/*
  * OpenH264 video decoder
  * Copyright (C) 2016 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/common.h"
 #include "libavutil/fifo.h"
 #include "libavutil/imgutils.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/mathematics.h"
 #include "libavutil/opt.h"
 
 #include "avcodec.h"
 #include "internal.h"
 #include "libopenh264.h"
 
 typedef struct SVCContext {
     ISVCDecoder *decoder;
 } SVCContext;
 
 static av_cold int svc_decode_close(AVCodecContext *avctx)
 {
     SVCContext *s = avctx->priv_data;
 
     if (s->decoder)
         WelsDestroyDecoder(s->decoder);
 
     return 0;
 }
 
 static av_cold int svc_decode_init(AVCodecContext *avctx)
 {
     SVCContext *s = avctx->priv_data;
     SDecodingParam param = { 0 };
     int err;
     int log_level;
     WelsTraceCallback callback_function;
 
     if ((err = ff_libopenh264_check_version(avctx)) < 0)
         return err;
 
     if (WelsCreateDecoder(&s->decoder)) {
         av_log(avctx, AV_LOG_ERROR, "Unable to create decoder\n");

         return AVERROR_UNKNOWN;

     }
 
     // Pass all libopenh264 messages to our callback, to allow ourselves to filter them.
     log_level = WELS_LOG_DETAIL;
     callback_function = ff_libopenh264_trace_callback;
     (*s->decoder)->SetOption(s->decoder, DECODER_OPTION_TRACE_LEVEL, &log_level);
     (*s->decoder)->SetOption(s->decoder, DECODER_OPTION_TRACE_CALLBACK, (void *)&callback_function);
     (*s->decoder)->SetOption(s->decoder, DECODER_OPTION_TRACE_CALLBACK_CONTEXT, (void *)&avctx);
 

 #if !OPENH264_VER_AT_LEAST(1, 6)

     param.eOutputColorFormat = videoFormatI420;

 #endif

     param.eEcActiveIdc       = ERROR_CON_DISABLE;
     param.sVideoProperty.eVideoBsType = VIDEO_BITSTREAM_DEFAULT;
 
     if ((*s->decoder)->Initialize(s->decoder, &param) != cmResultSuccess) {
         av_log(avctx, AV_LOG_ERROR, "Initialize failed\n");

         return AVERROR_UNKNOWN;

     }
 
     avctx->pix_fmt = AV_PIX_FMT_YUV420P;
 

     return 0;

 }
 
 static int svc_decode_frame(AVCodecContext *avctx, void *data,
                             int *got_frame, AVPacket *avpkt)
 {
     SVCContext *s = avctx->priv_data;
     SBufferInfo info = { 0 };
     uint8_t* ptrs[3];

     int ret, linesize[3];

     AVFrame *avframe = data;
     DECODING_STATE state;
 

     state = (*s->decoder)->DecodeFrame2(s->decoder, avpkt->data, avpkt->size, ptrs, &info);
     if (state != dsErrorFree) {
         av_log(avctx, AV_LOG_ERROR, "DecodeFrame2 failed\n");
         return AVERROR_UNKNOWN;
     }
     if (info.iBufferStatus != 1) {
         av_log(avctx, AV_LOG_DEBUG, "No frame produced\n");
         return avpkt->size;

     }
 

     ret = ff_set_dimensions(avctx, info.UsrData.sSystemBuffer.iWidth, info.UsrData.sSystemBuffer.iHeight);
     if (ret < 0)
         return ret;

     // The decoder doesn't (currently) support decoding into a user
     // provided buffer, so do a copy instead.
     if (ff_get_buffer(avctx, avframe, 0) < 0) {
         av_log(avctx, AV_LOG_ERROR, "Unable to allocate buffer\n");
         return AVERROR(ENOMEM);
     }
 
     linesize[0] = info.UsrData.sSystemBuffer.iStride[0];
     linesize[1] = linesize[2] = info.UsrData.sSystemBuffer.iStride[1];
     av_image_copy(avframe->data, avframe->linesize, (const uint8_t **) ptrs, linesize, avctx->pix_fmt, avctx->width, avctx->height);
 
     avframe->pts     = avpkt->pts;
     avframe->pkt_dts = avpkt->dts;

 #if FF_API_PKT_PTS
 FF_DISABLE_DEPRECATION_WARNINGS

     avframe->pkt_pts = avpkt->pts;

 FF_ENABLE_DEPRECATION_WARNINGS
 #endif

     *got_frame = 1;

     return avpkt->size;
 }
 
 AVCodec ff_libopenh264_decoder = {
     .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_decode_init,
     .decode         = svc_decode_frame,
     .close          = svc_decode_close,
     // The decoder doesn't currently support B-frames, and the decoder's API
     // doesn't support reordering/delay, but the BSF could incur delay.
     .capabilities   = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_DR1,
     .caps_internal  = FF_CODEC_CAP_SETS_PKT_DTS | FF_CODEC_CAP_INIT_THREADSAFE |
                       FF_CODEC_CAP_INIT_CLEANUP,

     .bsfs           = "h264_mp4toannexb",

 };