void Interpolator::create(int phaseSteps, double sampleRate, double cutoff)
{
free();
std::vector<Real> taps = createPolyphaseLowPass(
phaseSteps, // number of polyphases
1.0, // gain
phaseSteps * sampleRate, // sampling frequency
cutoff, // hz beginning of transition band
sampleRate / 5.0, // hz width of transition band
20.0); // out of band attenuation
// init state
m_ptr = 0;
m_nTaps = taps.size() / phaseSteps;
m_phaseSteps = phaseSteps;
m_samples.resize(m_nTaps + 2);
for(int i = 0; i < m_nTaps + 2; i++)
m_samples[i] = 0;
// reorder into polyphase
std::vector<Real> polyphase(taps.size());
for(int phase = 0; phase < phaseSteps; phase++) {
for(int i = 0; i < m_nTaps; i++)
polyphase[phase * m_nTaps + i] = taps[i * phaseSteps + phase];
}
// normalize phase filters
for(int phase = 0; phase < phaseSteps; phase++) {
Real sum = 0;
for(int i = phase * m_nTaps; i < phase * m_nTaps + m_nTaps; i++)
sum += polyphase[i];
for(int i = phase * m_nTaps; i < phase * m_nTaps + m_nTaps; i++)
polyphase[i] /= sum;
}
// move taps around to match sse storage requirements
m_taps = new float[2 * taps.size() + 8];
for(int i = 0; i < 2 * taps.size() + 8; ++i)
m_taps[i] = 0;
m_alignedTaps = (float*)((((quint64)m_taps) + 15) & ~15);
for(int i = 0; i < taps.size(); ++i) {
m_alignedTaps[2 * i + 0] = polyphase[i];
m_alignedTaps[2 * i + 1] = polyphase[i];
}
m_taps2 = new float[2 * taps.size() + 8];
for(int i = 0; i < 2 * taps.size() + 8; ++i)
m_taps2[i] = 0;
m_alignedTaps2 = (float*)((((quint64)m_taps2) + 15) & ~15);
for(int i = 1; i < taps.size(); ++i) {
m_alignedTaps2[2 * (i - 1) + 0] = polyphase[i];
m_alignedTaps2[2 * (i - 1) + 1] = polyphase[i];
}
}
bool AMPDecoder::L3_DecodeFrame() {
int gr, ch, sb, ss;
profile_set(0);
// bring in new bits
fillbits(frame_size);
// rewind read point back to beginning of data for this frame
//_RPT2(0,"Layer III: added %ld bytes, rewind to %ld\n", frame_size, sideinfo.main_data_begin + frame_size);
rewind(sideinfo.main_data_begin + frame_size);
profile_add(p_header);
// process granules.
//
// 2 for MPEG-1, 1 for MPEG-2
for (gr=0;gr<(is_mpeg2 ? 1 : 2);gr++) {
float lr[2][SBLIMIT][SSLIMIT],ro[SBLIMIT][SSLIMIT];
III_scalefac_t scalefac;
int sample_end[2];
int new_end;
// process each channel in the granule.
for (ch=0; ch<channels; ch++) {
long int is[SBLIMIT*SSLIMIT]; /* Quantized samples. */
int part2_start;
part2_start = tellbits();
int limit;
// decode scale factors
if (is_mpeg2)
L3_GetScaleFactors2(&scalefac, ch);
else
L3_GetScaleFactors1(&scalefac, gr, ch);
profile_add(p_scalefac);
// decode samples
limit = L3_HuffmanDecode(is, ch, gr, part2_start);
profile_add(p_huffdec);
// dequantize samples
sample_end[ch] = L3_DequantizeSample(is, (float *)lr[ch], &scalefac[ch],
&sideinfo.ch[ch].gr[gr], ch, limit);
profile_add(p_dequan);
}
// process joint stereo in lr
new_end = L3_Stereo((float (*)[576])lr, &scalefac, &sideinfo.ch[0].gr[gr], sample_end[0], sample_end[1]);
if (new_end > 0)
sample_end[0] = sample_end[1] = new_end;
profile_add(p_stereo);
float polyPhaseIn[2][SSLIMIT][SBLIMIT];
for (ch=0; ch<channels; ch++) {
// reorder samples; use 'hybridOut' as our out here, to reuse memory
L3_Reorder((float *)lr[ch],(float *)ro,&sideinfo.ch[ch].gr[gr]);
// antialiasing
L3_Antialias(lr[ch], /* Antialias butterflies. */
&sideinfo.ch[ch].gr[gr]);
profile_add(p_antialias);
// Hybrid synthesis.
L3_Hybrid(lr[ch], polyPhaseIn[ch], ch, &sideinfo.ch[ch].gr[gr], sample_end[ch]);
profile_add(p_hybrid);
}
if (mode == MODE_MONO)
for(ss=0; ss<18; ss++)
polyphase(polyPhaseIn[0][ss], NULL, psDest + 32*ss + 576*gr, !!(ss&1));
else
for(ss=0; ss<18; ss++)
polyphase(polyPhaseIn[0][ss], polyPhaseIn[1][ss], psDest + 64*ss + 1152*gr, !!(ss&1));
profile_add(p_polyphase2);
}
#ifdef RDTSC_PROFILE
if (!(++p_frames & 127)) {
static char buf[256];
sprintf(buf, "%d frames: total %I64d, header %d%%, scalefac %d%%, huffdec %d%%, dequan %d%%, stereo %d%%, antialias %d%%, hybrid %d%%, poly %d%%/%d%%\n"
,p_frames
,p_total
,(long)((p_header*100)/p_total)
,(long)((p_scalefac*100)/p_total)
,(long)((p_huffdec*100)/p_total)
,(long)((p_dequan*100)/p_total)
,(long)((p_stereo*100)/p_total)
,(long)((p_antialias*100)/p_total)
,(long)((p_hybrid*100)/p_total)
,(long)((p_polyphase1*100)/p_total)
,(long)((p_polyphase2*100)/p_total)
);
OutputDebugString(buf);
}
#endif
// set sample count
lSampleCount = 1152;
if (is_mpeg2)
lSampleCount = 576;
if (channels>1)
lSampleCount <<=1;
// _RPT2(0,"Layer III: terminated with %ld bits left (%ld bytes)\n", tellbits(), tellbits()/8);
return true;
}
