static ResampleContext *resample_init(ResampleContext *c, int out_rate, int in_rate, int filter_size, int phase_shift, int linear, double cutoff0, enum AVSampleFormat format, enum SwrFilterType filter_type, int kaiser_beta, double precision, int cheby){ double cutoff = cutoff0? cutoff0 : 0.97; double factor= FFMIN(out_rate * cutoff / in_rate, 1.0); int phase_count= 1<<phase_shift; if (!c || c->phase_shift != phase_shift || c->linear!=linear || c->factor != factor || c->filter_length != FFMAX((int)ceil(filter_size/factor), 1) || c->format != format || c->filter_type != filter_type || c->kaiser_beta != kaiser_beta) { c = av_mallocz(sizeof(*c)); if (!c) return NULL; c->format= format; c->felem_size= av_get_bytes_per_sample(c->format); switch(c->format){ case AV_SAMPLE_FMT_S16P: c->filter_shift = 15; break; case AV_SAMPLE_FMT_S32P: c->filter_shift = 30; break; case AV_SAMPLE_FMT_FLTP: case AV_SAMPLE_FMT_DBLP: c->filter_shift = 0; break; default: av_log(NULL, AV_LOG_ERROR, "Unsupported sample format\n"); av_assert0(0); c->phase_shift = phase_shift; c->phase_mask = phase_count - 1; c->linear = linear; c->factor = factor; c->filter_length = FFMAX((int)ceil(filter_size/factor), 1); c->filter_alloc = FFALIGN(c->filter_length, 8); c->filter_bank = av_calloc(c->filter_alloc, (phase_count+1)*c->felem_size); c->filter_type = filter_type; c->kaiser_beta = kaiser_beta; if (!c->filter_bank) if (build_filter(c, (void*)c->filter_bank, factor, c->filter_length, c->filter_alloc, phase_count, 1<<c->filter_shift, filter_type, kaiser_beta)) memcpy(c->filter_bank + (c->filter_alloc*phase_count+1)*c->felem_size, c->filter_bank, (c->filter_alloc-1)*c->felem_size); memcpy(c->filter_bank + (c->filter_alloc*phase_count )*c->felem_size, c->filter_bank + (c->filter_alloc - 1)*c->felem_size, c->felem_size); c->compensation_distance= 0; if(!av_reduce(&c->src_incr, &c->dst_incr, out_rate, in_rate * (int64_t)phase_count, INT32_MAX/2)) c->ideal_dst_incr= c->dst_incr; c->index= -phase_count*((c->filter_length-1)/2); c->frac= 0; return c; error: av_freep(&c->filter_bank); av_free(c); return NULL;