Additional Sample Format for USB Audio Streaming in usb_device_uac (AEGHB-1139)

[Schuwi]

Description

This PR addresses several issues and improvements in the usb_host_uac library:

1. Fix build failure when no microphone/speaker channel is configured:

   • Resolved compilation errors that occurred when UAC_MIC_CHANNEL_NUM or UAC_SPK_CHANNEL_NUM were set to 0.

2. Add configurable sample format:

   • Introduced support for floating-point precision in audio streaming, enabling higher data precision beyond 16-bit PCM.
   • The library now supports two sample formats: 16-bit PCM and floating-point precision. Supporting arbitrary data sizes would require more extensive API changes.

3. Fix mixup of TX/RX, IN/OUT:

   • Corrected inconsistencies in naming and functionality for TX/RX and IN/OUT, reducing confusion and improving reliability during development/debugging.

These changes make it easier to stream microphone data over USB with enhanced precision and fix critical issues in the library.

Related

• No specific issue linked.
• This PR is related to debugging and development improvements for USB audio streaming.

Testing

• Tested the changes in my application with a microphone-only setup (no speaker).
• Verified that audio streaming worked correctly with the new floating-point sample format and fixed TX/RX and IN/OUT mixups.
• Confirmed that the library builds successfully and streams audio data as expected.

---

Checklist

Before submitting a Pull Request, please ensure the following:

• 🚨 This PR does not introduce breaking changes. (I don't think so, the Kconfig changes are backward-compatible)
• All CI checks (GH Actions) pass.
• Documentation is updated as needed. (Unclear)
• Tests are updated or added as necessary. (I didn't find any related tests)
• Code is well-commented, especially in complex areas.
• Git history is clean — commits are squashed to the minimum necessary.

[CLAassistant]

All committers have signed the CLA.

[github-actions]

	Fails
🚫	node failed.

Warnings

⚠️

Some issues found for the commit messages in this PR: the commit message "fix(usb_host_uac): mixup of mic/spk": summary looks too short Please fix these commit messages - here are some basic tips: follow Conventional Commits style correct format of commit message should be: <type/action>(<scope/component>): <summary>, for example fix(esp32): Fixed startup timeout issue allowed types are: change,ci,docs,feat,fix,refactor,remove,revert,test sufficiently descriptive message summary should be between 20 to 72 characters and start with upper case letter avoid Jira references in commit messages (unavailable/irrelevant for our customers) TIP: Install pre-commit hooks and run this check when committing (uses the Conventional Precommit Linter).

	Messages
📖	You might consider squashing your 4 commits (simplifying branch history).

Log

Details

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danger-results://tmp/danger-results-b19a25be.json

Generated by 🚫 dangerJS against 8afba53

[Copilot]

Pull Request Overview

This PR enhances the USB Device UAC (USB Audio Class) library with configurable sample formats and fixes critical TX/RX and IN/OUT terminology mixups. The changes enable floating-point audio precision beyond 16-bit PCM and resolve build failures when microphone or speaker channels are disabled.

• Corrected TX/RX and IN/OUT naming confusion throughout the codebase to align with USB perspective conventions
• Added configurable sample format support for both PCM (16-bit) and IEEE floating-point (32-bit) formats
• Fixed conditional compilation guards to prevent build failures when channels are set to 0

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
usb_device_uac.c	Fixed TX/RX macro confusion and added conditional guards for channel configuration
uac_descriptors.h	Added sample format macros and updated descriptor definitions to use configurable formats
uac_config.h	Added sample format configuration macros based on Kconfig settings
tusb_config_uac.h	Corrected TX/RX channel assignments, added format-specific configurations, and improved documentation
Kconfig.uac	Added new configuration choices for SPK and MIC sample formats

[Copilot]

The macro SPK_FORMAT_PCM may be undefined when neither PCM nor FLOAT is selected, leading to undefined behavior. Consider adding an #else clause with a default format or an #error directive to catch invalid configurations.

[Copilot]

The macro MIC_FORMAT_PCM may be undefined when neither PCM nor FLOAT is selected, leading to undefined behavior. Consider adding an #else clause with a default format or an #error directive to catch invalid configurations.

[Copilot]

Missing #else clause for SPK format configuration. If neither SPK_FORMAT_PCM nor SPK_FORMAT_FLOAT is defined, the RX sample configuration will be undefined, leading to compilation errors.

[Copilot]

Missing #else clause for MIC format configuration. If neither MIC_FORMAT_PCM nor MIC_FORMAT_FLOAT is defined, the TX sample configuration will be undefined, leading to compilation errors.