YouTube upload H.264 settings: what Sume's exact trim sets
YouTube lists H.264 High Profile, 4:2:0 and progressive scan. Sume's exact trim re-encodes with libx264 and yuv420p; profile, GOP and CABAC are not fields.
Sume's video trim in its default exact mode re-encodes with libx264 and yuv420p, which lines up with two items on YouTube's H.264 list: the codec and 4:2:0 chroma subsampling. The docs name no other encoder settings, so High Profile, two B-frames, closed GOP and CABAC are not something you set or can confirm from the trim page.
Sources: YouTube Help and Sume's video trim docs, read 2026-10-01.
What does YouTube recommend for H.264?
The page lists H.264 video, progressive scan, High Profile, 2 consecutive B frames, a closed GOP of half the frame rate, CABAC, variable bitrate and 4:2:0 chroma. It states no bitrate limit is required.
Which of those does exact trim cover?
Treat the last two rows as unknown, not as met or failed. If an upload is processed fine by YouTube, that is the practical check.
| YouTube item | What the trim docs say |
|---|---|
| H.264 codec | exact is a re-encode with libx264 |
| 4:2:0 chroma | yuv420p |
| Progressive scan | Not stated; input scan type is not addressed |
| High Profile, B-frames, closed GOP, CABAC | Not stated; no field for them |
What do I send?
The program fields are start, then exactly one of end or duration, plus optional precision, audio and output. output takes width, height (256 to 2160) and fps (24, 25, 30, 60) and works only with exact.
Anything codec-shaped is refused: a client sending vf, filter, ffmpeg, cmd, codec or crf gets ffmpeg_fields_rejected, because the server compiles ffmpeg itself. More on that in ffmpeg fields rejected.
What about the audio and the cost?
With audio left at keep, the docs say exact mode remuxes kept audio as AAC. YouTube lists AAC-LC among its accepted audio codecs. The docs list the public rate as $0.02 per job and say to confirm it live in GET /v1/catalog.
Where must the source live?
On media.sume.com. Off-host URLs are rejected with unsupported_media_source, so import the file first. The source is limited to 1800 seconds.
Sources
Related posts
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- ffmpeg_fields_rejected: why the API refuses ffmpeg flags
- YouTube moov atom and edit lists: keyframe trim vs exact trim
- YouTube 1080p bitrate: 8 Mbps, and Sume has no bitrate field
- FFmpeg trim video: cut by time, with or without re-encoding
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