avcodec/yuv4enc: drop coded_frame usage

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/yuv4enc.c

@@ -39,9 +39,6 @@ static int yuv4_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
         return ret;
     dst = pkt->data;
 
-    avctx->coded_frame->key_frame = 1;
-    avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
-
     y = pic->data[0];
     u = pic->data[1];
     v = pic->data[2];
@@ -79,4 +76,5 @@ AVCodec ff_yuv4_encoder = {
     .encode2      = yuv4_encode_frame,
     .close        = yuv4_encode_close,
     .pix_fmts     = (const enum AVPixelFormat[]){ AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE },
+    .capabilities = AV_CODEC_CAP_INTRA_ONLY,
 };