hello,

In the I2SCONF register bits 12-15 signify the number of extra bits shifted out after each 16 bits. Using 4 bits however, I cannot set this to 16, which would be required for 24-bit audio data within a 32-bit sample. The Rx FIFO mode in bits 16-18 of the I2S_FIFO_CONF register is set to 2 (= 24 bits per channel full data discontinue). Looking at the data being received from the ADC, it seems that the most significant bit is lost when I set I2S_BITS_MOD to 15.
How do I setup the I2S registers to receive 24-bit audio data in a 32-bit word?

Han

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pratik
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Re: I2S bits per sample

Postby pratik » Thu Nov 10, 2016 12:53 pm

Hello,
Which register map file are you referring to when programming the I2S registers? Can you please attach that?
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Pratik Panda
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JoshuaQ
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Joined: Sun Feb 05, 2017 4:22 pm

Re: I2S bits per sample

Postby JoshuaQ » Mon Feb 06, 2017 11:06 am

1. 800 bit/s - minimum necessary for recognizable speech
2. 2.15 kbit/s - minimum bitrate available through the open-source Speex codec
3. 8 kbit/s - telephone quality (using speech codecs)
4. 32-500 kbit/s - lossy audio as used in Ogg Vorbis
5. 256 kbit/s - Digital Audio Broadcasting (DAB) MP2 bit rate required to achieve a high quality signal
6. 400 kbit/s-1,411kbit/s - lossless audio as used in formats such as Free Lossless Audio Codec, WavPack or Monkey's Audio to compress CD audio
7. 1,411.2 kbit/s - Linear PCM sound format of Compact Disc Digital Audio
8. 5,644.8 kbit/s - DSD sound format of Super Audio CD
Above is the reference to the bit rate. Hope it helps! And the mp3 to aac converter can help you change the video/audio bit rate at will.

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