text: /*
   * libquicktime yuv4 decoder
   *
   * Copyright (c) 2011 Carl Eugen Hoyos
   *
   * 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"
  
  static av_cold int yuv4_decode_init(AVCodecContext *avctx)
  {
      avctx->pix_fmt = AV_PIX_FMT_YUV420P;
  
      return 0;
  }
  
  static int yuv4_decode_frame(AVCodecContext *avctx, void *data,
                               int *got_frame, AVPacket *avpkt)
  {
      AVFrame *pic = data;
      const uint8_t *src = avpkt->data;
      uint8_t *y, *u, *v;
      int i, j, ret;
  
      if (avpkt->size < 6 * (avctx->width + 1 >> 1) * (avctx->height + 1 >> 1)) {
          av_log(avctx, AV_LOG_ERROR, "Insufficient input data.\n");
          return AVERROR(EINVAL);
      }
  
      if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
          return ret;
  
      pic->key_frame = 1;
      pic->pict_type = AV_PICTURE_TYPE_I;
  
      y = pic->data[0];
      u = pic->data[1];
      v = pic->data[2];
  
      for (i = 0; i < (avctx->height + 1) >> 1; i++) {
          for (j = 0; j < (avctx->width + 1) >> 1; j++) {
              u[j] = *src++ ^ 0x80;
              v[j] = *src++ ^ 0x80;
              y[                   2 * j    ] = *src++;
              y[                   2 * j + 1] = *src++;
              y[pic->linesize[0] + 2 * j    ] = *src++;
              y[pic->linesize[0] + 2 * j + 1] = *src++;
          }
  
          y += 2 * pic->linesize[0];
          u +=     pic->linesize[1];
          v +=     pic->linesize[2];
      }
  
      *got_frame = 1;
  
      return avpkt->size;
  }
  
  AVCodec ff_yuv4_decoder = {
  	.name         = "yuv4",
      .long_name    = NULL_IF_CONFIG_SMALL("Uncompressed packed 4:2:0"),
      .type         = AVMEDIA_TYPE_VIDEO,
      .id           = AV_CODEC_ID_YUV4,
      .init         = yuv4_decode_init,
      .decode       = yuv4_decode_frame,
      .capabilities = CODEC_CAP_DR1,
  };
  