unsigned int AmAudio::downMix(unsigned int size)
{
unsigned int s = size;
if(fmt->channels == 2){
stereo2mono(samples.back_buffer(),(unsigned char*)samples,s);
samples.swap();
}
#ifdef USE_LIBSAMPLERATE
if (fmt->rate != SYSTEM_SAMPLERATE) {
if (!resample_state) {
int src_error;
// for better quality but more CPU usage, use SRC_SINC_ converters
resample_state = src_new(SRC_LINEAR, 1, &src_error);
if (!resample_state) {
ERROR("samplerate initialization error: ");
}
}
if (resample_state) {
if (resample_buf_samples + PCM16_B2S(s) > PCM16_B2S(AUDIO_BUFFER_SIZE) * 2) {
WARN("resample input buffer overflow! (%d)\n",
resample_buf_samples + PCM16_B2S(s));
} else {
signed short* samples_s = (signed short*)(unsigned char*)samples;
src_short_to_float_array(samples_s, &resample_in[resample_buf_samples], PCM16_B2S(s));
resample_buf_samples += PCM16_B2S(s);
}
SRC_DATA src_data;
src_data.data_in = resample_in;
src_data.input_frames = resample_buf_samples;
src_data.data_out = resample_out;
src_data.output_frames = PCM16_B2S(AUDIO_BUFFER_SIZE);
src_data.src_ratio = (double)SYSTEM_SAMPLERATE / (double)fmt->rate;
src_data.end_of_input = 0;
int src_err = src_process(resample_state, &src_data);
if (src_err) {
DBG("resample error: '%s'\n", src_strerror(src_err));
}else {
signed short* samples_s = (signed short*)(unsigned char*)samples;
src_float_to_short_array(resample_out, samples_s, src_data.output_frames_gen);
s = PCM16_S2B(src_data.output_frames_gen);
if (resample_buf_samples != (unsigned int)src_data.input_frames_used) {
memmove(resample_in, &resample_in[src_data.input_frames_used],
(resample_buf_samples - src_data.input_frames_used) * sizeof(float));
}
resample_buf_samples = resample_buf_samples - src_data.input_frames_used;
}
}
}
#endif
return s;
}
unsigned int AmAudio::downMix(unsigned int size)
{
unsigned int s = size;
if(fmt->channels == 2){
stereo2mono(samples.back_buffer(),(unsigned char*)samples,s);
samples.swap();
}
return s;
}
