shithub: libvpx

Download patch

ref: cfbfd39de8da61644ff0fd3a149d3a8957c28b1d
parent: ef86bad0d1bad5bfc68b80783d56a3a476002924
parent: c99f9d7abf90538bc569a5683299766276b287c9
author: John Koleszar <jkoleszar@google.com>
date: Mon Apr 25 06:49:32 EDT 2011

Merge "Change rc undershoot/overshoot semantics"

--- a/vp8/common/onyx.h
+++ b/vp8/common/onyx.h
@@ -140,8 +140,9 @@
 
         int end_usage; // vbr or cbr
 
-        // shoot to keep buffer full at all times by undershooting a bit 95 recommended
+        // buffer targeting aggressiveness
         int under_shoot_pct;
+        int over_shoot_pct;
 
         // buffering parameters
         int starting_buffer_level;  // in seconds
--- a/vp8/encoder/ratectrl.c
+++ b/vp8/encoder/ratectrl.c
@@ -817,11 +817,6 @@
         }
     }
 
-    // Set a reduced data rate target for our initial Q calculation.
-    // This should help to save bits during earier sections.
-    if ((cpi->oxcf.under_shoot_pct > 0) && (cpi->oxcf.under_shoot_pct <= 100))
-        cpi->this_frame_target = (cpi->this_frame_target * cpi->oxcf.under_shoot_pct) / 100;
-
     // Sanity check that the total sum of adjustments is not above the maximum allowed
     // That is that having allowed for KF and GF penalties we have not pushed the
     // current interframe target to low. If the adjustment we apply here is not capable of recovering
@@ -858,11 +853,6 @@
                     percent_low =
                         (cpi->oxcf.optimal_buffer_level - cpi->buffer_level) /
                         one_percent_bits;
-
-                    if (percent_low > 100)
-                        percent_low = 100;
-                    else if (percent_low < 0)
-                        percent_low = 0;
                 }
                 // Are we overshooting the long term clip data rate...
                 else if (cpi->bits_off_target < 0)
@@ -870,16 +860,16 @@
                     // Adjust per frame data target downwards to compensate.
                     percent_low = (int)(100 * -cpi->bits_off_target /
                                        (cpi->total_byte_count * 8));
-
-                    if (percent_low > 100)
-                        percent_low = 100;
-                    else if (percent_low < 0)
-                        percent_low = 0;
                 }
 
+                if (percent_low > cpi->oxcf.under_shoot_pct)
+                    percent_low = cpi->oxcf.under_shoot_pct;
+                else if (percent_low < 0)
+                    percent_low = 0;
+
                 // lower the target bandwidth for this frame.
-                cpi->this_frame_target =
-                    (cpi->this_frame_target * (100 - (percent_low / 2))) / 100;
+                cpi->this_frame_target -= (cpi->this_frame_target * percent_low)
+                                          / 200;
 
                 // Are we using allowing control of active_worst_allowed_q
                 // according to buffer level.
@@ -950,20 +940,29 @@
             }
             else
             {
-                int percent_high;
+                int percent_high = 0;
 
-                if (cpi->bits_off_target > cpi->oxcf.optimal_buffer_level)
+                if ((cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER)
+                     && (cpi->buffer_level > cpi->oxcf.optimal_buffer_level))
                 {
-                    percent_high = (int)(100 * (cpi->bits_off_target - cpi->oxcf.optimal_buffer_level) / (cpi->total_byte_count * 8));
+                    percent_high = (cpi->buffer_level
+                                    - cpi->oxcf.optimal_buffer_level)
+                                   / one_percent_bits;
+                }
+                else if (cpi->bits_off_target > cpi->oxcf.optimal_buffer_level)
+                {
+                    percent_high = (int)((100 * cpi->bits_off_target)
+                                         / (cpi->total_byte_count * 8));
+                }
 
-                    if (percent_high > 100)
-                        percent_high = 100;
-                    else if (percent_high < 0)
-                        percent_high = 0;
+                if (percent_high > cpi->oxcf.over_shoot_pct)
+                    percent_high = cpi->oxcf.over_shoot_pct;
+                else if (percent_high < 0)
+                    percent_high = 0;
 
-                    cpi->this_frame_target = (cpi->this_frame_target * (100 + (percent_high / 2))) / 100;
+                cpi->this_frame_target += (cpi->this_frame_target *
+                                           percent_high) / 200;
 
-                }
 
                 // Are we allowing control of active_worst_allowed_q according to bufferl level.
                 if (cpi->auto_worst_q)
@@ -1538,7 +1537,7 @@
     cpi->key_frame_count++;
 }
 
-
+void vp8_compute_frame_size_bounds(VP8_COMP *cpi, int *frame_under_shoot_limit, int *frame_over_shoot_limit)
 void vp8_compute_frame_size_bounds(VP8_COMP *cpi, int *frame_under_shoot_limit, int *frame_over_shoot_limit)
 {
     // Set-up bounds on acceptable frame size:
--- a/vp8/vp8_cx_iface.c
+++ b/vp8/vp8_cx_iface.c
@@ -151,7 +151,8 @@
     RANGE_CHECK_HI(cfg, g_lag_in_frames,    0);
 #endif
     RANGE_CHECK(cfg, rc_end_usage,          VPX_VBR, VPX_CQ);
-    RANGE_CHECK_HI(cfg, rc_undershoot_pct,  100);
+    RANGE_CHECK_HI(cfg, rc_undershoot_pct,  1000);
+    RANGE_CHECK_HI(cfg, rc_overshoot_pct,   1000);
     RANGE_CHECK_HI(cfg, rc_2pass_vbr_bias_pct, 100);
     RANGE_CHECK(cfg, kf_mode,               VPX_KF_DISABLED, VPX_KF_AUTO);
     //RANGE_CHECK_BOOL(cfg,                 g_delete_firstpassfile);
@@ -312,7 +313,7 @@
     oxcf->fixed_q = -1;
 
     oxcf->under_shoot_pct         = cfg.rc_undershoot_pct;
-    //oxcf->over_shoot_pct        = cfg.rc_overshoot_pct;
+    oxcf->over_shoot_pct          = cfg.rc_overshoot_pct;
 
     oxcf->maximum_buffer_size     = cfg.rc_buf_sz;
     oxcf->starting_buffer_level   = cfg.rc_buf_initial_sz;
@@ -358,6 +359,7 @@
         printf("key_freq: %d\n", oxcf->key_freq);
         printf("end_usage: %d\n", oxcf->end_usage);
         printf("under_shoot_pct: %d\n", oxcf->under_shoot_pct);
+        printf("over_shoot_pct: %d\n", oxcf->over_shoot_pct);
         printf("starting_buffer_level: %d\n", oxcf->starting_buffer_level);
         printf("optimal_buffer_level: %d\n",  oxcf->optimal_buffer_level);
         printf("maximum_buffer_size: %d\n", oxcf->maximum_buffer_size);
@@ -1087,8 +1089,8 @@
         0,                  /* rc_max_intra_bitrate_pct */
         4,                  /* rc_min_quantizer */
         63,                 /* rc_max_quantizer */
-        95,                 /* rc_undershoot_pct */
-        200,                /* rc_overshoot_pct */
+        100,                /* rc_undershoot_pct */
+        100,                /* rc_overshoot_pct */
 
         6000,               /* rc_max_buffer_size */
         4000,               /* rc_buffer_initial_size; */
--- a/vpx/vpx_encoder.h
+++ b/vpx/vpx_encoder.h
@@ -445,20 +445,28 @@
          */
 
 
-        /*!\brief Rate control undershoot tolerance
+        /*!\brief Rate control adaptation undershoot control
          *
-         * This value, expressed as a percentage of the target bitrate, describes
-         * the target bitrate for easier frames, allowing bits to be saved for
-         * harder frames. Set to zero to use the codec default.
+         * This value, expressed as a percentage of the target bitrate,
+         * controls the maximum allowed adaptation speed of the codec.
+         * This factor controls the maximum amount of bits that can
+         * be subtracted from the target bitrate in order to compensate
+         * for prior overshoot.
+         *
+         * Valid values in the range 0-1000.
          */
         unsigned int           rc_undershoot_pct;
 
 
-        /*!\brief Rate control overshoot tolerance
+        /*!\brief Rate control adaptation overshoot control
          *
-         * This value, expressed as a percentage of the target bitrate, describes
-         * the maximum allowed bitrate for a given frame.  Set to zero to use the
-         * codec default.
+         * This value, expressed as a percentage of the target bitrate,
+         * controls the maximum allowed adaptation speed of the codec.
+         * This factor controls the maximum amount of bits that can
+         * be added to the target bitrate in order to compensate for
+         * prior undershoot.
+         *
+         * Valid values in the range 0-1000.
          */
         unsigned int           rc_overshoot_pct;