A source that answers with a JSON error body still reached ffprobe and
produced `moov atom not found`. Replicate returns
`{"detail": "requested file not found"}` for a dead asset, and a gateway
in front of it can relay that body with a success status.
The sniff now treats `<`, `{`, or `[` as the opening byte of a text
document. No supported container starts with any of them, so this is the
same trade as before: three bytes instead of an allowlist that grows one
entry per payload shape observed in production.
Renamed accordingly, since the class now covers JSON as well as markup:
MARKUP_NOT_MEDIA -> NOT_MEDIA_PAYLOAD, MarkupNotMediaError ->
NotMediaPayloadError, markupPayload.ts -> notMediaPayload.ts. Registry
entries in the Lambda name map, the CDK and SAM plan lists, the Cloud Run
set, and SAFE_RENDER_ERROR_CODES move with it.
Also documents the reachability boundary on the error class: only a 2xx
response gets here. `downloadToTemp` rejects 404/410 as `http_not_found`
before writing a byte, and every ffprobe input is local because
videoFrameExtractor downloads http srcs first. So the shapes this
classifies are soft-404 and interstitial HTML, S3/CloudFront error
documents, and JSON API error bodies -- each served with a success
status. A genuine 404 surfaces as a download failure, not as this error.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Review follow-up on the STUDIO-5433 defense.
Correctness
- The sniff ran above the documented video/audio failure split, so an
<audio> src that resolved to an HTML payload aborted the whole render
instead of degrading to duration 0. It now runs inside the same try, so
video surfaces the typed error while audio still drops out, with a
warning naming the element.
- Raw fs errors (EISDIR on a directory src, EACCES, the existsSync->open
ENOENT race, EMFILE) escaped and failed the compile with an unclassified
error carrying an unredacted temp path. The sniff is now a classifier that
never throws: an unreadable file reports "not markup" and the real probe
produces the real error.
- Elements whose duration the compiler never resolves (a data-end video, a
looping audio) skipped the sniff entirely, so the original ffprobe error
still escaped, and looping audio was reported as owner "system" after
every frame had been captured. Video is now caught in the asset preflight,
which sees every local src regardless of authored timing; audio is
classified per-element in audioMixer as source/invalid_media/owner "user",
keeping audio failures non-fatal as they already were.
- Detection is a byte-level check for a leading "<" (BOM-, whitespace- and
NUL-tolerant, looped read) instead of a <!doctype|<html|<?xml string
prefix, which missed a NUL-prefixed payload, >256B of leading whitespace,
UTF-16-encoded HTML, and a prolog-less <svg. No supported container starts
with "<", so the allowlist no longer grows per payload shape.
- finally { await fh.close() } could replace the in-flight typed error with
the close error.
Routing and privacy
- MARKUP_NOT_MEDIA is now in SAFE_RENDER_ERROR_CODES, the Lambda terminal
name map, the CDK and SAM non-retryable plan lists, and the Cloud Run
non-retryable set, and the class carries owner/retryable. Previously the
API emitted errorCode: undefined and a deterministic authoring bug burned
the full distributed retry budget.
- The message no longer carries 32 raw payload bytes or the src.
redactTelemetryString preserves host and path for HTTP srcs, so
per-tenant CDN paths reached a message the server forwards to clients.
Correlation is a sha256 element fingerprint, matching
AssetMediaTypeMismatchError.
- The message names both causes (unresolved nested-composition URL, or an
HTML/XML error page served as 200) rather than misdiagnosing an S3 403
body as an authoring bug.
Tests
- Byte-level detection is unit-tested in engine: markup shapes, BOMs,
UTF-16, nine container signatures, unreadable inputs.
- Replaced the tautological assertions. The old checks for "html" in and
"moov" absent from a fixed message template could not fail for any input.
- New coverage for audio degradation, the audioMixer classification, the
preflight video/image/audio split, and the API error metadata.
- The sibling htmlCompiler.mediaType failure was a vitest-under-bun runner
mismatch, not a missing ffmpeg binary. It passes, including the 4-wide
probe-semaphore invariant the sniff now runs inside.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
## What
- enforce a finite, validated `meta/videos.json` contract shared by Plan v1 and Plan v2
- preserve authored finite ends and source-derived trim-aware ends; bound any still-open end at the validated composition end
- fail distributed planning when any declared video source did not extract instead of publishing a blank-capable plan
- make the v1 chunk reader reject malformed/null video timing before frame injection
- route deterministic video-source/metadata failures as non-retryable in AWS and GCP while retaining retries for transient extraction failures
## Why
An open-ended video whose remote source could not be resolved retained `Infinity` through planning. Plan v2 correctly rejected that value, while Plan v1 serialized it as `null`; the v1 frame lookup could then suppress injected frames and silently produce incorrect output.
The invariant belongs at the shared metadata boundary. Both protocols must receive identical finite timing, and unavailable sources must fail closed before plan publication.
## Test plan
- [x] producer distributed planning, metadata, v1 chunk boundary, Plan v2 conversion/materialization, and public exports
- [x] core runtime media semantics (authored slots, natural duration, looping, non-looping hold)
- [x] engine video extraction and frame lookup
- [x] AWS Lambda/CDK/SAM and GCP Cloud Run error normalization/retry classification
- [x] producer, core, engine, AWS, and GCP typechecks/builds
- [x] formatting, oxlint, tracked-artifact, fallow, and commit hooks
- [x] exact incident composition replayed through the AWS Lambda handler's Lambda-local path in a Lambda-like container; Plan v1 and Plan v2 both fail closed as `VIDEO_SOURCE_UNRENDERABLE` during planning, before plan publication
- [x] full PR CI, including all nine regression shards and Windows render/tests
No production flags or deployment/release workflows are changed.
* feat(lambda): add SAM template and sample events for AWS deployment
Phase 6.2 of the distributed rendering plan (DISTRIBUTED-RENDERING-PLAN.md
§15). Reference SAM template for deploying HyperFrames distributed
rendering on AWS — one Lambda function in three roles, choreographed by
a Step Functions standard workflow with a Map state for parallel chunk
rendering.
Resources created by the template:
- Lambda function pointing at the Phase 6.1 ZIP
- Step Functions state machine: Plan -> Map(N) RenderChunk -> Assemble
- S3 bucket for plan tarballs, chunk outputs, final mp4
- IAM role for the state machine
- CloudWatch alarm guarding against runaway chunk invocations
Retry policy: 4 attempts, 2s initial, 2x backoff, max 60s, with the
typed non-retryable error codes from plan §9.3 explicitly opted out.
CodeUri points at packages/aws-lambda/dist/handler.zip; sam deploy
resolves the local path and uploads to a SAM-managed bucket on first
deploy.
Validated: sam validate --lint passes against the template.
This is part of the 8-PR Phase 6 stack; PR 6.2 of 8.
* fix(lambda): address PR 879 review feedback
- Add CloudWatch alarms for Lambda Errors metric (5min window, threshold 1)
and Step Functions ExecutionsFailed metric. The existing runaway-
invocations alarm catches too-many-calls but missed silent per-chunk
failures and retry-exhaustion.
- Document VersioningConfiguration: Suspended tradeoff inline. Adopters
treating the final mp4 as user-keepable should bump to Enabled.
- Cost-allocation Tags on RenderBucket + Lambda Globals.
- Lambda Tracing: Active so X-Ray spans don't terminate at the SF→Lambda
boundary (the state machine already had tracing).
- State-machine top-level TimeoutSeconds: 3600 as defensive ceiling on
the whole choreography — catches Plan-retry storms before they hit
individual task budgets.
- AssertChunkCount Choice state: if Plan ever returns ChunkCount=0 the
Map would silently iterate zero times and Assemble would receive an
empty ChunkS3Uris[] producing an empty output. Fail-fast with typed
PLAN_TOO_LARGE error instead.
- Architecture comment: explicit x86_64-only constraint from
@sparticuz/chromium so adopters trying Graviton don't get bitten.
* docs(lambda): drop internal plan-doc refs from SAM example + template
