diff --git a/libavcodec/i386/motion_est_mmx.c b/libavcodec/i386/motion_est_mmx.c
index 5c4b32dcd3..9e88ce2ce1 100644
--- a/libavcodec/i386/motion_est_mmx.c
+++ b/libavcodec/i386/motion_est_mmx.c
@@ -26,7 +26,7 @@ static const __attribute__ ((aligned(8))) uint64_t round_tab[3]={
 0x0002000200020002,
 };
 
-static __attribute__ ((aligned(8))) uint64_t bone= 0x0101010101010101LL;
+static __attribute__ ((aligned(8), unused)) uint64_t bone= 0x0101010101010101LL;
 
 static inline void sad8_mmx(uint8_t *blk1, uint8_t *blk2, int stride, int h)
 {
diff --git a/libavcodec/mjpeg.c b/libavcodec/mjpeg.c
index 80a3aba071..647e71d966 100644
--- a/libavcodec/mjpeg.c
+++ b/libavcodec/mjpeg.c
@@ -289,6 +289,7 @@ void mjpeg_close(MpegEncContext *s)
         case 4: ret= left   +   top - topleft; break;\
         case 5: ret= left   + ((top - topleft)>>1); break;\
         case 6: ret= top + ((left   - topleft)>>1); break;\
+        default:\
         case 7: ret= (left + top)>>1; break;\
     }
 
@@ -1364,7 +1365,7 @@ static int mjpeg_decode_scan(MJpegDecodeContext *s){
 
 static int mjpeg_decode_sos(MJpegDecodeContext *s)
 {
-    int len, nb_components, i, h, v, predictor, point_transform, ilv;
+    int len, nb_components, i, h, v, predictor, point_transform;
     int vmax, hmax, index, id;
     const int block_size= s->lossless ? 1 : 8;
 
diff --git a/libavcodec/mpegvideo.h b/libavcodec/mpegvideo.h
index db56c3ba52..58af196ea2 100644
--- a/libavcodec/mpegvideo.h
+++ b/libavcodec/mpegvideo.h
@@ -869,6 +869,7 @@ int msmpeg4_decode_ext_header(MpegEncContext * s, int buf_size);
 int ff_msmpeg4_decode_init(MpegEncContext *s);
 void ff_msmpeg4_encode_init(MpegEncContext *s);
 int ff_wmv2_decode_picture_header(MpegEncContext * s);
+int ff_wmv2_decode_secondary_picture_header(MpegEncContext * s);
 void ff_wmv2_add_mb(MpegEncContext *s, DCTELEM block[6][64], uint8_t *dest_y, uint8_t *dest_cb, uint8_t *dest_cr);
 void ff_mspel_motion(MpegEncContext *s,
                                uint8_t *dest_y, uint8_t *dest_cb, uint8_t *dest_cr,
diff --git a/libavcodec/ratecontrol.c b/libavcodec/ratecontrol.c
index 23c74784da..2aeb12b3e0 100644
--- a/libavcodec/ratecontrol.c
+++ b/libavcodec/ratecontrol.c
@@ -602,6 +602,7 @@ float ff_rate_estimate_qscale(MpegEncContext *s)
 
     var= pict_type == I_TYPE ? pic->mb_var_sum : pic->mc_mb_var_sum;
     
+    short_term_q = 0; /* avoid warning */
     if(s->flags&CODEC_FLAG_PASS2){
         if(pict_type!=I_TYPE)
             assert(pict_type == rce->new_pict_type);
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index c2705889ba..f441ca2a84 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -222,6 +222,7 @@ void avcodec_default_release_buffer(AVCodecContext *s, AVFrame *pic){
     assert(pic->type==FF_BUFFER_TYPE_INTERNAL);
     assert(s->internal_buffer_count);
 
+    buf = NULL; /* avoids warning */
     for(i=0; i<s->internal_buffer_count; i++){ //just 3-5 checks so is not worth to optimize
         buf= &((InternalBuffer*)s->internal_buffer)[i];
         if(buf->data[0] == pic->data[0])