The OGG-FLAC specification requires that each audio data packet contains
one complete FLAC frame. The previous implementation was bundling multiple
FLAC frames into a single OGG page, which caused decode errors in strict
decoders like ffplay/ffmpeg (though VLC was tolerant enough to play it).
Changes:
- Modified broadcast_ogg_flac_stream() to process FLAC frames one at a time
- Each FLAC frame is now wrapped in its own OGG page (per spec)
- Granule position is updated per frame (cumulative sample count)
- Added garbage data detection and skipping
This fixes decode errors while maintaining compatibility with all players.
Ref: https://xiph.org/flac/ogg_mapping.html
"Each audio data packet contains one complete FLAC frame"
Both StreamingFlacSink and StreamingOggFlacSink had duplicate FLAC frame
detection logic. The OGG-FLAC sink had the improved validation, but the
regular FLAC sink was still using the old unvalidated detection.
Changes:
- Created new module: pmoaudio-ext/src/sinks/flac_frame_utils.rs
* parse_flac_block_size() - comprehensive frame header validation
* find_complete_frames_boundary() - for regular FLAC streaming
* find_complete_frames_with_samples() - for OGG-FLAC with granule tracking
* Includes unit tests for validation
- Updated streaming_ogg_flac_sink.rs:
* Removed duplicate functions
* Now uses shared flac_frame_utils module
- Updated streaming_flac_sink.rs:
* Removed old unvalidated find_complete_frames_boundary()
* Now uses shared flac_frame_utils with improved validation
* Benefits from same false positive prevention as OGG-FLAC
- Updated mod.rs to include flac_frame_utils module
Result: Both FLAC and OGG-FLAC streams now use the same comprehensive
frame header validation to prevent false positive sync code detection.
The OGG-FLAC stream was producing decode errors in ffplay/ffmpeg due to
false positive sync code detection. The sync pattern 0xFF 0xF8-0xFE can
appear randomly in compressed audio data, causing invalid frame boundaries.
Changes:
- Enhanced parse_flac_block_size() with comprehensive FLAC frame header validation:
* Reserved bit validation (must be 0)
* Sample rate code validation (0x0F is invalid)
* Channel assignment validation (0x0B-0x0F are reserved)
* Bits per sample validation (0x03 and 0x07 are reserved)
- Fixed frame detection loop to only add validated sync codes to the list
(previously added candidates before validation)
- Removed verbose diagnostic logging
Result: OGG-FLAC stream now decodes correctly in ffplay/ffmpeg without
any 'invalid sync code' or 'invalid frame header' errors.
Tested with: ffmpeg -v error -i http://localhost:8080/test/stream-ogg -f null -
- Added extract_sample_rate_from_streaminfo() to parse STREAMINFO block
- Added debug logs to track frame boundary detection
- Granule position tracking with add_samples()
Problem persists: No OGG pages are broadcast after headers. The condition
'boundary >= 4096 && samples_in_frames > 0' is never satisfied, meaning
frame detection is failing.
Root cause unclear - need deeper investigation of:
1. Why find_complete_frames_with_samples() returns (0, 0)
2. Whether FLAC sync codes are being detected at all
3. If there's an issue with how FLAC encoder outputs data
