Here are juste two added #ifdef CONFIG_ENCODERS to allow

libavcodec to compile without CONFIG_ENCODERS defined
patch by (Aurelien Jacobs <aurel at gnuage dot org>)

Originally committed as revision 2604 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/i386/dsputil_mmx.c

@@ -1937,7 +1937,9 @@ void dsputil_init_mmx(DSPContext* c, AVCodecContext *avctx)
             SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_mmx2)
 #endif
 
+#ifdef CONFIG_ENCODERS
             c->sub_hfyu_median_prediction= sub_hfyu_median_prediction_mmx2;
+#endif //CONFIG_ENCODERS
         } else if (mm_flags & MM_3DNOW) {
             c->put_pixels_tab[0][1] = put_pixels16_x2_3dnow;
             c->put_pixels_tab[0][2] = put_pixels16_y2_3dnow;

libavcodec/mpegvideo.c

@@ -4362,6 +4362,8 @@ static void encode_picture(MpegEncContext *s, int picture_number)
     }
 }
 
+#endif //CONFIG_ENCODERS
+
 void ff_denoise_dct(MpegEncContext *s, DCTELEM *block){
     const int intra= s->mb_intra;
     int i;
@@ -4386,6 +4388,8 @@ void ff_denoise_dct(MpegEncContext *s, DCTELEM *block){
     }
 }
 
+#ifdef CONFIG_ENCODERS
+
 static int dct_quantize_trellis_c(MpegEncContext *s, 
                         DCTELEM *block, int n,
                         int qscale, int *overflow){