コード例 #1
0
inline void synthbuf(void)
{
   long *outptr;
   register int i;
   static int currentSample=0;
   int synthtemp[2];

#ifndef SYNC
   if(lastswap==swap) return;
   lastswap=swap;

   outptr=(swap ? gmbuf : gmbuf+BUF_SIZE);
#else
   outptr=gmbuf;
#endif

   for(i=0; i<BUF_SIZE/2; i++)
   {
      synthSample(&synthtemp[0], &synthtemp[1]);
      currentSample++;
      *outptr=((synthtemp[0]&0xFFFF) << 16) | (synthtemp[1]&0xFFFF);
      outptr++;
      if(currentSample==numberOfSamples)
      {
            if(playState == STATE_PLAYING)
            {
                stepFlag=1;
            }

            currentSample=0;
      }
   }
}
コード例 #2
0
ファイル: midi2wav.c プロジェクト: BackupTheBerlios/bimmerbox
int midimain(void * filename)
{

    printf("\nHello.\n");

    rb->splash(HZ/5, true, "LOADING MIDI");

    struct MIDIfile * mf = loadFile(filename);

    rb->splash(HZ/5, true, "LOADING PATCHES");
    if (initSynth(mf, "/.rockbox/patchset/patchset.cfg", "/.rockbox/patchset/drums.cfg") == -1)
    {
        return -1;
    }

/*
 *  This lets you hear the music through the sound card if you are on Simulator
 *  Make a symlink, archos/dsp.raw and make it point to /dev/dsp or whatever
 *  your sound device is.
 */

#if defined(LOCAL_DSP)
    fd=rb->open("/dsp.raw", O_WRONLY);
    int arg, status;
    int bit, samp, ch;

    arg = 16;          /* sample size */
    status = ioctl(fd, SOUND_PCM_WRITE_BITS, &arg);
    status = ioctl(fd, SOUND_PCM_READ_BITS, &arg);
    bit=arg;


    arg = 2;        /* Number of channels, 1=mono */
    status = ioctl(fd, SOUND_PCM_WRITE_CHANNELS, &arg);
    status = ioctl(fd, SOUND_PCM_READ_CHANNELS, &arg);
    ch=arg;

    arg = SAMPLE_RATE; /* Yeah. sampling rate */
    status = ioctl(fd, SOUND_PCM_WRITE_RATE, &arg);
    status = ioctl(fd, SOUND_PCM_READ_RATE, &arg);
    samp=arg;
#else

/* xxx2wav stuff, removed for now, will move to the real way of outputting sound soon */
/*
    file_info_struct file_info;
    file_info.samplerate = SAMPLE_RATE;
    file_info.infile = fd;
    file_info.channels = 2;
    file_info.bitspersample = 16;
    local_init("/miditest.tmp", "/miditest.wav", &file_info, rb);
    fd = file_info.outfile;
*/
#endif


    rb->splash(HZ/5, true, "  I hope this works...  ");




    /*
     * tick() will do one MIDI clock tick. Then, there's a loop here that
     * will generate the right number of samples per MIDI tick. The whole
     * MIDI playback is timed in terms of this value.. there are no forced
     * delays or anything. It just produces enough samples for each tick, and
     * the playback of these samples is what makes the timings right.
     *
     * This seems to work quite well.
     */

    printf("\nOkay, starting sequencing");


    currentSample=0;            /* Sample counting variable */
    outputBufferPosition = 0;


    bpm=mf->div*1000000/tempo;
    numberOfSamples=SAMPLE_RATE/bpm;



    /* Tick() will return 0 if there are no more events left to play */
    while(tick(mf))
    {
        /*
         * Tempo recalculation moved to sequencer.c to be done on a tempo event only
         *
         */
        for(currentSample=0; currentSample<numberOfSamples; currentSample++)
        {

            synthSample(&outputSampleOne, &outputSampleTwo);


            /*
             * 16-bit audio because, well, it's better
             * But really because ALSA's OSS emulation sounds extremely
             * noisy and distorted when in 8-bit mode. I still do not know
             * why this happens.
             */

            outputBuffer[outputBufferPosition]=outputSampleOne&0XFF; // Low byte first
            outputBufferPosition++;
            outputBuffer[outputBufferPosition]=outputSampleOne>>8;   //High byte second
            outputBufferPosition++;

            outputBuffer[outputBufferPosition]=outputSampleTwo&0XFF; // Low byte first
            outputBufferPosition++;
            outputBuffer[outputBufferPosition]=outputSampleTwo>>8;   //High byte second
            outputBufferPosition++;


            /*
             * As soon as we produce 2000 bytes of sound,
             * write it to the sound card. Why 2000? I have
             * no idea. It's 1 AM and I am dead tired.
             */
            if(outputBufferPosition>=2000)
            {
                rb->write(fd, outputBuffer, 2000);
                outputBufferPosition=0;
            }
        }
    }

    printf("\n");

#if !defined(LOCAL_DSP)

/* again, xxx2wav stuff, removed for now */

    /* close_wav(&file_info); */
#else
    rb->close(fd);
#endif
    return 0;
}