Simplify ff_split_xiph_headers

Originally committed as revision 12914 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/xiph.c

@@ -24,7 +24,7 @@ int ff_split_xiph_headers(uint8_t *extradata, int extradata_size,
                           int first_header_size, uint8_t *header_start[3],
                           int header_len[3])
 {
-    int i, j;
+    int i;
 
     if (extradata_size >= 6 && AV_RB16(extradata) == first_header_size) {
         int overall_len = 6;
@@ -39,20 +39,19 @@ int ff_split_xiph_headers(uint8_t *extradata, int extradata_size,
         }
     } else if (extradata_size >= 3 && extradata_size < INT_MAX - 0x1ff && extradata[0] == 2) {
         int overall_len = 3;
-        for (i=0,j=1; i<2; i++,j++) {
+        extradata++;
+        for (i=0; i<2; i++, extradata++) {
             header_len[i] = 0;
-            for (; overall_len < extradata_size && extradata[j]==0xff; j++) {
+            for (; overall_len < extradata_size && *extradata==0xff; extradata++) {
                 header_len[i] += 0xff;
                 overall_len   += 0xff + 1;
             }
-            overall_len   += extradata[j];
+            header_len[i] += *extradata;
+            overall_len   += *extradata;
             if (overall_len > extradata_size)
                 return -1;
-
-            header_len[i] += extradata[j];
         }
-        header_len[2] = extradata_size - header_len[0] - header_len[1] - j;
-        extradata += j;
+        header_len[2] = extradata_size - overall_len;
         header_start[0] = extradata;
         header_start[1] = header_start[0] + header_len[0];
         header_start[2] = header_start[1] + header_len[1];