ref: 8628d3a7ae25331d898d84d208b7d30c6b4a3119
parent: 81bb41fafe86fd33c932cc60c4a0c7bcd6cf1452
parent: 6122ca87a33c0e00d09df4311644226ef72b1d7f
author: Paul Wilkins <[email protected]>
date: Wed May 14 06:08:11 EDT 2014
Merge "Simplify 2 pass KF bitrate allocation"
--- a/vp9/encoder/vp9_firstpass.c
+++ b/vp9/encoder/vp9_firstpass.c
@@ -1474,7 +1474,8 @@
int boost, int64_t total_group_bits) {int allocation_chunks;
- if (!boost)
+ // return 0 for invalid inputs (could arise e.g. through rounding errors)
+ if (!boost || (total_group_bits <= 0) || (frame_count <= 0) )
return 0;
allocation_chunks = (frame_count * 100) + boost;
@@ -2030,15 +2031,15 @@
} else {twopass->kf_group_bits = 0;
}
+ twopass->kf_group_bits = MAX(0, twopass->kf_group_bits);
+
// Reset the first pass file position.
reset_fpf_position(twopass, start_position);
- // Determine how big to make this keyframe based on how well the subsequent
- // frames use inter blocks.
+ // Scan through the kf group collating various stats used to deteermine
+ // how many bits to spend on it.
decay_accumulator = 1.0;
boost_score = 0.0;
-
- // Scan through the kf group collating various stats.
for (i = 0; i < rc->frames_to_key; ++i) {if (EOF == input_stats(twopass, &next_frame))
break;
@@ -2075,84 +2076,27 @@
}
}
+ // Store the zero motion percentage
+ twopass->kf_zeromotion_pct = (int)(zero_motion_accumulator * 100.0);
+
// Calculate a section intra ratio used in setting max loop filter.
calculate_section_intra_ratio(twopass, start_position, rc->frames_to_key);
// Work out how many bits to allocate for the key frame itself.
- if (1) {- int kf_boost = (int)boost_score;
- int allocation_chunks;
+ rc->kf_boost = (int)boost_score;
- if (kf_boost < (rc->frames_to_key * 3))
- kf_boost = (rc->frames_to_key * 3);
+ if (rc->kf_boost < (rc->frames_to_key * 3))
+ rc->kf_boost = (rc->frames_to_key * 3);
+ if (rc->kf_boost < MIN_KF_BOOST)
+ rc->kf_boost = MIN_KF_BOOST;
- if (kf_boost < MIN_KF_BOOST)
- kf_boost = MIN_KF_BOOST;
+ twopass->kf_bits = calculate_boost_bits((rc->frames_to_key - 1),
+ rc->kf_boost, twopass->kf_group_bits);
- // Make a note of baseline boost and the zero motion
- // accumulator value for use elsewhere.
- rc->kf_boost = kf_boost;
- twopass->kf_zeromotion_pct = (int)(zero_motion_accumulator * 100.0);
+ twopass->kf_group_bits -= twopass->kf_bits;
- // Key frame size depends on:
- // (1) the error score for the whole key frame group,
- // (2) the key frames' own error if this is smaller than the
- // average for the group (optional),
- // (3) insuring that the frame receives at least the allocation it would
- // have received based on its own error score vs the error score
- // remaining.
- // Special case:
- // If the sequence appears almost totally static we want to spend almost
- // all of the bits on the key frame.
- //
- // We use (cpi->rc.frames_to_key - 1) below because the key frame itself is
- // taken care of by kf_boost.
- if (zero_motion_accumulator >= 0.99) {- allocation_chunks = ((rc->frames_to_key - 1) * 10) + kf_boost;
- } else {- allocation_chunks = ((rc->frames_to_key - 1) * 100) + kf_boost;
- }
-
- // Prevent overflow.
- if (kf_boost > 1028) {- const int divisor = kf_boost >> 10;
- kf_boost /= divisor;
- allocation_chunks /= divisor;
- }
-
- twopass->kf_group_bits = MAX(0, twopass->kf_group_bits);
- // Calculate the number of bits to be spent on the key frame.
- twopass->kf_bits = (int)((double)kf_boost *
- ((double)twopass->kf_group_bits / allocation_chunks));
-
- // If the key frame is actually easier than the average for the
- // kf group (which does sometimes happen, e.g. a blank intro frame)
- // then use an alternate calculation based on the kf error score
- // which should give a smaller key frame.
- if (kf_mod_err < kf_group_err / rc->frames_to_key) {- double alt_kf_grp_bits = ((double)twopass->bits_left *
- (kf_mod_err * (double)rc->frames_to_key) /
- DOUBLE_DIVIDE_CHECK(twopass->modified_error_left));
-
- const int alt_kf_bits = (int)((double)kf_boost *
- (alt_kf_grp_bits / (double)allocation_chunks));
-
- if (twopass->kf_bits > alt_kf_bits)
- twopass->kf_bits = alt_kf_bits;
- } else {- // Else if it is much harder than other frames in the group make sure
- // it at least receives an allocation in keeping with its relative
- // error score.
- const int alt_kf_bits = (int)((double)twopass->bits_left * (kf_mod_err /
- DOUBLE_DIVIDE_CHECK(twopass->modified_error_left)));
-
- if (alt_kf_bits > twopass->kf_bits)
- twopass->kf_bits = alt_kf_bits;
- }
- twopass->kf_group_bits -= twopass->kf_bits;
- // Per frame bit target for this frame.
- vp9_rc_set_frame_target(cpi, twopass->kf_bits);
- }
+ // Per frame bit target for this frame.
+ vp9_rc_set_frame_target(cpi, twopass->kf_bits);
// Note the total error score of the kf group minus the key frame itself.
twopass->kf_group_error_left = (int)(kf_group_err - kf_mod_err);