On Aug 22, 2017, at 6:50 PM, ha.ppy.neko <ha.ppy.neko@gmail.com> wrote:I am not sure, but it looks like for given mode AMR and AMR-WB files have fixed frame size."The length of the speech frame is implicitly defined by the mode indicated in the FT field":Anyway, it is strange that mod_native_file registers AMR and AMR-WB formats if it could not support them.2017-08-23 0:21 GMT+03:00 Anthony Minessale <anthony.minessale@gmail.com>:The question was answered by the log line you supplied.-- "cannot play or record native files with variable length data".VBR codecs are not a predictable size so you cannot make a raw file of it because you don't have any idea how big each packet is.