Understanding Video Compression Techniques

What is the primary purpose of video compression?

• To reduce file size for storage and transmission.

• To increase file size for better resolution.

• To convert video formats for compatibility.

• To enhance video quality for playback.

Explain the main difference between H.261 and H.263.

• H.261 and H.263 have the same compression efficiency.

• H.263 offers better compression efficiency and quality compared to H.261.

• H.261 supports higher resolutions than H.263.

• H.263 is primarily used for audio compression, while H.261 is for video.

What are the key features of MPEG-1?

• Key features of MPEG-1 include video compression up to 352x288 resolution, audio compression (Layer I, II, III), and multiplexing of audio and video streams.

• No multiplexing of audio and video streams

• Audio compression only in Layer IV

• Video compression up to 1920x1080 resolution

How does MPEG-2 improve upon MPEG-1?

• MPEG-2 offers better video quality, higher resolutions, and improved audio support compared to MPEG-1.

• MPEG-2 does not support any form of digital video.

• MPEG-2 is primarily designed for audio compression only.

• MPEG-2 reduces video quality and supports only lower resolutions.

What is the significance of B-frames in video compression?

• B-frames only reference past frames, not future ones.

• B-frames are used exclusively for audio compression.

• B-frames increase file size by adding extra data.

• B-frames improve video compression efficiency by referencing both past and future frames, reducing file size while maintaining quality.

Describe the role of motion estimation in video codecs.

• Motion estimation only applies to still images and not to video sequences.

• Motion estimation increases the file size by adding extra frames.

• Motion estimation reduces data by predicting movement between frames, enabling efficient video compression.

• Motion estimation is used to enhance audio quality in video codecs.

What are the advantages of using MPEG-4 over earlier standards?

• Lower resolution video quality

• Limited support for audio formats

• Increased file size compared to MPEG-2

• Improved compression efficiency, support for diverse media types, enhanced error resilience, and better streaming capabilities.

How does lossy compression differ from lossless compression?

• Lossy compression loses some data and quality, while lossless compression retains all data.

• Lossy compression is faster than lossless compression, regardless of data type.

• Lossy compression retains all data and quality, while lossless compression loses some data.

• Lossy compression is used for text files, while lossless compression is used for images.

What types of applications commonly use H.263?

• Text messaging services

• Video conferencing, video telephony, streaming video applications.

• Online gaming applications

• Image editing software

Explain the concept of bitrate in video compression.

• Bitrate is the amount of data processed per second in video compression, affecting quality and file size.

• Bitrate is the number of frames per second in a video.

• Bitrate is the duration of the video file in seconds.

• Bitrate refers to the resolution of the video being compressed.