diff options
Diffstat (limited to 'media/ffvpx/libavcodec/flacdsp_lpc_template.c')
| -rw-r--r-- | media/ffvpx/libavcodec/flacdsp_lpc_template.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/media/ffvpx/libavcodec/flacdsp_lpc_template.c b/media/ffvpx/libavcodec/flacdsp_lpc_template.c new file mode 100644 index 0000000000..dd847d3b32 --- /dev/null +++ b/media/ffvpx/libavcodec/flacdsp_lpc_template.c @@ -0,0 +1,159 @@ +/* + * 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. + */ |