Create "empty" (ogg / matroska / ?) container, how? ( / .wav, even ?)
In need for a "placeholder" for missing tracks without audio, to keep metadata. Need to be able to create empty container file for metadata only. If that is technically invalid in the format in question, a good second would be if fb2k can read and tag it.
Any tool to quickly generate one and copy metadata? Seems that ffmpeg isn't happy about filling a file with nothing but metadata, but I was able to make zero-length speex-in-.ogg (and as .spx) and have fb2k read it.
If it matters, one can assume there is embedded art present (some formats may take that as a "video codec" in case they don't accept empty containers).