lavf/utils: use av_{i/o}format_next() instead of first_{i/o}format

Originally committed as revision 25738 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/utils.c

@@ -206,7 +206,7 @@ AVOutputFormat *guess_format(const char *short_name, const char *filename,
 AVOutputFormat *av_guess_format(const char *short_name, const char *filename,
                                 const char *mime_type)
 {
-    AVOutputFormat *fmt, *fmt_found;
+    AVOutputFormat *fmt = NULL, *fmt_found;
     int score_max, score;
 
     /* specific test for image sequences */
@@ -220,8 +220,7 @@ AVOutputFormat *av_guess_format(const char *short_name, const char *filename,
     /* Find the proper file type. */
     fmt_found = NULL;
     score_max = 0;
-    fmt = first_oformat;
-    while (fmt != NULL) {
+    while ((fmt = av_oformat_next(fmt))) {
         score = 0;
         if (fmt->name && short_name && !strcmp(fmt->name, short_name))
             score += 100;
@@ -235,7 +234,6 @@ AVOutputFormat *av_guess_format(const char *short_name, const char *filename,
             score_max = score;
             fmt_found = fmt;
         }
-        fmt = fmt->next;
     }
     return fmt_found;
 }
@@ -282,8 +280,8 @@ enum CodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
 
 AVInputFormat *av_find_input_format(const char *short_name)
 {
-    AVInputFormat *fmt;
-    for(fmt = first_iformat; fmt != NULL; fmt = fmt->next) {
+    AVInputFormat *fmt = NULL;
+    while ((fmt = av_iformat_next(fmt))) {
         if (match_format(short_name, fmt->name))
             return fmt;
     }
@@ -351,7 +349,7 @@ int av_filename_number_test(const char *filename)
 AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max)
 {
     AVProbeData lpd = *pd;
-    AVInputFormat *fmt1, *fmt;
+    AVInputFormat *fmt1 = NULL, *fmt;
     int score;
 
     if (lpd.buf_size > 10 && ff_id3v2_match(lpd.buf, ID3v2_DEFAULT_MAGIC)) {
@@ -363,7 +361,7 @@ AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score
     }
 
     fmt = NULL;
-    for(fmt1 = first_iformat; fmt1 != NULL; fmt1 = fmt1->next) {
+    while ((fmt1 = av_iformat_next(fmt1))) {
         if (!is_opened == !(fmt1->flags & AVFMT_NOFILE))
             continue;
         score = 0;