ref: c382caa4d15caa31d783fa74a0a4f457ca213d36
dir: /examples/svc_encodeframe.c/
/* * 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 "./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 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 % 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)); 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 i, 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) { 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 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) { 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; } }