make av_find_stream_info find frame_size for aac too

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@13976 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavformat/utils.c

@@ -1729,7 +1729,9 @@ static int has_codec_parameters(AVCodecContext *enc)
     switch(enc->codec_type) {
     case CODEC_TYPE_AUDIO:
         val = enc->sample_rate && enc->channels;
-        if(enc->codec_id == CODEC_ID_VORBIS && !enc->frame_size)
+        if(!enc->frame_size &&
+           (enc->codec_id == CODEC_ID_VORBIS ||
+            enc->codec_id == CODEC_ID_AAC))
             return 0;
         break;
     case CODEC_TYPE_VIDEO: