text: /*
   * AVS2 decoding using the davs2 library
   *
   * Copyright (C) 2018 Yiqun Xu, <yiqun.xu@vipl.ict.ac.cn>
   *                    Falei Luo, <falei.luo@gmail.com>
   *                    Huiwen Ren, <hwrenx@gmail.com>
   *
   * 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 "avcodec.h"
  #include "internal.h"
  #include "davs2.h"
  
  typedef struct DAVS2Context {
      void *decoder;
  
      AVFrame *frame;
      davs2_param_t    param;      // decoding parameters
      davs2_packet_t   packet;     // input bitstream
  
      davs2_picture_t  out_frame;  // output data, frame data
      davs2_seq_info_t headerset;  // output data, sequence header
  
  }DAVS2Context;
  
  static av_cold int davs2_init(AVCodecContext *avctx)
  {
      DAVS2Context *cad = avctx->priv_data;
      int cpu_flags = av_get_cpu_flags();
  
      /* init the decoder */
      cad->param.threads      = avctx->thread_count;
      cad->param.info_level   = 0;
      cad->param.disable_avx  = !(cpu_flags & AV_CPU_FLAG_AVX &&
                                  cpu_flags & AV_CPU_FLAG_AVX2);
      cad->decoder            = davs2_decoder_open(&cad->param);
  
      if (!cad->decoder) {
          av_log(avctx, AV_LOG_ERROR, "decoder created error.");
          return AVERROR_EXTERNAL;
      }
  
      av_log(avctx, AV_LOG_VERBOSE, "decoder created. %p\n", cad->decoder);
      return 0;
  }
  
  static int davs2_dump_frames(AVCodecContext *avctx, davs2_picture_t *pic, int *got_frame,
                               davs2_seq_info_t *headerset, int ret_type, AVFrame *frame)
  {
      DAVS2Context *cad    = avctx->priv_data;
      int bytes_per_sample = pic->bytes_per_sample;
      int plane = 0;
      int line  = 0;
  
      if (!headerset) {
          *got_frame = 0;
          return 0;
      }
  
      if (!pic || ret_type == DAVS2_GOT_HEADER) {
          avctx->width     = headerset->width;
          avctx->height    = headerset->height;
          avctx->pix_fmt   = headerset->output_bit_depth == 10 ?
                             AV_PIX_FMT_YUV420P10 : AV_PIX_FMT_YUV420P;
  
          avctx->framerate = av_d2q(headerset->frame_rate,4096);
          *got_frame = 0;
          return 0;
      }
  
      switch (pic->type) {
      case DAVS2_PIC_I:
      case DAVS2_PIC_G:
          frame->pict_type = AV_PICTURE_TYPE_I;
          break;
      case DAVS2_PIC_P:
      case DAVS2_PIC_S:
          frame->pict_type = AV_PICTURE_TYPE_P;
          break;
      case DAVS2_PIC_B:
          frame->pict_type = AV_PICTURE_TYPE_B;
          break;
      case DAVS2_PIC_F:
          frame->pict_type = AV_PICTURE_TYPE_S;
          break;
      default:
          av_log(avctx, AV_LOG_ERROR, "Decoder error: unknown frame type\n");
          return AVERROR_EXTERNAL;
      }
  
      for (plane = 0; plane < 3; ++plane) {
          int size_line = pic->widths[plane] * bytes_per_sample;
          frame->buf[plane]  = av_buffer_alloc(size_line * pic->lines[plane]);
  
          if (!frame->buf[plane]){
              av_log(avctx, AV_LOG_ERROR, "Decoder error: allocation failure, can't dump frames.\n");
              return AVERROR(ENOMEM);
          }
  
          frame->data[plane]     = frame->buf[plane]->data;
          frame->linesize[plane] = size_line;
  
          for (line = 0; line < pic->lines[plane]; ++line)
              memcpy(frame->data[plane] + line * size_line,
                     pic->planes[plane] + line * pic->strides[plane],
                     pic->widths[plane] * bytes_per_sample);
      }
  
      frame->width     = cad->headerset.width;
      frame->height    = cad->headerset.height;
      frame->pts       = cad->out_frame.pts;
      frame->format    = avctx->pix_fmt;
  
      *got_frame = 1;
      return 0;
  }
  
  static void davs2_flush(AVCodecContext *avctx)
  {
      DAVS2Context *cad      = avctx->priv_data;
      int           ret      = DAVS2_GOT_FRAME;
  
      while (ret == DAVS2_GOT_FRAME) {
          ret = davs2_decoder_flush(cad->decoder, &cad->headerset, &cad->out_frame);
          davs2_decoder_frame_unref(cad->decoder, &cad->out_frame);
      }
  
      if (ret == DAVS2_ERROR) {
          av_log(avctx, AV_LOG_WARNING, "Decoder flushing failed.\n");
      }
  }
  
  static int send_delayed_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame)
  {
      DAVS2Context *cad      = avctx->priv_data;
      int           ret      = DAVS2_DEFAULT;
  
      ret = davs2_decoder_flush(cad->decoder, &cad->headerset, &cad->out_frame);
      if (ret == DAVS2_ERROR) {
          av_log(avctx, AV_LOG_ERROR, "Decoder error: can't flush delayed frame\n");
          return AVERROR_EXTERNAL;
      }
      if (ret == DAVS2_GOT_FRAME) {
          ret = davs2_dump_frames(avctx, &cad->out_frame, got_frame, &cad->headerset, ret, frame);
          davs2_decoder_frame_unref(cad->decoder, &cad->out_frame);
      }
      return ret;
  }
  
  static av_cold int davs2_end(AVCodecContext *avctx)
  {
      DAVS2Context *cad = avctx->priv_data;
  
      /* close the decoder */
      if (cad->decoder) {
          davs2_decoder_close(cad->decoder);
          cad->decoder = NULL;
      }
  
      return 0;
  }
  
  static int davs2_decode_frame(AVCodecContext *avctx, void *data,
                                int *got_frame, AVPacket *avpkt)
  {
      DAVS2Context *cad      = avctx->priv_data;
      int           buf_size = avpkt->size;
      uint8_t      *buf_ptr  = avpkt->data;
      AVFrame      *frame    = data;
      int           ret      = DAVS2_DEFAULT;
  
      /* end of stream, output what is still in the buffers */
      if (!buf_size) {
          return send_delayed_frame(avctx, frame, got_frame);
      }
  
      cad->packet.data = buf_ptr;
      cad->packet.len  = buf_size;
      cad->packet.pts  = avpkt->pts;
      cad->packet.dts  = avpkt->dts;
  
      ret = davs2_decoder_send_packet(cad->decoder, &cad->packet);
  
  
      if (ret == DAVS2_ERROR) {
          av_log(avctx, AV_LOG_ERROR, "Decoder error: can't read packet\n");
          return AVERROR_EXTERNAL;
      }
  
      ret = davs2_decoder_recv_frame(cad->decoder, &cad->headerset, &cad->out_frame);
  
      if (ret != DAVS2_DEFAULT) {
          ret = davs2_dump_frames(avctx, &cad->out_frame, got_frame, &cad->headerset, ret, frame);
          davs2_decoder_frame_unref(cad->decoder, &cad->out_frame);
      }
  
      return ret == 0 ? buf_size : ret;
  }
  
  AVCodec ff_libdavs2_decoder = {
      .name           = "libdavs2",
      .long_name      = NULL_IF_CONFIG_SMALL("libdavs2 AVS2-P2/IEEE1857.4"),
      .type           = AVMEDIA_TYPE_VIDEO,
      .id             = AV_CODEC_ID_AVS2,
      .priv_data_size = sizeof(DAVS2Context),
      .init           = davs2_init,
      .close          = davs2_end,
      .decode         = davs2_decode_frame,
      .flush          = davs2_flush,
      .capabilities   =  AV_CODEC_CAP_DELAY | AV_CODEC_CAP_OTHER_THREADS,
      .caps_internal  = FF_CODEC_CAP_AUTO_THREADS,
      .pix_fmts       = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV420P,
                                                       AV_PIX_FMT_NONE },
      .wrapper_name   = "libdavs2",
  };
  