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| package com.sun.media.sound; | |
| /** | |
| * A resampler that uses first-order (linear) interpolation. | |
| * | |
| * This one doesn't perform float to int casting inside the processing loop. | |
| * | |
| * @author Karl Helgason | |
| */ | |
| public final class SoftLinearResampler2 extends SoftAbstractResampler { | |
| @Override | |
| public int getPadding() { | |
| return 2; | |
| } | |
| @Override | |
| public void interpolate(float[] in, float[] in_offset, float in_end, | |
| float[] startpitch, float pitchstep, float[] out, int[] out_offset, | |
| int out_end) { | |
| float pitch = startpitch[0]; | |
| float ix = in_offset[0]; | |
| int ox = out_offset[0]; | |
| float ix_end = in_end; | |
| int ox_end = out_end; | |
| // Check if we have do anything | |
| if (!(ix < ix_end && ox < ox_end)) | |
| return; | |
| // 15 bit shift was chosen because | |
| // it resulted in no drift between p_ix and ix. | |
| int p_ix = (int) (ix * (1 << 15)); | |
| int p_ix_end = (int) (ix_end * (1 << 15)); | |
| int p_pitch = (int) (pitch * (1 << 15)); | |
| if (p_pitch == 0) { | |
| // If pitch falls below the minimum assume minimum pitch | |
| p_pitch = 1; | |
| } | |
| // Pitch needs to recalculated | |
| // to ensure no drift between p_ix and ix. | |
| pitch = p_pitch * (1f / (1 << 15)); | |
| if (pitchstep == 0f) { | |
| // To reduce | |
| // while (p_ix < p_ix_end && ox < ox_end) | |
| // into | |
| // while (ox < ox_end) | |
| // We need to calculate new ox_end value. | |
| int p_ix_len = p_ix_end - p_ix; | |
| int p_mod = p_ix_len % p_pitch; | |
| if (p_mod != 0) | |
| p_ix_len += p_pitch - p_mod; | |
| int ox_end2 = ox + p_ix_len / p_pitch; | |
| if (ox_end2 < ox_end) | |
| ox_end = ox_end2; | |
| while (ox < ox_end) { | |
| int iix = p_ix >> 15; | |
| float fix = ix - iix; | |
| float i = in[iix]; | |
| out[ox++] = i + (in[iix + 1] - i) * fix; | |
| p_ix += p_pitch; | |
| ix += pitch; | |
| } | |
| } else { | |
| int p_pitchstep = (int) (pitchstep * (1 << 15)); | |
| pitchstep = p_pitchstep * (1f / (1 << 15)); | |
| while (p_ix < p_ix_end && ox < ox_end) { | |
| int iix = p_ix >> 15; | |
| float fix = ix - iix; | |
| float i = in[iix]; | |
| out[ox++] = i + (in[iix + 1] - i) * fix; | |
| ix += pitch; | |
| p_ix += p_pitch; | |
| pitch += pitchstep; | |
| p_pitch += p_pitchstep; | |
| } | |
| } | |
| in_offset[0] = ix; | |
| out_offset[0] = ox; | |
| startpitch[0] = pitch; | |
| } | |
| } |