ref: b8c369053b8baffc2181b7b362262269f9e346e6
parent: 09a97012720200aa93b5871ef9014f57246e73b9
author: Paul Wilkins <paulwilkins@google.com>
date: Wed May 30 07:29:49 EDT 2012
Rate control fix. This fix addresses some problems with very complex clips like handling of flashes on clips like crew (which was made worse by an earlier patch (derf and std-hd)). Most clips a small effect but some between 1 & 2% Derf +0.039, +0.211% YT +0.042, +0.083% Change-Id: I65fc7c13afc31482040068544dd65b8808f5cb4a
--- a/vp8/encoder/firstpass.c
+++ b/vp8/encoder/firstpass.c
@@ -634,7 +634,14 @@
xd->pre.u_buffer = lst_yv12->u_buffer + recon_uvoffset;
xd->pre.v_buffer = lst_yv12->v_buffer + recon_uvoffset;
- sr_coded_error += gf_motion_error;
+ // In accumulating a score for the older reference frame
+ // take the best of the motion predicted score and
+ // the intra coded error (just as will be done for)
+ // accumulation of "coded_error" for the last frame.
+ if ( gf_motion_error < this_error )
+ sr_coded_error += gf_motion_error;
+ else
+ sr_coded_error += this_error;
}
else
sr_coded_error += motion_error;
@@ -799,12 +806,18 @@
}
// Copy the previous Last Frame back into gf and and arf buffers if
- // the prediction is good enough.
- if ((cm->current_video_frame > 0) &&
- (cpi->twopass.this_frame_stats->pcnt_inter > 0.20))
+ // the prediction is good enough... but also dont allow it to lag too far
+ if ((cpi->twopass.sr_update_lag > 3) ||
+ ((cm->current_video_frame > 0) &&
+ (cpi->twopass.this_frame_stats->pcnt_inter > 0.20) &&
+ ((cpi->twopass.this_frame_stats->intra_error /
+ cpi->twopass.this_frame_stats->coded_error) > 2.0)))
{vp8_yv12_copy_frame_ptr(lst_yv12, gld_yv12);
+ cpi->twopass.sr_update_lag = 1;
}
+ else
+ cpi->twopass.sr_update_lag ++;
// swap frame pointers so last frame refers to the frame we just compressed
vp8_swap_yv12_buffer(lst_yv12, new_yv12);
@@ -921,6 +934,11 @@
correction_factor = correction_factor * sr_correction;
#endif
+ // Clip range
+ correction_factor =
+ (correction_factor < 0.05)
+ ? 0.05 : (correction_factor > 2.0) ? 2.0 : correction_factor;
+
return correction_factor;
}
@@ -1214,6 +1232,9 @@
cpi->twopass.kf_intra_err_min = KF_MB_INTRA_MIN * cpi->common.MBs;
cpi->twopass.gf_intra_err_min = GF_MB_INTRA_MIN * cpi->common.MBs;
+ // This variable monitors how far behind the second ref update is lagging
+ cpi->twopass.sr_update_lag = 1;
+
// Scan the first pass file and calculate an average Intra / Inter error score ratio for the sequence
{double sum_iiratio = 0.0;
@@ -1277,14 +1298,13 @@
(cpi->common.MBs);
second_ref_decay = 1.0 - (mb_sr_err_diff / 512.0);
second_ref_decay = pow( second_ref_decay, 0.5 );
+ if ( second_ref_decay < 0.85 )
+ second_ref_decay = 0.85;
+ else if ( second_ref_decay > 1.0 )
+ second_ref_decay = 1.0;
if ( second_ref_decay < prediction_decay_rate )
prediction_decay_rate = second_ref_decay;
-
- if ( prediction_decay_rate < 0.85 )
- prediction_decay_rate = 0.85;
- else if ( prediction_decay_rate > 1.0 )
- prediction_decay_rate = 1.0;
return prediction_decay_rate;
}
--- a/vp8/encoder/onyx_int.h
+++ b/vp8/encoder/onyx_int.h
@@ -598,6 +598,8 @@
int gf_group_bits; // Projected Bits available for a group of frames including 1 GF or ARF
int gf_bits; // Bits for the golden frame or ARF - 2 pass only
int alt_extra_bits;
+
+ int sr_update_lag;
double est_max_qcorrection_factor;
} twopass;