/*
  * OpenH264 video encoder
  * Copyright (C) 2014 Martin Storsjo
  *

  * This file is part of FFmpeg.

  *

  * FFmpeg is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *

  * FFmpeg is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public

  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include <wels/codec_api.h>
 #include <wels/codec_ver.h>
 
 #include "libavutil/attributes.h"
 #include "libavutil/common.h"
 #include "libavutil/opt.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/mathematics.h"
 
 #include "avcodec.h"
 #include "internal.h"
 
 typedef struct SVCContext {
     const AVClass *av_class;
     ISVCEncoder *encoder;
     int slice_mode;
     int loopfilter;
     char *profile;
 } SVCContext;
 

 #define OPENH264_VER_AT_LEAST(maj, min) \
     ((OPENH264_MAJOR  > (maj)) || \
      (OPENH264_MAJOR == (maj) && OPENH264_MINOR >= (min)))
 

 #define OFFSET(x) offsetof(SVCContext, x)
 #define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
 static const AVOption options[] = {
     { "slice_mode", "Slice mode", OFFSET(slice_mode), AV_OPT_TYPE_INT, { .i64 = SM_AUTO_SLICE }, SM_SINGLE_SLICE, SM_RESERVED, VE, "slice_mode" },
     { "fixed", "A fixed number of slices", 0, AV_OPT_TYPE_CONST, { .i64 = SM_FIXEDSLCNUM_SLICE }, 0, 0, VE, "slice_mode" },
     { "rowmb", "One slice per row of macroblocks", 0, AV_OPT_TYPE_CONST, { .i64 = SM_ROWMB_SLICE }, 0, 0, VE, "slice_mode" },
     { "auto", "Automatic number of slices according to number of threads", 0, AV_OPT_TYPE_CONST, { .i64 = SM_AUTO_SLICE }, 0, 0, VE, "slice_mode" },
     { "loopfilter", "Enable loop filter", OFFSET(loopfilter), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, VE },
     { "profile", "Set profile restrictions", OFFSET(profile), AV_OPT_TYPE_STRING, { 0 }, 0, 0, VE },
     { NULL }
 };
 
 static const AVClass class = {
     "libopenh264enc", av_default_item_name, options, LIBAVUTIL_VERSION_INT
 };
 
 static av_cold int svc_encode_close(AVCodecContext *avctx)
 {
     SVCContext *s = avctx->priv_data;
 
     if (s->encoder)
         WelsDestroySVCEncoder(s->encoder);
     return 0;
 }
 
 static av_cold int svc_encode_init(AVCodecContext *avctx)
 {
     SVCContext *s = avctx->priv_data;
     SEncParamExt param = { 0 };
     int err = AVERROR_UNKNOWN;
 
     // 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;
     }
 
     (*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           = 0;
     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->slice_mode = SM_FIXEDSLCNUM_SLICE;
     param.sSpatialLayers[0].sSliceCfg.uiSliceMode               = s->slice_mode;
     param.sSpatialLayers[0].sSliceCfg.sSliceArgument.uiSliceNum = avctx->slices;
 
     if ((*s->encoder)->InitializeExt(s->encoder, &param) != cmResultSuccess) {
         av_log(avctx, AV_LOG_ERROR, "Initialize failed\n");
         goto fail;
     }
 
     if (avctx->flags & 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 + FF_INPUT_BUFFER_PADDING_SIZE);
         if (!avctx->extradata) {
             err = AVERROR(ENOMEM);
             goto fail;
         }
         avctx->extradata_size = size;
         memcpy(avctx->extradata, fbi.sLayerInfo[0].pBsBuf, size);
     }
 
     return 0;
 
 fail:
     svc_encode_close(avctx);
     return err;
 }
 
 static int svc_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
                             const AVFrame *frame, int *got_packet)
 {
     SVCContext *s = avctx->priv_data;
     SFrameBSInfo fbi = { 0 };
     int i, ret;
     int encoded;
     SSourcePicture sp = { 0 };
     int size = 0, layer, first_layer = 0;
     int layer_size[MAX_LAYER_NUM_OF_FRAME] = { 0 };
 
     sp.iColorFormat = videoFormatI420;
     for (i = 0; i < 3; i++) {
         sp.iStride[i] = frame->linesize[i];
         sp.pData[i]   = frame->data[i];
     }
     sp.iPicWidth  = avctx->width;
     sp.iPicHeight = avctx->height;
 
     encoded = (*s->encoder)->EncodeFrame(s->encoder, &sp, &fbi);
     if (encoded != cmResultSuccess) {
         av_log(avctx, AV_LOG_ERROR, "EncodeFrame failed\n");
         return AVERROR_UNKNOWN;
     }
     if (fbi.eFrameType == videoFrameTypeSkip) {
         av_log(avctx, AV_LOG_DEBUG, "frame skipped\n");
         return 0;
     }
     first_layer = 0;

     // Normal frames are returned with one single layer, while IDR

     // frames have two layers, where the first layer contains the SPS/PPS.
     // If using global headers, don't include the SPS/PPS in the returned
     // packet - thus, only return one layer.
     if (avctx->flags & CODEC_FLAG_GLOBAL_HEADER)
         first_layer = fbi.iLayerNum - 1;
 
     for (layer = first_layer; layer < fbi.iLayerNum; layer++) {
         for (i = 0; i < fbi.sLayerInfo[layer].iNalCount; i++)
             layer_size[layer] += fbi.sLayerInfo[layer].pNalLengthInByte[i];
         size += layer_size[layer];
     }

     av_log(avctx, AV_LOG_DEBUG, "%d slices\n", fbi.sLayerInfo[fbi.iLayerNum - 1].iNalCount);

 
     if ((ret = ff_alloc_packet(avpkt, size))) {
         av_log(avctx, AV_LOG_ERROR, "Error getting output packet\n");
         return ret;
     }
     size = 0;
     for (layer = first_layer; layer < fbi.iLayerNum; layer++) {
         memcpy(avpkt->data + size, fbi.sLayerInfo[layer].pBsBuf, layer_size[layer]);
         size += layer_size[layer];
     }
     avpkt->pts = frame->pts;
     if (fbi.eFrameType == videoFrameTypeIDR)
         avpkt->flags |= AV_PKT_FLAG_KEY;
     *got_packet = 1;
     return 0;
 }
 
 AVCodec ff_libopenh264_encoder = {
     .name           = "libopenh264",

     .long_name      = NULL_IF_CONFIG_SMALL("OpenH264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10"),

     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_H264,
     .priv_data_size = sizeof(SVCContext),
     .init           = svc_encode_init,
     .encode2        = svc_encode_frame,
     .close          = svc_encode_close,
     .capabilities   = CODEC_CAP_AUTO_THREADS,
     .pix_fmts       = (const enum PixelFormat[]){ AV_PIX_FMT_YUV420P,
                                                   AV_PIX_FMT_NONE },
     .priv_class     = &class,
 };