libvpx: Pull from upstream

source/libvpx/vpx/src/svc_encodeframe.c

Index: source/libvpx/vpx/src/svc_encodeframe.c
===================================================================
--- source/libvpx/vpx/src/svc_encodeframe.c	(revision 0)
+++ source/libvpx/vpx/src/svc_encodeframe.c	(revision 0)
@@ -0,0 +1,962 @@
+/*
+ *  Copyright (c) 2013 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+/**
+ * @file
+ * VP9 SVC encoding support via libvpx
+ */
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#define VPX_DISABLE_CTRL_TYPECHECKS 1
+#define VPX_CODEC_DISABLE_COMPAT 1
+#include "vpx/svc_context.h"
+#include "vpx/vp8cx.h"
+#include "vpx/vpx_encoder.h"
+
+#if defined(__MINGW32__) && !defined(MINGW_HAS_SECURE_API)
+#define strtok_r strtok_s
+// proto from /usr/x86_64-w64-mingw32/include/sec_api/string_s.h
+_CRTIMP char *__cdecl strtok_s(char *str, const char *delim, char **context);
+#endif
+
+#ifdef _MSC_VER
+#define strdup _strdup
+#define strtok_r strtok_s
+#endif
+
+#define SVC_REFERENCE_FRAMES 8
+#define SUPERFRAME_SLOTS (8)
+#define SUPERFRAME_BUFFER_SIZE (SUPERFRAME_SLOTS * sizeof(uint32_t) + 2)
+#define OPTION_BUFFER_SIZE 256
+
+static const char *DEFAULT_QUANTIZER_VALUES = "60,53,39,33,27";
+static const char *DEFAULT_SCALE_FACTORS = "4/16,5/16,7/16,11/16,16/16";
+
+typedef struct SvcInternal {
+  char options[OPTION_BUFFER_SIZE];        // set by vpx_svc_set_options
+  char quantizers[OPTION_BUFFER_SIZE];     // set by vpx_svc_set_quantizers
+  char scale_factors[OPTION_BUFFER_SIZE];  // set by vpx_svc_set_scale_factors
+
+  // values extracted from option, quantizers
+  int scaling_factor_num[VPX_SS_MAX_LAYERS];
+  int scaling_factor_den[VPX_SS_MAX_LAYERS];
+  int quantizer[VPX_SS_MAX_LAYERS];
+
+  // accumulated statistics
+  double psnr_in_layer[VPX_SS_MAX_LAYERS];
+  uint32_t bytes_in_layer[VPX_SS_MAX_LAYERS];
+
+  // codec encoding values
+  int width;    // width of highest layer
+  int height;   // height of highest layer
+  int kf_dist;  // distance between keyframes
+
+  // state variables
+  int encode_frame_count;
+  int frame_within_gop;
+  vpx_enc_frame_flags_t enc_frame_flags;
+  int layers;
+  int layer;
+  int is_keyframe;
+
+  size_t frame_size;
+  size_t buffer_size;
+  void *buffer;
+
+  char message_buffer[2048];
+  vpx_codec_ctx_t *codec_ctx;
+} SvcInternal;
+
+// Superframe is used to generate an index of individual frames (i.e., layers)
+struct Superframe {
+  int count;
+  uint32_t sizes[SUPERFRAME_SLOTS];
+  uint32_t magnitude;
+  uint8_t buffer[SUPERFRAME_BUFFER_SIZE];
+  size_t index_size;
+};
+
+// One encoded frame layer
+struct LayerData {
+  void *buf;    // compressed data buffer
+  size_t size;  // length of compressed data
+  struct LayerData *next;
+};
+
+// create LayerData from encoder output
+static struct LayerData *ld_create(void *buf, size_t size) {
+  struct LayerData *const layer_data = malloc(sizeof(*layer_data));
+  if (layer_data == NULL) {
+    return NULL;
+  }
+  layer_data->buf = malloc(size);
+  if (layer_data->buf == NULL) {
+    free(layer_data);
+    return NULL;
+  }
+  memcpy(layer_data->buf, buf, size);
+  layer_data->size = size;
+  return layer_data;
+}
+
+// free LayerData
+static void ld_free(struct LayerData *layer_data) {
+  if (layer_data) {
+    if (layer_data->buf) {
+      free(layer_data->buf);
+      layer_data->buf = NULL;
+    }
+    free(layer_data);
+  }
+}
+
+// add layer data to list
+static void ld_list_add(struct LayerData **list, struct LayerData *layer_data) {
+  struct LayerData **p = list;
+
+  while (*p != NULL) p = &(*p)->next;
+  *p = layer_data;
+  layer_data->next = NULL;
+}
+
+// get accumulated size of layer data
+static size_t ld_list_get_buffer_size(struct LayerData *list) {
+  struct LayerData *p;
+  size_t size = 0;
+
+  for (p = list; p != NULL; p = p->next) {
+    size += p->size;
+  }
+  return size;
+}
+
+// copy layer data to buffer
+static void ld_list_copy_to_buffer(struct LayerData *list, uint8_t *buffer) {
+  struct LayerData *p;
+
+  for (p = list; p != NULL; p = p->next) {
+    buffer[0] = 1;
+    memcpy(buffer, p->buf, p->size);
+    buffer += p->size;
+  }
+}
+
+// free layer data list
+static void ld_list_free(struct LayerData *list) {
+  struct LayerData *p = list;
+
+  while (p) {
+    list = list->next;
+    ld_free(p);
+    p = list;
+  }
+}
+
+static void sf_create_index(struct Superframe *sf) {
+  uint8_t marker = 0xc0;
+  int i;
+  uint32_t mag, mask;
+  uint8_t *bufp;
+
+  if (sf->count == 0 || sf->count >= 8) return;
+
+  // Add the number of frames to the marker byte
+  marker |= sf->count - 1;
+
+  // Choose the magnitude
+  for (mag = 0, mask = 0xff; mag < 4; ++mag) {
+    if (sf->magnitude < mask) break;
+    mask <<= 8;
+    mask |= 0xff;
+  }
+  marker |= mag << 3;
+
+  // Write the index
+  sf->index_size = 2 + (mag + 1) * sf->count;
+  bufp = sf->buffer;
+
+  *bufp++ = marker;
+  for (i = 0; i < sf->count; ++i) {
+    int this_sz = sf->sizes[i];
+    uint32_t j;
+
+    for (j = 0; j <= mag; ++j) {
+      *bufp++ = this_sz & 0xff;
+      this_sz >>= 8;
+    }
+  }
+  *bufp++ = marker;
+}
+
+static SvcInternal *get_svc_internal(SvcContext *svc_ctx) {
+  if (svc_ctx == NULL) return NULL;
+  if (svc_ctx->internal == NULL) {
+    SvcInternal *const si = malloc(sizeof(*si));
+    if (si != NULL) {
+      memset(si, 0, sizeof(*si));
+    }
+    svc_ctx->internal = si;
+  }
+  return svc_ctx->internal;
+}
+
+static const SvcInternal *get_const_svc_internal(const SvcContext *svc_ctx) {
+  if (svc_ctx == NULL) return NULL;
+  return svc_ctx->internal;
+}
+
+static void svc_log_reset(SvcContext *svc_ctx) {
+  SvcInternal *const si = (SvcInternal *)svc_ctx->internal;
+  si->message_buffer[0] = '\0';
+}
+
+static int svc_log(SvcContext *svc_ctx, int level, const char *fmt, ...) {
+  char buf[512];
+  int retval = 0;
+  va_list ap;
+  SvcInternal *const si = get_svc_internal(svc_ctx);
+
+  if (level > svc_ctx->log_level) {
+    return retval;
+  }
+
+  va_start(ap, fmt);
+  retval = vsnprintf(buf, sizeof(buf), fmt, ap);
+  va_end(ap);
+
+  if (svc_ctx->log_print) {
+    printf("%s", buf);
+  } else {
+    strncat(si->message_buffer, buf,
+            sizeof(si->message_buffer) - strlen(si->message_buffer) - 1);
+  }
+
+  if (level == SVC_LOG_ERROR) {
+    si->codec_ctx->err_detail = si->message_buffer;
+  }
+  return retval;
+}
+
+static vpx_codec_err_t set_option_encoding_mode(SvcContext *svc_ctx,
+                                                const char *value_str) {
+  if (strcmp(value_str, "i") == 0) {
+    svc_ctx->encoding_mode = INTER_LAYER_PREDICTION_I;
+  } else if (strcmp(value_str, "alt-ip") == 0) {
+    svc_ctx->encoding_mode = ALT_INTER_LAYER_PREDICTION_IP;
+  } else if (strcmp(value_str, "ip") == 0) {
+    svc_ctx->encoding_mode = INTER_LAYER_PREDICTION_IP;
+  } else if (strcmp(value_str, "gf") == 0) {
+    svc_ctx->encoding_mode = USE_GOLDEN_FRAME;
+  } else {
+    svc_log(svc_ctx, SVC_LOG_ERROR, "invalid encoding mode: %s", value_str);
+    return VPX_CODEC_INVALID_PARAM;
+  }
+  return VPX_CODEC_OK;
+}
+
+static vpx_codec_err_t parse_quantizer_values(SvcContext *svc_ctx,
+                                              const char *quantizer_values) {
+  char *input_string;
+  char *token;
+  const char *delim = ",";
+  char *save_ptr;
+  int found = 0;
+  int i, q;
+  int res = VPX_CODEC_OK;
+  SvcInternal *const si = get_svc_internal(svc_ctx);
+
+  if (quantizer_values == NULL || strlen(quantizer_values) == 0) {
+    input_string = strdup(DEFAULT_QUANTIZER_VALUES);
+  } else {
+    input_string = strdup(quantizer_values);
+  }
+
+  token = strtok_r(input_string, delim, &save_ptr);
+  for (i = 0; i < svc_ctx->spatial_layers; ++i) {
+    if (token != NULL) {
+      q = atoi(token);
+      if (q <= 0 || q > 100) {
+        svc_log(svc_ctx, SVC_LOG_ERROR,
+                "svc-quantizer-values: invalid value %s\n", token);
+        res = VPX_CODEC_INVALID_PARAM;
+        break;
+      }
+      token = strtok_r(NULL, delim, &save_ptr);
+      found = i + 1;
+    } else {
+      q = 0;
+    }
+    si->quantizer[i + VPX_SS_MAX_LAYERS - svc_ctx->spatial_layers] = q;
+  }
+  if (res == VPX_CODEC_OK && found != svc_ctx->spatial_layers) {
+    svc_log(svc_ctx, SVC_LOG_ERROR,
+            "svc: quantizers: %d values required, but only %d specified\n",
+            svc_ctx->spatial_layers, found);
+    res = VPX_CODEC_INVALID_PARAM;
+  }
+  free(input_string);
+  return res;
+}
+
+static void log_invalid_scale_factor(SvcContext *svc_ctx, const char *value) {
+  svc_log(svc_ctx, SVC_LOG_ERROR, "svc scale-factors: invalid value %s\n",
+          value);
+}
+
+static vpx_codec_err_t parse_scale_factors(SvcContext *svc_ctx,
+                                           const char *scale_factors) {
+  char *input_string;
+  char *token;
+  const char *delim = ",";
+  char *save_ptr;
+  int found = 0;
+  int i;
+  int64_t num, den;
+  int res = VPX_CODEC_OK;
+  SvcInternal *const si = get_svc_internal(svc_ctx);
+
+  if (scale_factors == NULL || strlen(scale_factors) == 0) {
+    input_string = strdup(DEFAULT_SCALE_FACTORS);
+  } else {
+    input_string = strdup(scale_factors);
+  }
+  token = strtok_r(input_string, delim, &save_ptr);
+  for (i = 0; i < svc_ctx->spatial_layers; ++i) {
+    num = den = 0;
+    if (token != NULL) {
+      num = strtol(token, &token, 10);
+      if (num <= 0) {
+        log_invalid_scale_factor(svc_ctx, token);
+        res = VPX_CODEC_INVALID_PARAM;
+        break;
+      }
+      if (*token++ != '/') {
+        log_invalid_scale_factor(svc_ctx, token);
+        res = VPX_CODEC_INVALID_PARAM;
+        break;
+      }
+      den = strtol(token, &token, 10);
+      if (den <= 0) {
+        log_invalid_scale_factor(svc_ctx, token);
+        res = VPX_CODEC_INVALID_PARAM;
+        break;
+      }
+      token = strtok_r(NULL, delim, &save_ptr);
+      found = i + 1;
+    }
+    si->scaling_factor_num[i + VPX_SS_MAX_LAYERS - svc_ctx->spatial_layers] =
+        (int)num;
+    si->scaling_factor_den[i + VPX_SS_MAX_LAYERS - svc_ctx->spatial_layers] =
+        (int)den;
+  }
+  if (res == VPX_CODEC_OK && found != svc_ctx->spatial_layers) {
+    svc_log(svc_ctx, SVC_LOG_ERROR,
+            "svc: scale-factors: %d values required, but only %d specified\n",
+            svc_ctx->spatial_layers, found);
+    res = VPX_CODEC_INVALID_PARAM;
+  }
+  free(input_string);
+  return res;
+}
+
+/**
+ * Parse SVC encoding options
+ * Format: encoding-mode=<svc_mode>,layers=<layer_count>
+ *         scale-factors=<n1>/<d1>,<n2>/<d2>,...
+ *         quantizers=<q1>,<q2>,...
+ * svc_mode = [i|ip|alt_ip|gf]
+ */
+static vpx_codec_err_t parse_options(SvcContext *svc_ctx, const char *options) {
+  char *input_string;
+  char *option_name;
+  char *option_value;
+  char *input_ptr;
+  int res = VPX_CODEC_OK;
+
+  if (options == NULL) return VPX_CODEC_OK;
+  input_string = strdup(options);
+
+  // parse option name
+  option_name = strtok_r(input_string, "=", &input_ptr);
+  while (option_name != NULL) {
+    // parse option value
+    option_value = strtok_r(NULL, " ", &input_ptr);
+    if (option_value == NULL) {
+      svc_log(svc_ctx, SVC_LOG_ERROR, "option missing value: %s\n",
+              option_name);
+      res = VPX_CODEC_INVALID_PARAM;
+      break;
+    }
+    if (strcmp("encoding-mode", option_name) == 0) {
+      res = set_option_encoding_mode(svc_ctx, option_value);
+      if (res != VPX_CODEC_OK) break;
+    } else if (strcmp("layers", option_name) == 0) {
+      svc_ctx->spatial_layers = atoi(option_value);
+    } else if (strcmp("scale-factors", option_name) == 0) {
+      res = parse_scale_factors(svc_ctx, option_value);
+      if (res != VPX_CODEC_OK) break;
+    } else if (strcmp("quantizers", option_name) == 0) {
+      res = parse_quantizer_values(svc_ctx, option_value);
+      if (res != VPX_CODEC_OK) break;
+    } else {
+      svc_log(svc_ctx, SVC_LOG_ERROR, "invalid option: %s\n", option_name);
+      res = VPX_CODEC_INVALID_PARAM;
+      break;
+    }
+    option_name = strtok_r(NULL, "=", &input_ptr);
+  }
+  free(input_string);
+  return res;
+}
+
+vpx_codec_err_t vpx_svc_set_options(SvcContext *svc_ctx, const char *options) {
+  SvcInternal *const si = get_svc_internal(svc_ctx);
+  if (svc_ctx == NULL || options == NULL || si == NULL) {
+    return VPX_CODEC_INVALID_PARAM;
+  }
+  strncpy(si->options, options, sizeof(si->options));
+  si->options[sizeof(si->options) - 1] = '\0';
+  return VPX_CODEC_OK;
+}
+
+vpx_codec_err_t vpx_svc_set_quantizers(SvcContext *svc_ctx,
+                                       const char *quantizers) {
+  SvcInternal *const si = get_svc_internal(svc_ctx);
+  if (svc_ctx == NULL || quantizers == NULL || si == NULL) {
+    return VPX_CODEC_INVALID_PARAM;
+  }
+  strncpy(si->quantizers, quantizers, sizeof(si->quantizers));
+  si->quantizers[sizeof(si->quantizers) - 1] = '\0';
+  return VPX_CODEC_OK;
+}
+
+vpx_codec_err_t vpx_svc_set_scale_factors(SvcContext *svc_ctx,
+                                          const char *scale_factors) {
+  SvcInternal *const si = get_svc_internal(svc_ctx);
+  if (svc_ctx == NULL || scale_factors == NULL || si == NULL) {
+    return VPX_CODEC_INVALID_PARAM;
+  }
+  strncpy(si->scale_factors, scale_factors, sizeof(si->scale_factors));
+  si->scale_factors[sizeof(si->scale_factors) - 1] = '\0';
+  return VPX_CODEC_OK;
+}
+
+vpx_codec_err_t vpx_svc_init(SvcContext *svc_ctx, vpx_codec_ctx_t *codec_ctx,
+                             vpx_codec_iface_t *iface,
+                             vpx_codec_enc_cfg_t *enc_cfg) {
+  int max_intra_size_pct;
+  vpx_codec_err_t res;
+  SvcInternal *const si = get_svc_internal(svc_ctx);
+  if (svc_ctx == NULL || codec_ctx == NULL || iface == NULL ||
+      enc_cfg == NULL) {
+    return VPX_CODEC_INVALID_PARAM;
+  }
+  if (si == NULL) return VPX_CODEC_MEM_ERROR;
+
+  si->codec_ctx = codec_ctx;
+
+  si->width = enc_cfg->g_w;
+  si->height = enc_cfg->g_h;
+
+  if (enc_cfg->kf_max_dist < 2) {
+    svc_log(svc_ctx, SVC_LOG_ERROR, "key frame distance too small: %d\n",
+            enc_cfg->kf_max_dist);
+    return VPX_CODEC_INVALID_PARAM;
+  }
+  si->kf_dist = enc_cfg->kf_max_dist;
+
+  if (svc_ctx->spatial_layers == 0)
+    svc_ctx->spatial_layers = VPX_SS_DEFAULT_LAYERS;
+  if (svc_ctx->spatial_layers < 1 ||
+      svc_ctx->spatial_layers > VPX_SS_MAX_LAYERS) {
+    svc_log(svc_ctx, SVC_LOG_ERROR, "spatial layers: invalid value: %d\n",
+            svc_ctx->spatial_layers);
+    return VPX_CODEC_INVALID_PARAM;
+  }
+  // use SvcInternal value for number of layers to enable forcing single layer
+  // for first frame
+  si->layers = svc_ctx->spatial_layers;
+
+  res = parse_quantizer_values(svc_ctx, si->quantizers);
+  if (res != VPX_CODEC_OK) return res;
+
+  res = parse_scale_factors(svc_ctx, si->scale_factors);
+  if (res != VPX_CODEC_OK) return res;
+
+  // parse aggregate command line options
+  res = parse_options(svc_ctx, si->options);
+  if (res != VPX_CODEC_OK) return res;
+
+  // modify encoder configuration
+  enc_cfg->ss_number_layers = si->layers;
+  enc_cfg->kf_mode = VPX_KF_DISABLED;
+  enc_cfg->g_pass = VPX_RC_ONE_PASS;
+  // Lag in frames not currently supported
+  enc_cfg->g_lag_in_frames = 0;
+
+  // TODO(ivanmaltz): determine if these values need to be set explicitly for
+  // svc, or if the normal default/override mechanism can be used
+  enc_cfg->rc_dropframe_thresh = 0;
+  enc_cfg->rc_end_usage = VPX_CBR;
+  enc_cfg->rc_resize_allowed = 0;
+  enc_cfg->rc_min_quantizer = 33;
+  enc_cfg->rc_max_quantizer = 33;
+  enc_cfg->rc_undershoot_pct = 100;
+  enc_cfg->rc_overshoot_pct = 15;
+  enc_cfg->rc_buf_initial_sz = 500;
+  enc_cfg->rc_buf_optimal_sz = 600;
+  enc_cfg->rc_buf_sz = 1000;
+  enc_cfg->g_error_resilient = 1;
+
+  // Initialize codec
+  res = vpx_codec_enc_init(codec_ctx, iface, enc_cfg, VPX_CODEC_USE_PSNR);
+  if (res != VPX_CODEC_OK) {
+    svc_log(svc_ctx, SVC_LOG_ERROR, "svc_enc_init error\n");
+    return res;
+  }
+
+  vpx_codec_control(codec_ctx, VP9E_SET_SVC, 1);
+  vpx_codec_control(codec_ctx, VP8E_SET_CPUUSED, 1);
+  vpx_codec_control(codec_ctx, VP8E_SET_STATIC_THRESHOLD, 1);
+  vpx_codec_control(codec_ctx, VP8E_SET_NOISE_SENSITIVITY, 1);
+  vpx_codec_control(codec_ctx, VP8E_SET_TOKEN_PARTITIONS, 1);
+
+  max_intra_size_pct =
+      (int)(((double)enc_cfg->rc_buf_optimal_sz * 0.5) *
+            ((double)enc_cfg->g_timebase.den / enc_cfg->g_timebase.num) / 10.0);
+  vpx_codec_control(codec_ctx, VP8E_SET_MAX_INTRA_BITRATE_PCT,
+                    max_intra_size_pct);
+  return VPX_CODEC_OK;
+}
+
+// SVC Algorithm flags - these get mapped to VP8_EFLAG_* defined in vp8cx.h
+
+// encoder should reference the last frame
+#define USE_LAST (1 << 0)
+
+// encoder should reference the alt ref frame
+#define USE_ARF (1 << 1)
+
+// encoder should reference the golden frame
+#define USE_GF (1 << 2)
+
+// encoder should copy current frame to the last frame buffer
+#define UPDATE_LAST (1 << 3)
+
+// encoder should copy current frame to the alt ref frame buffer
+#define UPDATE_ARF (1 << 4)
+
+// encoder should copy current frame to the golden frame
+#define UPDATE_GF (1 << 5)
+
+static int map_vp8_flags(int svc_flags) {
+  int flags = 0;
+
+  if (!(svc_flags & USE_LAST)) flags |= VP8_EFLAG_NO_REF_LAST;
+  if (!(svc_flags & USE_ARF)) flags |= VP8_EFLAG_NO_REF_ARF;
+  if (!(svc_flags & USE_GF)) flags |= VP8_EFLAG_NO_REF_GF;
+
+  if (svc_flags & UPDATE_LAST) {
+    // last is updated automatically
+  } else {
+    flags |= VP8_EFLAG_NO_UPD_LAST;
+  }
+  if (svc_flags & UPDATE_ARF) {
+    flags |= VP8_EFLAG_FORCE_ARF;
+  } else {
+    flags |= VP8_EFLAG_NO_UPD_ARF;
+  }
+  if (svc_flags & UPDATE_GF) {
+    flags |= VP8_EFLAG_FORCE_GF;
+  } else {
+    flags |= VP8_EFLAG_NO_UPD_GF;
+  }
+  return flags;
+}
+
+static void calculate_enc_frame_flags(SvcContext *svc_ctx) {
+  vpx_enc_frame_flags_t flags = VPX_EFLAG_FORCE_KF;
+  SvcInternal *const si = get_svc_internal(svc_ctx);
+  const int is_keyframe = (si->frame_within_gop == 0);
+
+  // keyframe layer zero is identical for all modes
+  if (is_keyframe && si->layer == 0) {
+    si->enc_frame_flags = VPX_EFLAG_FORCE_KF;
+    return;
+  }
+
+  switch (svc_ctx->encoding_mode) {
+    case ALT_INTER_LAYER_PREDICTION_IP:
+      if (si->layer == 0) {
+        flags = map_vp8_flags(USE_LAST | UPDATE_LAST);
+      } else if (is_keyframe) {
+        if (si->layer == si->layers - 1) {
+          flags = map_vp8_flags(USE_ARF | UPDATE_LAST);
+        } else {
+          flags = map_vp8_flags(USE_ARF | UPDATE_LAST | UPDATE_GF);
+        }
+      } else {
+        flags = map_vp8_flags(USE_LAST | USE_ARF | UPDATE_LAST);
+      }
+      break;
+    case INTER_LAYER_PREDICTION_I:
+      if (si->layer == 0) {
+        flags = map_vp8_flags(USE_LAST | UPDATE_LAST);
+      } else if (is_keyframe) {
+        flags = map_vp8_flags(USE_ARF | UPDATE_LAST);
+      } else {
+        flags = map_vp8_flags(USE_LAST | UPDATE_LAST);
+      }
+      break;
+    case INTER_LAYER_PREDICTION_IP:
+      if (si->layer == 0) {
+        flags = map_vp8_flags(USE_LAST | UPDATE_LAST);
+      } else if (is_keyframe) {
+        flags = map_vp8_flags(USE_ARF | UPDATE_LAST);
+      } else {
+        flags = map_vp8_flags(USE_LAST | USE_ARF | UPDATE_LAST);
+      }
+      break;
+    case USE_GOLDEN_FRAME:
+      if (2 * si->layers - SVC_REFERENCE_FRAMES <= si->layer) {
+        if (si->layer == 0) {
+          flags = map_vp8_flags(USE_LAST | USE_GF | UPDATE_LAST);
+        } else if (is_keyframe) {
+          flags = map_vp8_flags(USE_ARF | UPDATE_LAST | UPDATE_GF);
+        } else {
+          flags = map_vp8_flags(USE_LAST | USE_ARF | USE_GF | UPDATE_LAST);
+        }
+      } else {
+        if (si->layer == 0) {
+          flags = map_vp8_flags(USE_LAST | UPDATE_LAST);
+        } else if (is_keyframe) {
+          flags = map_vp8_flags(USE_ARF | UPDATE_LAST);
+        } else {
+          flags = map_vp8_flags(USE_LAST | UPDATE_LAST);
+        }
+      }
+      break;
+    default:
+      svc_log(svc_ctx, SVC_LOG_ERROR, "unexpected encoding mode: %d\n",
+              svc_ctx->encoding_mode);
+      break;
+  }
+  si->enc_frame_flags = flags;
+}
+
+vpx_codec_err_t vpx_svc_get_layer_resolution(const SvcContext *svc_ctx,
+                                             int layer,
+                                             unsigned int *width,
+                                             unsigned int *height) {
+  int w, h, index, num, den;
+  const SvcInternal *const si = get_const_svc_internal(svc_ctx);
+
+  if (svc_ctx == NULL || si == NULL || width == NULL || height == NULL) {
+    return VPX_CODEC_INVALID_PARAM;
+  }
+  if (layer < 0 || layer >= si->layers) return VPX_CODEC_INVALID_PARAM;
+
+  index = layer + VPX_SS_MAX_LAYERS - si->layers;
+  num = si->scaling_factor_num[index];
+  den = si->scaling_factor_den[index];
+  if (num == 0 || den == 0) return VPX_CODEC_INVALID_PARAM;
+
+  w = si->width * num / den;
+  h = si->height * num / den;
+
+  // make height and width even to make chrome player happy
+  w += w % 2;
+  h += h % 2;
+
+  *width = w;
+  *height = h;
+
+  return VPX_CODEC_OK;
+}
+
+static void set_svc_parameters(SvcContext *svc_ctx,
+                               vpx_codec_ctx_t *codec_ctx) {
+  int layer, layer_index;
+  vpx_svc_parameters_t svc_params;
+  SvcInternal *const si = get_svc_internal(svc_ctx);
+
+  memset(&svc_params, 0, sizeof(svc_params));
+  svc_params.layer = si->layer;
+  svc_params.flags = si->enc_frame_flags;
+
+  layer = si->layer;
+  if (svc_ctx->encoding_mode == ALT_INTER_LAYER_PREDICTION_IP &&
+      si->frame_within_gop == 0) {
+    // layers 1 & 3 don't exist in this mode, use the higher one
+    if (layer == 0 || layer == 2) {
+      layer += 1;
+    }
+  }
+  if (VPX_CODEC_OK != vpx_svc_get_layer_resolution(svc_ctx, layer,
+                                                   &svc_params.width,
+                                                   &svc_params.height)) {
+    svc_log(svc_ctx, SVC_LOG_ERROR, "vpx_svc_get_layer_resolution failed\n");
+  }
+  layer_index = layer + VPX_SS_MAX_LAYERS - si->layers;
+  svc_params.min_quantizer = si->quantizer[layer_index];
+  svc_params.max_quantizer = si->quantizer[layer_index];
+  svc_params.distance_from_i_frame = si->frame_within_gop;
+
+  // Use buffer i for layer i LST
+  svc_params.lst_fb_idx = si->layer;
+
+  // Use buffer i-1 for layer i Alt (Inter-layer prediction)
+  if (si->layer != 0) {
+    const int use_higher_layer =
+        svc_ctx->encoding_mode == ALT_INTER_LAYER_PREDICTION_IP &&
+        si->frame_within_gop == 0;
+    svc_params.alt_fb_idx = use_higher_layer ? si->layer - 2 : si->layer - 1;
+  }
+
+  if (svc_ctx->encoding_mode == ALT_INTER_LAYER_PREDICTION_IP) {
+    svc_params.gld_fb_idx = si->layer + 1;
+  } else {
+    if (si->layer < 2 * si->layers - SVC_REFERENCE_FRAMES)
+      svc_params.gld_fb_idx = svc_params.lst_fb_idx;
+    else
+      svc_params.gld_fb_idx = 2 * si->layers - 1 - si->layer;
+  }
+
+  svc_log(svc_ctx, SVC_LOG_DEBUG, "SVC frame: %d, layer: %d, %dx%d, q: %d\n",
+          si->encode_frame_count, si->layer, svc_params.width,
+          svc_params.height, svc_params.min_quantizer);
+
+  if (svc_params.flags == VPX_EFLAG_FORCE_KF) {
+    svc_log(svc_ctx, SVC_LOG_DEBUG, "flags == VPX_EFLAG_FORCE_KF\n");
+  } else {
+    svc_log(
+        svc_ctx, SVC_LOG_DEBUG, "Using:    LST/GLD/ALT [%2d|%2d|%2d]\n",
+        svc_params.flags & VP8_EFLAG_NO_REF_LAST ? -1 : svc_params.lst_fb_idx,
+        svc_params.flags & VP8_EFLAG_NO_REF_GF ? -1 : svc_params.gld_fb_idx,
+        svc_params.flags & VP8_EFLAG_NO_REF_ARF ? -1 : svc_params.alt_fb_idx);
+    svc_log(
+        svc_ctx, SVC_LOG_DEBUG, "Updating: LST/GLD/ALT [%2d|%2d|%2d]\n",
+        svc_params.flags & VP8_EFLAG_NO_UPD_LAST ? -1 : svc_params.lst_fb_idx,
+        svc_params.flags & VP8_EFLAG_NO_UPD_GF ? -1 : svc_params.gld_fb_idx,
+        svc_params.flags & VP8_EFLAG_NO_UPD_ARF ? -1 : svc_params.alt_fb_idx);
+  }
+
+  vpx_codec_control(codec_ctx, VP9E_SET_SVC_PARAMETERS, &svc_params);
+}
+
+/**
+ * Encode a frame into multiple layers
+ * Create a superframe containing the individual layers
+ */
+vpx_codec_err_t vpx_svc_encode(SvcContext *svc_ctx, vpx_codec_ctx_t *codec_ctx,
+                               struct vpx_image *rawimg, vpx_codec_pts_t pts,
+                               int64_t duration, int deadline) {
+  vpx_codec_err_t res;
+  vpx_codec_iter_t iter;
+  const vpx_codec_cx_pkt_t *cx_pkt;
+  struct LayerData *cx_layer_list = NULL;
+  struct LayerData *layer_data;
+  struct Superframe superframe;
+  SvcInternal *const si = get_svc_internal(svc_ctx);
+  if (svc_ctx == NULL || codec_ctx == NULL || rawimg == NULL || si == NULL) {
+    return VPX_CODEC_INVALID_PARAM;
+  }
+
+  memset(&superframe, 0, sizeof(superframe));
+  svc_log_reset(svc_ctx);
+
+  si->layers = svc_ctx->spatial_layers;
+  if (si->frame_within_gop >= si->kf_dist ||
+      si->encode_frame_count == 0) {
+    si->frame_within_gop = 0;
+  }
+  si->is_keyframe = (si->frame_within_gop == 0);
+  si->frame_size = 0;
+
+  svc_log(svc_ctx, SVC_LOG_DEBUG,
+          "vpx_svc_encode  layers: %d, frame_count: %d, frame_within_gop: %d\n",
+          si->layers, si->encode_frame_count, si->frame_within_gop);
+
+  // encode each layer
+  for (si->layer = 0; si->layer < si->layers; ++si->layer) {
+    if (svc_ctx->encoding_mode == ALT_INTER_LAYER_PREDICTION_IP &&
+        si->is_keyframe && (si->layer == 1 || si->layer == 3)) {
+      svc_log(svc_ctx, SVC_LOG_DEBUG, "Skip encoding layer %d\n", si->layer);
+      continue;
+    }
+    calculate_enc_frame_flags(svc_ctx);
+
+    set_svc_parameters(svc_ctx, codec_ctx);
+
+    res = vpx_codec_encode(codec_ctx, rawimg, pts, (uint32_t)duration,
+                           si->enc_frame_flags, deadline);
+    if (res != VPX_CODEC_OK) {
+      return res;
+    }
+    // save compressed data
+    iter = NULL;
+    while ((cx_pkt = vpx_codec_get_cx_data(codec_ctx, &iter))) {
+      switch (cx_pkt->kind) {
+        case VPX_CODEC_CX_FRAME_PKT: {
+          const uint32_t frame_pkt_size = (uint32_t)(cx_pkt->data.frame.sz);
+          si->bytes_in_layer[si->layer] += frame_pkt_size;
+          svc_log(svc_ctx, SVC_LOG_DEBUG,
+                  "SVC frame: %d, layer: %d, size: %u\n",
+                  si->encode_frame_count, si->layer, frame_pkt_size);
+          layer_data =
+              ld_create(cx_pkt->data.frame.buf, (size_t)frame_pkt_size);
+          if (layer_data == NULL) {
+            svc_log(svc_ctx, SVC_LOG_ERROR, "Error allocating LayerData\n");
+            return 0;
+          }
+          ld_list_add(&cx_layer_list, layer_data);
+
+          // save layer size in superframe index
+          superframe.sizes[superframe.count++] = frame_pkt_size;
+          superframe.magnitude |= frame_pkt_size;
+          break;
+        }
+        case VPX_CODEC_PSNR_PKT: {
+          svc_log(svc_ctx, SVC_LOG_DEBUG,
+                  "SVC frame: %d, layer: %d, PSNR(Total/Y/U/V): "
+                  "%2.3f  %2.3f  %2.3f  %2.3f \n",
+                  si->encode_frame_count, si->layer,
+                  cx_pkt->data.psnr.psnr[0], cx_pkt->data.psnr.psnr[1],
+                  cx_pkt->data.psnr.psnr[2], cx_pkt->data.psnr.psnr[3]);
+          si->psnr_in_layer[si->layer] += cx_pkt->data.psnr.psnr[0];
+          break;
+        }
+        default: {
+          break;
+        }
+      }
+    }
+  }
+  // add superframe index to layer data list
+  sf_create_index(&superframe);
+  layer_data = ld_create(superframe.buffer, superframe.index_size);
+  ld_list_add(&cx_layer_list, layer_data);
+
+  // get accumulated size of layer data
+  si->frame_size = ld_list_get_buffer_size(cx_layer_list);
+  if (si->frame_size == 0) return VPX_CODEC_ERROR;
+
+  // all layers encoded, create single buffer with concatenated layers
+  if (si->frame_size > si->buffer_size) {
+    free(si->buffer);
+    si->buffer = malloc(si->frame_size);
+    if (si->buffer == NULL) {
+      ld_list_free(cx_layer_list);
+      return VPX_CODEC_MEM_ERROR;
+    }
+    si->buffer_size = si->frame_size;
+  }
+  // copy layer data into packet
+  ld_list_copy_to_buffer(cx_layer_list, si->buffer);
+
+  ld_list_free(cx_layer_list);
+
+  svc_log(svc_ctx, SVC_LOG_DEBUG, "SVC frame: %d, kf: %d, size: %d, pts: %d\n",
+          si->encode_frame_count, si->is_keyframe, (int)si->frame_size,
+          (int)pts);
+  ++si->frame_within_gop;
+  ++si->encode_frame_count;
+
+  return VPX_CODEC_OK;
+}
+
+const char *vpx_svc_get_message(const SvcContext *svc_ctx) {
+  const SvcInternal *const si = get_const_svc_internal(svc_ctx);
+  if (svc_ctx == NULL || si == NULL) return NULL;
+  return si->message_buffer;
+}
+
+void *vpx_svc_get_buffer(const SvcContext *svc_ctx) {
+  const SvcInternal *const si = get_const_svc_internal(svc_ctx);
+  if (svc_ctx == NULL || si == NULL) return NULL;
+  return si->buffer;
+}
+
+size_t vpx_svc_get_frame_size(const SvcContext *svc_ctx) {
+  const SvcInternal *const si = get_const_svc_internal(svc_ctx);
+  if (svc_ctx == NULL || si == NULL) return 0;
+  return si->frame_size;
+}
+
+int vpx_svc_get_encode_frame_count(const SvcContext *svc_ctx) {
+  const SvcInternal *const si = get_const_svc_internal(svc_ctx);
+  if (svc_ctx == NULL || si == NULL) return 0;
+  return si->encode_frame_count;
+}
+
+int vpx_svc_is_keyframe(const SvcContext *svc_ctx) {
+  const SvcInternal *const si = get_const_svc_internal(svc_ctx);
+  if (svc_ctx == NULL || si == NULL) return 0;
+  return si->is_keyframe;
+}
+
+void vpx_svc_set_keyframe(SvcContext *svc_ctx) {
+  SvcInternal *const si = get_svc_internal(svc_ctx);
+  if (svc_ctx == NULL || si == NULL) return;
+  si->frame_within_gop = 0;
+}
+
+// dump accumulated statistics and reset accumulated values
+const char *vpx_svc_dump_statistics(SvcContext *svc_ctx) {
+  int number_of_frames, number_of_keyframes, encode_frame_count;
+  int i;
+  uint32_t bytes_total = 0;
+  SvcInternal *const si = get_svc_internal(svc_ctx);
+  if (svc_ctx == NULL || si == NULL) return NULL;
+
+  svc_log_reset(svc_ctx);
+
+  encode_frame_count = si->encode_frame_count;
+  if (si->encode_frame_count <= 0) return vpx_svc_get_message(svc_ctx);
+
+  svc_log(svc_ctx, SVC_LOG_INFO, "\n");
+  number_of_keyframes = encode_frame_count / si->kf_dist + 1;
+  for (i = 0; i < si->layers; ++i) {
+    number_of_frames = encode_frame_count;
+
+    if (svc_ctx->encoding_mode == ALT_INTER_LAYER_PREDICTION_IP &&
+        (i == 1 || i == 3)) {
+      number_of_frames -= number_of_keyframes;
+    }
+    svc_log(svc_ctx, SVC_LOG_INFO, "Layer %d PSNR=[%2.3f], Bytes=[%u]\n", i,
+            (double)si->psnr_in_layer[i] / number_of_frames,
+            si->bytes_in_layer[i]);
+    bytes_total += si->bytes_in_layer[i];
+    si->psnr_in_layer[i] = 0;
+    si->bytes_in_layer[i] = 0;
+  }
+
+  // only display statistics once
+  si->encode_frame_count = 0;
+
+  svc_log(svc_ctx, SVC_LOG_INFO, "Total Bytes=[%u]\n", bytes_total);
+  return vpx_svc_get_message(svc_ctx);
+}
+
+void vpx_svc_release(SvcContext *svc_ctx) {
+  SvcInternal *si;
+  if (svc_ctx == NULL) return;
+  // do not use get_svc_internal as it will unnecessarily allocate an
+  // SvcInternal if it was not already allocated
+  si = (SvcInternal *)svc_ctx->internal;
+  if (si != NULL) {
+    free(si->buffer);
+    free(si);
+    svc_ctx->internal = NULL;
+  }
+}