unsafe int encode_frame(out int size)
{
fixed (int* s = samplesBuffer, r = residualBuffer)
fixed (float* window = windowBuffer)
{
frame.InitSize(eparams.block_size, eparams.variable_block_size != 0);
if (frame.blocksize != _windowsize && frame.blocksize > 4)
{
_windowsize = frame.blocksize;
_windowcount = 0;
calculate_window(window, lpc.window_welch, WindowFunction.Welch);
calculate_window(window, lpc.window_tukey, WindowFunction.Tukey);
calculate_window(window, lpc.window_flattop, WindowFunction.Flattop);
calculate_window(window, lpc.window_hann, WindowFunction.Hann);
calculate_window(window, lpc.window_bartlett, WindowFunction.Bartlett);
if (_windowcount == 0)
throw new Exception("invalid windowfunction");
}
if (channels != 2 || frame.blocksize <= 32 || eparams.stereo_method == StereoMethod.Independent)
{
frame.window_buffer = window;
frame.current.residual = r + channels * Flake.MAX_BLOCKSIZE;
frame.ch_mode = channels != 2 ? ChannelMode.NotStereo : ChannelMode.LeftRight;
for (int ch = 0; ch < channels; ch++)
frame.subframes[ch].Init(s + ch * Flake.MAX_BLOCKSIZE, r + ch * Flake.MAX_BLOCKSIZE,
_pcm.BitsPerSample, get_wasted_bits(s + ch * Flake.MAX_BLOCKSIZE, frame.blocksize));
for (int ch = 0; ch < channels; ch++)
encode_residual_pass2(frame, ch);
}
else
{
//channel_decorrelation(s, s + Flake.MAX_BLOCKSIZE, s + 2 * Flake.MAX_BLOCKSIZE, s + 3 * Flake.MAX_BLOCKSIZE, frame.blocksize);
frame.window_buffer = window;
frame.current.residual = r + 4 * Flake.MAX_BLOCKSIZE;
for (int ch = 0; ch < 4; ch++)
frame.subframes[ch].Init(s + ch * Flake.MAX_BLOCKSIZE, r + ch * Flake.MAX_BLOCKSIZE,
_pcm.BitsPerSample + (ch == 3 ? 1 : 0), get_wasted_bits(s + ch * Flake.MAX_BLOCKSIZE, frame.blocksize));
//for (int ch = 0; ch < 4; ch++)
// for (int iWindow = 0; iWindow < _windowcount; iWindow++)
// frame.subframes[ch].lpc_ctx[iWindow].GetReflection(32, frame.subframes[ch].samples, frame.blocksize, frame.window_buffer + iWindow * Flake.MAX_BLOCKSIZE * 2);
estimate_frame(frame, true);
uint fs = measure_frame_size(frame, true);
if (0 != eparams.variable_block_size)
{
FlacFrame frame2 = new FlacFrame(channels * 2);
FlacFrame frame3 = new FlacFrame(channels * 2);
int tumbler = 1;
while ((frame.blocksize & 1) == 0 && frame.blocksize >= 1024)
{
frame2.InitSize(frame.blocksize / 2, true);
frame2.window_buffer = frame.window_buffer + frame.blocksize;
frame2.current.residual = r + tumbler * 5 * Flake.MAX_BLOCKSIZE;
for (int ch = 0; ch < 4; ch++)
frame2.subframes[ch].Init(frame.subframes[ch].samples, frame2.current.residual + (ch + 1) * frame2.blocksize,
frame.subframes[ch].obits + frame.subframes[ch].wbits, frame.subframes[ch].wbits);
estimate_frame(frame2, true);
uint fs2 = measure_frame_size(frame2, true);
uint fs3 = fs2;
if (eparams.variable_block_size == 2 || eparams.variable_block_size == 4)
{
frame3.InitSize(frame2.blocksize, true);
frame3.window_buffer = frame2.window_buffer;
frame3.current.residual = frame2.current.residual + 5 * frame2.blocksize;
for (int ch = 0; ch < 4; ch++)
frame3.subframes[ch].Init(frame2.subframes[ch].samples + frame2.blocksize, frame3.current.residual + (ch + 1) * frame3.blocksize,
frame.subframes[ch].obits + frame.subframes[ch].wbits, frame.subframes[ch].wbits);
estimate_frame(frame3, true);
fs3 = measure_frame_size(frame3, true);
}
if (fs2 + fs3 > fs)
break;
FlacFrame tmp = frame;
frame = frame2;
frame2 = tmp;
fs = fs2;
if (eparams.variable_block_size <= 2)
break;
tumbler = 1 - tumbler;
}
}
frame.ChooseSubframes();
encode_estimated_frame(frame);
}
BitWriter bitwriter = new BitWriter(frame_buffer, 0, max_frame_size);
output_frame_header(frame, bitwriter);
output_subframes(frame, bitwriter);
output_frame_footer(bitwriter);
if (bitwriter.Length >= max_frame_size)
throw new Exception("buffer overflow");
if (frame_buffer != null)
{
if (eparams.variable_block_size > 0)
frame_count += frame.blocksize;
else
frame_count++;
}
size = frame.blocksize;
return bitwriter.Length;
}
}