Module transcode 

Transcoding — the engine side of ffmpeg.

The pipeline is the classic FFmpeg shape:

  demuxer ─▶ decoder ─▶ [filters] ─▶ encoder ─▶ muxer
  (input)    (raw frames pass through the middle)      (output)

TranscodeSpec is the declarative description of a job — inputs, an output, and the codecs to use. run resolves that spec against an Engine (finding the demuxer, decoders, encoders, and muxer) and then drives the loop to completion.

Each input stream is either transcoded (decode → re-encode) when an output codec is requested for its media type, or stream-copied (remuxed packet-for-packet) when none is — the same -c:v copy distinction FFmpeg draws. Video runs through the -vf filter graph (scale/crop); audio is automatically resampled to a rate the target encoder accepts (FFmpeg’s implicit aresample).

Structs

InputSpec

One input file for a job.

MapSpec

One -map entry: pick stream(s) from input input.

OutputSpec

The output file for a job.

StreamCodec

Per-stream codec selection for the output.

TranscodeReport

A successful run’s summary (frames/packets moved, etc.). Fields will grow as the pipeline does.

TranscodeSpec

A complete, declarative transcoding job.

Enums

MapSelector

Which input stream(s) a -map entry selects.

Functions

run

Resolve and run a transcode job against engine.