wav ファイルのパース、音源は G.711 の PCMU

wav.erl

-module(wav).

-export([parse/0, parse/1]).

-include_lib("eunit/include/eunit.hrl").

%% http://www.graffiti.jp/pc/p030506a.htm
%% http://soundfile.sapp.org/doc/WaveFormat/
%% http://bb.watch.impress.co.jp/cda/parts/image_for_link/58934-16386-3-1.html

%% Erlang/OTP 19 [erts-8.0.2] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:10] [hipe] [kernel-poll:false] [dtrace] [sharing-preserving]
%% 
%% Eshell V8.0.2  (abort with ^G)
%% 1> c(wav).
%% {ok,wav}
%% 2> wav:parse().
%% wav.erl:44:<0.57.0>: ChunkSize = 203969
%% wav.erl:45:<0.57.0>: Format = <<"WAVE">>
%% wav.erl:46:<0.57.0>: Subchunk1Id = <<"fmt ">>
%% wav.erl:47:<0.57.0>: Subchunk1IdSize = 18
%% wav.erl:48:<0.57.0>: AudioFormat = 7
%% wav.erl:49:<0.57.0>: NumChannels = 1
%% wav.erl:50:<0.57.0>: SampleRate = 8000
%% wav.erl:51:<0.57.0>: ByteRate = 8000
%% wav.erl:52:<0.57.0>: BlockAlign = 1
%% wav.erl:53:<0.57.0>: BitsPerSample = 8
%% wav.erl:54:<0.57.0>: ExtraParamSize = 0
%% wav.erl:55:<0.57.0>: Subchunk2Id = <<"data">>
%% wav.erl:56:<0.57.0>: Subchunk2IdSize = 203931
%% wav.erl:57:<0.57.0>: byte_size ( _Rest ) = 203931
%% ok


parse() ->
    %% load sample file
    parse("g711-ulaw-25s.wav").


parse(Filename) ->
    {ok, Binary} = file:read_file(Filename),
    parse0(Binary).


parse0(<<"RIFF", ChunkSize:32/little, Format:32/bits,
         Subchunk1Id:32/bits, Subchunk1IdSize:32/little,
         AudioFormat:16/little, NumChannels:16/little,
         SampleRate:32/little, ByteRate:32/little,
         BlockAlign:16/little, BitsPerSample:16/little,
         ExtraParamSize:16/little,
         Subchunk2Id:32/bits, Subchunk2IdSize:32/little,
         _Rest/binary>>) ->
    ?debugVal(ChunkSize),
    ?debugVal(Format),
    ?debugVal(Subchunk1Id),
    ?debugVal(Subchunk1IdSize),
    ?debugVal(AudioFormat),
    ?debugVal(NumChannels),
    ?debugVal(SampleRate),
    ?debugVal(ByteRate),
    ?debugVal(BlockAlign),
    ?debugVal(BitsPerSample),
    ?debugVal(ExtraParamSize),
    ?debugVal(Subchunk2Id),
    ?debugVal(Subchunk2IdSize),
    ?debugVal(byte_size(_Rest)),
    ok.