how to convert pcap/pcapng file to btsnoop

edit

USB packets with USBPcap header

let me know if this link type CAN be converted to BTSnoop_HCI.log format.

Wireshark does not support converting from that link-layer type header BTSnoop format.

wiretap/btsnoop.c

/* Returns 0 if we could write the specified encapsulation type,
   an error indication otherwise. */
static int btsnoop_dump_can_write_encap(int encap)
{
    /* Per-packet encapsulations aren't supported. */
    if (encap == WTAP_ENCAP_PER_PACKET)
        return WTAP_ERR_ENCAP_PER_PACKET_UNSUPPORTED;

    /*
     * XXX - for now we only support WTAP_ENCAP_BLUETOOTH_HCI,
     * WTAP_ENCAP_BLUETOOTH_H4_WITH_PHDR, and
     * WTAP_ENCAP_BLUETOOTH_LINUX_MONITOR.
     */
    if (encap != WTAP_ENCAP_BLUETOOTH_HCI &&
        encap != WTAP_ENCAP_BLUETOOTH_H4_WITH_PHDR &&
        encap != WTAP_ENCAP_BLUETOOTH_LINUX_MONITOR)
        return WTAP_ERR_UNWRITABLE_ENCAP;

    return 0;
}

[output -> .pcapng file]

Can you remake the capture and output as a .pcap or other capture format?
Then check in Statistics -> Capture File Properties to see if the linktype is one of the supported types.

failure_message.c

        case WTAP_ERR_UNWRITABLE_ENCAP:
            cmdarg_err("The capture file being read can't be written as a \"%s\" file.",
                       wtap_file_type_subtype_name(file_type_subtype));
            break;

        case WTAP_ERR_ENCAP_PER_PACKET_UNSUPPORTED:
            cmdarg_err("The capture file being read can't be written as a \"%s\" file.",
                       wtap_file_type_subtype_name(file_type_subtype));
            break;

wiretap/wtap.h

#define WTAP_ERR_UNWRITABLE_ENCAP              -8
    /**< Wiretap can't read or save files in the specified format with the
       specified encapsulation */

#define WTAP_ERR_ENCAP_PER_PACKET_UNSUPPORTED  -9
    /**< The specified format doesn't support per-packet encapsulations */