* Add VPX improvements from pion-mediadevices
- Add vpx_image.go: VpxImage wrapper for vpx_image_t with convenient methods
- Move BitrateTracker to vpx package: More specific to VPX codec usage
- Add bitrate_tracker_test.go: Test coverage for VPX-specific bitrate tracking
- Remove generic codec-level BitrateTracker: Replaced by VPX-specific version
These changes improve VPX codec functionality and organization by:
1. Adding image handling utilities specific to VPX
2. Providing better bitrate tracking for VPX codecs
3. Improving code organization by moving VPX-specific code to VPX package
* Revert bitrate tracker changes
- Remove vpx-specific bitrate tracker files
- Restore original codec-level bitrate tracker and test
- Keep only the vpx_image.go addition from pion-mediadevices
* Add comprehensive unit tests for VpxImage
- Add vpx_image_test.go with full test coverage for VpxImage wrapper
- Test interface compliance and constructor behavior
- Test nil pointer handling (documents expected panic behavior)
- Test common video format constants and plane indices
- All tests pass and integrate with existing VPX test suite
This improves test coverage for the new VpxImage utility from pion-mediadevices.
* Add comprehensive unit tests for VpxImage
- Add vpx_image_test.go with full test coverage for VpxImage wrapper
- Test interface compliance and constructor behavior
- Test nil pointer handling (documents expected panic behavior)
- Test common video format constants and plane indices
- All tests pass and integrate with existing VPX test suite
This improves test coverage for the new VpxImage utility from pion-mediadevices.
Haily Nguyen