internal static int frame_size_select(int frame_size, OpusFramesize variable_duration, int Fs)
{
int new_size;
if (frame_size < Fs / 400)
{
return(-1);
}
if (variable_duration == OpusFramesize.OPUS_FRAMESIZE_ARG)
{
new_size = frame_size;
}
else if (variable_duration == OpusFramesize.OPUS_FRAMESIZE_VARIABLE)
{
new_size = Fs / 50;
}
else if (variable_duration >= OpusFramesize.OPUS_FRAMESIZE_2_5_MS && variable_duration <= OpusFramesize.OPUS_FRAMESIZE_60_MS)
{
new_size = Inlines.IMIN(3 * Fs / 50, (Fs / 400) << (variable_duration - OpusFramesize.OPUS_FRAMESIZE_2_5_MS));
}
else
{
return(-1);
}
if (new_size > frame_size)
{
return(-1);
}
if (400 * new_size != Fs && 200 * new_size != Fs && 100 * new_size != Fs &&
50 * new_size != Fs && 25 * new_size != Fs && 50 * new_size != 3 * Fs)
{
return(-1);
}
return(new_size);
}
internal static int compute_frame_size <T>(T[] analysis_pcm, int analysis_pcm_ptr, int frame_size,
OpusFramesize variable_duration, int C, int Fs, int bitrate_bps,
int delay_compensation, Downmix.downmix_func <T> downmix, float[] subframe_mem, bool analysis_enabled
)
{
if (analysis_enabled && variable_duration == OpusFramesize.OPUS_FRAMESIZE_VARIABLE && frame_size >= Fs / 200)
{
int LM = 3;
LM = optimize_framesize(analysis_pcm, analysis_pcm_ptr, frame_size, C, Fs, bitrate_bps,
0, subframe_mem, delay_compensation, downmix);
while ((Fs / 400 << LM) > frame_size)
{
LM--;
}
frame_size = (Fs / 400 << LM);
}
else
{
frame_size = frame_size_select(frame_size, variable_duration, Fs);
}
if (frame_size < 0)
{
return(-1);
}
return(frame_size);
}
internal int opus_multistream_encoder_init(
int Fs,
int channels,
int streams,
int coupled_streams,
byte[] mapping,
OpusApplication application,
int surround
)
{
int i, ret;
int encoder_ptr;
if ((channels > 255) || (channels < 1) || (coupled_streams > streams) ||
(streams < 1) || (coupled_streams < 0) || (streams > 255 - coupled_streams))
{
return(OpusError.OPUS_BAD_ARG);
}
this.layout.nb_channels = channels;
this.layout.nb_streams = streams;
this.layout.nb_coupled_streams = coupled_streams;
this.subframe_mem[0] = this.subframe_mem[1] = this.subframe_mem[2] = 0;
if (surround == 0)
{
this.lfe_stream = -1;
}
this.bitrate_bps = OpusConstants.OPUS_AUTO;
this.application = application;
this.variable_duration = OpusFramesize.OPUS_FRAMESIZE_ARG;
for (i = 0; i < this.layout.nb_channels; i++)
{
this.layout.mapping[i] = mapping[i];
}
if (OpusMultistream.validate_layout(this.layout) == 0 || validate_encoder_layout(this.layout) == 0)
{
return(OpusError.OPUS_BAD_ARG);
}
encoder_ptr = 0;
for (i = 0; i < this.layout.nb_coupled_streams; i++)
{
ret = this.encoders[encoder_ptr].opus_init_encoder(Fs, 2, application);
if (ret != OpusError.OPUS_OK)
{
return(ret);
}
if (i == this.lfe_stream)
{
this.encoders[encoder_ptr].IsLFE = true;
}
encoder_ptr += 1;
}
for (; i < this.layout.nb_streams; i++)
{
ret = this.encoders[encoder_ptr].opus_init_encoder(Fs, 1, application);
if (i == this.lfe_stream)
{
this.encoders[encoder_ptr].IsLFE = true;
}
if (ret != OpusError.OPUS_OK)
{
return(ret);
}
encoder_ptr += 1;
}
if (surround != 0)
{
Arrays.MemSetInt(this.preemph_mem, 0, channels);
Arrays.MemSetInt(this.window_mem, 0, channels * 120);
}
this.surround = surround;
return(OpusError.OPUS_OK);
}