1 files changed, 634 insertions, 0 deletions

diff --git a/media/libvpx/libvpx/examples/svc_encodeframe.c b/media/libvpx/libvpx/examples/svc_encodeframe.c
new file mode 100644
index 0000000000..1dd731765c
--- /dev/null
+++ b/media/libvpx/libvpx/examples/svc_encodeframe.c
@@ -0,0 +1,634 @@
+/*
+ *  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 <assert.h>
+#include <math.h>
+#include <limits.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#define VPX_DISABLE_CTRL_TYPECHECKS 1
+#include "../tools_common.h"
+#include "./vpx_config.h"
+#include "./svc_context.h"
+#include "vpx/vp8cx.h"
+#include "vpx/vpx_encoder.h"
+#include "vpx_mem/vpx_mem.h"
+#include "vp9/common/vp9_onyxc_int.h"
+
+#ifdef __MINGW32__
+#define strtok_r strtok_s
+#ifndef MINGW_HAS_SECURE_API
+// 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 /* MINGW_HAS_SECURE_API */
+#endif /* __MINGW32__ */
+
+#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 MAX_QUANTIZER 63
+
+static const int DEFAULT_SCALE_FACTORS_NUM[VPX_SS_MAX_LAYERS] = { 4, 5, 7, 11,
+                                                                  16 };
+
+static const int DEFAULT_SCALE_FACTORS_DEN[VPX_SS_MAX_LAYERS] = { 16, 16, 16,
+                                                                  16, 16 };
+
+static const int DEFAULT_SCALE_FACTORS_NUM_2x[VPX_SS_MAX_LAYERS] = { 1, 2, 4 };
+
+static const int DEFAULT_SCALE_FACTORS_DEN_2x[VPX_SS_MAX_LAYERS] = { 4, 4, 4 };
+
+typedef enum {
+  QUANTIZER = 0,
+  BITRATE,
+  SCALE_FACTOR,
+  AUTO_ALT_REF,
+  ALL_OPTION_TYPES
+} LAYER_OPTION_TYPE;
+
+static const int option_max_values[ALL_OPTION_TYPES] = { 63, INT_MAX, INT_MAX,
+                                                         1 };
+
+static const int option_min_values[ALL_OPTION_TYPES] = { 0, 0, 1, 0 };
+
+// One encoded frame
+typedef struct FrameData {
+  void *buf;                     // compressed data buffer
+  size_t size;                   // length of compressed data
+  vpx_codec_frame_flags_t flags; /**< flags for this frame */
+  struct FrameData *next;
+} FrameData;
+
+static SvcInternal_t *get_svc_internal(SvcContext *svc_ctx) {
+  if (svc_ctx == NULL) return NULL;
+  if (svc_ctx->internal == NULL) {
+    SvcInternal_t *const si = (SvcInternal_t *)malloc(sizeof(*si));
+    if (si != NULL) {
+      memset(si, 0, sizeof(*si));
+    }
+    svc_ctx->internal = si;
+  }
+  return (SvcInternal_t *)svc_ctx->internal;
+}
+
+static const SvcInternal_t *get_const_svc_internal(const SvcContext *svc_ctx) {
+  if (svc_ctx == NULL) return NULL;
+  return (const SvcInternal_t *)svc_ctx->internal;
+}
+
+static VPX_TOOLS_FORMAT_PRINTF(3, 4) int svc_log(SvcContext *svc_ctx,
+                                                 SVC_LOG_LEVEL level,
+                                                 const char *fmt, ...) {
+  char buf[512];
+  int retval = 0;
+  va_list ap;
+
+  if (level > svc_ctx->log_level) {
+    return retval;
+  }
+
+  va_start(ap, fmt);
+  retval = vsnprintf(buf, sizeof(buf), fmt, ap);
+  va_end(ap);
+
+  printf("%s", buf);
+
+  return retval;
+}
+
+static vpx_codec_err_t extract_option(LAYER_OPTION_TYPE type, char *input,
+                                      int *value0, int *value1) {
+  if (type == SCALE_FACTOR) {
+    *value0 = (int)strtol(input, &input, 10);
+    if (*input++ != '/') return VPX_CODEC_INVALID_PARAM;
+    *value1 = (int)strtol(input, &input, 10);
+
+    if (*value0 < option_min_values[SCALE_FACTOR] ||
+        *value1 < option_min_values[SCALE_FACTOR] ||
+        *value0 > option_max_values[SCALE_FACTOR] ||
+        *value1 > option_max_values[SCALE_FACTOR] ||
+        *value0 > *value1)  // num shouldn't be greater than den
+      return VPX_CODEC_INVALID_PARAM;
+  } else {
+    *value0 = atoi(input);
+    if (*value0 < option_min_values[type] || *value0 > option_max_values[type])
+      return VPX_CODEC_INVALID_PARAM;
+  }
+  return VPX_CODEC_OK;
+}
+
+static vpx_codec_err_t parse_layer_options_from_string(SvcContext *svc_ctx,
+                                                       LAYER_OPTION_TYPE type,
+                                                       const char *input,
+                                                       int *option0,
+                                                       int *option1) {
+  int i;
+  vpx_codec_err_t res = VPX_CODEC_OK;
+  char *input_string;
+  char *token;
+  const char *delim = ",";
+  char *save_ptr;
+  int num_layers = svc_ctx->spatial_layers;
+  if (type == BITRATE)
+    num_layers = svc_ctx->spatial_layers * svc_ctx->temporal_layers;
+
+  if (input == NULL || option0 == NULL ||
+      (option1 == NULL && type == SCALE_FACTOR))
+    return VPX_CODEC_INVALID_PARAM;
+
+  input_string = strdup(input);
+  if (input_string == NULL) return VPX_CODEC_MEM_ERROR;
+  token = strtok_r(input_string, delim, &save_ptr);
+  for (i = 0; i < num_layers; ++i) {
+    if (token != NULL) {
+      res = extract_option(type, token, option0 + i, option1 + i);
+      if (res != VPX_CODEC_OK) break;
+      token = strtok_r(NULL, delim, &save_ptr);
+    } else {
+      break;
+    }
+  }
+  if (res == VPX_CODEC_OK && i != num_layers) {
+    svc_log(svc_ctx, SVC_LOG_ERROR,
+            "svc: layer params type: %d    %d values required, "
+            "but only %d specified\n",
+            type, num_layers, i);
+    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 = NULL;
+  SvcInternal_t *const si = get_svc_internal(svc_ctx);
+  vpx_codec_err_t res = VPX_CODEC_OK;
+  int i, alt_ref_enabled = 0;
+
+  if (options == NULL) return VPX_CODEC_OK;
+  input_string = strdup(options);
+  if (input_string == NULL) return VPX_CODEC_MEM_ERROR;
+
+  // 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("spatial-layers", option_name) == 0) {
+      svc_ctx->spatial_layers = atoi(option_value);
+    } else if (strcmp("temporal-layers", option_name) == 0) {
+      svc_ctx->temporal_layers = atoi(option_value);
+    } else if (strcmp("scale-factors", option_name) == 0) {
+      res = parse_layer_options_from_string(svc_ctx, SCALE_FACTOR, option_value,
+                                            si->svc_params.scaling_factor_num,
+                                            si->svc_params.scaling_factor_den);
+      if (res != VPX_CODEC_OK) break;
+    } else if (strcmp("max-quantizers", option_name) == 0) {
+      res =
+          parse_layer_options_from_string(svc_ctx, QUANTIZER, option_value,
+                                          si->svc_params.max_quantizers, NULL);
+      if (res != VPX_CODEC_OK) break;
+    } else if (strcmp("min-quantizers", option_name) == 0) {
+      res =
+          parse_layer_options_from_string(svc_ctx, QUANTIZER, option_value,
+                                          si->svc_params.min_quantizers, NULL);
+      if (res != VPX_CODEC_OK) break;
+    } else if (strcmp("auto-alt-refs", option_name) == 0) {
+      res = parse_layer_options_from_string(svc_ctx, AUTO_ALT_REF, option_value,
+                                            si->enable_auto_alt_ref, NULL);
+      if (res != VPX_CODEC_OK) break;
+    } else if (strcmp("bitrates", option_name) == 0) {
+      res = parse_layer_options_from_string(svc_ctx, BITRATE, option_value,
+                                            si->bitrates, NULL);
+      if (res != VPX_CODEC_OK) break;
+    } else if (strcmp("multi-frame-contexts", option_name) == 0) {
+      si->use_multiple_frame_contexts = atoi(option_value);
+    } 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);
+
+  for (i = 0; i < svc_ctx->spatial_layers; ++i) {
+    if (si->svc_params.max_quantizers[i] > MAX_QUANTIZER ||
+        si->svc_params.max_quantizers[i] < 0 ||
+        si->svc_params.min_quantizers[i] > si->svc_params.max_quantizers[i] ||
+        si->svc_params.min_quantizers[i] < 0)
+      res = VPX_CODEC_INVALID_PARAM;
+  }
+
+  if (si->use_multiple_frame_contexts &&
+      (svc_ctx->spatial_layers > 3 ||
+       svc_ctx->spatial_layers * svc_ctx->temporal_layers > 4))
+    res = VPX_CODEC_INVALID_PARAM;
+
+  for (i = 0; i < svc_ctx->spatial_layers; ++i)
+    alt_ref_enabled += si->enable_auto_alt_ref[i];
+  if (alt_ref_enabled > REF_FRAMES - svc_ctx->spatial_layers) {
+    svc_log(svc_ctx, SVC_LOG_ERROR,
+            "svc: auto alt ref: Maxinum %d(REF_FRAMES - layers) layers could"
+            "enabled auto alt reference frame, but %d layers are enabled\n",
+            REF_FRAMES - svc_ctx->spatial_layers, alt_ref_enabled);
+    res = VPX_CODEC_INVALID_PARAM;
+  }
+
+  return res;
+}
+
+vpx_codec_err_t vpx_svc_set_options(SvcContext *svc_ctx, const char *options) {
+  SvcInternal_t *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) - 1);
+  si->options[sizeof(si->options) - 1] = '\0';
+  return VPX_CODEC_OK;
+}
+
+static vpx_codec_err_t assign_layer_bitrates(
+    const SvcContext *svc_ctx, vpx_codec_enc_cfg_t *const enc_cfg) {
+  int i;
+  const SvcInternal_t *const si = get_const_svc_internal(svc_ctx);
+  int sl, tl, spatial_layer_target;
+
+  if (svc_ctx->temporal_layering_mode != 0) {
+    if (si->bitrates[0] != 0) {
+      unsigned int total_bitrate = 0;
+      for (sl = 0; sl < svc_ctx->spatial_layers; ++sl) {
+        total_bitrate += si->bitrates[sl * svc_ctx->temporal_layers +
+                                      svc_ctx->temporal_layers - 1];
+        for (tl = 0; tl < svc_ctx->temporal_layers; ++tl) {
+          enc_cfg->ss_target_bitrate[sl * svc_ctx->temporal_layers] +=
+              (unsigned int)si->bitrates[sl * svc_ctx->temporal_layers + tl];
+          enc_cfg->layer_target_bitrate[sl * svc_ctx->temporal_layers + tl] =
+              si->bitrates[sl * svc_ctx->temporal_layers + tl];
+          if (tl > 0 && (si->bitrates[sl * svc_ctx->temporal_layers + tl] <=
+                         si->bitrates[sl * svc_ctx->temporal_layers + tl - 1]))
+            return VPX_CODEC_INVALID_PARAM;
+        }
+      }
+      if (total_bitrate != enc_cfg->rc_target_bitrate)
+        return VPX_CODEC_INVALID_PARAM;
+    } else {
+      float total = 0;
+      float alloc_ratio[VPX_MAX_LAYERS] = { 0 };
+
+      for (sl = 0; sl < svc_ctx->spatial_layers; ++sl) {
+        if (si->svc_params.scaling_factor_den[sl] > 0) {
+          alloc_ratio[sl] = (float)(pow(2, sl));
+          total += alloc_ratio[sl];
+        }
+      }
+
+      for (sl = 0; sl < svc_ctx->spatial_layers; ++sl) {
+        enc_cfg->ss_target_bitrate[sl] = spatial_layer_target =
+            (unsigned int)(enc_cfg->rc_target_bitrate * alloc_ratio[sl] /
+                           total);
+        if (svc_ctx->temporal_layering_mode == 3) {
+          enc_cfg->layer_target_bitrate[sl * svc_ctx->temporal_layers] =
+              (spatial_layer_target * 6) / 10;  // 60%
+          enc_cfg->layer_target_bitrate[sl * svc_ctx->temporal_layers + 1] =
+              (spatial_layer_target * 8) / 10;  // 80%
+          enc_cfg->layer_target_bitrate[sl * svc_ctx->temporal_layers + 2] =
+              spatial_layer_target;
+        } else if (svc_ctx->temporal_layering_mode == 2 ||
+                   svc_ctx->temporal_layering_mode == 1) {
+          enc_cfg->layer_target_bitrate[sl * svc_ctx->temporal_layers] =
+              spatial_layer_target * 2 / 3;
+          enc_cfg->layer_target_bitrate[sl * svc_ctx->temporal_layers + 1] =
+              spatial_layer_target;
+        } else {
+          // User should explicitly assign bitrates in this case.
+          assert(0);
+        }
+      }
+    }
+  } else {
+    if (si->bitrates[0] != 0) {
+      unsigned int total_bitrate = 0;
+      for (i = 0; i < svc_ctx->spatial_layers; ++i) {
+        enc_cfg->ss_target_bitrate[i] = (unsigned int)si->bitrates[i];
+        enc_cfg->layer_target_bitrate[i] = (unsigned int)si->bitrates[i];
+        total_bitrate += si->bitrates[i];
+      }
+      if (total_bitrate != enc_cfg->rc_target_bitrate)
+        return VPX_CODEC_INVALID_PARAM;
+    } else {
+      float total = 0;
+      float alloc_ratio[VPX_MAX_LAYERS] = { 0 };
+
+      for (i = 0; i < svc_ctx->spatial_layers; ++i) {
+        if (si->svc_params.scaling_factor_den[i] > 0) {
+          alloc_ratio[i] = (float)(si->svc_params.scaling_factor_num[i] * 1.0 /
+                                   si->svc_params.scaling_factor_den[i]);
+
+          alloc_ratio[i] *= alloc_ratio[i];
+          total += alloc_ratio[i];
+        }
+      }
+      for (i = 0; i < VPX_SS_MAX_LAYERS; ++i) {
+        if (total > 0) {
+          enc_cfg->layer_target_bitrate[i] =
+              (unsigned int)(enc_cfg->rc_target_bitrate * alloc_ratio[i] /
+                             total);
+        }
+      }
+    }
+  }
+  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) {
+  vpx_codec_err_t res;
+  int sl, tl;
+  SvcInternal_t *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;
+
+  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;
+  }
+
+  // Note: temporal_layering_mode only applies to one-pass CBR
+  // si->svc_params.temporal_layering_mode = svc_ctx->temporal_layering_mode;
+  if (svc_ctx->temporal_layering_mode == 3) {
+    svc_ctx->temporal_layers = 3;
+  } else if (svc_ctx->temporal_layering_mode == 2 ||
+             svc_ctx->temporal_layering_mode == 1) {
+    svc_ctx->temporal_layers = 2;
+  }
+
+  for (sl = 0; sl < VPX_SS_MAX_LAYERS; ++sl) {
+    si->svc_params.scaling_factor_num[sl] = DEFAULT_SCALE_FACTORS_NUM[sl];
+    si->svc_params.scaling_factor_den[sl] = DEFAULT_SCALE_FACTORS_DEN[sl];
+    si->svc_params.speed_per_layer[sl] = svc_ctx->speed;
+  }
+  if (enc_cfg->rc_end_usage == VPX_CBR && enc_cfg->g_pass == VPX_RC_ONE_PASS &&
+      svc_ctx->spatial_layers <= 3) {
+    for (sl = 0; sl < svc_ctx->spatial_layers; ++sl) {
+      int sl2 = (svc_ctx->spatial_layers == 2) ? sl + 1 : sl;
+      si->svc_params.scaling_factor_num[sl] = DEFAULT_SCALE_FACTORS_NUM_2x[sl2];
+      si->svc_params.scaling_factor_den[sl] = DEFAULT_SCALE_FACTORS_DEN_2x[sl2];
+    }
+    if (svc_ctx->spatial_layers == 1) {
+      si->svc_params.scaling_factor_num[0] = 1;
+      si->svc_params.scaling_factor_den[0] = 1;
+    }
+  }
+  for (tl = 0; tl < svc_ctx->temporal_layers; ++tl) {
+    for (sl = 0; sl < svc_ctx->spatial_layers; ++sl) {
+      const int i = sl * svc_ctx->temporal_layers + tl;
+      si->svc_params.max_quantizers[i] = MAX_QUANTIZER;
+      si->svc_params.min_quantizers[i] = 0;
+      if (enc_cfg->rc_end_usage == VPX_CBR &&
+          enc_cfg->g_pass == VPX_RC_ONE_PASS) {
+        si->svc_params.max_quantizers[i] = 56;
+        si->svc_params.min_quantizers[i] = 2;
+      }
+    }
+  }
+
+  // Parse aggregate command line options. Options must start with
+  // "layers=xx" then followed by other options
+  res = parse_options(svc_ctx, si->options);
+  if (res != VPX_CODEC_OK) return res;
+
+  if (svc_ctx->spatial_layers < 1) svc_ctx->spatial_layers = 1;
+  if (svc_ctx->spatial_layers > VPX_SS_MAX_LAYERS)
+    svc_ctx->spatial_layers = VPX_SS_MAX_LAYERS;
+
+  if (svc_ctx->temporal_layers < 1) svc_ctx->temporal_layers = 1;
+  if (svc_ctx->temporal_layers > VPX_TS_MAX_LAYERS)
+    svc_ctx->temporal_layers = VPX_TS_MAX_LAYERS;
+
+  if (svc_ctx->temporal_layers * svc_ctx->spatial_layers > VPX_MAX_LAYERS) {
+    svc_log(
+        svc_ctx, SVC_LOG_ERROR,
+        "spatial layers * temporal layers (%d) exceeds the maximum number of "
+        "allowed layers of %d\n",
+        svc_ctx->spatial_layers * svc_ctx->temporal_layers, VPX_MAX_LAYERS);
+    return VPX_CODEC_INVALID_PARAM;
+  }
+  res = assign_layer_bitrates(svc_ctx, enc_cfg);
+  if (res != VPX_CODEC_OK) {
+    svc_log(svc_ctx, SVC_LOG_ERROR,
+            "layer bitrates incorrect: \n"
+            "1) spatial layer bitrates should sum up to target \n"
+            "2) temporal layer bitrates should be increasing within \n"
+            "a spatial layer \n");
+    return VPX_CODEC_INVALID_PARAM;
+  }
+
+  if (svc_ctx->temporal_layers > 1) {
+    int i;
+    for (i = 0; i < svc_ctx->temporal_layers; ++i) {
+      enc_cfg->ts_target_bitrate[i] =
+          enc_cfg->rc_target_bitrate / svc_ctx->temporal_layers;
+      enc_cfg->ts_rate_decimator[i] = 1 << (svc_ctx->temporal_layers - 1 - i);
+    }
+  }
+
+  if (svc_ctx->threads) enc_cfg->g_threads = svc_ctx->threads;
+
+  // Modify encoder configuration
+  enc_cfg->ss_number_layers = svc_ctx->spatial_layers;
+  enc_cfg->ts_number_layers = svc_ctx->temporal_layers;
+
+  if (enc_cfg->rc_end_usage == VPX_CBR) {
+    enc_cfg->rc_resize_allowed = 0;
+    enc_cfg->rc_min_quantizer = 2;
+    enc_cfg->rc_max_quantizer = 56;
+    enc_cfg->rc_undershoot_pct = 50;
+    enc_cfg->rc_overshoot_pct = 50;
+    enc_cfg->rc_buf_initial_sz = 500;
+    enc_cfg->rc_buf_optimal_sz = 600;
+    enc_cfg->rc_buf_sz = 1000;
+  }
+
+  for (tl = 0; tl < svc_ctx->temporal_layers; ++tl) {
+    for (sl = 0; sl < svc_ctx->spatial_layers; ++sl) {
+      const int i = sl * svc_ctx->temporal_layers + tl;
+      if (enc_cfg->rc_end_usage == VPX_CBR &&
+          enc_cfg->g_pass == VPX_RC_ONE_PASS) {
+        si->svc_params.max_quantizers[i] = enc_cfg->rc_max_quantizer;
+        si->svc_params.min_quantizers[i] = enc_cfg->rc_min_quantizer;
+      }
+    }
+  }
+
+  if (enc_cfg->g_error_resilient == 0 && si->use_multiple_frame_contexts == 0)
+    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;
+  }
+  if (svc_ctx->spatial_layers > 1 || svc_ctx->temporal_layers > 1) {
+    vpx_codec_control(codec_ctx, VP9E_SET_SVC, 1);
+    vpx_codec_control(codec_ctx, VP9E_SET_SVC_PARAMETERS, &si->svc_params);
+  }
+  return VPX_CODEC_OK;
+}
+
+/**
+ * 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;
+  SvcInternal_t *const si = get_svc_internal(svc_ctx);
+  if (svc_ctx == NULL || codec_ctx == NULL || si == NULL) {
+    return VPX_CODEC_INVALID_PARAM;
+  }
+
+  res =
+      vpx_codec_encode(codec_ctx, rawimg, pts, (uint32_t)duration, 0, 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_PSNR_PKT: ++si->psnr_pkt_received; break;
+      default: break;
+    }
+  }
+
+  return VPX_CODEC_OK;
+}
+
+static double calc_psnr(double d) {
+  if (d == 0) return 100;
+  return -10.0 * log(d) / log(10.0);
+}
+
+// dump accumulated statistics and reset accumulated values
+void vpx_svc_dump_statistics(SvcContext *svc_ctx) {
+  int number_of_frames;
+  int i, j;
+  uint32_t bytes_total = 0;
+  double scale[COMPONENTS];
+  double psnr[COMPONENTS];
+  double mse[COMPONENTS];
+  double y_scale;
+
+  SvcInternal_t *const si = get_svc_internal(svc_ctx);
+  if (svc_ctx == NULL || si == NULL) return;
+
+  number_of_frames = si->psnr_pkt_received;
+  if (number_of_frames <= 0) return;
+
+  svc_log(svc_ctx, SVC_LOG_INFO, "\n");
+  for (i = 0; i < svc_ctx->spatial_layers; ++i) {
+    svc_log(svc_ctx, SVC_LOG_INFO,
+            "Layer %d Average PSNR=[%2.3f, %2.3f, %2.3f, %2.3f], Bytes=[%u]\n",
+            i, si->psnr_sum[i][0] / number_of_frames,
+            si->psnr_sum[i][1] / number_of_frames,
+            si->psnr_sum[i][2] / number_of_frames,
+            si->psnr_sum[i][3] / number_of_frames, si->bytes_sum[i]);
+    // the following psnr calculation is deduced from ffmpeg.c#print_report
+    y_scale = si->width * si->height * 255.0 * 255.0 * number_of_frames;
+    scale[1] = y_scale;
+    scale[2] = scale[3] = y_scale / 4;  // U or V
+    scale[0] = y_scale * 1.5;           // total
+
+    for (j = 0; j < COMPONENTS; j++) {
+      psnr[j] = calc_psnr(si->sse_sum[i][j] / scale[j]);
+      mse[j] = si->sse_sum[i][j] * 255.0 * 255.0 / scale[j];
+    }
+    svc_log(svc_ctx, SVC_LOG_INFO,
+            "Layer %d Overall PSNR=[%2.3f, %2.3f, %2.3f, %2.3f]\n", i, psnr[0],
+            psnr[1], psnr[2], psnr[3]);
+    svc_log(svc_ctx, SVC_LOG_INFO,
+            "Layer %d Overall MSE=[%2.3f, %2.3f, %2.3f, %2.3f]\n", i, mse[0],
+            mse[1], mse[2], mse[3]);
+
+    bytes_total += si->bytes_sum[i];
+    // Clear sums for next time.
+    si->bytes_sum[i] = 0;
+    for (j = 0; j < COMPONENTS; ++j) {
+      si->psnr_sum[i][j] = 0;
+      si->sse_sum[i][j] = 0;
+    }
+  }
+
+  // only display statistics once
+  si->psnr_pkt_received = 0;
+
+  svc_log(svc_ctx, SVC_LOG_INFO, "Total Bytes=[%u]\n", bytes_total);
+}
+
+void vpx_svc_release(SvcContext *svc_ctx) {
+  SvcInternal_t *si;
+  if (svc_ctx == NULL) return;
+  // do not use get_svc_internal as it will unnecessarily allocate an
+  // SvcInternal_t if it was not already allocated
+  si = (SvcInternal_t *)svc_ctx->internal;
+  if (si != NULL) {
+    free(si);
+    svc_ctx->internal = NULL;
+  }
+}