ImmichI
Immich4mo ago
2 replies
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Casting / Playback Failures & Encoding Cache

Issue: Casting Failures and Transcode Cache Growth


1. Casting / Playback Failures

Some 4K videos cast fine, while others buffer every 2–3 seconds. The confusing part is that lower-bitrate files sometimes fail while higher-bitrate files play correctly.

What I observed

- ✅ Plays: HEVC Main10, bt709, clean CFR 59.94.
- ❌ Buffers: H.264 High or HEVC HDR10 (bt2020/smpte2084), sometimes variable framerate (~58.5 fps).
- When Immich transcodes:
- ffmpeg runs with Intel Quick Sync (QSV).
- Output is an uncapped CRF 4K60 stream which can still overwhelm Wi-Fi or the cast device.
- Tried adjustments:
- Advanced settings (B-frames 0, GOP 60, keyframe interval 60).
- Forced bitrate caps (10–20 Mbps).
- Lowered resolution (1080p).
- → Playback still inconsistent.

Question: How should Immich handle HDR/VFR files for reliable casting without forcing me to downscale or re-encode my entire library?

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2. Encoded Video Cache / Storage Growth

- Originals: ~3 TB.
- Immich encoded-video cache already: ~600 GB.
- ~5,400 jobs queued > cache could add 1–2 TB more, nearly doubling total storage.

Concerns

- I don’t want pre-transcoding of the entire library if I can simply trancsode and cast appropriately.

Question: What is the recommended way to disable/prevent massive background transcode jobs and have Immich only generate and store on-demand playback copies? Is this a bad idea? I do have a pretty diverse library.

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Summary

Two main issues:
1. Casting fails inconsistently (likely HDR/VFR handling, not just bitrate).
2. Encoded cache is ballooning storage usage, so I'm wondering if its even worth doing once casting is fixed? Or maybe I just don't do this and get a device that can handle all formats and plug it in with an HDMI.

Looking for guidance on best practices/configuration to solve both.
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