How HBR audio bitstream embedded to I2S output interface in parallel mode when audio input source is Dolby TrueHD and DTS-HD Master Audio?

Dir Sir.

We have questions about how ADV7622 put HBR audio bitstream to I2S output interface in paralle mode(4 data lines). Is there any format diff. output from ADV7622’s I2S between Dolby TrueHD, and DTS-HD Master Audio input from HDMI?

Attached file is a description how ADV7622 communicate with our chip if we play a blue disk with Dolby TrueHD audio. It is based on current HDMI R1.4 SW and ADV7622 setup. Our questions is: If we play a blue disk with DTS-HD Master Audio instead of Dolby TrueHD, will this be identical?

Description of ADV7622 communication with our chip if we play a blue disk with Dolby TrueHD audio:

The I2S Data format is 32bit per channel, but only 16 MSB contain valid HBR audio data. The HBR audio data bit sorting through the I2S datelines is described in Fig. 2

  • 0
    •  Analog Employees 
    on Aug 1, 2011 10:24 PM


    I'm afraid that part is covered by NDA so we can't discuss it in the public forum.  We've let your local support know so they should be in touch with you offline.


  • Hi, DaveD

    i am not sure following information can post or not?  please remove the message or tell me if it is covered by NDA.

    i have adv7842-> adv7511 ev board.

    i use hdmi source transmit dolby audio to ADV7842. how about the audio format on i2s out in i2s mode from  ADV7842?

    dolby digtial(AC-3) active data is  use IEC 60958 subframes, i.e. in time-slots 12 to 27,

    27 time slot is LSB of AC-3 16bits data ,  12 time slot is MSB of AC-3 16bits data ,

    i2s out in i2s mode

    1) i2s stanard MSB is which time slot bit, 27 or 12,

    2) how about the left not used bit in 16bit of 32bit, just padding with zeros?


  • 0
    •  Analog Employees 
    on Dec 3, 2012 8:55 PM


    Nothing NDA there, posting is fine.

    On page 223 (rev 0) of the Hardware Guide, it shows the format of the audio ouput.  Essentially, what comes in goes out though.  It will be padded with zeros to be left or right justified as you program the output.


  • Hi,DaveD

    Thank you for your reply.

    My main puzzle is how audio sub packet bits in hdmi data island map to audio out interface?
    There are 4 audio type, I know PCM audio(no compressed audio) map to i2s and spdif. But I puzzle on how ADV7612 transmit other 3 audio packet type?
    So please give me more detail information on them. These information is useful when connect FPGA between ADV7612 and ADV7511.
    The fpga function is audio data addition process.
    The puzzle of following 3 audio will list one by one in attachment

    High-Bitrate (HBR) Audio Stream Packet

    DSD(one bit) Audio

    DST Audio Packet


  • 0
    •  Analog Employees 
    on Dec 5, 2012 1:42 AM


    The part simply deserializes whatever comes in.  The audio sample packets you show as Table 5-13 correspond to normal I2S.  The others are different packet types as defined in the HDMI specification. 

    The APX pins are the mapping to the output pins.  In I2S mode, they map to I2S channels and in the other modes, they map as specified in the hardware guides like your copy of Table 23 in the document. The formats are all MSB first as far as I'm aware (including DSD mode as you ask about).

    There isn't any further ADI documentation on these modes-- just the specification documents for HDMI and the IEC specs it references.

    Sorry I can't  be more clear here.