Go backend:
- Add AudioCodec field to DownloadResult and DownloadResponse
- Extension download results can now include audio_codec/audioCodec
- ffmpegGetInfo and probeAudioQuality now return codec field
- Add trackItemBytes option to file.download() for custom progress handling
Flutter:
- Check audio_codec before container conversion
- Skip FLAC conversion if source codec is lossy (AAC, MP3, Opus, etc.)
- Prevents fake upscale from lossy to lossless containers
- Extract _formatDownloadProgressLabel() for cleaner code
- Show received/total size when bytesTotal is available
- Estimate total size from progress when only bytesReceived is known
- Add text overflow handling with ellipsis
New lyrics providers using Paxsenix API:
- Spotify: Synced lyrics from Spotify
- Deezer: Synced lyrics from Deezer
- YouTube: Lyrics from YouTube
- Kugou: Lyrics from Kugou (Chinese service)
- Genius: Plain text lyrics from Genius
Implementation:
- Add lyrics client implementations for all providers
- Smart search result scoring based on track name, artist, and duration
- Support for both synced (LRC) and unsynced lyrics formats
- Fallback search with simplified track names and primary artist
UI updates:
- Add provider entries to lyrics priority settings page
- Add display names for new providers in settings
FFmpeg doesn't always embed lyrics correctly to MP3 files. This adds
manual ID3v2.3 USLT (Unsynchronized Lyrics) frame writing after FFmpeg
metadata embedding to ensure lyrics are properly stored.
Implementation:
- Extract lyrics from metadata (UNSYNCEDLYRICS or LYRICS key)
- Build ID3v2.3 compliant USLT frame with UTF-16LE encoding
- Insert or replace USLT frame in existing ID3v2.3 tag
- Create new ID3v2.3 tag if file has no ID3 header
- Skip gracefully for unsupported ID3 versions or flags
Also includes minor audio analysis improvements:
- Consistent dynamic range calculation (peak - rms)
- Filter out 'unknown' and 'n/a' labels
- Add -vn -sn -dn flags for more robust stream selection
Audio Analysis Enhancements:
- Display codec name and container format
- Show decoded sample format (s16, s32, fltp, etc.)
- Add LUFS integrated loudness measurement (broadcast standard)
- Add true peak measurement (dBTP)
- Detect and count clipping samples per channel
- Estimate spectral cutoff frequency (helps detect fake upscales)
- Show per-channel statistics (Peak, RMS, DR, Clip count)
UI Improvements:
- MetricChip now handles long text with ellipsis
- Constrained max width for better layout
Cache version bumped to 4 to force rescan with new metrics.
Zarz Eleutherius