ret = avcodec_send_frame(avctx, frame);
if( !ret && frame ) return pkts;
if( ret < 0 && ret != AVERROR(EAGAIN) ) break;
+ if ( ret == AVERROR(EAGAIN) && !frame ) continue;
FFPacket opkt;
ret = avcodec_receive_packet(avctx, opkt);
if( !frame && ret == AVERROR_EOF ) return pkts;