問73
頻出度★☆☆
HDMIの説明として, 適切なものはどれか。
平成26年度 春期 ITパスポート試験 問73
テクノロジ系コンピュータ構成要素 › 入出力デバイス
This question's explanation and your answers so far.
解説
問 73
- ア
正解 The correct answer is ア. HDMI (High-Definition Multimedia Interface) is a digital video and audio interface used to connect AV equipment such as TVs, recorders, game consoles, and projectors, as well as PC displays. Its greatest feature is that it carries three kinds of signals — (1) digital video signals, (2) digital audio signals, and (3) control signals between devices (HDMI-CEC, that is, linked control such as operating a recorder with the TV remote) — bundled together over a single cable, instead of splitting them across many separate cables as in the analog era. The wording of choice ア, “an interface for AV equipment that inputs and outputs video, audio, and control signals over a single cable”, is exactly the definition of HDMI. It is also worth remembering that HDMI transmits digital signals without compression, so there is little loss of picture and sound quality, and that it supports copyright protection (HDCP).
Incorrectイ
“An interface that uses infrared light, used for exchanging information between mobile phones and similar purposes” describes IrDA (infrared communication). IrDA is a wireless method that uses light (infrared), so the devices must face each other at close range in order to communicate. HDMI is a wired digital interface connected with a cable and does not use infrared.
Incorrectウ
“A serial interface for connecting devices such as external hard disks via a cable” describes storage-connection interfaces such as USB and eSATA. They do use a cable, just like HDMI, but what they carry is mainly data, and this wording does not describe the defining feature of HDMI — carrying video, audio, and control signals together over a single cable for AV equipment.
Incorrectエ
“A wireless interface that uses radio waves and can communicate even with some obstacles in the way” describes Bluetooth (or wireless LAN). Unlike infrared, radio waves can travel around obstacles to some degree, so devices can communicate without facing each other. HDMI is not wireless but a wired connection using a cable, so this does not apply.
ここがポイント
- Definition of HDMI: a wired interface for AV equipment that digitally transmits video, audio, and control signals (HDMI-CEC) over a single cable. The identifying keywords are “bundled into one cable”, “digital”, and “for AV equipment”.
- Organize interfaces by whether they are wired or wireless and by what they connect: wired — HDMI (video and audio), USB / eSATA (peripherals, external hard disks); wireless — IrDA (infrared, needs a clear line of sight), Bluetooth (radio waves, works even with some obstacles).
用語