diff options
author | Lynne <dev@lynne.ee> | 2019-03-15 17:35:03 +0300 |
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committer | Carl Eugen Hoyos <ceffmpeg@gmail.com> | 2019-04-01 01:19:14 +0300 |
commit | 0cea3ca8943b5a3f28a3672037f424b4d03853b8 (patch) | |
tree | c7056e3dca217790886df80a44d6ba5e2d24584c /libavcodec/opusdsp.c | |
parent | 5468c1d075166fa1a8fea217b07e30abc6bdc4b1 (diff) |
opusdsp: create and move deemphasis and postfiltering from opus_celt
Diffstat (limited to 'libavcodec/opusdsp.c')
-rw-r--r-- | libavcodec/opusdsp.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/libavcodec/opusdsp.c b/libavcodec/opusdsp.c new file mode 100644 index 0000000000..615e7d6816 --- /dev/null +++ b/libavcodec/opusdsp.c @@ -0,0 +1,61 @@ +/* + * 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 "opusdsp.h" + +static void postfilter_c(float *data, int period, float *gains, int len) +{ + const float g0 = gains[0]; + const float g1 = gains[1]; + const float g2 = gains[2]; + + float x4 = data[-period - 2]; + float x3 = data[-period - 1]; + float x2 = data[-period + 0]; + float x1 = data[-period + 1]; + + for (int i = 0; i < len; i++) { + float x0 = data[i - period + 2]; + data[i] += g0 * x2 + + g1 * (x1 + x3) + + g2 * (x0 + x4); + x4 = x3; + x3 = x2; + x2 = x1; + x1 = x0; + } +} + +static float deemphasis_c(float *y, float *x, float coeff, int len) +{ + float state = coeff; + + for (int i = 0; i < len; i++) { + const float tmp = x[i] + state; + state = tmp * CELT_EMPH_COEFF; + y[i] = tmp; + } + + return state; +} + +av_cold void ff_opus_dsp_init(OpusDSP *ctx) +{ + ctx->postfilter = postfilter_c; + ctx->deemphasis = deemphasis_c; +} |