text: /*
   * LZO 1x decompression
   * copyright (c) 2006 Reimar Doeffinger
   *
   * 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
   */
  
  #ifndef AVUTIL_LZO_H
  #define AVUTIL_LZO_H
  
  /**
   * @defgroup lavu_lzo LZO
   * @ingroup lavu_crypto
   *
   * @{
   */
  
  #include <stdint.h>
  
  /** @name Error flags returned by av_lzo1x_decode
    * @{ */
  /// end of the input buffer reached before decoding finished
  #define AV_LZO_INPUT_DEPLETED 1
  /// decoded data did not fit into output buffer
  #define AV_LZO_OUTPUT_FULL 2
  /// a reference to previously decoded data was wrong
  #define AV_LZO_INVALID_BACKPTR 4
  /// a non-specific error in the compressed bitstream
  #define AV_LZO_ERROR 8
  /** @} */
  
  #define AV_LZO_INPUT_PADDING 8
  #define AV_LZO_OUTPUT_PADDING 12
  
  /**
   * @brief Decodes LZO 1x compressed data.
   * @param out output buffer
   * @param outlen size of output buffer, number of bytes left are returned here
   * @param in input buffer
   * @param inlen size of input buffer, number of bytes left are returned here
   * @return 0 on success, otherwise a combination of the error flags above
   *
   * Make sure all buffers are appropriately padded, in must provide
   * AV_LZO_INPUT_PADDING, out must provide AV_LZO_OUTPUT_PADDING additional bytes.
   */
  int av_lzo1x_decode(void *out, int *outlen, const void *in, int *inlen);
  
  /**
   * @brief deliberately overlapping memcpy implementation
   * @param dst destination buffer; must be padded with 12 additional bytes
   * @param back how many bytes back we start (the initial size of the overlapping window), must be > 0
   * @param cnt number of bytes to copy, must be >= 0
   *
   * cnt > back is valid, this will copy the bytes we just copied,
   * thus creating a repeating pattern with a period length of back.
   */
  void av_memcpy_backptr(uint8_t *dst, int back, int cnt);
  
  /**
   * @}
   */
  
  #endif /* AVUTIL_LZO_H */
  