How to encode FOA or 7.1.4 format with a specified total bitrate of xx kbps？

[bubing]

How to encode FOA or 7.1.4 format with a specified total bitrate of xx kbps (assuming Opus is used)? And how to verify that the encoded IAMF file has a bitrate of xx kbps?

[jwcullen]

We have template files for Opus FOA and Opus 7.1.4. These are preconfigured with target_bitrate_per_channel: 64000. This value represents the bitrate per audio channel in bits per second.

Effectively the templates result in an overall bitrate of:

FOA (4 channels): 4 channels * 64000 = 256000 bits / sec
7.1.4 (12 channels): 12 channels * 64000 = 768000 bits / sec

If you want a different overall bitrate, you can change target_bitrate_per_channel before encoding an IAMF file.