libavformat/metadata.c

   1 /*
   2  * copyright (c) 2009 Michael Niedermayer
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include "metadata.h"
  22
  23 AVMetadataTag *
  24 av_metadata_get(AVMetadata *m, const char *key, const AVMetadataTag *prev, int flags)
  25 {
  26     unsigned int i, j;
  27
  28     if(!m)
  29         return NULL;
  30
  31     if(prev) i= prev - m->elems + 1;
  32     else     i= 0;
  33
  34     for(; i<m->count; i++){
  35         const char *s= m->elems[i].key;
  36         if(flags & AV_METADATA_MATCH_CASE) for(j=0;         s[j]  ==         key[j]  && key[j]; j++);
  37         else                               for(j=0; toupper(s[j]) == toupper(key[j]) && key[j]; j++);
  38         if(key[j])
  39             continue;
  40         if(s[j] && !(flags & AV_METADATA_IGNORE_SUFFIX))
  41             continue;
  42         return &m->elems[i];
  43     }
  44     return NULL;
  45 }
  46
  47 int av_metadata_set(AVMetadata **pm, const char *key, const char *value)
  48 {
  49     AVMetadata *m= *pm;
  50     AVMetadataTag *tag= av_metadata_get(m, key, NULL, AV_METADATA_MATCH_CASE);
  51
  52     if(!m)
  53         m=*pm= av_mallocz(sizeof(*m));
  54
  55     if(tag){
  56         av_free(tag->value);
  57         av_free(tag->key);
  58         *tag= m->elems[--m->count];
  59     }else{
  60         AVMetadataTag *tmp= av_realloc(m->elems, (m->count+1) * sizeof(*m->elems));
  61         if(tmp){
  62             m->elems= tmp;
  63         }else
  64             return AVERROR(ENOMEM);
  65     }
  66     if(value){
  67         m->elems[m->count].key  = av_strdup(key  );
  68         m->elems[m->count].value= av_strdup(value);
  69         m->count++;
  70     }
  71     if(!m->count)
  72         av_freep(pm);
  73
  74     return 0;
  75 }
  76
  77 void av_metadata_free(AVMetadata **pm)
  78 {
  79     AVMetadata *m= *pm;
  80
  81     if(m){
  82         while(m->count--){
  83             av_free(m->elems[m->count].key);
  84             av_free(m->elems[m->count].value);
  85         }
  86         av_free(m->elems);
  87     }
  88     av_freep(pm);
  89 }