avfilter/vf_uspp: Check for encoding failure

Fixes CID1363015
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavfilter/vf_uspp.c

@@ -186,6 +186,7 @@ static void filter(USPPContext *p, uint8_t *dst[3], uint8_t *src[3],
 {
     int x, y, i, j;
     const int count = 1<<p->log2_count;
+    int ret;
 
     for (i = 0; i < 3; i++) {
         int is_chroma = !!i;
@@ -249,7 +250,12 @@ static void filter(USPPContext *p, uint8_t *dst[3], uint8_t *src[3],
         p->frame->data[2] = p->src[2] + x1c  + y1c  * p->frame->linesize[2];
         p->frame->format  = p->avctx_enc[i]->pix_fmt;
 
-        avcodec_encode_video2(p->avctx_enc[i], &pkt, p->frame, &got_pkt_ptr);
+        ret = avcodec_encode_video2(p->avctx_enc[i], &pkt, p->frame, &got_pkt_ptr);
+        if (ret < 0) {
+            av_log(p->avctx_enc[i], AV_LOG_ERROR, "Encoding failed\n");
+            continue;
+        }
+
         p->frame_dec = p->avctx_enc[i]->coded_frame;
 
         offset = (BLOCK-x1) + (BLOCK-y1) * p->frame_dec->linesize[0];