ref: 0529320a9e7082648f7cbec421103d80c38b67b2
parent: e237fd7c5ad8c0caf341ca50a4ea65495edce74f
author: Paul Wilkins <paulwilkins@google.com>
date: Tue May 15 10:58:13 EDT 2012
Firstpass.c refactoring Removed unused function. Added tentative code to take error score of an older frame into account when calculating Q range. However, for now it is disabled pending merging other changes and testing. Change-Id: Ie89955e70319dac31b79e3b833e3352712a061ec
--- a/vp8/encoder/firstpass.c
+++ b/vp8/encoder/firstpass.c
@@ -617,7 +617,7 @@
}
}
- // Experimental search in a second reference frame ((0,0) based only)
+ // Experimental search in an older reference frame
if (cm->current_video_frame > 1)
{first_pass_motion_search(cpi, x, &zero_ref_mv,
@@ -799,17 +799,13 @@
accumulate_stats(cpi->twopass.total_stats, &fps);
}
- // Copy the previous Last Frame into the GF buffer if specific conditions for doing so are met
+ // 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) &&
- ((cpi->twopass.this_frame_stats->intra_error /
- cpi->twopass.this_frame_stats->coded_error) > 2.0))
+ (cpi->twopass.this_frame_stats->pcnt_inter > 0.20))
{vp8_yv12_copy_frame_ptr(lst_yv12, gld_yv12);
}
- {- vp8_yv12_copy_frame_ptr(lst_yv12, gld_yv12);
- }
// swap frame pointers so last frame refers to the frame we just compressed
vp8_swap_yv12_buffer(lst_yv12, new_yv12);
@@ -886,7 +882,9 @@
return 0;
}
-static double calc_correction_factor( double err_per_mb,
+static double calc_correction_factor( VP8_COMP *cpi,
+ FIRSTPASS_STATS * fpstats,
+ double err_per_mb,
double err_divisor,
double pt_low,
double pt_high,
@@ -895,7 +893,10 @@
double power_term;
double error_term = err_per_mb / err_divisor;
double correction_factor;
+ double sr_err_diff;
+ double sr_correction;
+
// Adjustment based on actual quantizer to power term.
power_term = (vp8_convert_qindex_to_q(Q) * 0.01) + pt_low;
power_term = (power_term > pt_high) ? pt_high : power_term;
@@ -903,10 +904,25 @@
// Adjustments to error term
// TBD
- // Calculate correction factor
+ // Calculate a correction factor based on error per mb
correction_factor = pow(error_term, power_term);
- // Clip range
+#if 0
+ // Look at the drop in prediction quality between the last frame
+ // and the GF buffer (which contained an older frame).
+ sr_err_diff =
+ (fpstats->sr_coded_error - fpstats->coded_error) /
+ (fpstats->count * cpi->common.MBs * 32);
+ sr_correction = pow( sr_err_diff, 0.5 );
+ if ( sr_correction < 0.5 )
+ sr_correction = 0.5;
+ else if ( sr_correction > 1.25 )
+ sr_correction = 1.25;
+
+ correction_factor = correction_factor * sr_correction;
+#endif
+
+ // Clip final factor range
correction_factor =
(correction_factor < 0.05)
? 0.05 : (correction_factor > 5.0) ? 5.0 : correction_factor;
@@ -1017,15 +1033,17 @@
// Error per MB based correction factor
err_correction_factor =
- calc_correction_factor(err_per_mb, ERR_DIVISOR, 0.36, 0.90, Q);
+ calc_correction_factor(cpi, fpstats, err_per_mb,
+ ERR_DIVISOR, 0.36, 0.90, Q) *
+ speed_correction *
+ cpi->twopass.est_max_qcorrection_factor *
+ cpi->twopass.section_max_qfactor;
bits_per_mb_at_this_q =
vp8_bits_per_mb(INTER_FRAME, Q) + overhead_bits_per_mb;
- bits_per_mb_at_this_q = (int)(.5 + err_correction_factor
- * speed_correction * cpi->twopass.est_max_qcorrection_factor
- * cpi->twopass.section_max_qfactor
- * (double)bits_per_mb_at_this_q);
+ bits_per_mb_at_this_q = (int)(.5 + err_correction_factor *
+ (double)bits_per_mb_at_this_q);
// Mode and motion overhead
// As Q rises in real encode loop rd code will force overhead down
@@ -1032,7 +1050,7 @@
// We make a crude adjustment for this here as *.98 per Q step.
// PGW TODO.. This code is broken for the extended Q range
// for now overhead set to 0.
- overhead_bits_per_mb = (int)((double)overhead_bits_per_mb * 0.98);
+ //overhead_bits_per_mb = (int)((double)overhead_bits_per_mb * 0.98);
if (bits_per_mb_at_this_q <= target_norm_bits_per_mb)
break;
@@ -1119,8 +1137,8 @@
// Error per MB based correction factor
err_correction_factor =
- calc_correction_factor(err_per_mb, 100.0, 0.36, 0.90, Q);
-
+ calc_correction_factor(cpi, fpstats, err_per_mb,
+ 100.0, 0.36, 0.90, Q);
bits_per_mb_at_this_q =
vp8_bits_per_mb(INTER_FRAME, Q) + overhead_bits_per_mb;
@@ -1151,96 +1169,6 @@
return Q;
}
-// Estimate a worst case Q for a KF group
-static int estimate_kf_group_q(VP8_COMP *cpi, double section_err, int section_target_bandwitdh, double group_iiratio)
-{- int Q;
- int num_mbs = cpi->common.MBs;
- int target_norm_bits_per_mb = (512 * section_target_bandwitdh) / num_mbs;
- int bits_per_mb_at_this_q;
-
- double err_per_mb = section_err / num_mbs;
- double err_correction_factor;
- double corr_high;
- double speed_correction = 1.0;
- double current_spend_ratio = 1.0;
-
- double pow_highq = (POW1 < 0.6) ? POW1 + 0.3 : 0.90;
- double pow_lowq = (POW1 < 0.7) ? POW1 + 0.1 : 0.80;
-
- double iiratio_correction_factor = 1.0;
-
- double combined_correction_factor;
-
- // Trap special case where the target is <= 0
- if (target_norm_bits_per_mb <= 0)
- return MAXQ * 2;
-
- // Calculate a corrective factor based on a rolling ratio of bits spent vs target bits
- // This is clamped to the range 0.1 to 10.0
- if (cpi->long_rolling_target_bits <= 0)
- current_spend_ratio = 10.0;
- else
- {- current_spend_ratio = (double)cpi->long_rolling_actual_bits / (double)cpi->long_rolling_target_bits;
- current_spend_ratio = (current_spend_ratio > 10.0) ? 10.0 : (current_spend_ratio < 0.1) ? 0.1 : current_spend_ratio;
- }
-
- // Calculate a correction factor based on the quality of prediction in the sequence as indicated by intra_inter error score ratio (IIRatio)
- // The idea here is to favour subsampling in the hardest sections vs the easyest.
- iiratio_correction_factor = 1.0 - ((group_iiratio - 6.0) * 0.1);
-
- if (iiratio_correction_factor < 0.5)
- iiratio_correction_factor = 0.5;
-
- // Corrections for higher compression speed settings (reduced compression expected)
- if (cpi->compressor_speed == 1)
- {- if (cpi->oxcf.cpu_used <= 5)
- speed_correction = 1.04 + (cpi->oxcf.cpu_used * 0.04);
- else
- speed_correction = 1.25;
- }
-
- // Combine the various factors calculated above
- combined_correction_factor = speed_correction * iiratio_correction_factor * current_spend_ratio;
-
- // Try and pick a Q that should be high enough to encode the content at the given rate.
- for (Q = 0; Q < MAXQ; Q++)
- {- // Error per MB based correction factor
- err_correction_factor =
- calc_correction_factor(err_per_mb, ERR_DIVISOR, pow_lowq, pow_highq, Q);
-
- bits_per_mb_at_this_q =
- (int)(.5 + ( err_correction_factor *
- combined_correction_factor *
- (double)vp8_bits_per_mb(INTER_FRAME, Q)) );
-
- if (bits_per_mb_at_this_q <= target_norm_bits_per_mb)
- break;
- }
-
- // If we could not hit the target even at Max Q then estimate what Q would have bee required
- while ((bits_per_mb_at_this_q > target_norm_bits_per_mb) && (Q < (MAXQ * 2)))
- {-
- bits_per_mb_at_this_q = (int)(0.96 * bits_per_mb_at_this_q);
- Q++;
- }
-
- if (0)
- {- FILE *f = fopen("estkf_q.stt", "a");- fprintf(f, "%8d %8d %8d %8.2f %8.3f %8.2f %8.3f %8.3f %8.3f %8d\n", cpi->common.current_video_frame, bits_per_mb_at_this_q,
- target_norm_bits_per_mb, err_per_mb, err_correction_factor,
- current_spend_ratio, group_iiratio, iiratio_correction_factor,
- (double)cpi->buffer_level / (double)cpi->oxcf.optimal_buffer_level, Q);
- fclose(f);
- }
-
- return Q;
-}
extern void vp8_new_frame_rate(VP8_COMP *cpi, double framerate);