void AudioBuffer::convert(const AudioSpec &_new_spec)
{
if(_new_spec == m_spec) {
return;
}
AudioSpec new_spec = _new_spec;
AudioBuffer dest[2];
unsigned bufidx = 0;
AudioBuffer *source = this;
if(source->rate() != new_spec.rate) {
#if HAVE_LIBSAMPLERATE
if(source->format() != AUDIO_FORMAT_F32) {
dest[1].set_spec({AUDIO_FORMAT_F32, source->channels(), source->rate()});
source->convert_format(dest[1], source->frames());
source = &dest[1];
}
dest[0].set_spec({source->format(), source->channels(), new_spec.rate});
source->convert_rate(dest[0], source->frames(), nullptr);
source = &dest[0];
bufidx = 1;
#else
new_spec.rate = source->rate();
#endif
}
if(source->channels() != new_spec.channels) {
dest[bufidx].set_spec({source->format(),new_spec.channels,source->rate()});
source->convert_channels(dest[bufidx], source->frames());
source = &dest[bufidx];
bufidx = (bufidx + 1) % 2;
}
if(source->format() != new_spec.format) {
dest[bufidx].set_spec({new_spec.format,source->channels(),source->rate()});
source->convert_format(dest[bufidx], source->frames());
source = &dest[bufidx];
}
if(new_spec != m_spec) {
m_data = source->m_data;
m_spec = new_spec;
}
}
void AudioBuffer::convert_rate(AudioBuffer &_dest, unsigned _frames_count, SRC_STATE *_SRC)
{
AudioSpec destspec{AUDIO_FORMAT_F32, m_spec.channels, _dest.rate()};
if(m_spec.format != AUDIO_FORMAT_F32 || _dest.spec() != destspec) {
throw std::logic_error("unsupported format");
}
_frames_count = std::min(frames(),_frames_count);
double rate_ratio = double(destspec.rate)/double(m_spec.rate);
unsigned out_frames = unsigned(ceil(double(_frames_count) * rate_ratio));
if(out_frames==0) {
return;
}
unsigned destpos = _dest.samples();
unsigned destframes = _dest.frames();
_dest.resize_frames(_dest.frames()+out_frames);
#if HAVE_LIBSAMPLERATE
SRC_DATA srcdata;
srcdata.data_in = &at<float>(0);
srcdata.data_out = &_dest.at<float>(destpos);
srcdata.input_frames = _frames_count;
srcdata.output_frames = out_frames;
srcdata.src_ratio = rate_ratio;
int srcresult;
if(_SRC != nullptr) {
srcdata.end_of_input = 0;
srcresult = src_process(_SRC, &srcdata);
} else {
srcdata.end_of_input = 1;
srcresult = src_simple(&srcdata, SRC_SINC_BEST_QUALITY, destspec.channels) ;
}
if(srcresult != 0) {
throw std::runtime_error(std::string("error resampling: ") + src_strerror(srcresult));
}
assert(srcdata.output_frames_gen>=0 && srcdata.output_frames_gen<=out_frames);
if(srcdata.output_frames_gen != out_frames) {
_dest.resize_frames(destframes + srcdata.output_frames_gen);
}
PDEBUGF(LOG_V2, LOG_MIXER, "convert rate: f-in: %d, f-out: %d, gen: %d\n",
_frames_count, out_frames, srcdata.output_frames_gen);
#else
for(unsigned i=destpos; i<_dest.samples(); ++i) {
_dest.operator[]<float>(i) = 0.f;
}
#endif
}