ref: 5c166470a538090bad641c4580aa81bd66a2904b
parent: 346358a5b76f4624e20df762010139e889587799
parent: 212f6183739d448ad5fa2ccf1b4edd30829b2806
author: John Koleszar <jkoleszar@google.com>
date: Tue Jun 7 08:30:37 EDT 2011
Merge "Reduce overshoot in 1 pass rate control"
--- a/vp8/encoder/firstpass.c
+++ b/vp8/encoder/firstpass.c
@@ -243,33 +243,58 @@
int max_bits;
// For CBR we need to also consider buffer fullness.
- // If we are running below the optimal level then we need to gradually tighten up on max_bits.
if (cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER)
{- double buffer_fullness_ratio = (double)cpi->buffer_level / DOUBLE_DIVIDE_CHECK((double)cpi->oxcf.optimal_buffer_level);
+ max_bits = 2 * cpi->av_per_frame_bandwidth;
+ max_bits -= cpi->buffered_av_per_frame_bandwidth;
+ max_bits *= ((double)cpi->oxcf.two_pass_vbrmax_section / 100.0);
+ }
+ // VBR
+ else
+ {+ // For VBR base this on the bits and frames left plus the two_pass_vbrmax_section rate passed in by the user
+ max_bits = (int)(((double)cpi->twopass.bits_left / (cpi->twopass.total_stats->count - (double)cpi->common.current_video_frame)) * ((double)cpi->oxcf.two_pass_vbrmax_section / 100.0));
+ }
- // For CBR base this on the target average bits per frame plus the maximum sedction rate passed in by the user
- max_bits = (int)(cpi->av_per_frame_bandwidth * ((double)cpi->oxcf.two_pass_vbrmax_section / 100.0));
+ // Trap case where we are out of bits
+ if (max_bits < 0)
+ max_bits = 0;
- // If our buffer is below the optimum level
- if (buffer_fullness_ratio < 1.0)
- {- // The lower of max_bits / 4 or cpi->av_per_frame_bandwidth / 4.
- int min_max_bits = ((cpi->av_per_frame_bandwidth >> 2) < (max_bits >> 2)) ? cpi->av_per_frame_bandwidth >> 2 : max_bits >> 2;
+ return max_bits;
+}
- max_bits = (int)(max_bits * buffer_fullness_ratio);
- if (max_bits < min_max_bits)
- max_bits = min_max_bits; // Lowest value we will set ... which should allow the buffer to refil.
+static int gf_group_max_bits(VP8_COMP *cpi)
+{+ // Max allocation for a golden frame group
+ int max_bits;
+
+ // For CBR we need to also consider buffer fullness.
+ if (cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER)
+ {+ max_bits = cpi->av_per_frame_bandwidth * cpi->baseline_gf_interval;
+ if (max_bits > cpi->oxcf.optimal_buffer_level)
+ {+ max_bits -= cpi->oxcf.optimal_buffer_level;
+ max_bits += cpi->buffer_level;
}
+ else
+ {+ max_bits -= (cpi->buffered_av_per_frame_bandwidth
+ - cpi->av_per_frame_bandwidth)
+ * cpi->baseline_gf_interval;
+ }
+
+ max_bits *= ((double)cpi->oxcf.two_pass_vbrmax_section / 100.0);
}
- // VBR
else
{// For VBR base this on the bits and frames left plus the two_pass_vbrmax_section rate passed in by the user
max_bits = (int)(((double)cpi->twopass.bits_left / (cpi->twopass.total_stats->count - (double)cpi->common.current_video_frame)) * ((double)cpi->oxcf.two_pass_vbrmax_section / 100.0));
+ max_bits *= cpi->baseline_gf_interval;
}
+
// Trap case where we are out of bits
if (max_bits < 0)
max_bits = 0;
@@ -1362,7 +1387,7 @@
double abs_mv_in_out_accumulator = 0.0;
double mod_err_per_mb_accumulator = 0.0;
- int max_bits = frame_max_bits(cpi); // Max for a single frame
+ int max_group_bits;
unsigned int allow_alt_ref =
cpi->oxcf.play_alternate && cpi->oxcf.lag_in_frames;
@@ -1715,8 +1740,9 @@
cpi->twopass.gf_group_bits = (cpi->twopass.gf_group_bits < 0) ? 0 : (cpi->twopass.gf_group_bits > cpi->twopass.kf_group_bits) ? cpi->twopass.kf_group_bits : cpi->twopass.gf_group_bits;
// Clip cpi->twopass.gf_group_bits based on user supplied data rate variability limit (cpi->oxcf.two_pass_vbrmax_section)
- if (cpi->twopass.gf_group_bits > max_bits * cpi->baseline_gf_interval)
- cpi->twopass.gf_group_bits = max_bits * cpi->baseline_gf_interval;
+ max_group_bits = gf_group_max_bits(cpi);
+ if (cpi->twopass.gf_group_bits > max_group_bits)
+ cpi->twopass.gf_group_bits = max_group_bits;
// Reset the file position
reset_fpf_position(cpi, start_pos);
@@ -1808,13 +1834,6 @@
{cpi->twopass.gf_bits = alt_gf_bits;
}
- }
-
- // Apply an additional limit for CBR
- if (cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER)
- {- if (cpi->twopass.gf_bits > (cpi->buffer_level >> 1))
- cpi->twopass.gf_bits = cpi->buffer_level >> 1;
}
// Dont allow a negative value for gf_bits
--- a/vp8/encoder/onyx_if.c
+++ b/vp8/encoder/onyx_if.c
@@ -1477,6 +1477,7 @@
cpi->rolling_actual_bits = cpi->av_per_frame_bandwidth;
cpi->long_rolling_target_bits = cpi->av_per_frame_bandwidth;
cpi->long_rolling_actual_bits = cpi->av_per_frame_bandwidth;
+ cpi->buffered_av_per_frame_bandwidth = cpi->av_per_frame_bandwidth;
cpi->total_actual_bits = 0;
cpi->total_target_vs_actual = 0;
@@ -1572,7 +1573,7 @@
break;
}
- if (cpi->pass == 0)
+ if (cpi->pass == 0 && cpi->oxcf.end_usage != USAGE_STREAM_FROM_SERVER)
cpi->auto_worst_q = 1;
cpi->oxcf.worst_allowed_q = q_trans[oxcf->worst_allowed_q];
@@ -3453,7 +3454,8 @@
// For CBR if the buffer reaches its maximum level then we can no longer
// save up bits for later frames so we might as well use them up
// on the current frame.
- if ((cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER) &&
+ if (cpi->pass == 2
+ && (cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER) &&
(cpi->buffer_level >= cpi->oxcf.optimal_buffer_level) && cpi->buffered_mode)
{int Adjustment = cpi->active_worst_quality / 4; // Max adjustment is 1/4
@@ -3544,6 +3546,9 @@
}
else
{+ if(cpi->pass != 2)
+ Q = cpi->avg_frame_qindex;
+
cpi->active_best_quality = inter_minq[Q];
// For the constant/constrained quality mode we dont want
@@ -3845,15 +3850,16 @@
(cpi->active_worst_quality < cpi->worst_quality) &&
(cpi->projected_frame_size > frame_over_shoot_limit))
{- int over_size_percent = ((cpi->projected_frame_size - frame_over_shoot_limit) * 100) / frame_over_shoot_limit;
+ /* step down active_worst_quality such that the corresponding
+ * active_best_quality will be equal to the current
+ * active_worst_quality + 1
+ */
+ int i;
- // If so is there any scope for relaxing it
- while ((cpi->active_worst_quality < cpi->worst_quality) && (over_size_percent > 0))
- {- cpi->active_worst_quality++;
- top_index = cpi->active_worst_quality;
- over_size_percent = (int)(over_size_percent * 0.96); // Assume 1 qstep = about 4% on frame size.
- }
+ for(i=cpi->active_worst_quality; i<cpi->worst_quality; i++)
+ if(inter_minq[i] >= cpi->active_worst_quality + 1)
+ break;
+ cpi->active_worst_quality = i;
// If we have updated the active max Q do not call vp8_update_rate_correction_factors() this loop.
active_worst_qchanged = TRUE;
@@ -4241,10 +4247,9 @@
// Update the buffer level variable.
// Non-viewable frames are a special case and are treated as pure overhead.
- if ( !cm->show_frame )
- cpi->bits_off_target -= cpi->projected_frame_size;
- else
- cpi->bits_off_target += cpi->av_per_frame_bandwidth - cpi->projected_frame_size;
+ if ( cm->show_frame )
+ cpi->bits_off_target += cpi->av_per_frame_bandwidth;
+ cpi->bits_off_target -= cpi->projected_frame_size;
// Rolling monitors of whether we are over or underspending used to help regulate min and Max Q in two pass.
cpi->rolling_target_bits = ((cpi->rolling_target_bits * 3) + cpi->this_frame_target + 2) / 4;
@@ -4258,7 +4263,33 @@
// Debug stats
cpi->total_target_vs_actual += (cpi->this_frame_target - cpi->projected_frame_size);
- cpi->buffer_level = cpi->bits_off_target;
+ // Update the buffered average bitrate
+ {+ long long numerator;
+
+ numerator = cpi->oxcf.maximum_buffer_size
+ - cpi->buffered_av_per_frame_bandwidth
+ + cpi->projected_frame_size;
+ numerator *= cpi->buffered_av_per_frame_bandwidth;
+ cpi->buffered_av_per_frame_bandwidth = numerator
+ / cpi->oxcf.maximum_buffer_size;
+ }
+
+ {+ long long tmp = (long long)cpi->buffered_av_per_frame_bandwidth
+ * cpi->oxcf.maximum_buffer_size
+ / cpi->av_per_frame_bandwidth;
+ cpi->buffer_level = cpi->oxcf.maximum_buffer_size
+ - tmp
+ + cpi->oxcf.optimal_buffer_level;
+ }
+
+ // Accumulate overshoot error.
+ cpi->accumulated_overshoot +=
+ (cpi->projected_frame_size > cpi->av_per_frame_bandwidth)
+ ? cpi->projected_frame_size - cpi->av_per_frame_bandwidth
+ : 0;
+
// Update bits left to the kf and gf groups to account for overshoot or undershoot on these frames
if (cm->frame_type == KEY_FRAME)
--- a/vp8/encoder/onyx_int.h
+++ b/vp8/encoder/onyx_int.h
@@ -351,6 +351,10 @@
int per_frame_bandwidth; // Current section per frame bandwidth target
int av_per_frame_bandwidth; // Average frame size target for clip
int min_frame_bandwidth; // Minimum allocation that should be used for any frame
+ int buffered_av_per_frame_bandwidth; // Average bitrate over the last buffer
+ int buffered_av_per_frame_bandwidth_rem; // Average bitrate remainder
+ int accumulated_overshoot; // Accumulated # of bits spent > target
+
int inter_frame_target;
double output_frame_rate;
long long last_time_stamp_seen;
--- a/vp8/encoder/ratectrl.c
+++ b/vp8/encoder/ratectrl.c
@@ -605,10 +605,10 @@
static void calc_pframe_target_size(VP8_COMP *cpi)
{- int min_frame_target;
+ int min_frame_target, max_frame_target;
int Adjustment;
- min_frame_target = 0;
+ min_frame_target = 1;
if (cpi->pass == 2)
{@@ -616,10 +616,19 @@
if (min_frame_target < (cpi->av_per_frame_bandwidth >> 5))
min_frame_target = cpi->av_per_frame_bandwidth >> 5;
+
+ max_frame_target = INT_MAX;
}
- else if (min_frame_target < cpi->per_frame_bandwidth / 4)
- min_frame_target = cpi->per_frame_bandwidth / 4;
+ else
+ {+ if (min_frame_target < cpi->per_frame_bandwidth / 4)
+ min_frame_target = cpi->per_frame_bandwidth / 4;
+ /* Don't allow the target to completely deplete the buffer. */
+ max_frame_target = cpi->buffer_level + cpi->av_per_frame_bandwidth;
+ if(max_frame_target < min_frame_target)
+ max_frame_target = min_frame_target;
+ }
// Special alt reference frame case
if (cpi->common.refresh_alt_ref_frame)
@@ -1112,6 +1121,32 @@
}
}
+
+ if (cpi->pass==0 && cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER){+ /* determine the accumulated error to apply to this frame. Apply
+ * more of the error when we've been undershooting, less when
+ * we've been overshooting
+ */
+ long long adjust;
+ int bitrate_error;
+
+ bitrate_error = cpi->av_per_frame_bandwidth
+ - cpi->buffered_av_per_frame_bandwidth;
+
+ adjust = cpi->accumulated_overshoot;
+ adjust *= cpi->av_per_frame_bandwidth + bitrate_error;
+ adjust /= cpi->oxcf.maximum_buffer_size;
+ if (adjust > (cpi->this_frame_target - min_frame_target))
+ adjust = (cpi->this_frame_target - min_frame_target);
+ else if (adjust < 0)
+ adjust = 0;
+
+ cpi->this_frame_target -= adjust;
+ cpi->accumulated_overshoot -= adjust;
+ }
+
+ if(cpi->this_frame_target > max_frame_target)
+ cpi->this_frame_target = max_frame_target;
}