diff options
Diffstat (limited to 'libswresample/resample_template.c')
| -rw-r--r-- | libswresample/resample_template.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/libswresample/resample_template.c b/libswresample/resample_template.c new file mode 100644 index 0000000000..7e80ef995a --- /dev/null +++ b/libswresample/resample_template.c @@ -0,0 +1,187 @@ +/* + * audio resampling + * Copyright (c) 2004-2012 Michael Niedermayer <michaelni@gmx.at> + * + * 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 + */ + +/** + * @file + * audio resampling + * @author Michael Niedermayer <michaelni@gmx.at> + */ + +#if defined(TEMPLATE_RESAMPLE_DBL) + +# define RENAME(N) N ## _double +# define FILTER_SHIFT 0 +# define DELEM double +# define FELEM double +# define FELEM2 double +# define OUT(d, v) d = v + +#elif defined(TEMPLATE_RESAMPLE_FLT) + +# define RENAME(N) N ## _float +# define FILTER_SHIFT 0 +# define DELEM float +# define FELEM float +# define FELEM2 float +# define OUT(d, v) d = v + +#elif defined(TEMPLATE_RESAMPLE_S32) + +# define RENAME(N) N ## _int32 +# define FILTER_SHIFT 30 +# define DELEM int32_t +# define FELEM int32_t +# define FELEM2 int64_t +# define FELEM_MAX INT32_MAX +# define FELEM_MIN INT32_MIN +# define OUT(d, v) (v) = ((v) + (1<<(FILTER_SHIFT-1)))>>FILTER_SHIFT;\ + (d) = (uint64_t)((v) + 0x80000000) > 0xFFFFFFFF ? ((v)>>63) ^ 0x7FFFFFFF : (v) + +#elif defined(TEMPLATE_RESAMPLE_S16) + +# define RENAME(N) N ## _int16 +# define FILTER_SHIFT 15 +# define DELEM int16_t +# define FELEM int16_t +# define FELEM2 int32_t +# define FELEML int64_t +# define FELEM_MAX INT16_MAX +# define FELEM_MIN INT16_MIN +# define OUT(d, v) (v) = ((v) + (1<<(FILTER_SHIFT-1)))>>FILTER_SHIFT;\ + (d) = (unsigned)((v) + 32768) > 65535 ? ((v)>>31) ^ 32767 : (v) + +#endif + +static void RENAME(resample_one)(void *dest, const void *source, + int dst_size, int64_t index2, int64_t incr) +{ + DELEM *dst = dest; + const DELEM *src = source; + int dst_index; + + for (dst_index = 0; dst_index < dst_size; dst_index++) { + dst[dst_index] = src[index2 >> 32]; + index2 += incr; + } +} + +static int RENAME(resample_common)(ResampleContext *c, + void *dest, const void *source, + int n, int update_ctx) +{ + DELEM *dst = dest; + const DELEM *src = source; + int dst_index; + int index= c->index; + int frac= c->frac; + int sample_index = index >> c->phase_shift; + + index &= c->phase_mask; + for (dst_index = 0; dst_index < n; dst_index++) { + FELEM *filter = ((FELEM *) c->filter_bank) + c->filter_alloc * index; + + FELEM2 val=0; + int i; + for (i = 0; i < c->filter_length; i++) { + val += src[sample_index + i] * (FELEM2)filter[i]; + } + OUT(dst[dst_index], val); + + frac += c->dst_incr_mod; + index += c->dst_incr_div; + if (frac >= c->src_incr) { + frac -= c->src_incr; + index++; + } + sample_index += index >> c->phase_shift; + index &= c->phase_mask; + } + + if(update_ctx){ + c->frac= frac; + c->index= index; + } + + return sample_index; +} + +static int RENAME(resample_linear)(ResampleContext *c, + void *dest, const void *source, + int n, int update_ctx) +{ + DELEM *dst = dest; + const DELEM *src = source; + int dst_index; + int index= c->index; + int frac= c->frac; + int sample_index = index >> c->phase_shift; +#if FILTER_SHIFT == 0 + double inv_src_incr = 1.0 / c->src_incr; +#endif + + index &= c->phase_mask; + for (dst_index = 0; dst_index < n; dst_index++) { + FELEM *filter = ((FELEM *) c->filter_bank) + c->filter_alloc * index; + FELEM2 val=0, v2 = 0; + + int i; + for (i = 0; i < c->filter_length; i++) { + val += src[sample_index + i] * (FELEM2)filter[i]; + v2 += src[sample_index + i] * (FELEM2)filter[i + c->filter_alloc]; + } +#ifdef FELEML + val += (v2 - val) * (FELEML) frac / c->src_incr; +#else +# if FILTER_SHIFT == 0 + val += (v2 - val) * inv_src_incr * frac; +# else + val += (v2 - val) / c->src_incr * frac; +# endif +#endif + OUT(dst[dst_index], val); + + frac += c->dst_incr_mod; + index += c->dst_incr_div; + if (frac >= c->src_incr) { + frac -= c->src_incr; + index++; + } + sample_index += index >> c->phase_shift; + index &= c->phase_mask; + } + + if(update_ctx){ + c->frac= frac; + c->index= index; + } + + return sample_index; +} + +#undef RENAME +#undef FILTER_SHIFT +#undef DELEM +#undef FELEM +#undef FELEM2 +#undef FELEML +#undef FELEM_MAX +#undef FELEM_MIN +#undef OUT |