remove useless cast, it does not remove warning, encode prototype must be changed

Originally committed as revision 17044 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/utils.c

@@ -471,7 +471,7 @@ int attribute_align_arg avcodec_encode_audio(AVCodecContext *avctx, uint8_t *buf
         return -1;
     }
     if((avctx->codec->capabilities & CODEC_CAP_DELAY) || samples){
-        int ret = avctx->codec->encode(avctx, buf, buf_size, (void *)samples);
+        int ret = avctx->codec->encode(avctx, buf, buf_size, samples);
         avctx->frame_number++;
         return ret;
     }else
@@ -488,7 +488,7 @@ int attribute_align_arg avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf
     if(avcodec_check_dimensions(avctx,avctx->width,avctx->height))
         return -1;
     if((avctx->codec->capabilities & CODEC_CAP_DELAY) || pict){
-        int ret = avctx->codec->encode(avctx, buf, buf_size, (void *)pict);
+        int ret = avctx->codec->encode(avctx, buf, buf_size, pict);
         avctx->frame_number++;
         emms_c(); //needed to avoid an emms_c() call before every return;
 
@@ -501,7 +501,7 @@ int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
                             const AVSubtitle *sub)
 {
     int ret;
-    ret = avctx->codec->encode(avctx, buf, buf_size, (void *)sub);
+    ret = avctx->codec->encode(avctx, buf, buf_size, sub);
     avctx->frame_number++;
     return ret;
 }