62 lines
1.9 KiB
C
62 lines
1.9 KiB
C
/* SoX Resampler Library Copyright (c) 2007-16 robs@users.sourceforge.net
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* Licence for this file: LGPL v2.1 See LICENCE for details. */
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/* Decimate by 2 using a FIR with odd length (LEN). */
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/* Input must be preceded and followed by LEN >> 1 samples. */
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#define COEFS ((sample_t const *)p->coefs)
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#if SIMD_SSE
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#define BEGINNING v4_t sum, q1, q2, t
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#define ____ \
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q1 = _mm_shuffle_ps(t=vLdu(input+2*j),vLdu(input+2*j+4),_MM_SHUFFLE(3,1,3,1)); \
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q2 = _mm_shuffle_ps(vLdu(input-2*j-4),vLdu(input-2*j-8),_MM_SHUFFLE(1,3,1,3)); \
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sum = vAdd(j? sum : vMul(vSet1(.5), t), vMul(vAdd(q1, q2), vLd(COEFS+j))); \
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j += 4;
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#define __ \
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q1 = _mm_shuffle_ps(vLdu(input+2*j), vLdu(input-2*j-4), _MM_SHUFFLE(1,3,3,1)); \
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q2 = _mm_loadl_pi(q2, (__m64*)(COEFS+j)), q2 = _mm_movelh_ps(q2, q2); \
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sum = vAdd(sum, vMul(q1, q2)); \
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j += 2;
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#define _ \
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q1 = _mm_add_ss(_mm_load_ss(input+2*j+1), _mm_load_ss(input-2*j-1)); \
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sum = _mm_add_ss(sum, _mm_mul_ss(q1, _mm_load_ss(COEFS+j))); \
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++j;
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#define END vStorSum(output+i, sum)
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/* #elif SIMD_AVX; No good solution found. */
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/* #elif SIMD_NEON; No need: gcc -O3 does a good job by itself. */
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#else
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#define BEGINNING sample_t sum = input[0] * .5f
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#define ____ __ __
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#define __ _ _
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#define _ sum += (input[-(2*j +1)] + input[(2*j +1)]) * COEFS[j], ++j;
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#define END output[i] = sum
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#endif
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static void FUNCTION_H(stage_t * p, fifo_t * output_fifo)
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{
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sample_t const * __restrict input = stage_read_p(p);
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int num_in = min(stage_occupancy(p), p->input_size);
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int i, num_out = (num_in + 1) >> 1;
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sample_t * __restrict output = fifo_reserve(output_fifo, num_out);
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for (i = 0; i < num_out; ++i, input += 2) {
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int j = 0;
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BEGINNING; CONVOLVE; END;
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}
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fifo_read(&p->fifo, 2 * num_out, NULL);
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}
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#undef _
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#undef __
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#undef ____
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#undef BEGINNING
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#undef END
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#undef COEFS
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#undef CONVOLVE
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#undef FUNCTION_H
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