simplify, use pointer to codec context in struct instead of only id

Originally committed as revision 13477 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/swf.h

@@ -75,8 +75,7 @@ typedef struct {
     int frame_rate;
     int tag;
     AVFifoBuffer audio_fifo;
-    int video_type;
-    int audio_type;
+    AVCodecContext *audio_enc, *video_enc;
 } SWFContext;
 
 static const AVCodecTag swf_codec_tags[] = {