add wavplay() support for Windows, minor doc tweaks

README.md

@@ -34,11 +34,11 @@ using WAV
 fs = 8e3
 t = 0.0:1/fs:prevfloat(1.0)
 f = 1e3
-y = sin.(2pi * f * t)
+y = sin.(2pi * f * t) * 0.1
 wavwrite(y, "example.wav", Fs=fs)
 
 y, fs = wavread("example.wav")
-y = sin.(2pi * 2f * t)
+y = sin.(2pi * 2f * t) * 0.1
 wavappend(y, "example.wav")
 
 y, fs = wavread("example.wav")

src/WAV.jl

@@ -24,11 +24,11 @@ using WAV
 fs = 8e3
 t = 0.0:1/fs:prevfloat(1.0)
 f = 1e3
-y = sin.(2pi * f * t)
+y = sin.(2pi * f * t) * 0.1
 wavwrite(y, "example.wav", Fs=fs)
 
 y, fs = wavread("example.wav")
-y = sin.(2pi * 2f * t)
+y = sin.(2pi * 2f * t) * 0.1
 wavappend(y, "example.wav")
 
 y, fs = wavread("example.wav")
@@ -45,38 +45,6 @@ import Libdl
 using FileIO
 using Logging
 
-"""
-    wavplay(data, fs)
-    wavplay(filename)
-
-Plays the audio waveform `data` at sampling frequency `fs`, or read
-both from the WAV file named `filename`.
-
-The supported backends are:
-* AudioQueue (macOS)
-* PulseAudio (Linux, libpulse-simple)
-
-There is not a native backend for Windows yet.
-"""
-function wavplay end
-wavplay(fname) = wavplay(wavread(fname)[1:2]...)
-@static if Sys.islinux()
-    @static if Libdl.find_library(["libpulse-simple", "libpulse-simple.so.0"]) != ""
-        include("wavplay-pulse.jl")
-    else
-        wavplay(data, fs) = @warn "libpulse-simple not found, wavplay will not work"
-    end
-elseif Sys.isapple()
-    @static if Libdl.find_library(["AudioToolbox"],
-                                  ["/System/Library/Frameworks/AudioToolbox.framework/Versions/A"]) != ""
-        include("wavplay-audioqueue.jl")
-    else
-        wavplay(data, fs) = @warn "AudioToolbox.framework not found, wavplay will not work"
-    end
-else
-    wavplay(data, fs) = @warn "wavplay is not currently implemented on $(Sys.KERNEL)"
-end
-
 include("AudioDisplay.jl")
 include("WAVChunk.jl")
 
@@ -720,7 +688,7 @@ make_range(subrange::Number) = 1:convert(Int, subrange)
 
 """
     wavread(io::IO; subrange=:, format="double")
-    wavread(filename::String; subrange=:, format="double")
+    wavread(filename::AbstractString; subrange=:, format="double")
 
 Reads the samples from a WAV file. The samples are converted to
 floating point values in the range −1.0 to 1.0 by default.
@@ -1079,4 +1047,34 @@ save(s::Stream{format"WAV"}, data; kwargs...) = wavwrite(data, s.io; kwargs...)
 load(f::File{format"WAV"}; kwargs...) = wavread(f.filename; kwargs...)
 save(f::File{format"WAV"}, data; kwargs...) = wavwrite(data, f.filename; kwargs...)
 
+"""
+    wavplay(data, fs)
+    wavplay(filename::AbstractString)
+
+Plays the audio waveform `data` at sampling frequency `fs` (in hertz).
+To play a stereo signal, provide two columns in array `data` (left and
+right channel), as in [`wavwrite`](@ref).
+
+The `filename` form reads both waveform data and sampling frequency
+from the named WAV file to play it.
+
+The supported backends are:
+* AudioQueue (macOS)
+* PulseAudio (Linux, libpulse-simple)
+* PlaySound  (Windows)
+
+See also: [`wavwrite`](@ref)
+"""
+function wavplay end
+wavplay(fname::AbstractString) = wavplay(wavread(fname)[1:2]...)
+@static if Sys.islinux()
+    include("wavplay-pulse.jl")
+elseif Sys.isapple()
+    include("wavplay-audioqueue.jl")
+elseif Sys.iswindows()
+    include("wavplay-win32.jl")
+else
+    wavplay(data, fs) = @warn "wavplay is not currently implemented on $(Sys.KERNEL)"
+end
+
 end # module

src/wavplay-win32.jl

@@ -0,0 +1,27 @@
+# -*- mode: julia; -*-
+module WAVPlay
+import WAV: wavplay, wavwrite
+
+# some standard Win32 API types and constants, see [MS-DTYP]
+const BOOL = Cint
+const DWORD = Culong
+const TRUE = 1
+# PlaySound flags from Winmm.h
+const SND_SYNC      = 0x0
+const SND_ASYNC     = 0x1
+const SND_NODEFAULT = 0x2
+const SND_MEMORY    = 0x4
+const SND_FILENAME  = 0x20000
+
+function wavplay(data, fs)
+    # produce an in-memory WAV file ...
+    buf=IOBuffer()
+    wavwrite(data, buf, Fs=fs)
+    wav = take!(buf)
+    # ... and pass it to PlaySound
+    success = ccall((:PlaySoundA, "Winmm.dll"), stdcall, BOOL,
+                    (Ptr{Cvoid}, Ptr{Cvoid}, DWORD),
+                    wav, C_NULL, SND_MEMORY | SND_SYNC | SND_NODEFAULT)
+    Base.windowserror("PlaySound", success != TRUE)
+end
+end # module

test/runtests.jl

@@ -638,11 +638,15 @@ end
 end
 
 ### playback
-# The playback tests don't work on travis.
-@testset "13" begin
-    fs = 44100.0
-    t = 1:44100;
-    in_data = sin.(5.0 * t / fs) * 1e-6;
-    #WAV.wavplay(in_data, fs);
-    #WAV.wavplay([in_data in_data], fs);
+if !haskey(ENV, "CI")
+    @testset "13" begin
+        fs = 44100.0
+        t = 0.0:fs-1.0;
+        left_data  = sin.(2pi * 500.0 * t / fs) * 1e-1;
+        right_data = sin.(2pi * 800.0 * t / fs) * 1e-1;
+        # 500 Hz mono
+        @test WAV.wavplay(left_data, fs) === nothing;
+        # 500 Hz left, 800 Hz right stereo
+        @test WAV.wavplay([left_data right_data], fs) === nothing;
+    end
 end