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FFmpeg decoder

Register name used to load filter: ffdec
This filter may be automatically loaded during graph resolution.

This filter decodes audio and video streams using FFmpeg.
See FFmpeg documentation ( for more details.
To list all supported decoders for your GPAC build, use gpac -h ffdec:*.

Options can be passed from prompt using --OPT=VAL
The default threading mode is to let libavcodec decide how many threads to use. To enforce single thread, use --threads=1

Codec Map

The ffcmap option allows specifying FFmpeg codecs for codecs not supported by GPAC.
Each entry in the list is formatted as GID@name or GID@+name, with:

  • GID: 4CC or 32 bit identifier of codec ID, as indicated by gpac -i source inspect:full
  • name: FFmpeg codec name
  • `+': is set and extra data is set and formatted as an ISOBMFF box, removes box header


gpac -i source.mp4 --ffcmap=BKV1@binkvideo vout

This will map an ISOBMFF track declared with coding type BKV1 to binkvideo.


ffcmap (strl): codec map
c (str): codec name (GPAC or ffmpeg), only used to query possible arguments - updated to ffmpeg codec name after initialization
* (str): any possible options defined for AVCodecContext and sub-classes. See gpac -hx ffdec and gpac -hx ffdec:*