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 <strings.h>
  22 #include "avformat.h"
  23 #include "metadata.h"
  24
  25 AVMetadataTag *
  26 av_metadata_get(AVMetadata *m, const char *key, const AVMetadataTag *prev, int flags)
  27 {
  28     unsigned int i, j;
  29
  30     if(!m)
  31         return NULL;
  32
  33     if(prev) i= prev - m->elems + 1;
  34     else     i= 0;
  35
  36     for(; i<m->count; i++){
  37         const char *s= m->elems[i].key;
  38         if(flags & AV_METADATA_MATCH_CASE) for(j=0;         s[j]  ==         key[j]  && key[j]; j++);
  39         else                               for(j=0; toupper(s[j]) == toupper(key[j]) && key[j]; j++);
  40         if(key[j])
  41             continue;
  42         if(s[j] && !(flags & AV_METADATA_IGNORE_SUFFIX))
  43             continue;
  44         return &m->elems[i];
  45     }
  46     return NULL;
  47 }
  48
  49 int av_metadata_set(AVMetadata **pm, const char *key, const char *value)
  50 {
  51     AVMetadata *m= *pm;
  52     AVMetadataTag *tag= av_metadata_get(m, key, NULL, AV_METADATA_MATCH_CASE);
  53
  54     if(!m)
  55         m=*pm= av_mallocz(sizeof(*m));
  56
  57     if(tag){
  58         av_free(tag->value);
  59         av_free(tag->key);
  60         *tag= m->elems[--m->count];
  61     }else{
  62         AVMetadataTag *tmp= av_realloc(m->elems, (m->count+1) * sizeof(*m->elems));
  63         if(tmp){
  64             m->elems= tmp;
  65         }else
  66             return AVERROR(ENOMEM);
  67     }
  68     if(value){
  69         m->elems[m->count].key  = av_strdup(key  );
  70         m->elems[m->count].value= av_strdup(value);
  71         m->count++;
  72     }
  73     if(!m->count) {
  74         av_free(m->elems);
  75         av_freep(pm);
  76     }
  77
  78     return 0;
  79 }
  80
  81 void av_metadata_free(AVMetadata **pm)
  82 {
  83     AVMetadata *m= *pm;
  84
  85     if(m){
  86         while(m->count--){
  87             av_free(m->elems[m->count].key);
  88             av_free(m->elems[m->count].value);
  89         }
  90         av_free(m->elems);
  91     }
  92     av_freep(pm);
  93 }
  94
  95 static void metadata_conv(AVMetadata **pm, const AVMetadataConv *d_conv,
  96                                            const AVMetadataConv *s_conv)
  97 {
  98     /* TODO: use binary search to look up the two conversion tables
  99        if the tables are getting big enough that it would matter speed wise */
 100     const AVMetadataConv *sc, *dc;
 101     AVMetadataTag *mtag = NULL;
 102     AVMetadata *dst = NULL;
 103     const char *key;
 104
 105     while((mtag=av_metadata_get(*pm, "", mtag, AV_METADATA_IGNORE_SUFFIX))) {
 106         key = mtag->key;
 107         if (s_conv != d_conv) {
 108             if (s_conv)
 109                 for (sc=s_conv; sc->native; sc++)
 110                 if (!strcasecmp(key, sc->native)) {
 111                     key = sc->generic;
 112                     break;
 113                 }
 114             if (d_conv)
 115                 for (dc=d_conv; dc->native; dc++)
 116                     if (!strcasecmp(key, dc->generic)) {
 117                     key = dc->native;
 118                     break;
 119                 }
 120         }
 121         av_metadata_set(&dst, key, mtag->value);
 122     }
 123     av_metadata_free(pm);
 124     *pm = dst;
 125 }
 126
 127 void av_metadata_conv(AVFormatContext *ctx, const AVMetadataConv *d_conv,
 128                                             const AVMetadataConv *s_conv)
 129 {
 130     int i;
 131     metadata_conv(&ctx->metadata, d_conv, s_conv);
 132     for (i=0; i<ctx->nb_streams ; i++)
 133         metadata_conv(&ctx->streams [i]->metadata, d_conv, s_conv);
 134     for (i=0; i<ctx->nb_chapters; i++)
 135         metadata_conv(&ctx->chapters[i]->metadata, d_conv, s_conv);
 136     for (i=0; i<ctx->nb_programs; i++)
 137         metadata_conv(&ctx->programs[i]->metadata, d_conv, s_conv);
 138 }