ref: cdc954fdc842c8bba298d8ca523511bd242cbc8c
parent: 95fb9008f85a035c35f5bcd3c9278dc1f6a26f66
author: Pengchong Jin <pengchong@google.com>
date: Mon Jun 16 05:17:45 EDT 2014
skip the un-necessary motion search in the first pass This patch allows the VP9 encoder to skip the un-necessary motion search in the first pass. It computes the motion error of 0,0 motion using the last source frame as the reference, and skips the further motion search if this error is small. Borg test shows overall the patch gives PSNR gain (derf -0.001%, yt 0.341%, hd 0.282%). Individual clips may have PSNR gain or loss. The best PSNR performance is 7.347% and the worst is -0.662%. The first pass encoding speedup for slideshow clips is over 30%. Change-Id: I4cac4dbd911f277ee858e161f3ca652c771344fe
--- a/vp9/encoder/vp9_firstpass.c
+++ b/vp9/encoder/vp9_firstpass.c
@@ -594,8 +594,9 @@
// Other than for the first frame do a motion search.
if (cm->current_video_frame > 0) {- int tmp_err, motion_error;
+ int tmp_err, motion_error, raw_motion_error;
int_mv mv, tmp_mv;
+ struct buf_2d unscaled_last_source_buf_2d;
xd->plane[0].pre[0].buf = first_ref_buf->y_buffer + recon_yoffset;
motion_error = get_prediction_error(bsize, &x->plane[0].src,
@@ -603,67 +604,82 @@
// Assume 0,0 motion with no mv overhead.
mv.as_int = tmp_mv.as_int = 0;
- // Test last reference frame using the previous best mv as the
- // starting point (best reference) for the search.
- first_pass_motion_search(cpi, x, &best_ref_mv.as_mv, &mv.as_mv,
- &motion_error);
- if (cpi->oxcf.aq_mode == VARIANCE_AQ) {- vp9_clear_system_state();
- motion_error = (int)(motion_error * error_weight);
- }
+ // Compute the motion error of the 0,0 motion using the last source
+ // frame as the reference. Skip the further motion search on
+ // reconstructed frame if this error is small.
+ unscaled_last_source_buf_2d.buf =
+ cpi->unscaled_last_source->y_buffer + recon_yoffset;
+ unscaled_last_source_buf_2d.stride =
+ cpi->unscaled_last_source->y_stride;
+ raw_motion_error = get_prediction_error(bsize, &x->plane[0].src,
+ &unscaled_last_source_buf_2d);
- // If the current best reference mv is not centered on 0,0 then do a 0,0
- // based search as well.
- if (best_ref_mv.as_int) {- tmp_err = INT_MAX;
- first_pass_motion_search(cpi, x, &zero_mv, &tmp_mv.as_mv,
- &tmp_err);
+ // TODO(pengchong): Replace the hard-coded threshold
+ if (raw_motion_error > 25) {+ // Test last reference frame using the previous best mv as the
+ // starting point (best reference) for the search.
+ first_pass_motion_search(cpi, x, &best_ref_mv.as_mv, &mv.as_mv,
+ &motion_error);
if (cpi->oxcf.aq_mode == VARIANCE_AQ) {vp9_clear_system_state();
- tmp_err = (int)(tmp_err * error_weight);
+ motion_error = (int)(motion_error * error_weight);
}
- if (tmp_err < motion_error) {- motion_error = tmp_err;
- mv.as_int = tmp_mv.as_int;
+ // If the current best reference mv is not centered on 0,0 then do a
+ // 0,0 based search as well.
+ if (best_ref_mv.as_int) {+ tmp_err = INT_MAX;
+ first_pass_motion_search(cpi, x, &zero_mv, &tmp_mv.as_mv, &tmp_err);
+ if (cpi->oxcf.aq_mode == VARIANCE_AQ) {+ vp9_clear_system_state();
+ tmp_err = (int)(tmp_err * error_weight);
+ }
+
+ if (tmp_err < motion_error) {+ motion_error = tmp_err;
+ mv.as_int = tmp_mv.as_int;
+ }
}
- }
- // Search in an older reference frame.
- if (cm->current_video_frame > 1 && gld_yv12 != NULL) {- // Assume 0,0 motion with no mv overhead.
- int gf_motion_error;
+ // Search in an older reference frame.
+ if (cm->current_video_frame > 1 && gld_yv12 != NULL) {+ // Assume 0,0 motion with no mv overhead.
+ int gf_motion_error;
- xd->plane[0].pre[0].buf = gld_yv12->y_buffer + recon_yoffset;
- gf_motion_error = get_prediction_error(bsize, &x->plane[0].src,
- &xd->plane[0].pre[0]);
+ xd->plane[0].pre[0].buf = gld_yv12->y_buffer + recon_yoffset;
+ gf_motion_error = get_prediction_error(bsize, &x->plane[0].src,
+ &xd->plane[0].pre[0]);
- first_pass_motion_search(cpi, x, &zero_mv, &tmp_mv.as_mv,
- &gf_motion_error);
- if (cpi->oxcf.aq_mode == VARIANCE_AQ) {- vp9_clear_system_state();
- gf_motion_error = (int)(gf_motion_error * error_weight);
- }
+ first_pass_motion_search(cpi, x, &zero_mv, &tmp_mv.as_mv,
+ &gf_motion_error);
+ if (cpi->oxcf.aq_mode == VARIANCE_AQ) {+ vp9_clear_system_state();
+ gf_motion_error = (int)(gf_motion_error * error_weight);
+ }
- if (gf_motion_error < motion_error && gf_motion_error < this_error)
- ++second_ref_count;
+ if (gf_motion_error < motion_error && gf_motion_error < this_error)
+ ++second_ref_count;
- // Reset to last frame as reference buffer.
- xd->plane[0].pre[0].buf = first_ref_buf->y_buffer + recon_yoffset;
- xd->plane[1].pre[0].buf = first_ref_buf->u_buffer + recon_uvoffset;
- xd->plane[2].pre[0].buf = first_ref_buf->v_buffer + recon_uvoffset;
+ // Reset to last frame as reference buffer.
+ xd->plane[0].pre[0].buf = first_ref_buf->y_buffer + recon_yoffset;
+ xd->plane[1].pre[0].buf = first_ref_buf->u_buffer + recon_uvoffset;
+ xd->plane[2].pre[0].buf = first_ref_buf->v_buffer + recon_uvoffset;
- // 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;
+ // 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;
+ }
} else {sr_coded_error += motion_error;
}
+
// Start by assuming that intra mode is best.
best_ref_mv.as_int = 0;