Hi All, currently the WAV files generated by WSJT-X only contain the audio format description and the PCM sample data. I note that there has been some investigation into adding some metadata to the files as well. The WAV file format allows for various optional chunks to be included which we could gain advantage from. First off I have amended the current WAV file reading code such that any standard format WAV file can be read rather than the strict subset supported previously. This will allow metadata to be added to recorded files while still allowing them to be read by the current application and test tools.
Old versions of the application and test tools will choke on WAV files with optional metadata but a trivial tool to rewrite WAV files with optional metadata stripped could be written. I propose that we stay within the recognized formats of metadata. I say this because sometimes it is handy to read the files with other tools like sound analysis and editing tools e.g. Audacity. The WAV file format is slightly vague so even though virtually anything may be inserted as optional chunks, many applications only handle particular types. The most commonly used is the LIST-INFO chunk, this allows variable length character data to be added under various identifiers as documented here: http://bwfmetaedit.sourceforge.net/listinfo.html I propose that we use some of these ID tags to store our metadata, for example: ISRC: "G4WJS, IO91np" ISFT: "WSJT-X v1.7.0-devel r6333" ICRD: "2016-01-02 16:41:00Z" ICMT: "Mode=JT9+JT65, TRPeriod=60" The comments (ICMT) chunk could contain a list of several optional tags allowing mode specific metadata to be recorded similar to the example above. I have a C++ class written that allows WAV file reading and writing including entries in the LIST-INFO chunk that is suitable for use in WSJT-X. It is checked in but not yet used. Comments, suggestions? 73 Bill G4WJS. ------------------------------------------------------------------------------ _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
