32 lines
1.6 KiB
Markdown
32 lines
1.6 KiB
Markdown
# ADR-0002: K-TV owns the stream via a Playout Service
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## Status
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Accepted
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## Context
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The original design proxied streaming to each provider — Jellyfin served its own HLS, local files were either served directly or transcoded individually. This made it impossible to:
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- Inject SCTE-35 markers for mid-roll breaks
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- Insert timed metadata for overlays
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- Stitch interstitial content between program items into a continuous stream
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- Guarantee consistent stream format across providers
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## Decision
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K-TV owns the stream end-to-end via a Playout Service. Providers expose a source URI (network URL or local file path) instead of a viewer-facing playback URL. The Playout Service reads from the source URI using FFmpeg on-demand (no full file download), and produces the HLS output with all audio/subtitle tracks, segmentation, SCTE-35, and timed metadata.
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## Alternatives considered
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- **Continue proxying to provider streams** — rejected because mid-roll breaks, interstitials, and overlays require playlist-level control that provider-owned streams don't offer.
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- **Download files locally then transcode** — rejected because it duplicates storage and defeats the purpose of having providers manage content.
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## Consequences
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- Provider port changes from "give me a playback URL" to "give me a source URI."
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- Every stream goes through FFmpeg — CPU cost scales with concurrent viewers. Caching segments mitigates repeat access.
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- Subtitles and audio tracks come from the source container — no separate subtitle API needed.
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- All viewers get a uniform HLS experience regardless of provider.
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- Disk space management becomes critical — HLS segments must be cleaned up.
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