diff --git a/libavcodec/mpeg12.h b/libavcodec/mpeg12.h
index fc76511435..9132dc3d2d 100644
--- a/libavcodec/mpeg12.h
+++ b/libavcodec/mpeg12.h
@@ -41,21 +41,6 @@ extern VLC ff_mb_btype_vlc;
 extern VLC ff_mb_pat_vlc;
 extern VLC ff_mv_vlc;
 
-typedef struct Mpeg1Context {
-    MpegEncContext mpeg_enc_ctx;
-    int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
-    int repeat_field; /* true if we must repeat the field */
-    AVPanScan pan_scan;              /**< some temporary storage for the panscan */
-    int slice_count;
-    int swap_uv;//indicate VCR2
-    int save_aspect_info;
-    int save_width, save_height, save_progressive_seq;
-    AVRational frame_rate_ext;       ///< MPEG-2 specific framerate modificator
-    int sync;                        ///< Did we reach a sync point like a GOP/SEQ/KEYFrame?
-    int closed_gop;                  ///< GOP is closed
-    int extradata_decoded;
-} Mpeg1Context;
-
 extern uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
 
 void ff_mpeg12_common_init(MpegEncContext *s);
diff --git a/libavcodec/mpeg12dec.c b/libavcodec/mpeg12dec.c
index 6c95f0f0d8..3bf20c69cd 100644
--- a/libavcodec/mpeg12dec.c
+++ b/libavcodec/mpeg12dec.c
@@ -43,6 +43,21 @@
 //#undef NDEBUG
 //#include <assert.h>
 
+typedef struct Mpeg1Context {
+    MpegEncContext mpeg_enc_ctx;
+    int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
+    int repeat_field; /* true if we must repeat the field */
+    AVPanScan pan_scan;              /**< some temporary storage for the panscan */
+    int slice_count;
+    int swap_uv;//indicate VCR2
+    int save_aspect_info;
+    int save_width, save_height, save_progressive_seq;
+    AVRational frame_rate_ext;       ///< MPEG-2 specific framerate modificator
+    int sync;                        ///< Did we reach a sync point like a GOP/SEQ/KEYFrame?
+    int closed_gop;                  ///< GOP is closed
+    int extradata_decoded;
+} Mpeg1Context;
+
 /* as H.263, but only 17 codes */
 static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
 {