Function init_pass2

libavcodec/ratecontrol.c:333–494

}

static int init_pass2(MPVMainEncContext *const m)
{
    RateControlContext *const rcc = &m->rc_context;
    MPVEncContext      *const   s = &m->s;
    AVCodecContext     *const avctx = s->c.avctx;
    int i, toobig;
    AVRational fps         = get_fpsQ(avctx);
    double complexity[5]   = { 0 }; // approximate bits at quant=1
    uint64_t const_bits[5] = { 0 }; // quantizer independent bits
    uint64_t all_const_bits;
    uint64_t all_available_bits = av_rescale_q(m->bit_rate,
                                               (AVRational){rcc->num_entries,1},
                                               fps);
    double rate_factor          = 0;
    double step;
    const int filter_size = (int)(avctx->qblur * 4) | 1;
    double expected_bits = 0; // init to silence gcc warning
    double *qscale, *blurred_qscale, qscale_sum;

    /* find complexity & const_bits & decide the pict_types */
    for (i = 0; i < rcc->num_entries; i++) {
        RateControlEntry *rce = &rcc->entry[i];

        rce->new_pict_type                = rce->pict_type;
        rcc->i_cplx_sum[rce->pict_type]  += rce->i_tex_bits * rce->qscale;
        rcc->p_cplx_sum[rce->pict_type]  += rce->p_tex_bits * rce->qscale;
        rcc->mv_bits_sum[rce->pict_type] += rce->mv_bits;
        rcc->frame_count[rce->pict_type]++;

        complexity[rce->new_pict_type] += (rce->i_tex_bits + rce->p_tex_bits) *
                                          (double)rce->qscale;
        const_bits[rce->new_pict_type] += rce->mv_bits + rce->misc_bits;
    }

    all_const_bits = const_bits[AV_PICTURE_TYPE_I] +
                     const_bits[AV_PICTURE_TYPE_P] +
                     const_bits[AV_PICTURE_TYPE_B];

    if (all_available_bits < all_const_bits) {
        av_log(avctx, AV_LOG_ERROR, "requested bitrate is too low\n");
        return -1;
    }

    qscale         = av_malloc_array(rcc->num_entries, sizeof(double));
    blurred_qscale = av_malloc_array(rcc->num_entries, sizeof(double));
    if (!qscale || !blurred_qscale) {
        av_free(qscale);
        av_free(blurred_qscale);
        return AVERROR(ENOMEM);
    }
    toobig = 0;

    for (step = 256 * 256; step > 0.0000001; step *= 0.5) {
        expected_bits = 0;
        rate_factor  += step;

        rcc->buffer_index = avctx->rc_buffer_size / 2;