Bluetooth SIG Request for Information

Date of RFI: 23 September 2024
Deadline of RFI Response: 30 November 2024

The Bluetooth SIG is a global community of over 40,000 companies that unifies, harmonizes, and drives innovation in the vast range of connected devices all around us. Through collective creation and shared technical standards, Bluetooth® technology simplifies, secures, and enriches the technology experience of users worldwide.

The Bluetooth SIG is working on enhancing support for both high-resolution and lossless audio within LE Audio. This project’s scope includes giving our members access to high-resolution and/or lossless audio codecs.

This Request for Information (RFI) is to understand high-resolution and/or lossless codecs that could be contributed and under what terms licenses to these codecs will be offered. It is anticipated this RFI provides the Bluetooth SIG with information that enables a future Request for Proposal (RFP). Responding to this RFI does not imply a commitment to contribute a high resolution or lossless codec.

The list below describes High Resolution Audio codec requirements. RFI responses should meet as many of the following requirements as possible.

High Resolution Audio Codec Requirements:

1. The supported sample rates shall include 96 kHz
2. The supported bits per sample shall include 24 bits
3. The Total Harmonic Distortion Plus Noise (THD+N) value of the codec shall be no worse than -115 dB when using 24 bits per sample for a full-scale 1 kHz sinusoid signal at 96 kHz sample rate
4. The codec shall include support for 7.5 ms and 10 ms frame durations

Selection Criteria for a High-Resolution Codec that meets the above Requirements:

1. Bitrate of operation
2. The codec should have Hi-Res certification, or be able to achieve Hi-Res certification, from the Japan Audio Society (JAS)
3. Weighted million operations per second (WMOPS) per frame, for encoding and decoding
4. Packet loss resilience and recovery e.g., interframe dependency.
5. Total latency for encoding and decoding
6. Support for seamless adaptive bit rate (ABR)

The list below describes Lossless Audio codec requirements. RFI responses should meet as many of the following requirements as possible.

Lossless Audio Codec Requirements:

1. The codec audio output shall be bit exact to the audio input for all bits up to the bit depth. For example, all 16 bits or all 24 bits should match exactly
2. The codec shall include audio input at the sample rate of 44.1 kHz and 48 kHz, with other values allowed
3. The codec shall support audio inputs at 16 bits or higher
4. The codec shall support frame duration ranging from 7.5 ms to 90 ms

Selection Criteria for a Lossless Codec:

1. Weighted million operations per second (WMOPS) per frame, for encoding and decoding
2. Bitrate of operation
3. Packet loss resilience and recovery e.g., interframe dependency.
4. Total latency for encoding and decoding

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FAQ

Are there guidelines for how WMOPS should be measured? Or further clarification on the #7 High Resolution codec and #5 for Lossless Coded from the attached RFI document.

No specific guidelines currently defined on how WMOPS should be measured. We are planning to define this as part of codec selection criteria.

Can RFI responder provide Terms and Conditions in their response?

Please add any T&Cs that are appropriate for the RFI.

Is the RFI response governed under the terms of the Bluetooth SIG contracts?

The RFI is not governed under the terms of the Bluetooth SIG contracts.

Is the requirement for the high-res and lossless codec to support a frame size of exactly 7.5ms or approximately 7.5ms?

High-Res recommends a range from 2.5 ms to 10 ms. Within that range it specifically requires exactly 7.5 ms and exactly 10 ms. Lossless can accept a frame duration within a range.