| /* |
| * 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> |
| */ |
| |
| int RENAME(swri_resample)(ResampleContext *c, DELEM *dst, const DELEM *src, int *consumed, int src_size, int dst_size, int update_ctx){ |
| int dst_index, i; |
| int index= c->index; |
| int frac= c->frac; |
| int dst_incr_frac= c->dst_incr % c->src_incr; |
| int dst_incr= c->dst_incr / c->src_incr; |
| int compensation_distance= c->compensation_distance; |
| |
| av_assert1(c->filter_shift == FILTER_SHIFT); |
| av_assert1(c->felem_size == sizeof(FELEM)); |
| |
| if(compensation_distance == 0 && c->filter_length == 1 && c->phase_shift==0){ |
| int64_t index2= ((int64_t)index)<<32; |
| int64_t incr= (1LL<<32) * c->dst_incr / c->src_incr; |
| dst_size= FFMIN(dst_size, (src_size-1-index) * (int64_t)c->src_incr / c->dst_incr); |
| |
| for(dst_index=0; dst_index < dst_size; dst_index++){ |
| dst[dst_index] = src[index2>>32]; |
| index2 += incr; |
| } |
| index += dst_index * dst_incr; |
| index += (frac + dst_index * (int64_t)dst_incr_frac) / c->src_incr; |
| frac = (frac + dst_index * (int64_t)dst_incr_frac) % c->src_incr; |
| }else{ |
| for(dst_index=0; dst_index < dst_size; dst_index++){ |
| FELEM *filter= ((FELEM*)c->filter_bank) + c->filter_length*(index & c->phase_mask); |
| int sample_index= index >> c->phase_shift; |
| FELEM2 val=0; |
| |
| if(sample_index + c->filter_length > src_size || -sample_index >= src_size){ |
| break; |
| }else if(sample_index < 0){ |
| for(i=0; i<c->filter_length; i++) |
| val += src[FFABS(sample_index + i)] * filter[i]; |
| }else if(c->linear){ |
| FELEM2 v2=0; |
| 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_length]; |
| } |
| val+=(v2-val)*(FELEML)frac / c->src_incr; |
| }else{ |
| for(i=0; i<c->filter_length; i++){ |
| val += src[sample_index + i] * (FELEM2)filter[i]; |
| } |
| } |
| |
| OUT(dst[dst_index], val); |
| |
| frac += dst_incr_frac; |
| index += dst_incr; |
| if(frac >= c->src_incr){ |
| frac -= c->src_incr; |
| index++; |
| } |
| |
| if(dst_index + 1 == compensation_distance){ |
| compensation_distance= 0; |
| dst_incr_frac= c->ideal_dst_incr % c->src_incr; |
| dst_incr= c->ideal_dst_incr / c->src_incr; |
| } |
| } |
| } |
| *consumed= FFMAX(index, 0) >> c->phase_shift; |
| if(index>=0) index &= c->phase_mask; |
| |
| if(compensation_distance){ |
| compensation_distance -= dst_index; |
| assert(compensation_distance > 0); |
| } |
| if(update_ctx){ |
| c->frac= frac; |
| c->index= index; |
| c->dst_incr= dst_incr_frac + c->src_incr*dst_incr; |
| c->compensation_distance= compensation_distance; |
| } |
| #if 0 |
| if(update_ctx && !c->compensation_distance){ |
| #undef rand |
| av_resample_compensate(c, rand() % (8000*2) - 8000, 8000*2); |
| av_log(NULL, AV_LOG_DEBUG, "%d %d %d\n", c->dst_incr, c->ideal_dst_incr, c->compensation_distance); |
| } |
| #endif |
| |
| return dst_index; |
| } |