Media formats overview in HTML - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main purpose of using different media formats on the web?

Different media formats help deliver images, audio, and video efficiently and clearly across various devices and browsers.

beginner

Name a common image format that supports transparency and is widely used on the web.

PNG (Portable Network Graphics) supports transparency and is commonly used for images on websites.

beginner

Which video format is widely supported by modern browsers and offers good compression?

MP4 (using H.264 codec) is widely supported and balances quality with file size for web videos.

intermediate

What is the difference between lossy and lossless media formats?

Lossy formats reduce file size by removing some data, which may lower quality. Lossless formats keep all data, preserving original quality but with larger files.

intermediate

Why is it important to provide multiple media formats for audio or video on a website?

Different browsers support different formats, so providing multiple formats ensures all users can play the media without issues.

Which image format is best for photographs on the web?

A GIF

B JPEG

C SVG

D BMP

JPEG compresses photos well, balancing quality and file size, making it ideal for photographs.

Which audio format is most commonly supported by web browsers?

A WAV

B OGG

C FLAC

D MP3

MP3 is widely supported across browsers and devices for audio playback.

What does 'lossless' mean in media formats?

A No data is lost during compression

B File size is very small

C Quality is reduced to save space

D Only images are supported

Lossless means the media keeps all original data, so quality stays the same after compression.

Which video format is NOT commonly supported by all browsers?

A MP4

B WebM

C AVI

D OGG Theora

AVI is an older format and not widely supported in browsers for direct playback.

Why use SVG images on websites?

A They are vector-based and scale without losing quality

B They are pixel-based and lose quality when scaled

C They only support black and white colors

D They are only for audio files

SVG images are vector graphics, so they scale smoothly without losing sharpness.

Explain why it is important to choose the right media format for images, audio, and video on a website.

Think about how different devices and internet speeds affect media playback.

List common media formats for images, audio, and video and describe one key feature of each.

Focus on what makes each format useful on the web.

Practice

1. Which HTML tag is used to add a sound file to a web page?

easy

A. <audio>

B. <img>

C. <video>

D. <sound>

Solution

1. Step 1: Identify the tag for sound

   The <audio> tag is designed to embed sound files like music or voice recordings.

2. Step 2: Compare with other tags

   <img> is for images, <video> is for videos, and <sound> is not a valid HTML tag.

3. Final Answer:

   <audio> -> Option A

4. Quick Check:

   Sound tag = <audio> [OK]

Hint: Sound files use <audio>, images use <img> [OK]

Common Mistakes:

• Confusing <audio> with <video>
• Using <sound> which is not valid
• Choosing <img> for sound

2. Which of the following is the correct syntax to embed an image in HTML?

easy

A. <img src='image.jpg' alt='Description'>

B. <image src='image.jpg' alt='Description'>

C. <img href='image.jpg' alt='Description'>

D. <img src='image.jpg'>Description</img>

Solution

1. Step 1: Check the tag and attributes for image

   The correct tag is <img> with a src attribute for the file path and an alt attribute for accessibility.

2. Step 2: Validate the syntax

   <img> is self-closing and does not have a closing tag. The href attribute is incorrect for images.

3. Final Answer:

   <img src='image.jpg' alt='Description'> -> Option A

4. Quick Check:

   Image tag uses src and alt attributes [OK]

Hint: Use for images [OK]

Common Mistakes:

• Using <image> instead of <img>
• Using href instead of src
• Adding closing tag to <img>

3. What will the following HTML code display in a browser?

<video controls>
  <source src='movie.mp4' type='video/mp4'>
  <source src='movie.webm' type='video/webm'>
  Your browser does not support the video tag.
</video>

medium

A. An error message because multiple sources are not allowed

B. A video player with controls that plays movie.mp4 or movie.webm

C. Only the text 'Your browser does not support the video tag.'

D. A static image of the video without controls

Solution

1. Step 1: Understand the <video> tag with multiple sources

   The <video> tag can have multiple <source> elements to provide different video formats for browser compatibility.

2. Step 2: Analyze the controls attribute and fallback text

   The controls attribute shows play/pause buttons. The fallback text appears only if the browser cannot play any source.

3. Final Answer:

   A video player with controls that plays movie.mp4 or movie.webm -> Option B

4. Quick Check:

   Video tag with sources and controls shows player [OK]

Hint: Multiple sources provide fallback formats for video [OK]

Common Mistakes:

• Thinking multiple sources cause error
• Ignoring controls attribute
• Assuming fallback text always shows

4. Identify the error in this HTML snippet for embedding audio:

<audio src='sound.mp3' controls>
  <source src='sound.ogg' type='audio/ogg'>
</audio>

medium

A. The type attribute is invalid for audio sources

B. The controls attribute is missing

C. The <source> tag must be self-closing with />

D. The src attribute should not be used on <audio> when <source> is present

Solution

1. Step 1: Understand the use of src and source in <audio>

   When using <source> tags inside <audio>, the src attribute on <audio> should be omitted to avoid conflicts.

2. Step 2: Check other attributes and syntax

   The controls attribute is present, <source> tags do not require self-closing slash in HTML5, and type is valid.

3. Final Answer:

   Using src on <audio> with <source> tags is incorrect -> Option D

4. Quick Check:

   Use either src or source tags, not both [OK]

Hint: Use <source> tags inside <audio>, avoid src on <audio> [OK]

Common Mistakes:

• Using src on <audio> with <source> tags
• Thinking <source> must be self-closing
• Believing type attribute is invalid

5. You want to add a video that plays automatically, loops forever, and is muted by default for accessibility. Which HTML snippet correctly achieves this?

hard

A. <video src='clip.mp4' autoplay muted></video>

B. <video src='clip.mp4' autoplay loop></video>

C. <video src='clip.mp4' autoplay loop muted controls></video>

D. <video src='clip.mp4' loop muted controls></video>

Solution

1. Step 1: Identify required attributes for video behavior

   To play automatically, use autoplay. To loop forever, use loop. To mute sound by default, use muted. Controls help user control playback.

2. Step 2: Check each option for all attributes

   <video src='clip.mp4' autoplay loop muted controls></video> has all: autoplay, loop, muted, and controls. Others miss one or more attributes.

3. Final Answer:

   <video src='clip.mp4' autoplay loop muted controls></video> -> Option C

4. Quick Check:

   All needed attributes present in <video src='clip.mp4' autoplay loop muted controls></video> [OK]

Hint: Use autoplay, loop, muted together for auto-looping muted video [OK]

Common Mistakes:

• Omitting muted causes sound to play unexpectedly
• Forgetting loop to repeat video
• Missing controls reduces user control