Banker's Wrapped v1.5.0

Fixed

• FFmpeg OOM-kill on Railway (0 frames, encoder opened then died in ~1 s) (ffmpeg_composer.py) — libx264 auto-detects the host core count (32 on Railway), not the container's allocation, and spawned 32 thread contexts whose buffers blew past the container memory limit → SIGKILL at encoder init. Capped concurrency with -filter_complex_threads 2 and -threads 4; negligible speed impact on a ~75 s video. Also log the FFmpeg returncode on failure (137 = SIGKILL/OOM, 139 = SIGSEGV) for unambiguous diagnosis.
• Progress timer for active step (page.tsx) — each SSE event marks a step's start, but the UI treated arrival as done, so "Writing narrative script" flipped to ✅ instantly and showed no timer during the ~30 s NIM call. Now the latest-started step is active (live timer counting from its own start event) and a step is done only once a later step starts. Removed the generating_images/scripting special-casing — it falls out naturally.
• FFmpeg xfade "constant frame rate" failure on Railway (ffmpeg_composer.py) — looped image inputs (-loop 1) have an undefined rate (1/0); stricter ffmpeg builds (Railway's apt package vs. local 8.1.1) reject this with "The inputs needs to be a constant frame rate; current rate of 1/0 is invalid" → 0-frame output, pipeline failed. Fixed by setting -framerate 25 on each input and fps=25 in each scene's filter chain so xfade receives true CFR. Verified by rebuilding the failed session's B2 assets locally (avg_frame_rate=25/1).
• Browser playback "file is corrupt" (ffmpeg_composer.py) — output was H.264 High 4:4:4 / yuvj444p because seedream JPEGs are full-range 4:4:4 and the in-filter format=yuv420p did not survive xfade format negotiation. Browsers cannot decode 4:4:4 H.264 (VLC can — hence "plays locally, corrupt on web"). Forced -pix_fmt yuv420p as an explicit output option → High / 4:2:0, decodable everywhere. Added -movflags +faststart so the moov atom is at the front for progressive streaming. Regression test asserts both flags.
• Composer migrated to xfade filter_complex as the permanent path (was concat demuxer). Scene duration now auto-stretches from the probed audio length so the video always covers the full narration; -shortest trims to the exact audio end — fixes narration being cut off (~40 s) on longer scripts.
• ffprobe path resolution — deriving ffprobe from ffmpeg via a naive replace("ffmpeg","ffprobe") mangled install directories such as ffmpeg-8.1.1-full_build; now replaces only the filename. Same bug fixed in scripts/recompose.py.
• Thumbnail key extension .png → .jpg (b2_client.py) — scene 0 is a JPEG; the .png key produced a content-type mismatch and a broken share-page thumbnail.
• Progress timer double-count (page.tsx) — per-step duration was measured against the previous event, so "Generating scenes" and "Composing video" both counted the same span (the "6m30s → 5m2s" jump). Now measured forward: (next step start) − (this step start). Pipeline timer also starts on the first SSE event (safe against React batched updates that skipped length === 1).
• FFmpeg 0-frame bug (root cause of 500 on Railway) — n_total = n + 1 without a matching lavfi input caused xfade to reference non-existent [v5]; added branded ending card (dark overlay + drawtext title) as the 6th input.
• Dockerfile — added fonts-liberation so drawtext finds a system font on Debian slim.
• SSE race condition (progress.py) — frontend opens SSE before the POST creates the session; previously returned 404 immediately ("spinner hangs forever"). Now polls up to 10 s for session creation.
• SSE final event ts: 0 — terminal event now uses time.time() so per-step duration is correct for the last stage.
• Demo button — fetch("/data/synthetic/…") now has ok check + .catch() to surface errors visibly instead of silently sending a garbage blob.

Added

• scripts/recompose.py — offline tool that downloads a session's existing B2 assets and rebuilds the MP4 locally with zero API cost (no image/LLM/TTS calls). Used to isolate and prove the pixel-format fix. Supports --prefix USER_ID/SESSION_ID (paste straight from the B2 console), --ffmpeg PATH, graceful NoSuchKey messaging, and UTF-8 console output on Windows.
• Video poster thumbnail — the recap thumbnail is set as the <video poster> on both the main and share pages, so the preview frame shows instantly while the file buffers.
• Per-step latency (page.tsx + globals.css) — each completed step shows elapsed time (e.g. 44.4s, 1m 4s) from consecutive SSE timestamps. Steps container widened to 360 px; .bw-step-duration class added.
• FFMPEG_BIN config (config.py + media_agent.py) — override FFmpeg binary path via env var without rebuilding.
• README Interactive Demo Notebook section — scenario table + quickstart added before "What Is This?" so it's the first thing judges see.

Changed

• Progress UI (page.tsx) — collapsed the five per-scene rows into a single "Generating scenes + narration — X/5 scenes" sub-label; that step stays active (⏳) until composing_video fires (the generating_images event marks the start of media work). The "Uploading all artifacts" label corrected to "Saving recap video to Backblaze B2" (all pipeline/ assets are already uploaded during scene generation). Estimated-time weights retuned to a realistic ~5 min total (observed 4–7 min).

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