How to find musical key of a given sample?

[apoorv569]

I am trying to implement key detection for a application that I am developing. Basically I want the key as in "A" "A#" "C" "F#" etc, but I will do the freq to key conversion later. I am using aubio_pitch but it is not working as intended.

    float cUtils::GetMusicalKey(const std::string& path)
    {
        uint_t buff_size = 1024, hop_size = buff_size / 4, frames = 0, samplerate = 0, read = 0;
        aubio_pitch_t* pitch;
        fvec_t* in, *out;
        aubio_source_t* source = new_aubio_source(path.c_str(), samplerate, hop_size);

        float key = 0.0f;

        if (!source)
            return 0.0f;
        else
        {
            try
            {
                if (samplerate == 0)
                    samplerate = aubio_source_get_samplerate(source);

                pitch = new_aubio_pitch("default", buff_size, hop_size, samplerate);

                if (!pitch)
                    return 0.0f;

                in = new_fvec(hop_size);
                out = new_fvec(1);

                do
                {
                    aubio_source_do(source, in, &read);
                    aubio_pitch_do(pitch, in, out);

                    frames ++;

                    key = fvec_get_sample(out, 0);
                }
                while (read == hop_size);

                if (new_aubio_pitch("default", buff_size, hop_size, samplerate))
                {
                    SH_LOG_DEBUG("Track: {}, with confidence: {}, silence: {}, tolerance: {} key: {}",
                                 path, aubio_pitch_get_confidence(pitch), aubio_pitch_get_silence(pitch), aubio_pitch_get_tolerance(pitch), key);
                }

                if (aubio_pitch_set_unit(pitch, "Hz"))
                    SH_LOG_DEBUG("Pitch unit set to Hz");

                // Clean up memory
                del_aubio_pitch(pitch);
                del_fvec(out);
                del_fvec(in);
                del_aubio_source(source);
                aubio_cleanup();
            }
            catch (std::exception& e)
            {
                SH_LOG_ERROR("Aubio Error! {}", e.what());
            }
        }

        return key;
    }