gramps
dd51f7842a
The last resilience slice. When a drop ends the broadcast, YouTube cannot resume it, so the only way
back is a new one — and that is what the app now offers, in one click.
- `Services/BroadcastTitle.cs` — the resume marker is applied to the title the show was using, and any
existing marker is REPLACED rather than stacked ("Show (resumed)" → "Show (resumed 2)"), with the base
truncated so the whole title fits YouTube's 100-character limit. Otherwise a channel grows two
identically named videos and the creator has to explain it.
- `MainViewModel.BackOnAirCommand` — reuses the ordinary go-live path with the saved details and the
cached stream: new broadcast, new VOD, no dialog. It appears only after a drop ended the session and
the ordinary start button steps aside, so there is exactly one way forward.
- The running line goes red OFF AIR (not amber) in that state; the button reads "● Back on air".
Tests: `BackOnAirTests` — first re-air marks the title, a second drop counts instead of stacking, the
100-character limit holds, an empty title still works, and the post-drop state exposes exactly one
start affordance. FAST gate: 552 passed, 0 failed, 0 warnings.
TASK 32 is now complete: fragmented MP4, blip retry, poll-driven RECONNECTING, ingest pre-flight, Back
on air.
5.9 KiB
TASK 32 — Stream resilience (queued 2026-09-01 — merges the orphaned TASK 2 resume clause into the pills/signs architecture)
Catalog:
TASKS.md— status and requirements live here.
Goal: a dropped stream heals itself when physically possible, tells the truth when it isn't, and gets the creator back on air in one click. The ON-AIR sign + primary button in the top bar are the surface — they already mean "reality" (pills = intent, lights = reality, TASK 18/30); reality just isn't two-state. Resumption of a completed broadcast is explicitly out of scope (impossible via the API — creator ruling 2026-09-01): no lying in the copy.
Slices (one integration test each, in order):
-
✅ Blip retry (shipped 2026-11-05) — app-side encoder restart: push dies while live (ProcessFailed / stdin backpressure death) → bounded-backoff relaunch (2s/5s/10s, N attempts) against the cached constant reusable-stream ingest URL. Success = push running again while the broadcast is still live; viewers never know. Fixes the map's stale "ffmpeg does reconnect" claim (corrected 2026-09-01: reconnect flags are input-side only). Test: fake process fails once then starts → pump recovers without surfacing to the VM. Shipped:
Services/StreamRetryPolicy.cs(immediate, +1 s, +2 s, +3 s — minimum waits, because YouTube's grace is short),Services/StreamRecovery.cs(the loop, with the audio pipe recreated per attempt because its single-instance server is unusable after the old client died), andFramePump.EncoderFailedseparating a dead push (recoverable) from a fatal pump fault. Each episode reports into the left panel's alert stack; a reconnect that lands on a complete broadcast is reported as such instead of showing a live sign over a dead stream. Tests:StreamRecoveryTests. -
🔶 Poll-driven sign — NO invented countdown (spec revised 2026-11-05, creator challenge: "I really don't think that's going to be a constant — it's going to depend on so many variables, some that are dark to us"). The original plan was a measured grace constant and a countdown to YouTube's cutoff. Dropped: YouTube's cutoff is server-side and depends on things we cannot observe (ingest node health, prior stream quality, region, load), so any pinned number is a guess wearing a timer. What ships instead:
- Amber RECONNECTING in the top bar, with measured facts only: elapsed time and attempt count ("RECONNECTING · 0:12 · attempt 2 of 4"). No countdown.
- The status poll speeds up while recovering (30 s → ~4 s) and drives the truth. Signals used,
cheapest first:
liveBroadcasts.liststatus.lifeCycleStatus(authoritativecomplete),liveStreams.liststatus.streamStatus/healthStatus(is the push being received), and thechatEndedEventYouTube already puts in the chat feed we poll — free, and previously skipped. - At
complete: red OFF AIR, stop retrying, and (slice 3) offer Back on air. Test: a fake status provider drives the sign through live → reconnecting → off air; achatEndedEventtriggers an immediate status check rather than a decision of its own.
-
✅ One-click Back on air (shipped 2026-11-05) — the relabeled button fires the existing go-live path with saved
Broadcast.*+ cached stream, dialog skipped: new broadcast, new VOD (accepted cost, stated in-product). Test: seeded saved form + fake stream service → click creates + pushes, no dialog. Shipped:Services/BroadcastTitle.cs(pure — resume marker replaces rather than stacks, base truncated to YouTube's 100 characters) andMainViewModel.BackOnAirCommand, which reuses the ordinary go-live path with the saved details and the cached stream: new broadcast, new VOD, no dialog. The button appears only after a drop ended the session, in place of the normal start button, and the ordinary start button steps aside so there is exactly one way forward. Tests:BackOnAirTests. -
✅ Crash-safe recording (shipped 2026-11-05) — fragmented MP4 on the record block (
-movflags frag_keyframe+empty_moov+default_base_moof): plain MP4's trailing moov atom means a power loss kills the WHOLE file. Rename-on-stop unchanged. Closes the TASK 18 "MKV as an option" design-note remnant (fragmented MP4 chosen over MKV: single container, YouTube-upload-native — verify player/ editor tolerance, cite the research). Test:Args_RecordBlock_IsFragmentedMp4_SoACrashKeepsTheFile— the flags are on the record block and absent from the streaming block. Verified by construction only: the file still needs one real interrupted-take check on Windows (kill ffmpeg mid-recording, play the result). -
✅ Pre-flight (shipped 2026-11-05) — before broadcast insert, one TCP probe to the ingest host:1935 (~2s timeout). Unreachable → Error toast, no insert, no ghost broadcast ("check VPN/network"). The "forgot the VPN" story, solved as prevention instead of recovery. Test: fake probe failure aborts go-live before any API call. Shipped:
Services/IngestProbe.cs(IIngestProbe+TcpIngestProbe, 2 s timeout, rtmp→1935 / rtmps→443) andMainViewModel.IngestPreflightAsync, called BEFORE the first API call whenever a cached ingest URL exists (first run probes after resolving the stream, still before any broadcast is created). Tests:IngestPreflightTests— unreachable aborts, reachable continues, and the probe is exercised against real sockets (a listening port answers true, the same port closed answers false quickly).
Design decisions
- The sign is the status, the button is the action — no new chrome, no log lines, no spinners.
- Honest windows: countdown = observed grace; at zero we say OFF AIR, we don't pretend to reconnect.
- Why us > incumbents: constant reusable stream + persisted form make retry/restart cheap; OBS shows a reconnecting log line and Streamlabs silently dies.