Merge pull request #28 from ssfrr/int32

adds workaround for int32 files, fixes #27

Author: ssfrr

src/WAVDisplay.jl

@@ -129,8 +129,15 @@ end
 const WAVE_FORMAT_PCM = 0x0001
 const SAMPLE_TYPE = PCM16Sample
 
-# we always write 16-bit PCM wav data, because that's what Firefox understands
+# floating-point and 16-bit fixed point buffer display works, but Int32 is
+# broken, so for now we convert to Float32 first. This hack should go away once
+# we switch over to just using WAV.jl
 function wavwrite(io::IO, buf::SampleBuf)
+    wavwrite(io, Float32.(buf))
+end
+
+# we always write 16-bit PCM wav data, because that's what Firefox understands
+function wavwrite(io::IO, buf::SampleBuf{<:Union{Int16, SAMPLE_TYPE, AbstractFloat}, N}) where N
     nbits = 16
     nchans = nchannels(buf)
     blockalign = 2 * nchans

test/WAVDisplay.jl

@@ -65,8 +65,8 @@ end
     #     @test !hasiconbtn(output, "fa-stop")
     # end
 
-    @testset "wavwrite Generates valid WAV file" begin
-        buf = SampleBuf(rand(Int16, 16, 2), 48000)
+    @testset "wavwrite Generates valid WAV file with raw Int16" begin
+        buf = SampleBuf(rand(Int16, 4, 2), 48000)
         io = IOBuffer()
         SampledSignals.wavwrite(io, buf)
         samples, fs, nbits, opt = wavread(IOBuffer(take!(io)), format="native")
@@ -75,8 +75,18 @@ end
         @test nbits == 16
     end
 
+    @testset "wavwrite Generates valid WAV file with raw 16-bit Fixed-point" begin
+        buf = SampleBuf(reinterpret.(Fixed{Int16, 15}, rand(Int16, 4, 2)), 48000)
+        io = IOBuffer()
+        SampledSignals.wavwrite(io, buf)
+        samples, fs, nbits, opt = wavread(IOBuffer(take!(io)), format="native")
+        @test samples == reinterpret.(convert(Array, buf))
+        @test fs == 48000
+        @test nbits == 16
+    end
+
     @testset "wavwrite converts float values to 16-bit int wav" begin
-        buf = SampleBuf(rand(16, 2), 48000)
+        buf = SampleBuf(rand(4, 2), 48000)
         io = IOBuffer()
         SampledSignals.wavwrite(io, buf)
         samples, fs, nbits, opt = wavread(IOBuffer(take!(io)), format="native")
@@ -85,6 +95,18 @@ end
         @test nbits == 16
     end
 
+    @testset "wavwrite converts Int32 values to 16-bit int wav" begin
+        data = rand(4, 2)*0.9
+        buf = SampleBuf(Fixed{Int32, 31}.(data), 48000)
+        io = IOBuffer()
+        SampledSignals.wavwrite(io, buf)
+        samples, fs, nbits, opt = wavread(IOBuffer(take!(io)), format="native")
+        # convert 32-bit int buf to float, then to 16-bit, for testing
+        @test samples == reinterpret.(convert(Array{PCM16Sample}, Float32.(buf)))
+        @test fs == 48000
+        @test nbits == 16
+    end
+
     # this is used to display spectrum magnitudes using the same infrastructure
     # as displaying/playing time-domain buffers
     # @testset "wavwrite converts complex float values to 16-bit int wav" begin