34 lines
1.7 KiB
Markdown
34 lines
1.7 KiB
Markdown
## Context
|
||
|
||
`FragmentPayload` currently stops at 16 × 1,179 bytes and the independent test client assumes ordered fragments. Native Apollo output enters count-only buffered channels, so realistic complete frames have neither a byte ceiling nor an explicit residence bound.
|
||
|
||
## Goals / Non-Goals
|
||
|
||
**Goals:**
|
||
|
||
- Implement Protocol datagram-v2 for complete encoded frames up to 1 MiB.
|
||
- Reassemble bounded duplicate/reordered QUIC datagrams independently.
|
||
- Bound native video queue count, bytes, and residence time while retaining latest-frame replacement and drop telemetry.
|
||
|
||
**Non-Goals:**
|
||
|
||
- Codec inspection, retransmission, provider fallback, generic queue/transport APIs, or Server behavior changes.
|
||
|
||
## Decisions
|
||
|
||
- Keep the existing `Frame`/QUIC path and add version-aware encode/decode rather than a second transport.
|
||
- Use one sequence per provider frame and the Protocol 1,177-byte fragment size.
|
||
- Keep the existing native video channel at 16 entries, add exact atomic byte
|
||
accounting capped at 4 MiB, and use per-entry timers for the 250 ms residence
|
||
bound. This matches the Protocol's reviewed incomplete-unit timeout and covers
|
||
bounded keyframe serialization; the transport performs a final stale check.
|
||
- Audio and events keep their independent existing limits.
|
||
|
||
## Risks / Trade-offs
|
||
|
||
- [Latest-frame eviction drops decodable dependencies] → preserve truthful drops and existing IDR feedback; never grow memory or block every session.
|
||
- [Large frames multiply fragment sends] → cap both complete bytes and fragment count before allocation.
|
||
- [Expiry races with dequeue or cleanup] → stop each package-private timer on
|
||
dequeue/replacement, serialize channel expiry and close, and retain the
|
||
transport stale check.
|