Commit 07cfdf84 authored by Fiona Glaser's avatar Fiona Glaser

Reduce the aggressiveness of 2-pass VBV

Now that B-frames are properly covered, we don't have to be as aggressive.
This eliminates some issues with skyrocketing QPs in B-frames in 2-pass VBV.
parent a0b07e91
......@@ -1108,22 +1108,22 @@ void x264_ratecontrol_mb( x264_t *h, int bits )
if( y < h->sps->i_mb_height-1 )
{
int prev_row_qp = h->fdec->i_row_qp[y];
int b0 = predict_row_size_sum( h, y, rc->qpm );
int b1 = b0;
int i_qp_max = X264_MIN( prev_row_qp + h->param.rc.i_qp_step, h->param.rc.i_qp_max );
int i_qp_min = X264_MAX( prev_row_qp - h->param.rc.i_qp_step, h->param.rc.i_qp_min );
float buffer_left_planned = rc->buffer_fill - rc->frame_size_planned;
/* B-frames shouldn't use lower QP than their reference frames. */
if( h->sh.i_type == SLICE_TYPE_B )
i_qp_min = X264_MAX( i_qp_min, X264_MIN( h->fref0[0]->i_row_qp[y+1], h->fref1[0]->i_row_qp[y+1] ) );
{
i_qp_min = X264_MAX( i_qp_min, X264_MAX( h->fref0[0]->i_row_qp[y+1], h->fref1[0]->i_row_qp[y+1] ) );
rc->qpm = X264_MAX( rc->qpm, i_qp_min );
}
int b0 = predict_row_size_sum( h, y, rc->qpm );
int b1 = b0;
float buffer_left_planned = rc->buffer_fill - rc->frame_size_planned;
/* More threads means we have to be more cautious in letting ratecontrol use up extra bits.
* In 2-pass mode we can be more trusting of the planned frame sizes, since they were decided
* by actual encoding instead of SATD prediction. */
/* More threads means we have to be more cautious in letting ratecontrol use up extra bits. */
float rc_tol = buffer_left_planned / h->param.i_threads * rc->rate_tolerance;
if( h->param.rc.b_stat_read )
rc_tol *= rc->frame_size_planned / rc->buffer_size;
/* Don't modify the row QPs until a sufficent amount of the bits of the frame have been processed, in case a flat */
/* area at the top of the frame was measured inaccurately. */
......@@ -1696,8 +1696,12 @@ static float rate_estimate_qscale( x264_t *h )
else
q += rcc->pb_offset;
rcc->frame_size_planned = predict_size( rcc->pred_b_from_p, q, h->fref1[h->i_ref1-1]->i_satd );
if( rcc->b_2pass && rcc->b_vbv )
rcc->frame_size_planned = qscale2bits( &rce, q );
else
rcc->frame_size_planned = predict_size( rcc->pred_b_from_p, q, h->fref1[h->i_ref1-1]->i_satd );
x264_ratecontrol_set_estimated_size(h, rcc->frame_size_planned);
/* For row SATDs */
if( rcc->b_vbv )
rcc->last_satd = x264_rc_analyse_slice( h );
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment