libavcodec/zlib_wrapper.h

   1 /*
   2  * Wrappers for zlib
   3  * Copyright (C) 2022 Andreas Rheinhardt
   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 AVCODEC_ZLIB_WRAPPER_H
  23 #define AVCODEC_ZLIB_WRAPPER_H
  24
  25 #include <zlib.h>
  26
  27 typedef struct FFZStream {
  28     z_stream zstream;
  29     int inited;
  30 } FFZStream;
  31
  32 /**
  33  * Wrapper around inflateInit(). It initializes the fields that zlib
  34  * requires to be initialized before inflateInit().
  35  * In case of error it also returns an error message to the provided logctx;
  36  * in any case, it sets zstream->inited to indicate whether inflateInit()
  37  * succeeded.
  38  * @return Returns 0 on success or a negative error code on failure
  39  */
  40 int ff_inflate_init(FFZStream *zstream, void *logctx);
  41
  42 /**
  43  * Wrapper around inflateEnd(). It calls inflateEnd() iff
  44  * zstream->inited is set and resets zstream->inited.
  45  * It is therefore safe to be called even if
  46  * ff_inflate_init() has never been called on it (or errored out)
  47  * provided that the FFZStream (or just FFZStream.inited) has been zeroed.
  48  */
  49 void ff_inflate_end(FFZStream *zstream);
  50
  51 /**
  52  * Wrapper around deflateInit(). It works analogously to ff_inflate_init().
  53  */
  54 int ff_deflate_init(FFZStream *zstream, int level, void *logctx);
  55
  56 /**
  57  * Wrapper around deflateEnd(). It works analogously to ff_inflate_end().
  58  */
  59 void ff_deflate_end(FFZStream *zstream);
  60
  61 #endif /* AVCODEC_ZLIB_WRAPPER_H */