This experimental mod originated to interact with the Google speech-to-text API using speex. Chromium sourcecode provided a hint about the (then) unsupported MIME-type being used when interacting with the google API and we implemented the binary format in speexenc and speexdec for fellow pioneers and curious users out there in need of this format.
% speexenc --headerbyte --vbr --w --quality 3 input_file_16bit.wav compressed_file.spx
% speexdec --headerbyte compressed_file.spx decompressed_file.wav
To test encoded speex against gapi:
% curl --data-binary @compressed_file.spx --header 'Content-type: audio/x-speex-with-header-byte; rate=16000' 'https://www.google.com/speech-api/v1/recognize?client=chromium&lang=en-US&maxresults=2'
This is experimental and might not always produce results or work as intended. Feedback helps us step further.
A link to the original QXIP wiki post: SIP-SIR