Issue Description
When attempting to configure a custom audio bitrate of 192 kbps via private parameters, the setting fails to take effect. The actual audio transmission bitrate remains unchanged despite the updated configuration.
Platform and SDK Context
Platform: Windows
Codec & Audio Module: HEAAC 78 Codec (Agora RTC SDK)
Error Message
No explicit error code or system exception is thrown by the SDK. The configuration attempt is silently ignored, and the system continues running with default bitrate parameters.
Root Cause Analysis
This issue occurs due to a codec parameter limitation within the audio processing pipeline. The current implementation of the HEAAC 78 codec does not support dynamic override or direct allocation of a custom bitrate up to 192 kbps. Any custom bitrate parameters passed to the engine are ignored when HEAAC 78 is active.
Solution and Resolution Steps
Switch Audio Encoding Codec to Opus
Reconfigure the audio pipeline settings to use the Opus codec instead of HEAAC 78. Opus fully supports custom high-bitrate configurations up to 192 kbps.
Apply Custom Bitrate Configuration
Once the active codec is set to Opus, re-apply the desired 192 kbps bitrate setting through your audio profile or private parameter configuration to confirm it takes effect.
Track Internal Fixes and Releases
Agora internal tracking (reference: CSD-76991, PR #14080) indicates planned enhancements for HEAAC codec parameter mapping. Monitor future SDK release notes if HEAAC 78 support is strictly required for your integration.
Prevention and Best Practice
Validate Codec Capabilities Before Configuration: Before enforcing high-bitrate audio profiles (such as 192 kbps for high-fidelity music or broadcasting), ensure the selected audio codec explicitly supports the targeted bitrate range.
Standardize on Opus for Custom Audio Profiles: Use Opus as the default choice for scenarios requiring flexible, high-bitrate audio tuning across desktop platforms.