4 Replies Latest reply on Jun 10, 2019 11:31 PM by AnjanaM_61

    What AVK audio receiving timeout should we set?

    swlic_3187821

      Hi experts,

       

          We are using Linux BSA_Server to implement BT Sink function. Application layer uses UIPC_Open(tUIPC_RVC_CBACK) to receive AVK PCM/AAC data from BSA_Server.

          The question is: what AVK audio receiving timeout should we set?  It also means how big of intermediate buffer should we use before sending the audio data to audio ALSA interface. We notice the receiving of most of the audio package is timely and stable. But some packages may arrive application layer with a significant delay, some one may be lost. We guess it may be due to interference and audio package re-transmission. 

          We want to make sure that all the audio packages arriving device end before Bluetooth A2DP timeout can be played out normally.

           What's the application layer audio receiving timeout should we set?

         Thanks very much for your time!

       

      Jevon

        • 1. Re: What AVK audio receiving timeout should we set?
          VinayakS_26

          Hi,

           

          BSA is not supported in the broad market.

          For BSA access, reach out to your local Cypress Sales team and they can request BSA access through their internal channels.

           

          Regards,

          Vinayak

          • 2. Re: What AVK audio receiving timeout should we set?
            AnjanaM_61
            Hello,

            Regarding to the timeout which you mentioned in the problem description,
            >>what AVK audio receiving timeout should we set?
            >>We want to make sure that all the audio packages arriving device end before Bluetooth A2DP timeout can be played out normally.
            Please make detail descriptions on the "AVK audio receiving timeout" and "Bluetooth A2DP timeout" 
            Also you mentioned "AVK PCM/AAC",
            PCM:
            app_avk_uipc_cback() will receive PCM format when the SBC codec is used.
            AAC:
            app_avk_uipc_cback() will receive AAC format and you have to add AAC decoder to convert the audio data to PCM.
            (you will have to add the decoder when you want to support other coding format for Audio) 
            intermediate buffer: do you want to buffer the PCM format? mainly it will be depend on how much/long interference/re-transmission you want to buffer.

            Thanks,

            Anjana

            • 3. Re: What AVK audio receiving timeout should we set?
              swlic_3187821

              Hi Anjana,

               

                 Thanks very much for your reply.

                 I want describe what we are concern first. When we have a long time to log app_avk_uipc_cback().

                 We found the invocation time points of this function are not stable. Most of the time the interval between two invocation is small, but sometimes it may reach more than 100ms. When the interval is small, we guess the transmission of this package is successful and has no re-transmission. If the interval is big, we guess this audio package is re-transmission at the final time before A2DP audio timeout. Is it right and reasonable?

                 If yes, we need to have an intermediate buffer to cover the A2DP re-transmission timeout which make sure the final successful re-transmitted package before timeout can be put into AlSA buffer.

                 So my question is what's the A2DP audio re-transmission timeout? and What is the size of intermediate buffer should we set?

               

              Jevon

              • 4. Re: What AVK audio receiving timeout should we set?
                AnjanaM_61

                >>Most of the time the interval between two invocation is small, but sometimes it may reach more than 100ms.

                >>If the interval is big, we guess this audio package is re-transmission at the final time before A2DP audio timeout.

                >>Is it right and reasonable?

                Yes. Need the air capture to see what is happening to be exact.

                A2DP audio timeout - I don't understand what timeout it is. Please make more description.

                 

                >>So my question is what's the A2DP audio re-transmission timeout? and What is the size of intermediate buffer should we set?

                If you want to make a "intermediate buffer"

                - the buffer size may vary depending on the duration and how much audio data to buffer.

                - there is no a fixed number of the intermediate buffer size, and it is application dependent.

                A2DP audio re-transmission timeout - what do you mean this timeout? Please make more description.

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