text: /*
   * LCL (LossLess Codec Library) Codec
   * Copyright (c) 2002-2004 Roberto Togni
   *
   * 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
   */
  
  /**
   * @file
   * LCL (LossLess Codec Library) Video Codec
   * Decoder for MSZH and ZLIB codecs
   * Experimental encoder for ZLIB RGB24
   *
   * Fourcc: MSZH, ZLIB
   *
   * Original Win32 dll:
   * Ver2.23 By Kenji Oshima 2000.09.20
   * avimszh.dll, avizlib.dll
   *
   * A description of the decoding algorithm can be found here:
   *   http://www.pcisys.net/~melanson/codecs
   *
   * Supports: BGR24 (RGB 24bpp)
   *
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  
  #include "libavutil/mem.h"
  #include "libavutil/pixdesc.h"
  #include "avcodec.h"
  #include "bytestream.h"
  #include "internal.h"
  #include "lcl.h"
  
  #if CONFIG_ZLIB_DECODER
  #include <zlib.h>
  #endif
  
  /*
   * Decoder context
   */
  typedef struct LclDecContext {
      AVFrame pic;
  
      // Image type
      int imgtype;
      // Compression type
      int compression;
      // Flags
      int flags;
      // Decompressed data size
      unsigned int decomp_size;
      // Decompression buffer
      unsigned char* decomp_buf;
  #if CONFIG_ZLIB_DECODER
      z_stream zstream;
  #endif
  } LclDecContext;
  
  
  /**
   * @param srcptr compressed source buffer, must be padded with at least 5 extra bytes
   * @param destptr must be padded sufficiently for av_memcpy_backptr
   */
  static unsigned int mszh_decomp(const unsigned char * srcptr, int srclen, unsigned char * destptr, unsigned int destsize)
  {
      unsigned char *destptr_bak = destptr;
      unsigned char *destptr_end = destptr + destsize;
      const unsigned char *srcptr_end = srcptr + srclen;
      unsigned mask = *srcptr++;
      unsigned maskbit = 0x80;
  
      while (srcptr < srcptr_end && destptr < destptr_end) {
          if (!(mask & maskbit)) {
              memcpy(destptr, srcptr, 4);
              destptr += 4;
              srcptr += 4;
          } else {
              unsigned ofs = bytestream_get_le16(&srcptr);
              unsigned cnt = (ofs >> 11) + 1;
              ofs &= 0x7ff;
              ofs = FFMIN(ofs, destptr - destptr_bak);
              cnt *= 4;
              cnt = FFMIN(cnt, destptr_end - destptr);
              if (ofs) {
                  av_memcpy_backptr(destptr, ofs, cnt);
              } else {
                  // Not known what the correct behaviour is, but
                  // this at least avoids uninitialized data.
                  memset(destptr, 0, cnt);
              }
              destptr += cnt;
          }
          maskbit >>= 1;
          if (!maskbit) {
              mask = *srcptr++;
              while (!mask) {
                  if (destptr_end - destptr < 32 || srcptr_end - srcptr < 32) break;
                  memcpy(destptr, srcptr, 32);
                  destptr += 32;
                  srcptr += 32;
                  mask = *srcptr++;
              }
              maskbit = 0x80;
          }
      }
  
      return destptr - destptr_bak;
  }
  
  
  #if CONFIG_ZLIB_DECODER
  /**
   * @brief decompress a zlib-compressed data block into decomp_buf
   * @param src compressed input buffer
   * @param src_len data length in input buffer
   * @param offset offset in decomp_buf
   * @param expected expected decompressed length
   */
  static int zlib_decomp(AVCodecContext *avctx, const uint8_t *src, int src_len, int offset, int expected)
  {
      LclDecContext *c = avctx->priv_data;
      int zret = inflateReset(&c->zstream);
      if (zret != Z_OK) {
          av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
          return AVERROR_UNKNOWN;
      }
      c->zstream.next_in = (uint8_t *)src;
      c->zstream.avail_in = src_len;
      c->zstream.next_out = c->decomp_buf + offset;
      c->zstream.avail_out = c->decomp_size - offset;
      zret = inflate(&c->zstream, Z_FINISH);
      if (zret != Z_OK && zret != Z_STREAM_END) {
          av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", zret);
          return AVERROR_UNKNOWN;
      }
      if (expected != (unsigned int)c->zstream.total_out) {
          av_log(avctx, AV_LOG_ERROR, "Decoded size differs (%d != %lu)\n",
                 expected, c->zstream.total_out);
          return AVERROR_UNKNOWN;
      }
      return c->zstream.total_out;
  }
  #endif
  
  
  /*
   *
   * Decode a frame
   *
   */
  static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
  {
      const uint8_t *buf = avpkt->data;
      int buf_size = avpkt->size;
      LclDecContext * const c = avctx->priv_data;
      unsigned char *encoded = (unsigned char *)buf;
      unsigned int pixel_ptr;
      int row, col;
      unsigned char *outptr;
      uint8_t *y_out, *u_out, *v_out;
      unsigned int width = avctx->width; // Real image width
      unsigned int height = avctx->height; // Real image height
      unsigned int mszh_dlen;
      unsigned char yq, y1q, uq, vq;
      int uqvq, ret;
      unsigned int mthread_inlen, mthread_outlen;
      unsigned int len = buf_size;
  
      if(c->pic.data[0])
          avctx->release_buffer(avctx, &c->pic);
  
      c->pic.reference = 0;
      c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
      if ((ret = ff_get_buffer(avctx, &c->pic)) < 0) {
          av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
          return ret;
      }
  
      outptr = c->pic.data[0]; // Output image pointer
  
      /* Decompress frame */
      switch (avctx->codec_id) {
      case AV_CODEC_ID_MSZH:
          switch (c->compression) {
          case COMP_MSZH:
              if (c->imgtype == IMGTYPE_RGB24 && len == width * height * 3) {
                  ;
              } else if (c->flags & FLAG_MULTITHREAD) {
                  mthread_inlen = AV_RL32(encoded);
                  if (len < 8) {
                      av_log(avctx, AV_LOG_ERROR, "len %d is too small\n", len);
                      return AVERROR_INVALIDDATA;
                  }
                  mthread_inlen = FFMIN(mthread_inlen, len - 8);
                  mthread_outlen = AV_RL32(encoded+4);
                  mthread_outlen = FFMIN(mthread_outlen, c->decomp_size);
                  mszh_dlen = mszh_decomp(encoded + 8, mthread_inlen, c->decomp_buf, c->decomp_size);
                  if (mthread_outlen != mszh_dlen) {
                      av_log(avctx, AV_LOG_ERROR, "Mthread1 decoded size differs (%d != %d)\n",
                             mthread_outlen, mszh_dlen);
                      return AVERROR_INVALIDDATA;
                  }
                  mszh_dlen = mszh_decomp(encoded + 8 + mthread_inlen, len - 8 - mthread_inlen,
                                          c->decomp_buf + mthread_outlen, c->decomp_size - mthread_outlen);
                  if (mthread_outlen != mszh_dlen) {
                      av_log(avctx, AV_LOG_ERROR, "Mthread2 decoded size differs (%d != %d)\n",
                             mthread_outlen, mszh_dlen);
                      return AVERROR_INVALIDDATA;
                  }
                  encoded = c->decomp_buf;
                  len = c->decomp_size;
              } else {
                  mszh_dlen = mszh_decomp(encoded, len, c->decomp_buf, c->decomp_size);
                  if (c->decomp_size != mszh_dlen) {
                      av_log(avctx, AV_LOG_ERROR, "Decoded size differs (%d != %d)\n",
                             c->decomp_size, mszh_dlen);
                      return AVERROR_INVALIDDATA;
                  }
                  encoded = c->decomp_buf;
                  len = mszh_dlen;
              }
              break;
          case COMP_MSZH_NOCOMP: {
              int bppx2;
              switch (c->imgtype) {
              case IMGTYPE_YUV111:
              case IMGTYPE_RGB24:
                  bppx2 = 6;
                  break;
              case IMGTYPE_YUV422:
              case IMGTYPE_YUV211:
                  bppx2 = 4;
                  break;
              case IMGTYPE_YUV411:
              case IMGTYPE_YUV420:
                  bppx2 = 3;
                  break;
              default:
                  bppx2 = 0; // will error out below
                  break;
              }
              if (len < ((width * height * bppx2) >> 1))
                  return AVERROR_INVALIDDATA;
              break;
          }
          default:
              av_log(avctx, AV_LOG_ERROR, "BUG! Unknown MSZH compression in frame decoder.\n");
              return AVERROR_INVALIDDATA;
          }
          break;
  #if CONFIG_ZLIB_DECODER
      case AV_CODEC_ID_ZLIB:
          /* Using the original dll with normal compression (-1) and RGB format
           * gives a file with ZLIB fourcc, but frame is really uncompressed.
           * To be sure that's true check also frame size */
          if (c->compression == COMP_ZLIB_NORMAL && c->imgtype == IMGTYPE_RGB24 &&
              len == width * height * 3) {
              if (c->flags & FLAG_PNGFILTER) {
                  memcpy(c->decomp_buf, encoded, len);
                  encoded = c->decomp_buf;
              } else {
                  break;
              }
          } else if (c->flags & FLAG_MULTITHREAD) {
              mthread_inlen = AV_RL32(encoded);
              mthread_inlen = FFMIN(mthread_inlen, len - 8);
              mthread_outlen = AV_RL32(encoded+4);
              mthread_outlen = FFMIN(mthread_outlen, c->decomp_size);
              ret = zlib_decomp(avctx, encoded + 8, mthread_inlen, 0, mthread_outlen);
              if (ret < 0) return ret;
              ret = zlib_decomp(avctx, encoded + 8 + mthread_inlen, len - 8 - mthread_inlen,
                                mthread_outlen, mthread_outlen);
              if (ret < 0) return ret;
          } else {
              int ret = zlib_decomp(avctx, encoded, len, 0, c->decomp_size);
              if (ret < 0) return ret;
          }
          encoded = c->decomp_buf;
          len = c->decomp_size;
          break;
  #endif
      default:
          av_log(avctx, AV_LOG_ERROR, "BUG! Unknown codec in frame decoder compression switch.\n");
          return AVERROR_INVALIDDATA;
      }
  
  
      /* Apply PNG filter */
      if (avctx->codec_id == AV_CODEC_ID_ZLIB && (c->flags & FLAG_PNGFILTER)) {
          switch (c->imgtype) {
          case IMGTYPE_YUV111:
          case IMGTYPE_RGB24:
              for (row = 0; row < height; row++) {
                  pixel_ptr = row * width * 3;
                  yq = encoded[pixel_ptr++];
                  uqvq = AV_RL16(encoded+pixel_ptr);
                  pixel_ptr += 2;
                  for (col = 1; col < width; col++) {
                      encoded[pixel_ptr] = yq -= encoded[pixel_ptr];
                      uqvq -= AV_RL16(encoded+pixel_ptr+1);
                      AV_WL16(encoded+pixel_ptr+1, uqvq);
                      pixel_ptr += 3;
                  }
              }
              break;
          case IMGTYPE_YUV422:
              for (row = 0; row < height; row++) {
                  pixel_ptr = row * width * 2;
                  yq = uq = vq =0;
                  for (col = 0; col < width/4; col++) {
                      encoded[pixel_ptr] = yq -= encoded[pixel_ptr];
                      encoded[pixel_ptr+1] = yq -= encoded[pixel_ptr+1];
                      encoded[pixel_ptr+2] = yq -= encoded[pixel_ptr+2];
                      encoded[pixel_ptr+3] = yq -= encoded[pixel_ptr+3];
                      encoded[pixel_ptr+4] = uq -= encoded[pixel_ptr+4];
                      encoded[pixel_ptr+5] = uq -= encoded[pixel_ptr+5];
                      encoded[pixel_ptr+6] = vq -= encoded[pixel_ptr+6];
                      encoded[pixel_ptr+7] = vq -= encoded[pixel_ptr+7];
                      pixel_ptr += 8;
                  }
              }
              break;
          case IMGTYPE_YUV411:
              for (row = 0; row < height; row++) {
                  pixel_ptr = row * width / 2 * 3;
                  yq = uq = vq =0;
                  for (col = 0; col < width/4; col++) {
                      encoded[pixel_ptr] = yq -= encoded[pixel_ptr];
                      encoded[pixel_ptr+1] = yq -= encoded[pixel_ptr+1];
                      encoded[pixel_ptr+2] = yq -= encoded[pixel_ptr+2];
                      encoded[pixel_ptr+3] = yq -= encoded[pixel_ptr+3];
                      encoded[pixel_ptr+4] = uq -= encoded[pixel_ptr+4];
                      encoded[pixel_ptr+5] = vq -= encoded[pixel_ptr+5];
                      pixel_ptr += 6;
                  }
              }
              break;
          case IMGTYPE_YUV211:
              for (row = 0; row < height; row++) {
                  pixel_ptr = row * width * 2;
                  yq = uq = vq =0;
                  for (col = 0; col < width/2; col++) {
                      encoded[pixel_ptr] = yq -= encoded[pixel_ptr];
                      encoded[pixel_ptr+1] = yq -= encoded[pixel_ptr+1];
                      encoded[pixel_ptr+2] = uq -= encoded[pixel_ptr+2];
                      encoded[pixel_ptr+3] = vq -= encoded[pixel_ptr+3];
                      pixel_ptr += 4;
                  }
              }
              break;
          case IMGTYPE_YUV420:
              for (row = 0; row < height/2; row++) {
                  pixel_ptr = row * width * 3;
                  yq = y1q = uq = vq =0;
                  for (col = 0; col < width/2; col++) {
                      encoded[pixel_ptr] = yq -= encoded[pixel_ptr];
                      encoded[pixel_ptr+1] = yq -= encoded[pixel_ptr+1];
                      encoded[pixel_ptr+2] = y1q -= encoded[pixel_ptr+2];
                      encoded[pixel_ptr+3] = y1q -= encoded[pixel_ptr+3];
                      encoded[pixel_ptr+4] = uq -= encoded[pixel_ptr+4];
                      encoded[pixel_ptr+5] = vq -= encoded[pixel_ptr+5];
                      pixel_ptr += 6;
                  }
              }
              break;
          default:
              av_log(avctx, AV_LOG_ERROR, "BUG! Unknown imagetype in pngfilter switch.\n");
              return AVERROR_INVALIDDATA;
          }
      }
  
      /* Convert colorspace */
      y_out = c->pic.data[0] + (height - 1) * c->pic.linesize[0];
      u_out = c->pic.data[1] + (height - 1) * c->pic.linesize[1];
      v_out = c->pic.data[2] + (height - 1) * c->pic.linesize[2];
      switch (c->imgtype) {
      case IMGTYPE_YUV111:
          for (row = 0; row < height; row++) {
              for (col = 0; col < width; col++) {
                  y_out[col] = *encoded++;
                  u_out[col] = *encoded++ + 128;
                  v_out[col] = *encoded++ + 128;
              }
              y_out -= c->pic.linesize[0];
              u_out -= c->pic.linesize[1];
              v_out -= c->pic.linesize[2];
          }
          break;
      case IMGTYPE_YUV422:
          for (row = 0; row < height; row++) {
              for (col = 0; col < width - 3; col += 4) {
                  memcpy(y_out + col, encoded, 4);
                  encoded += 4;
                  u_out[ col >> 1     ] = *encoded++ + 128;
                  u_out[(col >> 1) + 1] = *encoded++ + 128;
                  v_out[ col >> 1     ] = *encoded++ + 128;
                  v_out[(col >> 1) + 1] = *encoded++ + 128;
              }
              y_out -= c->pic.linesize[0];
              u_out -= c->pic.linesize[1];
              v_out -= c->pic.linesize[2];
          }
          break;
      case IMGTYPE_RGB24:
          for (row = height - 1; row >= 0; row--) {
              pixel_ptr = row * c->pic.linesize[0];
              memcpy(outptr + pixel_ptr, encoded, 3 * width);
              encoded += 3 * width;
          }
          break;
      case IMGTYPE_YUV411:
          for (row = 0; row < height; row++) {
              for (col = 0; col < width - 3; col += 4) {
                  memcpy(y_out + col, encoded, 4);
                  encoded += 4;
                  u_out[col >> 2] = *encoded++ + 128;
                  v_out[col >> 2] = *encoded++ + 128;
              }
              y_out -= c->pic.linesize[0];
              u_out -= c->pic.linesize[1];
              v_out -= c->pic.linesize[2];
          }
          break;
      case IMGTYPE_YUV211:
          for (row = 0; row < height; row++) {
              for (col = 0; col < width - 1; col += 2) {
                  memcpy(y_out + col, encoded, 2);
                  encoded += 2;
                  u_out[col >> 1] = *encoded++ + 128;
                  v_out[col >> 1] = *encoded++ + 128;
              }
              y_out -= c->pic.linesize[0];
              u_out -= c->pic.linesize[1];
              v_out -= c->pic.linesize[2];
          }
          break;
      case IMGTYPE_YUV420:
          u_out = c->pic.data[1] + ((height >> 1) - 1) * c->pic.linesize[1];
          v_out = c->pic.data[2] + ((height >> 1) - 1) * c->pic.linesize[2];
          for (row = 0; row < height - 1; row += 2) {
              for (col = 0; col < width - 1; col += 2) {
                  memcpy(y_out + col, encoded, 2);
                  encoded += 2;
                  memcpy(y_out + col - c->pic.linesize[0], encoded, 2);
                  encoded += 2;
                  u_out[col >> 1] = *encoded++ + 128;
                  v_out[col >> 1] = *encoded++ + 128;
              }
              y_out -= c->pic.linesize[0] << 1;
              u_out -= c->pic.linesize[1];
              v_out -= c->pic.linesize[2];
          }
          break;
      default:
          av_log(avctx, AV_LOG_ERROR, "BUG! Unknown imagetype in image decoder.\n");
          return AVERROR_INVALIDDATA;
      }
  
      *got_frame = 1;
      *(AVFrame*)data = c->pic;
  
      /* always report that the buffer was completely consumed */
      return buf_size;
  }
  
  /*
   *
   * Init lcl decoder
   *
   */
  static av_cold int decode_init(AVCodecContext *avctx)
  {
      LclDecContext * const c = avctx->priv_data;
      unsigned int basesize = avctx->width * avctx->height;
      unsigned int max_basesize = FFALIGN(avctx->width,  4) *
                                  FFALIGN(avctx->height, 4);
      unsigned int max_decomp_size;
      int subsample_h, subsample_v;
  
      avcodec_get_frame_defaults(&c->pic);
      if (avctx->extradata_size < 8) {
          av_log(avctx, AV_LOG_ERROR, "Extradata size too small.\n");
          return AVERROR_INVALIDDATA;
      }
  
      /* Check codec type */
      if ((avctx->codec_id == AV_CODEC_ID_MSZH  && avctx->extradata[7] != CODEC_MSZH) ||
          (avctx->codec_id == AV_CODEC_ID_ZLIB  && avctx->extradata[7] != CODEC_ZLIB)) {
          av_log(avctx, AV_LOG_ERROR, "Codec id and codec type mismatch. This should not happen.\n");
      }
  
      /* Detect image type */
      switch (c->imgtype = avctx->extradata[4]) {
      case IMGTYPE_YUV111:
          c->decomp_size = basesize * 3;
          max_decomp_size = max_basesize * 3;
          avctx->pix_fmt = AV_PIX_FMT_YUV444P;
          av_log(avctx, AV_LOG_DEBUG, "Image type is YUV 1:1:1.\n");
          break;
      case IMGTYPE_YUV422:
          c->decomp_size = basesize * 2;
          max_decomp_size = max_basesize * 2;
          avctx->pix_fmt = AV_PIX_FMT_YUV422P;
          av_log(avctx, AV_LOG_DEBUG, "Image type is YUV 4:2:2.\n");
          if (avctx->width % 4) {
              return AVERROR_INVALIDDATA;
          }
          break;
      case IMGTYPE_RGB24:
          c->decomp_size = basesize * 3;
          max_decomp_size = max_basesize * 3;
          avctx->pix_fmt = AV_PIX_FMT_BGR24;
          av_log(avctx, AV_LOG_DEBUG, "Image type is RGB 24.\n");
          break;
      case IMGTYPE_YUV411:
          c->decomp_size = basesize / 2 * 3;
          max_decomp_size = max_basesize / 2 * 3;
          avctx->pix_fmt = AV_PIX_FMT_YUV411P;
          av_log(avctx, AV_LOG_DEBUG, "Image type is YUV 4:1:1.\n");
          break;
      case IMGTYPE_YUV211:
          c->decomp_size = basesize * 2;
          max_decomp_size = max_basesize * 2;
          avctx->pix_fmt = AV_PIX_FMT_YUV422P;
          av_log(avctx, AV_LOG_DEBUG, "Image type is YUV 2:1:1.\n");
          break;
      case IMGTYPE_YUV420:
          c->decomp_size = basesize / 2 * 3;
          max_decomp_size = max_basesize / 2 * 3;
          avctx->pix_fmt = AV_PIX_FMT_YUV420P;
          av_log(avctx, AV_LOG_DEBUG, "Image type is YUV 4:2:0.\n");
          break;
      default:
          av_log(avctx, AV_LOG_ERROR, "Unsupported image format %d.\n", c->imgtype);
          return AVERROR_INVALIDDATA;
      }
  
      av_pix_fmt_get_chroma_sub_sample(avctx->pix_fmt, &subsample_h, &subsample_v);
      if (avctx->width % (1<<subsample_h) || avctx->height % (1<<subsample_v)) {
          return AVERROR_INVALIDDATA;
      }
  
      /* Detect compression method */
      c->compression = (int8_t)avctx->extradata[5];
      switch (avctx->codec_id) {
      case AV_CODEC_ID_MSZH:
          switch (c->compression) {
          case COMP_MSZH:
              av_log(avctx, AV_LOG_DEBUG, "Compression enabled.\n");
              break;
          case COMP_MSZH_NOCOMP:
              c->decomp_size = 0;
              av_log(avctx, AV_LOG_DEBUG, "No compression.\n");
              break;
          default:
              av_log(avctx, AV_LOG_ERROR, "Unsupported compression format for MSZH (%d).\n", c->compression);
              return AVERROR_INVALIDDATA;
          }
          break;
  #if CONFIG_ZLIB_DECODER
      case AV_CODEC_ID_ZLIB:
          switch (c->compression) {
          case COMP_ZLIB_HISPEED:
              av_log(avctx, AV_LOG_DEBUG, "High speed compression.\n");
              break;
          case COMP_ZLIB_HICOMP:
              av_log(avctx, AV_LOG_DEBUG, "High compression.\n");
              break;
          case COMP_ZLIB_NORMAL:
              av_log(avctx, AV_LOG_DEBUG, "Normal compression.\n");
              break;
          default:
              if (c->compression < Z_NO_COMPRESSION || c->compression > Z_BEST_COMPRESSION) {
                  av_log(avctx, AV_LOG_ERROR, "Unsupported compression level for ZLIB: (%d).\n", c->compression);
                  return AVERROR_INVALIDDATA;
              }
              av_log(avctx, AV_LOG_DEBUG, "Compression level for ZLIB: (%d).\n", c->compression);
          }
          break;
  #endif
      default:
          av_log(avctx, AV_LOG_ERROR, "BUG! Unknown codec in compression switch.\n");
          return AVERROR_INVALIDDATA;
      }
  
      /* Allocate decompression buffer */
      if (c->decomp_size) {
          if ((c->decomp_buf = av_malloc(max_decomp_size)) == NULL) {
              av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
              return AVERROR(ENOMEM);
          }
      }
  
      /* Detect flags */
      c->flags = avctx->extradata[6];
      if (c->flags & FLAG_MULTITHREAD)
          av_log(avctx, AV_LOG_DEBUG, "Multithread encoder flag set.\n");
      if (c->flags & FLAG_NULLFRAME)
          av_log(avctx, AV_LOG_DEBUG, "Nullframe insertion flag set.\n");
      if (avctx->codec_id == AV_CODEC_ID_ZLIB && (c->flags & FLAG_PNGFILTER))
          av_log(avctx, AV_LOG_DEBUG, "PNG filter flag set.\n");
      if (c->flags & FLAGMASK_UNUSED)
          av_log(avctx, AV_LOG_ERROR, "Unknown flag set (%d).\n", c->flags);
  
      /* If needed init zlib */
  #if CONFIG_ZLIB_DECODER
      if (avctx->codec_id == AV_CODEC_ID_ZLIB) {
          int zret;
          c->zstream.zalloc = Z_NULL;
          c->zstream.zfree = Z_NULL;
          c->zstream.opaque = Z_NULL;
          zret = inflateInit(&c->zstream);
          if (zret != Z_OK) {
              av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
              av_freep(&c->decomp_buf);
              return AVERROR_UNKNOWN;
          }
      }
  #endif
  
      return 0;
  }
  
  /*
   *
   * Uninit lcl decoder
   *
   */
  static av_cold int decode_end(AVCodecContext *avctx)
  {
      LclDecContext * const c = avctx->priv_data;
  
      av_freep(&c->decomp_buf);
      if (c->pic.data[0])
          avctx->release_buffer(avctx, &c->pic);
  #if CONFIG_ZLIB_DECODER
      if (avctx->codec_id == AV_CODEC_ID_ZLIB)
          inflateEnd(&c->zstream);
  #endif
  
      return 0;
  }
  
  #if CONFIG_MSZH_DECODER
  AVCodec ff_mszh_decoder = {
      .name           = "mszh",
      .type           = AVMEDIA_TYPE_VIDEO,
      .id             = AV_CODEC_ID_MSZH,
      .priv_data_size = sizeof(LclDecContext),
      .init           = decode_init,
      .close          = decode_end,
      .decode         = decode_frame,
      .capabilities   = CODEC_CAP_DR1,
      .long_name      = NULL_IF_CONFIG_SMALL("LCL (LossLess Codec Library) MSZH"),
  };
  #endif
  
  #if CONFIG_ZLIB_DECODER
  AVCodec ff_zlib_decoder = {
      .name           = "zlib",
      .type           = AVMEDIA_TYPE_VIDEO,
      .id             = AV_CODEC_ID_ZLIB,
      .priv_data_size = sizeof(LclDecContext),
      .init           = decode_init,
      .close          = decode_end,
      .decode         = decode_frame,
      .capabilities   = CODEC_CAP_DR1,
      .long_name      = NULL_IF_CONFIG_SMALL("LCL (LossLess Codec Library) ZLIB"),
  };
  #endif
  