From FFMpegCore, ffprobe and ffmpeg · onemedia docs

Basis: the FFMpegCore README (main branch, which says its CI runs against ffmpeg 8.1) and the ffmpeg user documentation (https://ffmpeg.org/ffprobe.html, https://ffmpeg.org/ffmpeg.html, https://ffmpeg.org/ffmpeg-formats.html, https://ffmpeg.org/ffmpeg-codecs.html), all fetched 2026-11-02 and checked flag by flag. Source of neither tool was read.

FFMpegCore builds ffmpeg command lines and parses ffprobe output. OneMedia does the container work in-process and has no subprocess, so there is no binary to locate, no argument builder and no temp-file folder to configure.

Probing

Theirs	OneMedia
`FFProbe.Analyse(path)` / `AnalyseAsync`	`Media.Open(path)` / `Media.OpenAsync(path)`
`ffprobe -show_format`	`media.Format`, `media.ExactDuration`, `media.Tags`, `media.Defects`
`ffprobe -show_streams`	`media.Tracks` (kind, codec, `Rfc6381Codec()`, language, disposition, edit info)
`ffprobe -show_packets`	`media.Packets(track)`: pts, dts, duration, keyframe flag, size, source byte range
`ffprobe -show_chapters`, `-show_data`, or any raw tag or box value	`media.Native[system, key]` (chapters through the native layer)

using RecursiveAI.OneMedia;
using var media = Media.Open("in.mp4");
string line = $"{media.Format}, {media.ExactDuration}, {media.Tracks.Count} tracks";
foreach (MediaTrack track in media.Tracks)
    line += $"; #{track.Index} {track.Kind} {track.Codec} {track.Rfc6381Codec()} {track.Language}";

using RecursiveAI.OneMedia;
using var media = Media.Open("in.mp4");
foreach (OwnedPacket packet in media.Packets(media.Video!))
{
    using (packet) { if (packet.Info.IsKeyframe) { /* packet.Info.Pts, packet.Info.Dts, packet.Data */ } }
}

Times are MediaTime (integer ticks plus timescale), not floating seconds; media.Duration gives a TimeSpan? for convenience. For allocation-free loops use the demuxer's TryReadPacket into a caller buffer.

Operations

Theirs	OneMedia
`ffmpeg -i in -c copy out.mkv`	`Media.Remux("in.mp4", "out.mkv")` returns a `RemuxReport` (`HasLosses`, dropped tracks); `-map`-style selection: `Media.Remux(in, out, new RemuxOptions { Select = ... })`
`FFMpeg.SubVideo(in, out, from, to)`, `-ss -to -c copy`	`Media.Trim(in, out, from, to)`; `TrimMode.FrameAccurate` (default, edit list hides pre-roll) or keyframe
`-movflags +faststart` (mov/mp4 muxer option), FFMpegCore `.WithFastStart()`	`Media.Faststart(in, out)`
`FFMpeg.Join(out, parts...)`	`Media.Concat(out, parts...)` (mismatched configurations are refused or reported)
`-metadata title=...`	`media.Tags.Title = ...; media.SaveAs(out)`
`-map_metadata -1` (disables automatic metadata copy), strip location	`Media.StripLocation(in, out)`, `Media.StripDeviceIds(in, out)`
`-f hls` / `-f dash` (the hls and dash muxers)	`Media.PackageHls(in, dir)` / `Media.PackageDash(in, dir)`
`-c:s webvtt` (subtitle codec) on a sidecar	`Subtitles.Convert("a.srt", "a.vtt")` returns a `ConversionReport`
make it play in a browser	`Media.CanPlay(path, BrowserProfiles.Chrome)`, `Media.MakePlayable(in, out, profile)`
`FFMpeg.ExtractAudio` / `-vn -c copy` (audio track to a file, no re-encode)	`Media.Remux(in, "audio.m4a", new RemuxOptions { Select = t => t.Kind == TrackKind.Audio })` (container from the extension; the options are the remux layer's)
decoded audio (PCM)	`media.Decode()` (package `RecursiveAI.OneMedia.Audio`) gives decoded PCM through OneAudio
`FFMpeg.Snapshot`, `GifSnapshot`, scaling, filters, `-c:v libx264`	out of scope: OneMedia decodes and encodes no video

using RecursiveAI.OneMedia;
using RecursiveAI.OneMedia.Editing;
using RecursiveAI.OneMedia.Playback;
using RecursiveAI.OneMedia.Remuxing;
 
RemuxReport remux = Media.Remux("in.mp4", "out.mkv");
var clip = Media.Trim("in.mp4", "clip.mp4", TimeSpan.FromSeconds(0.5), TimeSpan.FromSeconds(1.5));
Media.Faststart("in.mp4", "fast.mp4");
using (MediaFile media = Media.Open("in.mp4")) { media.Tags.Title = "Hello"; media.SaveAs("titled.mp4"); }
RemuxReport audioOnly = Media.Remux("in.mp4", "audio.m4a", new RemuxOptions { Select = t => t.Kind == TrackKind.Audio });
Media.PackageHls("in.mp4", "hls");
Subtitles.Convert("sample.srt", "migrated.vtt");

Differences that matter

Copy-only. Where -c copy would fail or quietly drop a stream, the report lists it (RemuxReport.HasLosses, LostMediaTracks).
Payload bytes are copied, never re-serialised; trims cut with edit lists, so a frame-accurate cut keeps the pre-roll frames hidden in the file.
Operations are verbs on paths and return reports; there is no builder and no process, so nothing to cancel by killing a child.
Malformed input raises typed exceptions (TryParse variants beside them) or lands in media.Defects; there is no stderr to scrape.