private void Initialize(Header header)
{
// REVIEW: allow customizable scale factor
float scalefactor = 32700.0f;
int mode = header.mode();
int layer = header.layer();
int channels = mode == Header.SINGLE_CHANNEL ? 1 : 2;
// set up output buffer if not set up by client.
if (m_Output == null)
{
m_Output = new SampleBuffer(header.frequency(), channels);
}
float[] factors = m_Equalizer.BandFactors;
//Console.WriteLine("NOT CREATING SYNTHESIS FILTERS");
m_LeftChannelFilter = new SynthesisFilter(0, scalefactor, factors);
// REVIEW: allow mono output for stereo
if (channels == 2)
{
m_RightChannelFilter = new SynthesisFilter(1, scalefactor, factors);
}
m_OutputChannels = channels;
m_OutputFrequency = header.frequency();
m_IsInitialized = true;
}
private void Initialize(Header header)
{
// REVIEW: allow customizable scale factor
float scalefactor = 32700.0f;
int mode = header.mode();
int layer = header.layer();
int channels = mode == Header.SINGLE_CHANNEL ? 1 : 2;
// set up output buffer if not set up by client.
if (m_Output == null)
m_Output = new SampleBuffer(header.frequency(), channels);
float[] factors = m_Equalizer.BandFactors;
//Console.WriteLine("NOT CREATING SYNTHESIS FILTERS");
m_LeftChannelFilter = new SynthesisFilter(0, scalefactor, factors);
// REVIEW: allow mono output for stereo
if (channels == 2)
m_RightChannelFilter = new SynthesisFilter(1, scalefactor, factors);
m_OutputChannels = channels;
m_OutputFrequency = header.frequency();
m_IsInitialized = true;
}
private void compute_pcm_samples3(ABuffer buffer)
{
float[] vp = actual_v;
float[] tmpOut = _tmpOut;
int dvp = 0;
for (int i = 0; i < 32; i++)
{
float[] dp = d16[i];
float pcm_sample = ((vp[3 + dvp]*dp[0]) + (vp[2 + dvp]*dp[1]) + (vp[1 + dvp]*dp[2]) + (vp[0 + dvp]*dp[3]) +
(vp[15 + dvp]*dp[4]) + (vp[14 + dvp]*dp[5]) + (vp[13 + dvp]*dp[6]) + (vp[12 + dvp]*dp[7]) +
(vp[11 + dvp]*dp[8]) + (vp[10 + dvp]*dp[9]) + (vp[9 + dvp]*dp[10]) + (vp[8 + dvp]*dp[11]) +
(vp[7 + dvp]*dp[12]) + (vp[6 + dvp]*dp[13]) + (vp[5 + dvp]*dp[14]) + (vp[4 + dvp]*dp[15]))*
scalefactor;
tmpOut[i] = pcm_sample;
dvp += 16;
}
}
private void compute_pcm_samples2(ABuffer buffer)
{
float[] vp = actual_v;
//int inc = v_inc;
float[] tmpOut = _tmpOut;
int dvp = 0;
// fat chance of having this loop unroll
for (int i = 0; i < 32; i++)
{
float[] dp = d16[i];
float pcm_sample;
pcm_sample =
((vp[2 + dvp]*dp[0]) + (vp[1 + dvp]*dp[1]) + (vp[0 + dvp]*dp[2]) + (vp[15 + dvp]*dp[3]) +
(vp[14 + dvp]*dp[4]) + (vp[13 + dvp]*dp[5]) + (vp[12 + dvp]*dp[6]) + (vp[11 + dvp]*dp[7]) +
(vp[10 + dvp]*dp[8]) + (vp[9 + dvp]*dp[9]) + (vp[8 + dvp]*dp[10]) + (vp[7 + dvp]*dp[11]) +
(vp[6 + dvp]*dp[12]) + (vp[5 + dvp]*dp[13]) + (vp[4 + dvp]*dp[14]) + (vp[3 + dvp]*dp[15]))*
scalefactor;
tmpOut[i] = pcm_sample;
dvp += 16;
}
// for
}
/// <summary>
/// Calculate 32 PCM samples and put the into the Obuffer-object.
/// </summary>
public void calculate_pcm_samples(ABuffer buffer)
{
compute_new_v();
compute_pcm_samples(buffer);
actual_write_pos = (actual_write_pos + 1) & 0xf;
actual_v = (actual_v == v1) ? v2 : v1;
// initialize samples[]:
//for (register float *floatp = samples + 32; floatp > samples; )
// *--floatp = 0.0f;
// MDM: this may not be necessary. The Layer III decoder always
// outputs 32 subband samples, but I haven't checked layer I & II.
for (int p = 0; p < 32; p++)
samples[p] = 0.0f;
}
private void compute_pcm_samples(ABuffer buffer)
{
switch (actual_write_pos)
{
case 0:
compute_pcm_samples0(buffer);
break;
case 1:
compute_pcm_samples1(buffer);
break;
case 2:
compute_pcm_samples2(buffer);
break;
case 3:
compute_pcm_samples3(buffer);
break;
case 4:
compute_pcm_samples4(buffer);
break;
case 5:
compute_pcm_samples5(buffer);
break;
case 6:
compute_pcm_samples6(buffer);
break;
case 7:
compute_pcm_samples7(buffer);
break;
case 8:
compute_pcm_samples8(buffer);
break;
case 9:
compute_pcm_samples9(buffer);
break;
case 10:
compute_pcm_samples10(buffer);
break;
case 11:
compute_pcm_samples11(buffer);
break;
case 12:
compute_pcm_samples12(buffer);
break;
case 13:
compute_pcm_samples13(buffer);
break;
case 14:
compute_pcm_samples14(buffer);
break;
case 15:
compute_pcm_samples15(buffer);
break;
}
if (buffer != null)
{
buffer.AppendSamples(channel, _tmpOut);
}
}
