3 files changed, 13 insertions, 0 deletions
diff --git a/src/libffmpeg/libavcodec/h263dec.c b/src/libffmpeg/libavcodec/h263dec.c
index 758f9ed52..ec14c09e2 100644
--- a/src/libffmpeg/libavcodec/h263dec.c
+++ b/src/libffmpeg/libavcodec/h263dec.c
@@ -114,6 +114,14 @@ static int h263_decode_frame(AVCodecContext *avctx,
     if (ret < 0)
         return -1;
 
+    /* make sure we start with an I-frame */
+    if (s->waiting_for_keyframe) {
+      if (s->pict_type != I_TYPE)
+	return -1;
+      else
+	s->waiting_for_keyframe = 0;
+    }
+
     MPV_frame_start(s);
 
 #ifdef DEBUG
diff --git a/src/libffmpeg/libavcodec/mpegvideo.c b/src/libffmpeg/libavcodec/mpegvideo.c
index 5c66b3189..9f7236f98 100644
--- a/src/libffmpeg/libavcodec/mpegvideo.c
+++ b/src/libffmpeg/libavcodec/mpegvideo.c
@@ -101,6 +101,8 @@ int MPV_common_init(MpegEncContext *s)
     int c_size, i;
     UINT8 *pict;
 
+    s->waiting_for_keyframe = 1;
+
     if (s->out_format == FMT_H263) 
         s->dct_unquantize = dct_unquantize_h263_c;
     else
@@ -212,6 +214,7 @@ int MPV_common_init(MpegEncContext *s)
         if (s->aux_picture_base[i])
             free(s->aux_picture_base[i]);
     }
+
     return -1;
 }
 
diff --git a/src/libffmpeg/libavcodec/mpegvideo.h b/src/libffmpeg/libavcodec/mpegvideo.h
index 31243471e..9abe75a7c 100644
--- a/src/libffmpeg/libavcodec/mpegvideo.h
+++ b/src/libffmpeg/libavcodec/mpegvideo.h
@@ -181,6 +181,8 @@ typedef struct MpegEncContext {
     DCTELEM block[6][64] __align8;
     void (*dct_unquantize)(struct MpegEncContext *s, 
                            DCTELEM *block, int n, int qscale);
+
+    int waiting_for_keyframe;
 } MpegEncContext;
 
 int MPV_common_init(MpegEncContext *s);