mirror of
https://github.com/heygen-com/hyperframes.git
synced 2026-09-03 04:38:33 +00:00
Miguel Ángel
f5f94a9495
* fix(cli): warn when a WebM render loses its requested alpha channel HyperFrames always encodes WebM with an alpha-capable pixel format (yuva420p), but some ffmpeg/libvpx builds silently emit opaque yuv420p even when handed alpha input and -pix_fmt yuva420p. The render succeeds and plays back fine, so the lost transparency is only discovered after compositing (users report shipping a solid-black clip and colorkeying it out by hand). After a WebM render, best-effort ffprobe the output's pix_fmt; if it lacks alpha, print a non-blocking warning that names the concrete remedy (--format mov / ProRes 4444). Only WebM is checked (mp4 is intentionally opaque; mov/png carry alpha through paths that don't hit libvpx-vp9), and a failed probe stays silent rather than warning speculatively. Pure decision (pixelFormatHasAlpha / webmAlphaAdvisory) unit-tested; verified end-to-end that a transparent WebM render now surfaces the warning while an MP4 render stays silent. * fix(cli): key WebM alpha check on ALPHA_MODE tag, not pix_fmt (R1 blocker) R1 (Rames/Via) correctly flagged the detection as ~100% false-positive on working builds. libvpx-vp9 stores the alpha plane in a Matroska BlockAdditional sidecar, so ffprobe ALWAYS reports pix_fmt=yuv420p for a correct transparent WebM (per docs/guides/rendering.mdx #1823 and the webm-concat-copy smoke test). The real signal is the stream-level ALPHA_MODE=1 tag: a working encode writes it; a build that can't emit the sidecar omits it and produces genuinely opaque output. Re-cut the probe to read stream_tags=alpha_mode (JSON, case-insensitive) and warn only when a probed WebM lacks ALPHA_MODE=1. Tests inverted accordingly (alphaMode:true → silent; alphaMode:false → warn). Verified end-to-end: a transparent webm render on an alpha-preserving build (ALPHA_MODE=1) now emits 0 warnings; previously it warned on every webm.