func: static av_cold int svc_encode_init(AVCodecContext *avctx)
  
  {
  
      SVCContext *s = avctx->priv_data;
  
      SEncParamExt param = { 0 };
  
      int err = AVERROR_UNKNOWN;
  
      int log_level;
  
      WelsTraceCallback callback_function;
  
      AVCPBProperties *props;
  
  
  
      // Mingw GCC < 4.7 on x86_32 uses an incorrect/buggy ABI for the WelsGetCodecVersion
  
      // function (for functions returning larger structs), thus skip the check in those
  
      // configurations.
  
  #if !defined(_WIN32) || !defined(__GNUC__) || !ARCH_X86_32 || AV_GCC_VERSION_AT_LEAST(4, 7)
  
      OpenH264Version libver = WelsGetCodecVersion();
  
      if (memcmp(&libver, &g_stCodecVersion, sizeof(libver))) {
  
          av_log(avctx, AV_LOG_ERROR, "Incorrect library version loaded\n");
  
          return AVERROR(EINVAL);
  
      }
  
  #endif
  
  
  
      if (WelsCreateSVCEncoder(&s->encoder)) {
  
          av_log(avctx, AV_LOG_ERROR, "Unable to create encoder\n");
  
          return AVERROR_UNKNOWN;
  
      }
  
  
  
      // Pass all libopenh264 messages to our callback, to allow ourselves to filter them.
  
      log_level = WELS_LOG_DETAIL;
  
      (*s->encoder)->SetOption(s->encoder, ENCODER_OPTION_TRACE_LEVEL, &log_level);
  
  
  
      // Set the logging callback function to one that uses av_log() (see implementation above).
  
      callback_function = (WelsTraceCallback) libopenh264_trace_callback;
  
      (*s->encoder)->SetOption(s->encoder, ENCODER_OPTION_TRACE_CALLBACK, (void *)&callback_function);
  
  
  
      // Set the AVCodecContext as the libopenh264 callback context so that it can be passed to av_log().
  
      (*s->encoder)->SetOption(s->encoder, ENCODER_OPTION_TRACE_CALLBACK_CONTEXT, (void *)&avctx);
  
  
  
      (*s->encoder)->GetDefaultParams(s->encoder, &param);
  
  
  
      param.fMaxFrameRate              = avctx->time_base.den / avctx->time_base.num;
  
      param.iPicWidth                  = avctx->width;
  
      param.iPicHeight                 = avctx->height;
  
      param.iTargetBitrate             = avctx->bit_rate;
  
      param.iMaxBitrate                = FFMAX(avctx->rc_max_rate, avctx->bit_rate);
  
      param.iRCMode                    = RC_QUALITY_MODE;
  
      param.iTemporalLayerNum          = 1;
  
      param.iSpatialLayerNum           = 1;
  
      param.bEnableDenoise             = 0;
  
      param.bEnableBackgroundDetection = 1;
  
      param.bEnableAdaptiveQuant       = 1;
  
      param.bEnableFrameSkip           = s->skip_frames;
  
      param.bEnableLongTermReference   = 0;
  
      param.iLtrMarkPeriod             = 30;
  
      param.uiIntraPeriod              = avctx->gop_size;
  
  #if OPENH264_VER_AT_LEAST(1, 4)
  
      param.eSpsPpsIdStrategy          = CONSTANT_ID;
  
  #else
  
      param.bEnableSpsPpsIdAddition    = 0;
  
  #endif
  
      param.bPrefixNalAddingCtrl       = 0;
  
      param.iLoopFilterDisableIdc      = !s->loopfilter;
  
      param.iEntropyCodingModeFlag     = 0;
  
      param.iMultipleThreadIdc         = avctx->thread_count;
  
      if (s->profile && !strcmp(s->profile, "main"))
  
          param.iEntropyCodingModeFlag = 1;
  
      else if (!s->profile && avctx->coder_type == FF_CODER_TYPE_AC)
  
          param.iEntropyCodingModeFlag = 1;
  
  
  
      param.sSpatialLayers[0].iVideoWidth         = param.iPicWidth;
  
      param.sSpatialLayers[0].iVideoHeight        = param.iPicHeight;
  
      param.sSpatialLayers[0].fFrameRate          = param.fMaxFrameRate;
  
      param.sSpatialLayers[0].iSpatialBitrate     = param.iTargetBitrate;
  
      param.sSpatialLayers[0].iMaxSpatialBitrate  = param.iMaxBitrate;
  
  
  
      if ((avctx->slices > 1) && (s->max_nal_size)){
  
          av_log(avctx,AV_LOG_ERROR,"Invalid combination -slices %d and -max_nal_size %d.\n",avctx->slices,s->max_nal_size);
  
          goto fail;
  
      }
  
  
  
      if (avctx->slices > 1)
  
          s->slice_mode = SM_FIXEDSLCNUM_SLICE;
  
  
  
      if (s->max_nal_size)
  
          s->slice_mode = SM_DYN_SLICE;
  
  
  
      param.sSpatialLayers[0].sSliceCfg.uiSliceMode               = s->slice_mode;
  
      param.sSpatialLayers[0].sSliceCfg.sSliceArgument.uiSliceNum = avctx->slices;
  
  
  
      if (s->slice_mode == SM_DYN_SLICE) {
  
          if (s->max_nal_size){
  
              param.uiMaxNalSize = s->max_nal_size;
  
              param.sSpatialLayers[0].sSliceCfg.sSliceArgument.uiSliceSizeConstraint = s->max_nal_size;
  
          } else {
  
              if (avctx->rtp_payload_size) {
  
                  av_log(avctx,AV_LOG_DEBUG,"Using RTP Payload size for uiMaxNalSize");
  
                  param.uiMaxNalSize = avctx->rtp_payload_size;
  
                  param.sSpatialLayers[0].sSliceCfg.sSliceArgument.uiSliceSizeConstraint = avctx->rtp_payload_size;
  
              } else {
  
                  av_log(avctx,AV_LOG_ERROR,"Invalid -max_nal_size, specify a valid max_nal_size to use -slice_mode dyn\n");
  
                  goto fail;
  
              }
  
          }
  
      }
  
  
  
      if ((*s->encoder)->InitializeExt(s->encoder, &param) != cmResultSuccess) {
  
          av_log(avctx, AV_LOG_ERROR, "Initialize failed\n");
  
          goto fail;
  
      }
  
  
  
      if (avctx->flags & AV_CODEC_FLAG_GLOBAL_HEADER) {
  
          SFrameBSInfo fbi = { 0 };
  
          int i, size = 0;
  
          (*s->encoder)->EncodeParameterSets(s->encoder, &fbi);
  
          for (i = 0; i < fbi.sLayerInfo[0].iNalCount; i++)
  
              size += fbi.sLayerInfo[0].pNalLengthInByte[i];
  
          avctx->extradata = av_mallocz(size + AV_INPUT_BUFFER_PADDING_SIZE);
  
          if (!avctx->extradata) {
  
              err = AVERROR(ENOMEM);
  
              goto fail;
  
          }
  
          avctx->extradata_size = size;
  
          memcpy(avctx->extradata, fbi.sLayerInfo[0].pBsBuf, size);
  
      }
  
  
  
      props = ff_add_cpb_side_data(avctx);
  
      if (!props) {
  
          err = AVERROR(ENOMEM);
  
          goto fail;
  
      }
  
      props->max_bitrate = param.iMaxBitrate;
  
      props->avg_bitrate = param.iTargetBitrate;
  
  
  
      return 0;
  
  
  
  fail:
  
      svc_encode_close(avctx);
  
      return err;
  
  }
  