Move id3v2 parsing code from mp3.c to id3v2.h and id3v2.c.

patch by Patrick Dehne, patrick mysonicweb com

Originally committed as revision 19155 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 147 insertions, 0 deletions

diff --git a/libavformat/id3v2.c b/libavformat/id3v2.c
index 018fd51dc8..a0581e6149 100644
--- a/libavformat/id3v2.c
+++ b/libavformat/id3v2.c
@@ -20,6 +20,8 @@
  */
 
 #include "id3v2.h"
+#include "id3v1.h"
+#include "libavutil/avstring.h"
 
 int ff_id3v2_match(const uint8_t *buf)
 {
@@ -45,3 +47,148 @@ int ff_id3v2_tag_len(const uint8_t * buf)
         len += ID3v2_HEADER_SIZE;
     return len;
 }
+
+static unsigned int get_size(ByteIOContext *s, int len)
+{
+    int v=0;
+    while(len--)
+        v= (v<<7) + (get_byte(s)&0x7F);
+    return v;
+}
+
+static void read_ttag(AVFormatContext *s, int taglen, const char *key)
+{
+    char *q, dst[512];
+    int len, dstlen = sizeof(dst) - 1;
+    unsigned genre;
+
+    dst[0]= 0;
+    if(taglen < 1)
+        return;
+
+    taglen--; /* account for encoding type byte */
+
+    switch(get_byte(s->pb)) { /* encoding type */
+
+    case 0:  /* ISO-8859-1 (0 - 255 maps directly into unicode) */
+        q = dst;
+        while(taglen--) {
+            uint8_t tmp;
+            PUT_UTF8(get_byte(s->pb), tmp, if (q - dst < dstlen - 1) *q++ = tmp;)
+        }
+        *q = '\0';
+        break;
+
+    case 3:  /* UTF-8 */
+        len = FFMIN(taglen, dstlen-1);
+        get_buffer(s->pb, dst, len);
+        dst[len] = 0;
+        break;
+    }
+
+    if (!strcmp(key, "genre")
+        && (sscanf(dst, "(%d)", &genre) == 1 || sscanf(dst, "%d", &genre) == 1)
+        && genre <= ID3v1_GENRE_MAX)
+        av_strlcpy(dst, ff_id3v1_genre_str[genre], sizeof(dst));
+
+    if (*dst)
+        av_metadata_set(&s->metadata, key, dst);
+}
+
+void ff_id3v2_parse(AVFormatContext *s, int len, uint8_t version, uint8_t flags)
+{
+    int isv34, tlen;
+    uint32_t tag;
+    int64_t next;
+    int taghdrlen;
+    const char *reason;
+
+    switch(version) {
+    case 2:
+        if(flags & 0x40) {
+            reason = "compression";
+            goto error;
+        }
+        isv34 = 0;
+        taghdrlen = 6;
+        break;
+
+    case 3:
+    case 4:
+        isv34 = 1;
+        taghdrlen = 10;
+        break;
+
+    default:
+        reason = "version";
+        goto error;
+    }
+
+    if(flags & 0x80) {
+        reason = "unsynchronization";
+        goto error;
+    }
+
+    if(isv34 && flags & 0x40) /* Extended header present, just skip over it */
+        url_fskip(s->pb, get_size(s->pb, 4));
+
+    while(len >= taghdrlen) {
+        if(isv34) {
+            tag  = get_be32(s->pb);
+            tlen = get_size(s->pb, 4);
+            get_be16(s->pb); /* flags */
+        } else {
+            tag  = get_be24(s->pb);
+            tlen = get_size(s->pb, 3);
+        }
+        len -= taghdrlen + tlen;
+
+        if(len < 0)
+            break;
+
+        next = url_ftell(s->pb) + tlen;
+
+        switch(tag) {
+        case MKBETAG('T', 'I', 'T', '2'):
+        case MKBETAG(0,   'T', 'T', '2'):
+            read_ttag(s, tlen, "title");
+            break;
+        case MKBETAG('T', 'P', 'E', '1'):
+        case MKBETAG(0,   'T', 'P', '1'):
+            read_ttag(s, tlen, "author");
+            break;
+        case MKBETAG('T', 'A', 'L', 'B'):
+        case MKBETAG(0,   'T', 'A', 'L'):
+            read_ttag(s, tlen, "album");
+            break;
+        case MKBETAG('T', 'C', 'O', 'N'):
+        case MKBETAG(0,   'T', 'C', 'O'):
+            read_ttag(s, tlen, "genre");
+            break;
+        case MKBETAG('T', 'C', 'O', 'P'):
+        case MKBETAG(0,   'T', 'C', 'R'):
+            read_ttag(s, tlen, "copyright");
+            break;
+        case MKBETAG('T', 'R', 'C', 'K'):
+        case MKBETAG(0,   'T', 'R', 'K'):
+            read_ttag(s, tlen, "track");
+            break;
+        case 0:
+            /* padding, skip to end */
+            url_fskip(s->pb, len);
+            len = 0;
+            continue;
+        }
+        /* Skip to end of tag */
+        url_fseek(s->pb, next, SEEK_SET);
+    }
+
+    if(version == 4 && flags & 0x10) /* Footer preset, always 10 bytes, skip over it */
+        url_fskip(s->pb, 10);
+    return;
+
+  error:
+    av_log(s, AV_LOG_INFO, "ID3v2.%d tag skipped, cannot handle %s\n", version, reason);
+    url_fskip(s->pb, len);
+}
+