reactos/dll/win32/avifil32/extrachunk.c

   1 /*
   2  * Copyright 2002 Michael Günnewig
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  17  */
  18
  19 #include "avifile_private.h"
  20
  21 /* reads a chunk out of the extrachunk-structure */
  22 HRESULT ReadExtraChunk(const EXTRACHUNKS *extra,FOURCC ckid,LPVOID lpData,LPLONG size)
  23 {
  24   LPBYTE lp;
  25   DWORD  cb;
  26
  27   /* pre-conditions */
  28   assert(extra != NULL);
  29   assert(size != NULL);
  30
  31   lp = extra->lp;
  32   cb = extra->cb;
  33
  34   if (lp != NULL) {
  35     while (cb > 0) {
  36       if (((FOURCC*)lp)[0] == ckid) {
  37         /* found correct chunk */
  38         if (lpData != NULL && *size > 0)
  39           memcpy(lpData, lp + 2 * sizeof(DWORD),
  40                  min(((LPDWORD)lp)[1], *(LPDWORD)size));
  41
  42         *(LPDWORD)size = ((LPDWORD)lp)[1];
  43
  44         return AVIERR_OK;
  45       } else {
  46         /* skip to next chunk */
  47         cb -= ((LPDWORD)lp)[1] + 2 * sizeof(DWORD);
  48         lp += ((LPDWORD)lp)[1] + 2 * sizeof(DWORD);
  49       }
  50     }
  51   }
  52
  53   /* wanted chunk doesn't exist */
  54   *size = 0;
  55
  56   return AVIERR_NODATA;
  57 }
  58
  59 /* writes a chunk into the extrachunk-structure */
  60 HRESULT WriteExtraChunk(LPEXTRACHUNKS extra,FOURCC ckid,LPCVOID lpData, LONG size)
  61 {
  62   LPDWORD lp;
  63
  64   /* pre-conditions */
  65   assert(extra != NULL);
  66   assert(lpData != NULL);
  67   assert(size > 0);
  68
  69   if (extra->lp)
  70     lp = HeapReAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, extra->lp, extra->cb + size + 2 * sizeof(DWORD));
  71   else
  72     lp = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, size + 2 * sizeof(DWORD));
  73
  74   if (lp == NULL)
  75     return AVIERR_MEMORY;
  76
  77   extra->lp  = lp;
  78   lp = (LPDWORD) ((LPBYTE)lp + extra->cb);
  79   extra->cb += size + 2 * sizeof(DWORD);
  80
  81   /* insert chunk-header in block */
  82   lp[0] = ckid;
  83   lp[1] = size;
  84
  85   if (lpData != NULL && size > 0)
  86     memcpy(lp + 2, lpData, size);
  87
  88   return AVIERR_OK;
  89 }
  90
  91 /* reads a chunk from the HMMIO into the extrachunk-structure */
  92 HRESULT ReadChunkIntoExtra(LPEXTRACHUNKS extra,HMMIO hmmio,const MMCKINFO *lpck)
  93 {
  94   LPDWORD lp;
  95   DWORD   cb;
  96
  97   /* pre-conditions */
  98   assert(extra != NULL);
  99   assert(hmmio != NULL);
 100   assert(lpck  != NULL);
 101
 102   cb  = lpck->cksize + 2 * sizeof(DWORD);
 103   cb += (cb & 1);
 104
 105   if (extra->lp != NULL)
 106     lp = HeapReAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, extra->lp, extra->cb + cb);
 107   else
 108     lp = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, cb);
 109
 110   if (lp == NULL)
 111     return AVIERR_MEMORY;
 112
 113   extra->lp  = lp;
 114   lp = (LPDWORD) ((LPBYTE)lp + extra->cb);
 115   extra->cb += cb;
 116
 117   /* insert chunk-header in block */
 118   lp[0] = lpck->ckid;
 119   lp[1] = lpck->cksize;
 120
 121   if (lpck->cksize > 0) {
 122     if (mmioSeek(hmmio, lpck->dwDataOffset, SEEK_SET) == -1)
 123       return AVIERR_FILEREAD;
 124     if (mmioRead(hmmio, (HPSTR)&lp[2], lpck->cksize) != (LONG)lpck->cksize)
 125       return AVIERR_FILEREAD;
 126   }
 127
 128   return AVIERR_OK;
 129 }
 130
 131 /* reads all non-junk chunks into the extrachunk-structure until it finds
 132  * the given chunk or the optional parent-chunk is at the end */
 133 HRESULT FindChunkAndKeepExtras(LPEXTRACHUNKS extra,HMMIO hmmio,MMCKINFO *lpck,
 134                                MMCKINFO *lpckParent,UINT flags)
 135 {
 136   FOURCC  ckid;
 137   FOURCC  fccType;
 138   MMRESULT mmr;
 139
 140   /* pre-conditions */
 141   assert(extra != NULL);
 142   assert(hmmio != NULL);
 143   assert(lpck  != NULL);
 144
 145   TRACE("({%p,%u},%p,%p,%p,0x%X)\n", extra->lp, extra->cb, hmmio, lpck,
 146         lpckParent, flags);
 147
 148   /* what chunk id and form/list type should we search? */
 149   if (flags & MMIO_FINDCHUNK) {
 150     ckid    = lpck->ckid;
 151     fccType = 0;
 152   } else if (flags & MMIO_FINDLIST) {
 153     ckid    = FOURCC_LIST;
 154     fccType = lpck->fccType;
 155   } else if (flags & MMIO_FINDRIFF) {
 156     ckid    = FOURCC_RIFF;
 157     fccType = lpck->fccType;
 158   } else
 159     ckid = fccType = (FOURCC)-1; /* collect everything into extra! */
 160
 161   TRACE(": find ckid=0x%08X fccType=0x%08X\n", ckid, fccType);
 162
 163   for (;;) {
 164     mmr = mmioDescend(hmmio, lpck, lpckParent, 0);
 165     if (mmr != MMSYSERR_NOERROR) {
 166       /* No extra chunks in front of desired chunk? */
 167       if (flags == 0 && mmr == MMIOERR_CHUNKNOTFOUND)
 168         return AVIERR_OK;
 169       else
 170         return AVIERR_FILEREAD;
 171     }
 172
 173     /* Have we found what we search for? */
 174     if ((lpck->ckid == ckid) &&
 175         (fccType == 0 || lpck->fccType == fccType))
 176       return AVIERR_OK;
 177
 178     /* Skip padding chunks, the others put into the extrachunk-structure */
 179     if (lpck->ckid == ckidAVIPADDING ||
 180         lpck->ckid == mmioFOURCC('p','a','d','d'))
 181     {
 182       mmr = mmioAscend(hmmio, lpck, 0);
 183       if (mmr != MMSYSERR_NOERROR) return AVIERR_FILEREAD;
 184     }
 185     else
 186     {
 187       HRESULT hr = ReadChunkIntoExtra(extra, hmmio, lpck);
 188       if (FAILED(hr))
 189         return hr;
 190     }
 191   }
 192 }