libavutil/lzo.h

   1 /*
   2  * LZO 1x decompression
   3  * copyright (c) 2006 Reimar Doeffinger
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #ifndef AVUTIL_LZO_H
  23 #define AVUTIL_LZO_H
  24
  25 #include <stdint.h>
  26
  27 /** \defgroup errflags Error flags returned by av_lzo1x_decode
  28   * \{ */
  29 //! end of the input buffer reached before decoding finished
  30 #define AV_LZO_INPUT_DEPLETED 1
  31 //! decoded data did not fit into output buffer
  32 #define AV_LZO_OUTPUT_FULL 2
  33 //! a reference to previously decoded data was wrong
  34 #define AV_LZO_INVALID_BACKPTR 4
  35 //! a non-specific error in the compressed bitstream
  36 #define AV_LZO_ERROR 8
  37 /** \} */
  38
  39 #define AV_LZO_INPUT_PADDING 8
  40 #define AV_LZO_OUTPUT_PADDING 12
  41
  42 /**
  43  * \brief Decodes LZO 1x compressed data.
  44  * \param out output buffer
  45  * \param outlen size of output buffer, number of bytes left are returned here
  46  * \param in input buffer
  47  * \param inlen size of input buffer, number of bytes left are returned here
  48  * \return 0 on success, otherwise a combination of the error flags above
  49  *
  50  * Make sure all buffers are appropriately padded, in must provide
  51  * AV_LZO_INPUT_PADDING, out must provide AV_LZO_OUTPUT_PADDING additional bytes.
  52  */
  53 int av_lzo1x_decode(void *out, int *outlen, const void *in, int *inlen);
  54
  55 /**
  56  * \brief deliberately overlapping memcpy implementation
  57  * \param dst destination buffer; must be padded with 12 additional bytes
  58  * \param back how many bytes back we start (the initial size of the overlapping window)
  59  * \param cnt number of bytes to copy, must be >= 0
  60  *
  61  * cnt > back is valid, this will copy the bytes we just copied,
  62  * thus creating a repeating pattern with a period length of back.
  63  */
  64 void av_memcpy_backptr(uint8_t *dst, int back, int cnt);
  65
  66 #endif /* AVUTIL_LZO_H */