예제 #1
0
univector<T> correlate(const univector_ref<const T>& src1, const univector_ref<const T>& src2)
{
    const size_t size                = next_poweroftwo(src1.size() + src2.size() - 1);
    univector<complex<T>> src1padded = src1;
    univector<complex<T>> src2padded = reverse(src2);
    src1padded.resize(size, 0);
    src2padded.resize(size, 0);
    dft_plan_ptr<T> dft = dft_cache::instance().get(ctype_t<T>(), size);
    univector<u8> temp(dft->temp_size);
    dft->execute(src1padded, src1padded, temp);
    dft->execute(src2padded, src2padded, temp);
    src1padded = src1padded * src2padded;
    dft->execute(src1padded, src1padded, temp, true);
    const T invsize = reciprocal<T>(size);
    return truncate(real(src1padded), src1.size() + src2.size() - 1) * invsize;
}
예제 #2
0
    size_t process(univector<T, Tag>& output, univector_ref<const T> input)
    {
        const itype required_input_size = input_size_for_output(output.size());

        const itype input_size = input.size();
        for (size_t i = 0; i < output.size(); i++)
        {
            const itype intermediate_index =
                output_position_to_intermediate(static_cast<itype>(i) + output_position);
            const itype intermediate_start = intermediate_index - taps + 1;
            const std::lldiv_t input_pos =
                floor_div(intermediate_start + interpolation_factor - 1, interpolation_factor);
            const itype input_start        = input_pos.quot; // first input sample
            const itype tap_start          = interpolation_factor - 1 - input_pos.rem;
            const univector_ref<T> tap_ptr = filter.slice(static_cast<size_t>(tap_start * depth));

            if (input_start >= input_position + input_size)
            {
                output[i] = T(0);
            }
            else if (input_start >= input_position)
            {
                output[i] = dotproduct(input.slice(input_start - input_position, depth), tap_ptr);
            }
            else
            {
                const itype prev_count = input_position - input_start;
                output[i]              = dotproduct(delay.slice(size_t(depth - prev_count)), tap_ptr) +
                            dotproduct(input.slice(0, size_t(depth - prev_count)),
                                       tap_ptr.slice(size_t(prev_count), size_t(depth - prev_count)));
            }
        }

        if (required_input_size >= depth)
        {
            delay.slice(0, delay.size()) = padded(input.slice(size_t(required_input_size - depth)));
        }
        else
        {
            delay.truncate(size_t(depth - required_input_size)) = delay.slice(size_t(required_input_size));
            delay.slice(size_t(depth - required_input_size))    = padded(input);
        }

        input_position += required_input_size;
        output_position += output.size();

        return required_input_size;
    }