| 36 | } |
| 37 | |
| 38 | int64_t reflect_index(int64_t index, int64_t length) { |
| 39 | while (index < 0 || index >= length) { |
| 40 | if (index < 0) { |
| 41 | index = -index; |
| 42 | } else { |
| 43 | index = 2 * length - index - 2; |
| 44 | } |
| 45 | } |
| 46 | return index; |
| 47 | } |
| 48 | |
| 49 | float hz_to_mel(float hz) { |
| 50 | constexpr float kFsp = 200.0f / 3.0f; |