avcodec/cngenc: Use ff_alloc_packet2()

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

libavcodec/cngenc.c

@@ -75,7 +75,7 @@ static int cng_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
     int qdbov;
     int16_t *samples = (int16_t*) frame->data[0];
 
-    if ((ret = ff_alloc_packet(avpkt, 1 + p->order))) {
+    if ((ret = ff_alloc_packet2(avctx, avpkt, 1 + p->order, 1 + p->order))) {
         av_log(avctx, AV_LOG_ERROR, "Error getting output packet\n");
         return ret;
     }
@@ -97,7 +97,7 @@ static int cng_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
         avpkt->data[1 + i] = p->ref_coef[i] * 127 + 127;
 
     *got_packet_ptr = 1;
-    avpkt->size = 1 + p->order;
+    av_assert1(avpkt->size == 1 + p->order);
 
     return 0;
 }