text: /*
   * 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",
      .wrapper_name   = "libopenh264",
  };
  