text: /* $Id: tif_compress.c,v 1.8 2013/11/29 22:22:01 drolon Exp $ */
  
  /*
   * Copyright (c) 1988-1997 Sam Leffler
   * Copyright (c) 1991-1997 Silicon Graphics, Inc.
   *
   * Permission to use, copy, modify, distribute, and sell this software and 
   * its documentation for any purpose is hereby granted without fee, provided
   * that (i) the above copyright notices and this permission notice appear in
   * all copies of the software and related documentation, and (ii) the names of
   * Sam Leffler and Silicon Graphics may not be used in any advertising or
   * publicity relating to the software without the specific, prior written
   * permission of Sam Leffler and Silicon Graphics.
   * 
   * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 
   * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 
   * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
   * 
   * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
   * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
   * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
   * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 
   * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 
   * OF THIS SOFTWARE.
   */
  
  /*
   * TIFF Library
   *
   * Compression Scheme Configuration Support.
   */
  #include "tiffiop.h"
  
  static int
  TIFFNoEncode(TIFF* tif, const char* method)
  {
  	const TIFFCodec* c = TIFFFindCODEC(tif->tif_dir.td_compression);
  
  	if (c) {
  		TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
  			     "%s %s encoding is not implemented",
  			     c->name, method);
  	} else {
  		TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
  			"Compression scheme %u %s encoding is not implemented",
  			     tif->tif_dir.td_compression, method);
  	}
  	return (-1);
  }
  
  int
  _TIFFNoRowEncode(TIFF* tif, uint8* pp, tmsize_t cc, uint16 s)
  {
  	(void) pp; (void) cc; (void) s;
  	return (TIFFNoEncode(tif, "scanline"));
  }
  
  int
  _TIFFNoStripEncode(TIFF* tif, uint8* pp, tmsize_t cc, uint16 s)
  {
  	(void) pp; (void) cc; (void) s;
  	return (TIFFNoEncode(tif, "strip"));
  }
  
  int
  _TIFFNoTileEncode(TIFF* tif, uint8* pp, tmsize_t cc, uint16 s)
  {
  	(void) pp; (void) cc; (void) s;
  	return (TIFFNoEncode(tif, "tile"));
  }
  
  static int
  TIFFNoDecode(TIFF* tif, const char* method)
  {
  	const TIFFCodec* c = TIFFFindCODEC(tif->tif_dir.td_compression);
  
  	if (c)
  		TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
  			     "%s %s decoding is not implemented",
  			     c->name, method);
  	else
  		TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
  			     "Compression scheme %u %s decoding is not implemented",
  			     tif->tif_dir.td_compression, method);
  	return (-1);
  }
  
  int
  _TIFFNoFixupTags(TIFF* tif)
  {
  	(void) tif;
  	return (1);
  }
  
  int
  _TIFFNoRowDecode(TIFF* tif, uint8* pp, tmsize_t cc, uint16 s)
  {
  	(void) pp; (void) cc; (void) s;
  	return (TIFFNoDecode(tif, "scanline"));
  }
  
  int
  _TIFFNoStripDecode(TIFF* tif, uint8* pp, tmsize_t cc, uint16 s)
  {
  	(void) pp; (void) cc; (void) s;
  	return (TIFFNoDecode(tif, "strip"));
  }
  
  int
  _TIFFNoTileDecode(TIFF* tif, uint8* pp, tmsize_t cc, uint16 s)
  {
  	(void) pp; (void) cc; (void) s;
  	return (TIFFNoDecode(tif, "tile"));
  }
  
  int
  _TIFFNoSeek(TIFF* tif, uint32 off)
  {
  	(void) off;
  	TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
  		     "Compression algorithm does not support random access");
  	return (0);
  }
  
  int
  _TIFFNoPreCode(TIFF* tif, uint16 s)
  {
  	(void) tif; (void) s;
  	return (1);
  }
  
  static int _TIFFtrue(TIFF* tif) { (void) tif; return (1); }
  static void _TIFFvoid(TIFF* tif) { (void) tif; }
  
  void
  _TIFFSetDefaultCompressionState(TIFF* tif)
  {
  	tif->tif_fixuptags = _TIFFNoFixupTags; 
  	tif->tif_decodestatus = TRUE;
  	tif->tif_setupdecode = _TIFFtrue;
  	tif->tif_predecode = _TIFFNoPreCode;
  	tif->tif_decoderow = _TIFFNoRowDecode;  
  	tif->tif_decodestrip = _TIFFNoStripDecode;
  	tif->tif_decodetile = _TIFFNoTileDecode;  
  	tif->tif_encodestatus = TRUE;
  	tif->tif_setupencode = _TIFFtrue;
  	tif->tif_preencode = _TIFFNoPreCode;
  	tif->tif_postencode = _TIFFtrue;
  	tif->tif_encoderow = _TIFFNoRowEncode;
  	tif->tif_encodestrip = _TIFFNoStripEncode;  
  	tif->tif_encodetile = _TIFFNoTileEncode;  
  	tif->tif_close = _TIFFvoid;
  	tif->tif_seek = _TIFFNoSeek;
  	tif->tif_cleanup = _TIFFvoid;
  	tif->tif_defstripsize = _TIFFDefaultStripSize;
  	tif->tif_deftilesize = _TIFFDefaultTileSize;
  	tif->tif_flags &= ~(TIFF_NOBITREV|TIFF_NOREADRAW);
  }
  
  int
  TIFFSetCompressionScheme(TIFF* tif, int scheme)
  {
  	const TIFFCodec *c = TIFFFindCODEC((uint16) scheme);
  
  	_TIFFSetDefaultCompressionState(tif);
  	/*
  	 * Don't treat an unknown compression scheme as an error.
  	 * This permits applications to open files with data that
  	 * the library does not have builtin support for, but which
  	 * may still be meaningful.
  	 */
  	return (c ? (*c->init)(tif, scheme) : 1);
  }
  
  /*
   * Other compression schemes may be registered.  Registered
   * schemes can also override the builtin versions provided
   * by this library.
   */
  typedef struct _codec {
  	struct _codec* next;
  	TIFFCodec* info;
  } codec_t;
  static codec_t* registeredCODECS = NULL;
  
  const TIFFCodec*
  TIFFFindCODEC(uint16 scheme)
  {
  	const TIFFCodec* c;
  	codec_t* cd;
  
  	for (cd = registeredCODECS; cd; cd = cd->next)
  		if (cd->info->scheme == scheme)
  			return ((const TIFFCodec*) cd->info);
  	for (c = _TIFFBuiltinCODECS; c->name; c++)
  		if (c->scheme == scheme)
  			return (c);
  	return ((const TIFFCodec*) 0);
  }
  
  TIFFCodec*
  TIFFRegisterCODEC(uint16 scheme, const char* name, TIFFInitMethod init)
  {
  	codec_t* cd = (codec_t*)
  	    _TIFFmalloc((tmsize_t)(sizeof (codec_t) + sizeof (TIFFCodec) + strlen(name)+1));
  
  	if (cd != NULL) {
  		cd->info = (TIFFCodec*) ((uint8*) cd + sizeof (codec_t));
  		cd->info->name = (char*)
  		    ((uint8*) cd->info + sizeof (TIFFCodec));
  		strcpy(cd->info->name, name);
  		cd->info->scheme = scheme;
  		cd->info->init = init;
  		cd->next = registeredCODECS;
  		registeredCODECS = cd;
  	} else {
  		TIFFErrorExt(0, "TIFFRegisterCODEC",
  		    "No space to register compression scheme %s", name);
  		return NULL;
  	}
  	return (cd->info);
  }
  
  void
  TIFFUnRegisterCODEC(TIFFCodec* c)
  {
  	codec_t* cd;
  	codec_t** pcd;
  
  	for (pcd = &registeredCODECS; (cd = *pcd); pcd = &cd->next)
  		if (cd->info == c) {
  			*pcd = cd->next;
  			_TIFFfree(cd);
  			return;
  		}
  	TIFFErrorExt(0, "TIFFUnRegisterCODEC",
  	    "Cannot remove compression scheme %s; not registered", c->name);
  }
  
  /************************************************************************/
  /*                       TIFFGetConfisuredCODECs()                      */
  /************************************************************************/
  
  /**
   * Get list of configured codecs, both built-in and registered by user.
   * Caller is responsible to free this structure.
   * 
   * @return returns array of TIFFCodec records (the last record should be NULL)
   * or NULL if function failed.
   */
  
  TIFFCodec*
  TIFFGetConfiguredCODECs()
  {
  	int i = 1;
  	codec_t *cd;
  	const TIFFCodec* c;
  	TIFFCodec* codecs = NULL;
  	TIFFCodec* new_codecs;
  
  	for (cd = registeredCODECS; cd; cd = cd->next) {
  		new_codecs = (TIFFCodec *)
  			_TIFFrealloc(codecs, i * sizeof(TIFFCodec));
  		if (!new_codecs) {
  			_TIFFfree (codecs);
  			return NULL;
  		}
  		codecs = new_codecs;
  		_TIFFmemcpy(codecs + i - 1, cd, sizeof(TIFFCodec));
  		i++;
  	}
  	for (c = _TIFFBuiltinCODECS; c->name; c++) {
  		if (TIFFIsCODECConfigured(c->scheme)) {
  			new_codecs = (TIFFCodec *)
  				_TIFFrealloc(codecs, i * sizeof(TIFFCodec));
  			if (!new_codecs) {
  				_TIFFfree (codecs);
  				return NULL;
  			}
  			codecs = new_codecs;
  			_TIFFmemcpy(codecs + i - 1, (const void*)c, sizeof(TIFFCodec));
  			i++;
  		}
  	}
  
  	new_codecs = (TIFFCodec *) _TIFFrealloc(codecs, i * sizeof(TIFFCodec));
  	if (!new_codecs) {
  		_TIFFfree (codecs);
  		return NULL;
  	}
  	codecs = new_codecs;
  	_TIFFmemset(codecs + i - 1, 0, sizeof(TIFFCodec));
  
  	return codecs;
  }
  
  /* vim: set ts=8 sts=8 sw=8 noet: */
  /*
   * Local Variables:
   * mode: c
   * c-basic-offset: 8
   * fill-column: 78
   * End:
   */
  