gwutilz/gwencoder/docs/reference/DEFAULTS_COMPARISON.md

Defaults Comparison: Tdarr vs GWEncoder

⚠️ UPDATE: Default Transcoding Behavior

GWEncoder Default Behavior (Updated):

• ✅ All codecs EXCEPT AV1 are transcoded by default (H.264, HEVC, VP8, VP9, etc.)
• ⏭️ AV1 files are skipped by default (use --force or --force-transcode to transcode them)
• 🔄 HEVC files are now transcoded by default (SkipHEVC default changed from true to false)

This differs from Tdarr's behavior where HEVC files are skipped by default.

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Defaults Comparison: Tdarr vs GWEncoder

AV1 Advanced Parameters

Parameter	Tdarr Default	GWEncoder Default	Match
CRF	29	29	✅
Preset	10	10	✅
Tune	0 (VQ)	0 (VQ)	✅
SCD (Scene Change Detection)	1 (enabled)	true (enabled)	✅
AQ Mode (Adaptive Quantization)	2 (DeltaQ)	2 (DeltaQ)	✅
Lookahead	-1 (auto)	-1 (auto)	✅
Enable TF (Temporal Filtering)	1 (enabled)	true (enabled)	✅
Threads	0 (auto)	0 (auto)	✅
Keyint	-2	-2	✅
Maxrate Cap	0 (unlimited)	0 (unlimited)	✅
Resolution CRF Adjust	enabled	true	✅
Force Transcode	false	false	✅

Result: ✅ All AV1 defaults match

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Audio Standardization

Parameter	Tdarr Default	GWEncoder Default	Match
Codec	"aac"	"opus"	❌ MISMATCH
Skip If Compatible	"true"	true	✅
Bitrate Per Channel	"80"	80	✅
Stereo Bitrate	"160"	160	✅
Channel Mode	"preserve"	"preserve"	✅
Create Downmix	"false"	false	✅
Downmix Single Track	"false"	false	✅
Force Transcode	"false"	false	✅
Opus Application	"audio"	"audio"	✅
Opus VBR	"on"	"on"	✅
Quality Preset	"custom"	"custom"	✅

Result: ❌ One mismatch - Codec default

Issue:

• Tdarr defaults to AAC
• GWEncoder defaults to Opus

Reason for GWEncoder choice:

• GWEncoder uses container-based codec selection by default
• Opus is used for MKV/WEBM (most modes)
• AAC is used for MP4 (when needed)
• This provides better compression while maintaining compatibility

Recommendation:

• GWEncoder's approach is more flexible (container-aware)
• If exact Tdarr parity is needed, default should be "aac"
• Current behavior is intentional for better compression

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Stream Reordering

Parameter	Tdarr Default	GWEncoder Default	Match
Include Audio	"Yes" (true)	true	✅
Include Subtitles	"Yes" (true)	true	✅
Standardize To SRT	"Yes" (true)	true	✅
Extract Subtitles	"No" (false)	false	✅
Remove After Extract	"No" (false)	false	✅
Skip Commentary	"Yes" (true)	true	✅
Custom Language Codes	"eng,en,english,en-us,en-gb,en-ca,en-au"	["eng", "en", "english", "en-us", "en-gb", "en-ca", "en-au"]	✅
Use CC Extractor	"No" (false)	false	✅
Embed Extracted CC	"No" (false)	false	✅

Result: ✅ All stream reordering defaults match

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Summary

✅ Matches (2/3 categories)

• AV1 Advanced Parameters: 100% match
• Stream Reordering: 100% match

❌ Mismatch (1/3 categories)

• Audio Standardization: 1 mismatch (codec default)

Overall: 95% Match

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Recommendation

The only difference is the audio codec default:

• Tdarr: Always defaults to AAC
• GWEncoder: Defaults to Opus (with container-aware fallback to AAC for MP4)

Options:

1. Keep current behavior (recommended) - Better compression, container-aware
2. Change to match Tdarr - Default to AAC for exact parity

Current behavior is intentional because:

• Opus provides better compression (smaller files)
• GWEncoder automatically uses AAC for MP4 containers (compatibility)
• This provides the best of both worlds

If exact Tdarr parity is required, change encoding/audio.go:

// Change from:
Codec: "opus",

// To:
Codec: "aac",