Parse the vorbis header Vorbis Identification header from Vorbis_I_spec.html::vorbis-spec-codec [vorbis_version] = read 32 bits as unsigned integer | Not used [audio_channels] = read 8 bit integer as unsigned | Used [audio_sample_rate] = read 32 bits as unsigned integer | Used [bitrate_maximum] = read 32 bits as signed integer | Not used yet [bitrate_nominal] = read 32 bits as signed integer | Not used yet [bitrate_minimum] = read 32 bits as signed integer | Used as bitrate [blocksize_0] = read 4 bits as unsigned integer | Not Used [blocksize_1] = read 4 bits as unsigned integer | Not Used [framing_flag] = read one bit | Not Used