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| author | Ken D'Ambrosio <ken@jots.org> | 2026-06-18 22:33:09 +0000 |
|---|---|---|
| committer | Ken D'Ambrosio <ken@jots.org> | 2026-06-18 22:33:09 +0000 |
| commit | faec9c5448dfe3bbb7e187c7fb4d58557b70035d (patch) | |
| tree | ecd3d91946cc61372a76687a0a3735a59fcb3693 | |
| parent | c5ec42b2f42e285a95610f1b9b9efba4beef3d7e (diff) | |
Detect and fix non-4:2:0 chroma in H.264 MP4s during transcode
Browsers only decode H.264 4:2:0 (Baseline/Main/High). Files reported
as codec_name=h264 could still be High 4:2:2/4:4:4 profile if an
earlier transcode pass (or the source) used non-standard chroma —
ffprobe/ffmpeg read these fine, but real browsers reject them as
unsupported. update.rb now also checks pix_fmt and re-transcodes if
it isn't yuv420p/yuvj420p, and forces -pix_fmt yuv420p on output so
this can't recur.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
| -rw-r--r-- | scripts/update.rb | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/scripts/update.rb b/scripts/update.rb index 996ecbd..37cdf29 100644 --- a/scripts/update.rb +++ b/scripts/update.rb @@ -37,6 +37,7 @@ AUDIO_EXTS = %w[mp3 flac ogg wav m4a aac].freeze MEDIA_EXTS = (IMAGE_EXTS + VIDEO_EXTS + AUDIO_EXTS).freeze TRANSCODE_EXTS = %w[avi mkv mov].freeze WEB_VIDEO_CODECS = %w[h264 vp8 vp9 av1].freeze +WEB_PIX_FMTS = %w[yuv420p yuvj420p].freeze SENTINEL_FILE = '.albumen_scanned'.freeze # Explicit directory argument implies force — you asked for it, it should run. @@ -102,7 +103,8 @@ def process_dir(dir, idx, total) true elsif ext == 'mp4' || ext == 'm4v' codec = video_codec(full) - codec && !WEB_VIDEO_CODECS.include?(codec) + pix = video_pix_fmt(full) + codec && (!WEB_VIDEO_CODECS.include?(codec) || !WEB_PIX_FMTS.include?(pix)) else false end @@ -251,10 +253,21 @@ rescue StandardError nil end +def video_pix_fmt(path) + out = IO.popen( + ['ffprobe', '-v', 'quiet', '-select_streams', 'v:0', + '-show_entries', 'stream=pix_fmt', '-of', 'default=noprint_wrappers=1:nokey=1', path], + err: '/dev/null', &:read + ).strip + out.empty? ? nil : out +rescue StandardError + nil +end + def transcode_to_mp4(source, dest) system( 'ffmpeg', '-y', '-i', source, - '-c:v', 'libx264', '-crf', '23', '-preset', 'medium', + '-c:v', 'libx264', '-crf', '23', '-preset', 'medium', '-pix_fmt', 'yuv420p', '-c:a', 'aac', '-movflags', '+faststart', dest, |