Open-AVB AVTP Pipeline SDK  1.4
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Uncompressed audio Mapping


Uncompressed audio mapping module conforming to AVB 61883-6 encapsulation.

Mapping module configuration parameters

Name Description
map_nv_item_count The number of media queue elements to hold.
map_nv_tx_rate or map_nv_tx_interval Transmit interval in frames per second. 0 = default for talker class.
The transmit rate for the mapping module should be set according to the sample rate, so that the transmit interval meets the suggested values in 1722a
  • sample rate which are multiple of 8000Hz
    • 8000 for class A
    • 4000 for class B
  • sample rate which are multiple of 44100Hz
    • 7350 for class A
    • 3675 for class B
map_nv_packing_factorHow many frames of audio to accept in one media queue item
map_nv_audio_mcr Media clock recovery,
  • 0 - No Media Clock Recovery default option
  • 1 - MCR done using AVTP timestamps
  • 2 - MCR using Clock Reference Stream


There are additional parameters that have to be set by intf module during configuration process to make everything calulated properly inside mapping. Those variables have to be set before map_gen_init_cb is being called. One of the approaches might be setting them during reading of the ini configuration and setting of the interface parameters.

Fields of a structure media_q_pub_map_uncmp_audio_info_t that have to be set during interface configuration:

Name Description
audioRate Rate of the audio avb_audio_rate_t
audioType How the data is organized - what is the data type of samples avb_audio_type_t
audioBitDepth What is the bit depth of audio avb_audio_bit_depth_t
audioChannels How many channels there are avb_audio_channels_t
sparseMode Timestamping mode avb_audio_sparse_mode_t (not used in this mapping module)

Below you can find description of how to set up those variables in interfaces

Note: If one of those fields will not be set, mapping module will not configure media queue correctly.

Note: Both the talker and listner must be configured with matching sample parameters. If the received data does not match the configured parameters on the listener, the stream will still be setup and data will still flow - but no audio will be played.