Re: Need simple sound

[Sebastiaan Koppe via Digitalmars-d-learn]

On Wednesday, 5 July 2017 at 09:43:05 UTC, Martin Tschierschke 
wrote:
On Wednesday, 5 July 2017 at 07:21:45 UTC, Sebastiaan Koppe 
wrote:
On Wednesday, 5 July 2017 at 05:34:37 UTC, FoxyBrown wrote:
On Tuesday, 4 July 2017 at 20:37:44 UTC, Sebastiaan Koppe 
wrote:
Portaudio is simple as well. And nice cross platform.

are there any bindings?

Sure, see http://code.dlang.org/packages/portaudio

Sorry, for that question but now, as I have several different 
options -
all not 'overdocumented' -  so what would be the shortest 
possible D program waiting for input and playing a sound from a 
file in parallel?

Something short like the single-file dub example...?

#!/usr/bin/env dub
/+ dub.sdl:
        name "hello"
+/
void main() {
        
 writef("Do you like the music?");
          char[] answer;
          answer = readln();
          writef("This was your Answer: ", answer);
        
}

This one plays a wav file. Couldn't get dub to do single-file on 
it. It kept giving linker errors. (Took example from 
https://github.com/v--/portaudio/blob/master/examples/pa_test.d)

**dub.sdl
name "audio"
description "plays audio file"
authors "Sebastiaan Koppe"
dependency "portaudio" version="==1.0.0"
dependency "wave-d" version="~>1.0.6"

configuration "executable" {
  mainSourceFile "audio.d"
  targetType "executable"
}

**audio.d
import std.stdio;
import waved;
import deimos.portaudio;
import std.conv, std.stdio;
import std.algorithm : min;

struct Audio {
    float* samples;
    size_t frames;
    size_t position;
}

extern(C) int callback(const(void)* inputBuffer, void* 
outputBuffer,
                             size_t framesPerBuffer,
                             const(PaStreamCallbackTimeInfo)* 
timeInfo,
                             PaStreamCallbackFlags statusFlags,
                             void *userData)
{
    auto pout = cast(float*)outputBuffer;
    Audio* audio = cast(Audio*)userData;

    enum vol = 0.2f;
    size_t frames = min(audio.frames - audio.position, 
framesPerBuffer);

    foreach(i; 0 .. frames)
        *pout++ = vol * audio.samples[i + audio.position];
    foreach(i; frames .. framesPerBuffer)
        *pout++ = 0;

    audio.position += framesPerBuffer;
    return frames == framesPerBuffer ? paContinue : paComplete;
}

int main()
{
    PaStream* stream;
    PaError err;

    Sound input = decodeWAV("my_wav_file.wav");
    string answer;

    auto audio = Audio(input.samples.ptr, input.samples.length);

    if ((err = Pa_Initialize()) != paNoError) goto Lerror;

    if ((err = Pa_OpenDefaultStream(&stream,
                                    0,
                                    input.channels,
                                    paFloat32,
                                    cast(double)input.sampleRate,
                                    paFramesPerBufferUnspecified,
                                    &callback,
                                    &audio))
        != paNoError) goto Lerror;

    if ((err = Pa_StartStream(stream)) != paNoError) goto Lerror;

    writef("Do you like the music?");
    answer = readln();
    writefln("This was your Answer: %s", answer);

    if ((err = Pa_StopStream(stream)) != paNoError) goto Lerror;
    if ((err = Pa_CloseStream(stream)) != paNoError) goto Lerror;
    if ((err = Pa_Terminate()) != paNoError) goto Lerror;

    return 0;
 Lerror:
    stderr.writefln("error %s", to!string(Pa_GetErrorText(err)));
    return 1;
}