AVResampleContext *swr_resample_init(AVResampleContext *c, int out_rate, int in_rate, int filter_size, int phase_shift, int linear, double cutoff){

    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 = av_mallocz(sizeof(AVResampleContext));

        if (!c)

            return NULL;



        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_bank   = av_mallocz(c->filter_length*(phase_count+1)*sizeof(FELEM));

        if (!c->filter_bank)

            goto error;

        if (build_filter(c->filter_bank, factor, c->filter_length, phase_count, 1<<FILTER_SHIFT, WINDOW_TYPE))

            goto error;

        memcpy(&c->filter_bank[c->filter_length*phase_count+1], c->filter_bank, (c->filter_length-1)*sizeof(FELEM));

        c->filter_bank[c->filter_length*phase_count]= c->filter_bank[c->filter_length - 1];

    }



    c->compensation_distance= 0;

    c->src_incr= out_rate;

    c->ideal_dst_incr= c->dst_incr= in_rate * phase_count;

    c->index= -phase_count*((c->filter_length-1)/2);

    c->frac= 0;



    return c;

error:

    av_free(c->filter_bank);

    av_free(c);

    return NULL;

}
