diff --git a/libavcodec/wmv2.c b/libavcodec/wmv2.c
index 57e1267782..8d1d117dea 100644
--- a/libavcodec/wmv2.c
+++ b/libavcodec/wmv2.c
@@ -25,9 +25,9 @@
 #include "wmv2.h"
 
 
-av_cold void ff_wmv2_common_init(Wmv2Context *w)
+av_cold void ff_wmv2_common_init(MpegEncContext *s)
 {
-    MpegEncContext *const s = &w->s;
+    WMV2Context *const w = s->private_ctx;
 
     ff_blockdsp_init(&s->bdsp, s->avctx);
     ff_wmv2dsp_init(&w->wdsp);
@@ -52,7 +52,7 @@ void ff_mspel_motion(MpegEncContext *s, uint8_t *dest_y,
                      uint8_t **ref_picture, op_pixels_func (*pix_op)[4],
                      int motion_x, int motion_y, int h)
 {
-    Wmv2Context *const w = (Wmv2Context *) s;
+    WMV2Context *const w = s->private_ctx;
     uint8_t *ptr;
     int dxy, mx, my, src_x, src_y, v_edge_pos;
     ptrdiff_t offset, linesize, uvlinesize;
diff --git a/libavcodec/wmv2.h b/libavcodec/wmv2.h
index 1798dbabcd..4001093881 100644
--- a/libavcodec/wmv2.h
+++ b/libavcodec/wmv2.h
@@ -21,9 +21,6 @@
 #ifndef AVCODEC_WMV2_H
 #define AVCODEC_WMV2_H
 
-#include "libavutil/mem_internal.h"
-
-#include "intrax8.h"
 #include "mpegvideo.h"
 #include "wmv2dsp.h"
 
@@ -33,29 +30,12 @@
 #define SKIP_TYPE_COL  3
 
 
-typedef struct Wmv2Context {
-    MpegEncContext s;
-    IntraX8Context x8;
+typedef struct WMV2Context {
     WMV2DSPContext wdsp;
-    int j_type_bit;
-    int j_type;
-    int abt_flag;
-    int abt_type;
-    int abt_type_table[6];
-    int per_mb_abt;
-    int per_block_abt;
-    int mspel_bit;
-    int cbp_table_index;
-    int top_left_mv_flag;
-    int per_mb_rl_bit;
-    int skip_type;
     int hshift;
+} WMV2Context;
 
-    ScanTable abt_scantable[2];
-    DECLARE_ALIGNED(32, int16_t, abt_block2)[6][64];
-} Wmv2Context;
-
-void ff_wmv2_common_init(Wmv2Context *w);
+void ff_wmv2_common_init(MpegEncContext *s);
 
 int ff_wmv2_decode_mb(MpegEncContext *s, int16_t block[6][64]);
 int ff_wmv2_encode_picture_header(MpegEncContext * s, int picture_number);
diff --git a/libavcodec/wmv2dec.c b/libavcodec/wmv2dec.c
index dd0e2683f5..f9d91f9571 100644
--- a/libavcodec/wmv2dec.c
+++ b/libavcodec/wmv2dec.c
@@ -18,6 +18,8 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "libavutil/mem_internal.h"
+
 #include "avcodec.h"
 #include "h263dec.h"
 #include "internal.h"
@@ -31,8 +33,28 @@
 #include "wmv2.h"
 #include "wmv2data.h"
 
-
-static void wmv2_add_block(Wmv2Context *w, int16_t *block1,
+typedef struct WMV2DecContext {
+    MpegEncContext s;
+    WMV2Context common;
+    IntraX8Context x8;
+    int j_type_bit;
+    int j_type;
+    int abt_flag;
+    int abt_type;
+    int abt_type_table[6];
+    int per_mb_abt;
+    int per_block_abt;
+    int mspel_bit;
+    int cbp_table_index;
+    int top_left_mv_flag;
+    int per_mb_rl_bit;
+    int skip_type;
+
+    ScanTable abt_scantable[2];
+    DECLARE_ALIGNED(32, int16_t, abt_block2)[6][64];
+} WMV2DecContext;
+
+static void wmv2_add_block(WMV2DecContext *w, int16_t *block1,
                            uint8_t *dst, int stride, int n)
 {
     MpegEncContext *const s = &w->s;
@@ -40,7 +62,7 @@ static void wmv2_add_block(Wmv2Context *w, int16_t *block1,
     if (s->block_last_index[n] >= 0) {
         switch (w->abt_type_table[n]) {
         case 0:
-            w->wdsp.idct_add(dst, stride, block1);
+            w->common.wdsp.idct_add(dst, stride, block1);
             break;
         case 1:
             ff_simple_idct84_add(dst, stride, block1);
@@ -61,7 +83,7 @@ static void wmv2_add_block(Wmv2Context *w, int16_t *block1,
 void ff_wmv2_add_mb(MpegEncContext *s, int16_t block1[6][64],
                     uint8_t *dest_y, uint8_t *dest_cb, uint8_t *dest_cr)
 {
-    Wmv2Context *const w = (Wmv2Context *) s;
+    WMV2DecContext *const w = (WMV2DecContext *) s;
 
     wmv2_add_block(w, block1[0], dest_y,                       s->linesize, 0);
     wmv2_add_block(w, block1[1], dest_y + 8,                   s->linesize, 1);
@@ -75,7 +97,7 @@ void ff_wmv2_add_mb(MpegEncContext *s, int16_t block1[6][64],
     wmv2_add_block(w, block1[5], dest_cr, s->uvlinesize, 5);
 }
 
-static int parse_mb_skip(Wmv2Context *w)
+static int parse_mb_skip(WMV2DecContext *w)
 {
     int mb_x, mb_y;
     int coded_mb_count = 0;
@@ -140,7 +162,7 @@ static int parse_mb_skip(Wmv2Context *w)
     return 0;
 }
 
-static int decode_ext_header(Wmv2Context *w)
+static int decode_ext_header(WMV2DecContext *w)
 {
     MpegEncContext *const s = &w->s;
     GetBitContext gb;
@@ -180,7 +202,7 @@ static int decode_ext_header(Wmv2Context *w)
 
 int ff_wmv2_decode_picture_header(MpegEncContext *s)
 {
-    Wmv2Context *const w = (Wmv2Context *) s;
+    WMV2DecContext *const w = (WMV2DecContext *) s;
     int code;
 
     if (s->picture_number == 0)
@@ -215,7 +237,7 @@ int ff_wmv2_decode_picture_header(MpegEncContext *s)
 
 int ff_wmv2_decode_secondary_picture_header(MpegEncContext *s)
 {
-    Wmv2Context *const w = (Wmv2Context *) s;
+    WMV2DecContext *const w = (WMV2DecContext *) s;
 
     if (s->pict_type == AV_PICTURE_TYPE_I) {
         if (w->j_type_bit)
@@ -323,19 +345,19 @@ int ff_wmv2_decode_secondary_picture_header(MpegEncContext *s)
     return 0;
 }
 
-static inline void wmv2_decode_motion(Wmv2Context *w, int *mx_ptr, int *my_ptr)
+static inline void wmv2_decode_motion(WMV2DecContext *w, int *mx_ptr, int *my_ptr)
 {
     MpegEncContext *const s = &w->s;
 
     ff_msmpeg4_decode_motion(s, mx_ptr, my_ptr);
 
     if ((((*mx_ptr) | (*my_ptr)) & 1) && s->mspel)
-        w->hshift = get_bits1(&s->gb);
+        w->common.hshift = get_bits1(&s->gb);
     else
-        w->hshift = 0;
+        w->common.hshift = 0;
 }
 
-static int16_t *wmv2_pred_motion(Wmv2Context *w, int *px, int *py)
+static int16_t *wmv2_pred_motion(WMV2DecContext *w, int *px, int *py)
 {
     MpegEncContext *const s = &w->s;
     int xy, wrap, diff, type;
@@ -380,7 +402,7 @@ static int16_t *wmv2_pred_motion(Wmv2Context *w, int *px, int *py)
     return mot_val;
 }
 
-static inline int wmv2_decode_inter_block(Wmv2Context *w, int16_t *block,
+static inline int wmv2_decode_inter_block(WMV2DecContext *w, int16_t *block,
                                           int n, int cbp)
 {
     MpegEncContext *const s = &w->s;
@@ -422,7 +444,9 @@ static inline int wmv2_decode_inter_block(Wmv2Context *w, int16_t *block,
 
 int ff_wmv2_decode_mb(MpegEncContext *s, int16_t block[6][64])
 {
-    Wmv2Context *const w = (Wmv2Context *) s;
+    /* The following is only allowed because this encoder
+     * does not use slice threading. */
+    WMV2DecContext *const w = (WMV2DecContext *) s;
     int cbp, code, i, ret;
     uint8_t *coded_val;
 
@@ -440,7 +464,7 @@ int ff_wmv2_decode_mb(MpegEncContext *s, int16_t block[6][64])
             s->mv[0][0][0] = 0;
             s->mv[0][0][1] = 0;
             s->mb_skipped  = 1;
-            w->hshift      = 0;
+            w->common.hshift      = 0;
             return 0;
         }
         if (get_bits_left(&s->gb) <= 0)
@@ -537,14 +561,16 @@ int ff_wmv2_decode_mb(MpegEncContext *s, int16_t block[6][64])
 
 static av_cold int wmv2_decode_init(AVCodecContext *avctx)
 {
-    Wmv2Context *const w = avctx->priv_data;
+    WMV2DecContext *const w = avctx->priv_data;
     MpegEncContext *const s = &w->s;
     int ret;
 
+    s->private_ctx = &w->common;
+
     if ((ret = ff_msmpeg4_decode_init(avctx)) < 0)
         return ret;
 
-    ff_wmv2_common_init(w);
+    ff_wmv2_common_init(s);
     ff_init_scantable(s->idsp.idct_permutation, &w->abt_scantable[0],
                       ff_wmv2_scantableA);
     ff_init_scantable(s->idsp.idct_permutation, &w->abt_scantable[1],
@@ -557,7 +583,7 @@ static av_cold int wmv2_decode_init(AVCodecContext *avctx)
 
 static av_cold int wmv2_decode_end(AVCodecContext *avctx)
 {
-    Wmv2Context *w = avctx->priv_data;
+    WMV2DecContext *const w = avctx->priv_data;
 
     ff_intrax8_common_end(&w->x8);
     return ff_h263_decode_end(avctx);
@@ -568,7 +594,7 @@ const AVCodec ff_wmv2_decoder = {
     .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Video 8"),
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_WMV2,
-    .priv_data_size = sizeof(Wmv2Context),
+    .priv_data_size = sizeof(WMV2DecContext),
     .init           = wmv2_decode_init,
     .close          = wmv2_decode_end,
     .decode         = ff_h263_decode_frame,
diff --git a/libavcodec/wmv2enc.c b/libavcodec/wmv2enc.c
index ab5365d1f6..a7827f3194 100644
--- a/libavcodec/wmv2enc.c
+++ b/libavcodec/wmv2enc.c
@@ -25,8 +25,21 @@
 #include "msmpeg4data.h"
 #include "wmv2.h"
 
-
-static int encode_ext_header(Wmv2Context *w)
+typedef struct WMV2EncContext {
+    MpegEncContext s;
+    WMV2Context common;
+    int j_type_bit;
+    int j_type;
+    int abt_flag;
+    int abt_type;
+    int per_mb_abt;
+    int mspel_bit;
+    int cbp_table_index;
+    int top_left_mv_flag;
+    int per_mb_rl_bit;
+} WMV2EncContext;
+
+static int encode_ext_header(WMV2EncContext *w)
 {
     MpegEncContext *const s = &w->s;
     PutBitContext pb;
@@ -54,12 +67,14 @@ static int encode_ext_header(Wmv2Context *w)
 
 static av_cold int wmv2_encode_init(AVCodecContext *avctx)
 {
-    Wmv2Context *const w = avctx->priv_data;
+    WMV2EncContext *const w = avctx->priv_data;
+    MpegEncContext *const s = &w->s;
 
+    s->private_ctx = &w->common;
     if (ff_mpv_encode_init(avctx) < 0)
         return -1;
 
-    ff_wmv2_common_init(w);
+    ff_wmv2_common_init(&w->s);
 
     avctx->extradata_size = 4;
     avctx->extradata      = av_mallocz(avctx->extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
@@ -73,7 +88,7 @@ static av_cold int wmv2_encode_init(AVCodecContext *avctx)
 
 int ff_wmv2_encode_picture_header(MpegEncContext *s, int picture_number)
 {
-    Wmv2Context *const w = (Wmv2Context *) s;
+    WMV2EncContext *const w = (WMV2EncContext *) s;
 
     put_bits(&s->pb, 1, s->pict_type - 1);
     if (s->pict_type == AV_PICTURE_TYPE_I)
@@ -147,7 +162,7 @@ int ff_wmv2_encode_picture_header(MpegEncContext *s, int picture_number)
 void ff_wmv2_encode_mb(MpegEncContext *s, int16_t block[6][64],
                        int motion_x, int motion_y)
 {
-    Wmv2Context *const w = (Wmv2Context *) s;
+    WMV2EncContext *const w = (WMV2EncContext *) s;
     int cbp, coded_cbp, i;
     int pred_x, pred_y;
     uint8_t *coded_block;
@@ -220,7 +235,7 @@ const AVCodec ff_wmv2_encoder = {
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_WMV2,
     .priv_class     = &ff_mpv_enc_class,
-    .priv_data_size = sizeof(Wmv2Context),
+    .priv_data_size = sizeof(WMV2EncContext),
     .init           = wmv2_encode_init,
     .encode2        = ff_mpv_encode_picture,
     .close          = ff_mpv_encode_end,
