| /* | |
| * This file is part of FFmpeg. | |
| * | |
| * FFmpeg is free software; you can redistribute it and/or | |
| * modify it under the terms of the GNU Lesser General Public | |
| * License as published by the Free Software Foundation; either | |
| * version 2.1 of the License, or (at your option) any later version. | |
| * | |
| * FFmpeg is distributed in the hope that it will be useful, | |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| * Lesser General Public License for more details. | |
| * | |
| * You should have received a copy of the GNU Lesser General Public | |
| * License along with FFmpeg; if not, write to the Free Software | |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
| */ | |
| #include <stdint.h> | |
| #include "libavutil/common.h" | |
| #include "mathops.h" | |
| #undef FUNC | |
| #undef sum_type | |
| #undef MUL | |
| #undef CLIP | |
| #undef FSUF | |
| #define FUNC(n) AV_JOIN(n ## _, SAMPLE_SIZE) | |
| #if SAMPLE_SIZE == 32 | |
| # define sum_type int64_t | |
| # define MUL(a, b) MUL64(a, b) | |
| # define CLIP(x) av_clipl_int32(x) | |
| #else | |
| # define sum_type int32_t | |
| # define MUL(a, b) ((a) * (b)) | |
| # define CLIP(x) (x) | |
| #endif | |
| #define LPC1(x) { \ | |
| int c = coefs[(x)-1]; \ | |
| p0 += MUL(c, s); \ | |
| s = smp[i-(x)+1]; \ | |
| p1 += MUL(c, s); \ | |
| } | |
| static av_always_inline void FUNC(lpc_encode_unrolled)(int32_t *res, | |
| const int32_t *smp, int len, int order, | |
| const int32_t *coefs, int shift, int big) | |
| { | |
| int i; | |
| for (i = order; i < len; i += 2) { | |
| int s = smp[i-order]; | |
| sum_type p0 = 0, p1 = 0; | |
| if (big) { | |
| switch (order) { | |
| case 32: LPC1(32) | |
| case 31: LPC1(31) | |
| case 30: LPC1(30) | |
| case 29: LPC1(29) | |
| case 28: LPC1(28) | |
| case 27: LPC1(27) | |
| case 26: LPC1(26) | |
| case 25: LPC1(25) | |
| case 24: LPC1(24) | |
| case 23: LPC1(23) | |
| case 22: LPC1(22) | |
| case 21: LPC1(21) | |
| case 20: LPC1(20) | |
| case 19: LPC1(19) | |
| case 18: LPC1(18) | |
| case 17: LPC1(17) | |
| case 16: LPC1(16) | |
| case 15: LPC1(15) | |
| case 14: LPC1(14) | |
| case 13: LPC1(13) | |
| case 12: LPC1(12) | |
| case 11: LPC1(11) | |
| case 10: LPC1(10) | |
| case 9: LPC1( 9) | |
| LPC1( 8) | |
| LPC1( 7) | |
| LPC1( 6) | |
| LPC1( 5) | |
| LPC1( 4) | |
| LPC1( 3) | |
| LPC1( 2) | |
| LPC1( 1) | |
| } | |
| } else { | |
| switch (order) { | |
| case 8: LPC1( 8) | |
| case 7: LPC1( 7) | |
| case 6: LPC1( 6) | |
| case 5: LPC1( 5) | |
| case 4: LPC1( 4) | |
| case 3: LPC1( 3) | |
| case 2: LPC1( 2) | |
| case 1: LPC1( 1) | |
| } | |
| } | |
| res[i ] = smp[i ] - CLIP(p0 >> shift); | |
| res[i+1] = smp[i+1] - CLIP(p1 >> shift); | |
| } | |
| } | |
| static void FUNC(flac_lpc_encode_c)(int32_t *res, const int32_t *smp, int len, | |
| int order, const int32_t *coefs, int shift) | |
| { | |
| int i; | |
| for (i = 0; i < order; i++) | |
| res[i] = smp[i]; | |
| #if CONFIG_SMALL | |
| for (i = order; i < len; i += 2) { | |
| int j; | |
| int s = smp[i]; | |
| sum_type p0 = 0, p1 = 0; | |
| for (j = 0; j < order; j++) { | |
| int c = coefs[j]; | |
| p1 += MUL(c, s); | |
| s = smp[i-j-1]; | |
| p0 += MUL(c, s); | |
| } | |
| res[i ] = smp[i ] - CLIP(p0 >> shift); | |
| res[i+1] = smp[i+1] - CLIP(p1 >> shift); | |
| } | |
| #else | |
| switch (order) { | |
| case 1: FUNC(lpc_encode_unrolled)(res, smp, len, 1, coefs, shift, 0); break; | |
| case 2: FUNC(lpc_encode_unrolled)(res, smp, len, 2, coefs, shift, 0); break; | |
| case 3: FUNC(lpc_encode_unrolled)(res, smp, len, 3, coefs, shift, 0); break; | |
| case 4: FUNC(lpc_encode_unrolled)(res, smp, len, 4, coefs, shift, 0); break; | |
| case 5: FUNC(lpc_encode_unrolled)(res, smp, len, 5, coefs, shift, 0); break; | |
| case 6: FUNC(lpc_encode_unrolled)(res, smp, len, 6, coefs, shift, 0); break; | |
| case 7: FUNC(lpc_encode_unrolled)(res, smp, len, 7, coefs, shift, 0); break; | |
| case 8: FUNC(lpc_encode_unrolled)(res, smp, len, 8, coefs, shift, 0); break; | |
| default: FUNC(lpc_encode_unrolled)(res, smp, len, order, coefs, shift, 1); break; | |
| } | |
| #endif | |
| } | |
| /* Comment for clarity/de-obfuscation. | |
| * | |
| * for (int i = order; i < len; i++) { | |
| * int32_t p = 0; | |
| * for (int j = 0; j < order; j++) { | |
| * int c = coefs[j]; | |
| * int s = smp[(i-1)-j]; | |
| * p += c*s; | |
| * } | |
| * res[i] = smp[i] - (p >> shift); | |
| * } | |
| * | |
| * The CONFIG_SMALL code above simplifies to this, in the case of SAMPLE_SIZE | |
| * not being equal to 32 (at the present time that means for 16-bit audio). The | |
| * code above does 2 samples per iteration. Commit bfdd5bc (made all the way | |
| * back in 2007) says that way is faster. | |
| */ |