Merge remote branch 'origin/master' into experimental

Change-Id: Ida9204624fe3fb99fed1b149d1f88159480fdd83

7 files changed, 235 insertions, 42 deletions

diff --git a/vp8/common/onyxd.h b/vp8/common/onyxd.h
index 8a4703a8b..2dfdc66da 100644
--- a/vp8/common/onyxd.h
+++ b/vp8/common/onyxd.h
@@ -18,6 +18,7 @@
 extern "C"
 {
 #endif
+#include "vpx/vpx_codec.h"
 #include "type_aliases.h"
 #include "vpx_scale/yv12config.h"
 #include "ppflags.h"
diff --git a/vp8/encoder/firstpass.c b/vp8/encoder/firstpass.c
index bc19a4256..5422365f8 100644
--- a/vp8/encoder/firstpass.c
+++ b/vp8/encoder/firstpass.c
@@ -357,33 +357,58 @@ static int frame_max_bits(VP8_COMP *cpi)
     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));
+    }
+
+    // Trap case where we are out of bits
+    if (max_bits < 0)
+        max_bits = 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));
+    return max_bits;
+}
 
-        // 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;
 
-            max_bits = (int)(max_bits * buffer_fullness_ratio);
+static int gf_group_max_bits(VP8_COMP *cpi)
+{
+    // Max allocation for a golden frame group
+    int max_bits;
 
-            if (max_bits < min_max_bits)
-                max_bits = min_max_bits;       // Lowest value we will set ... which should allow the buffer to refil.
+    // 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;
@@ -1601,7 +1626,7 @@ static void define_gf_group(VP8_COMP *cpi, FIRSTPASS_STATS *this_frame)
     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;
@@ -1963,8 +1988,9 @@ static void define_gf_group(VP8_COMP *cpi, FIRSTPASS_STATS *this_frame)
 
     // 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);
@@ -2064,13 +2090,6 @@ static void define_gf_group(VP8_COMP *cpi, FIRSTPASS_STATS *this_frame)
             }
         }
 
-        // 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
         if (gf_bits < 0)
             gf_bits = 0;
diff --git a/vp8/encoder/onyx_if.c b/vp8/encoder/onyx_if.c
index e8fd5e07e..d936bac35 100644
--- a/vp8/encoder/onyx_if.c
+++ b/vp8/encoder/onyx_if.c
@@ -1524,6 +1524,7 @@ static void init_config(VP8_PTR ptr, VP8_CONFIG *oxcf)
     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;
@@ -1619,7 +1620,7 @@ void vp8_change_config(VP8_PTR ptr, VP8_CONFIG *oxcf)
         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];
@@ -3262,6 +3263,116 @@ void loopfilter_frame(VP8_COMP *cpi, VP8_COMMON *cm)
 
 }
 
+
+static void update_buffer_level(VP8_COMP *cpi)
+{
+    long long tmp;
+
+    /* Update the buffered average bitrate.
+     *
+     * The buffered average bitrate tracks the bitrate over the buffer
+     * window. Here we simulate taking a frame of average size out
+     * of the buffer, and putting in the new frame just encoded.
+     * It is calculated accordingly:
+     *
+     * A = Average Bits Per Frame In The Buffer
+     * P = New Frame Size
+     * N = Number of bits in the buffer
+     *
+     * We recalculate the average as so:
+     *      (N-A)*A + A*P    A * (N - A + P)
+     * A' = ------------- =  ---------------
+     *            N                 N
+     *
+     * This is modeled after a the standard algorithm for a moving
+     * average with fixed weighting (eg A' = ((N-1)*A + 1*P) / N). This makes
+     * the step response nonlinear but consistent with expected behavior --
+     * when A is large, the model adapts more quickly, since there are
+     * fewer frames in the buffer and conversely when A is small there
+     * will be more frames in the buffer so the average will adapt
+     * slowly.
+     *
+     * TODO(jkoleszar): This may give poor step response in some situations,
+     * for example motion following a long static section. It might be
+     * worth experimenting more with weighting by av_per_frame_bandwidth
+     * rather than buffered_av_per_frame_bandwidth or using a more accurate
+     * algorithm to get faster response. Current testing showed worse results
+     * with that setting though.
+     *
+     */
+
+    /* Guard against buffered_av_per_frame_bandwidth falling to 0. Should
+     * never happen, but without this check, it would be irrecoverable.
+     */
+    if(cpi->buffered_av_per_frame_bandwidth == 0)
+        cpi->buffered_av_per_frame_bandwidth = 1;
+
+    tmp = cpi->oxcf.maximum_buffer_size
+                - cpi->buffered_av_per_frame_bandwidth
+                + cpi->projected_frame_size;
+    tmp *= cpi->buffered_av_per_frame_bandwidth;
+    cpi->buffered_av_per_frame_bandwidth = tmp
+                                           / cpi->oxcf.maximum_buffer_size;
+
+    if(cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER)
+    {
+        /* In CBR mode, buffer level is synthesized from the buffered
+         * average per-frame bandwidth to get the response characteristics
+         * of that model, rather than using the unbounded (wrt buffer size)
+         * bits_off_target. ie, the long term average bitrate doesn't
+         * matter in CBR mode. If the clip is consistently undershooting
+         * because it is very static, for example, you don't want to blow
+         * your short term bitrate budget trying to the the long term spend
+         * up to the target when you hit a motion section.
+         *
+         * Instead, the ratio of buffered_av_per_frame_bandwidth to the
+         * target av_per_frame_bandwidth is taken, scaled by
+         * maximum_buffer_size and centered around optimal_buffer_level,
+         * which presents the expected behavior of buffer_level for the other
+         * parts of the rate control code which handle the targeting.
+         *
+         * Note that this only happens after the starting_buffer_level
+         * has passed, to give the model a chance to stabilize.
+         */
+        if(cpi->total_actual_bits > cpi->oxcf.starting_buffer_level)
+        {
+            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;
+        }
+        else
+            cpi->buffer_level = cpi->oxcf.optimal_buffer_level;
+
+        /* Accumulate recent overshoot error.
+         *
+         * If this frame is larger than the target, then accumulate
+         * that error to apply as a damping factor later. Only care about
+         * recent overshoot, so this value decays by (N-P)/N
+         */
+        if(cpi->total_actual_bits > cpi->oxcf.starting_buffer_level)
+        {
+            long long decayed_overshoot;
+
+            decayed_overshoot = cpi->accumulated_overshoot;
+            decayed_overshoot *= (cpi->oxcf.maximum_buffer_size
+                                  - cpi->projected_frame_size);
+            decayed_overshoot /= cpi->oxcf.maximum_buffer_size;
+            cpi->accumulated_overshoot = decayed_overshoot;
+
+            cpi->accumulated_overshoot +=
+                (cpi->projected_frame_size > cpi->av_per_frame_bandwidth)
+                ? cpi->projected_frame_size - cpi->av_per_frame_bandwidth
+                : 0;
+        }
+    }
+    else
+        cpi->buffer_level = cpi->bits_off_target;
+}
+
+
 static void encode_frame_to_data_rate
 (
     VP8_COMP *cpi,
@@ -3507,7 +3618,8 @@ static void encode_frame_to_data_rate
     // 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
@@ -3598,6 +3710,10 @@ static void encode_frame_to_data_rate
         }
         else
         {
+            if(cpi->pass != 2)
+                Q = cpi->auto_worst_q?
+                    cpi->active_worst_quality:cpi->avg_frame_qindex;
+
             cpi->active_best_quality = inter_minq[Q];
 
             // For the constant/constrained quality mode we dont want
@@ -3910,15 +4026,17 @@ static void encode_frame_to_data_rate
             (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. Once the limit on active_best_quality
+             * is reached, active_worst_quality will equal worst_quality.
+             */
+            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;
@@ -4306,10 +4424,9 @@ static void encode_frame_to_data_rate
 
     // 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;
@@ -4323,7 +4440,7 @@ static void encode_frame_to_data_rate
     // Debug stats
     cpi->total_target_vs_actual += (cpi->this_frame_target - cpi->projected_frame_size);
 
-    cpi->buffer_level = cpi->bits_off_target;
+    update_buffer_level(cpi);
 
     // Update bits left to the kf and gf groups to account for overshoot or undershoot on these frames
     if (cm->frame_type == KEY_FRAME)
diff --git a/vp8/encoder/onyx_int.h b/vp8/encoder/onyx_int.h
index be79cb0a5..341ece3e8 100644
--- a/vp8/encoder/onyx_int.h
+++ b/vp8/encoder/onyx_int.h
@@ -348,6 +348,10 @@ typedef struct VP8_COMP
     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;
diff --git a/vp8/encoder/ratectrl.c b/vp8/encoder/ratectrl.c
index 78b3b4715..dea690b13 100644
--- a/vp8/encoder/ratectrl.c
+++ b/vp8/encoder/ratectrl.c
@@ -653,7 +653,7 @@ static void calc_pframe_target_size(VP8_COMP *cpi)
     int min_frame_target;
     int Adjustment;
 
-    min_frame_target = 0;
+    min_frame_target = 1;
 
     if (cpi->pass == 2)
     {
@@ -662,9 +662,11 @@ static void calc_pframe_target_size(VP8_COMP *cpi)
         if (min_frame_target < (cpi->av_per_frame_bandwidth >> 5))
             min_frame_target = cpi->av_per_frame_bandwidth >> 5;
     }
-    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;
+    }
 
     // Special alt reference frame case
     if (cpi->common.refresh_alt_ref_frame)
@@ -1157,6 +1159,33 @@ static void calc_pframe_target_size(VP8_COMP *cpi)
 
         }
     }
+
+    if (cpi->pass==0
+        && cpi->common.refresh_golden_frame
+        && cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER) {
+        long long adjust;
+
+        /*
+        frames_in_buffer = cpi->oxcf.maximum_buffer_size
+                           / cpi->av_per_frame_bandwidth;
+        gf_in_buffer = frames_in_buffer /
+                       cpi->frames_till_gf_update_due;
+        overshoot_per_gf = cpi->accumulated_overshoot / gf_in_buffer;
+
+        */
+
+        adjust = cpi->accumulated_overshoot;
+        adjust *= cpi->frames_till_gf_update_due + 1;
+        adjust *= cpi->av_per_frame_bandwidth;
+        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;
+    }
 }
 
 
diff --git a/vpx/internal/vpx_codec_internal.h b/vpx/internal/vpx_codec_internal.h
index a1ff1921e..7cc2c3a62 100644
--- a/vpx/internal/vpx_codec_internal.h
+++ b/vpx/internal/vpx_codec_internal.h
@@ -45,6 +45,7 @@
 #define VPX_CODEC_INTERNAL_H
 #include "../vpx_decoder.h"
 #include "../vpx_encoder.h"
+#include "vpx_config.h"
 #include <stdarg.h>
 
 
@@ -435,6 +436,23 @@ vpx_codec_pkt_list_get(struct vpx_codec_pkt_list *list,
 
 #include <stdio.h>
 #include <setjmp.h>
+
+/* GLIBC started intercepting calls to longjmp in version 2.11, if the
+ * FORTIFY_SOURCE flag is defined (it's defined by default on Ubuntu).
+ * This can cause problems running under older versions of GLIBC (ie,
+ * for binary distributions), so work around it by linking to the
+ * underlying longjmp call directly.
+ */
+#if defined(__GNUC_PREREQ)
+#if __GNUC_PREREQ (2,11)
+#if ARCH_X86_64
+__asm__(".symver __longjmp_chk,longjmp@GLIBC_2.2.5");
+#else
+__asm__(".symver __longjmp_chk,longjmp@GLIBC_2.0");
+#endif
+#endif
+#endif
+
 struct vpx_internal_error_info
 {
     vpx_codec_err_t  error_code;
diff --git a/vpxenc.c b/vpxenc.c
index a3c8eadc0..d82a97fad 100644
--- a/vpxenc.c
+++ b/vpxenc.c
@@ -1339,6 +1339,11 @@ static void init_rate_histogram(struct rate_hist          *hist,
      * adjustment (5/4) to account for alt-refs
      */
     hist->samples = cfg->rc_buf_sz * 5 / 4 * fps->num / fps->den / 1000;
+
+    // prevent division by zero
+    if (hist->samples == 0)
+      hist->samples=1;
+
     hist->pts = calloc(hist->samples, sizeof(*hist->pts));
     hist->sz = calloc(hist->samples, sizeof(*hist->sz));
     for(i=0; i<RATE_BINS; i++)