Control amplitude and release of Env using sample Buffer ?

amplitude_and_release_via_sample_buffer.scd

// This doesn't work:

(

s = Server.local;

b = Buffer.read(s, "/Users/freen/Desktop/a_rook_is_placed.wav");

SynthDef("aRookIsPlaced", { arg out=0, bufnum=0, rate=1, trigger=1, startPos=0, loop=0;
    var sampleBuf,
        sig,
        bufRate = BufRateScale.kr(bufnum) * rate,
        bufStartPos = BufFrames.ir(bufnum) * startPos;

    sampleBuf = PlayBuf.ar(1, bufnum, bufRate, trigger, bufStartPos, loop);

    sig = Pulse.ar(90, 0.3, Amplitude.kr(sampleBuf));

    Out.ar(out, sig ! 2);
}).add;

Routine({
    while ({ true }, {

        Synth(\aRookIsPlaced, [\out, 0, \bufnum, b.bufnum]);

        rrand(0.9, 1.7).wait;
    });
}).play(AppClock);

)

// Although this works:

(

s = Server.local;

b = Buffer.read(s, "/Users/freen/Desktop/a_rook_is_placed.wav");

SynthDef("aRookIsPlaced", { arg out=0, bufnum=0, rate=1, trigger=1, startPos=0, loop=0;
    var sampleBuf,
        env,
        amp,
        sig,
        bufRate = BufRateScale.kr(bufnum) * rate,
        bufStartPos = BufFrames.ir(bufnum) * startPos;

    sampleBuf = PlayBuf.ar(1, bufnum, bufRate, trigger, bufStartPos, loop);

    amp = Amplitude.kr(sampleBuf);
    env = EnvGen.kr(Env.perc(0.001, 4, amp), doneAction: 2);
    sig = SinOsc.ar(300, mul:env);

    Out.ar(out, sig ! 2);
}).add;

Routine({
    while ({ true }, {

        Synth(\aRookIsPlaced, [\out, 0, \bufnum, b.bufnum]);

        rrand(0.9, 1.7).wait;
    });
}).play(AppClock);

)