Video compression is a technique that reduces the size of video files by removing redundant or irrelevant data, making them easier to store, transmit and stream. If you are applying for a job in video technology, you might be asked to explain video compression in an interview. Here are some tips on how to do it effectively.
Video compression is the process of encoding video data in a way that reduces the number of bits required to represent it, while maintaining an acceptable level of quality and fidelity. Video compression can be achieved by using different methods, such as spatial compression, temporal compression, and lossy or lossless compression.
Speaking short video compression is a method of saving space on your data storage by reducing some quality or data in each separate frame.
Video compression is important because it enables more efficient use of storage space, bandwidth, and processing power. Video files can be very large, especially if they have high resolution, frame rate, color depth, and audio quality. By compressing them, you can save disk space, reduce upload and download time, and improve streaming performance. Video compression also allows for more creative and diverse applications of video, such as video conferencing, online education, social media, and gaming.
It is important to know and control the compression on your footage. Reasonable video compression can reduce the space consumed by file on your hard drive, while gaining all important details. But without proper controll your video can lose to much details or be to compressed to be edited in the future. Low compressed video such as raw video formats however have all the details you will need during editing and does lower stress on your PC when you edit them.
Spatial compression is a method of video compression that reduces the number of bits needed to represent each frame or image of a video. Spatial compression works by exploiting the similarities and differences between adjacent pixels, regions, or blocks of an image. For example, spatial compression can use techniques such as run-length encoding, Huffman coding, or arithmetic coding to encode repeated or predictable patterns of pixels more efficiently. Spatial compression can also use techniques such as quantization, subsampling, or transform coding to reduce the precision or resolution of an image without affecting its perceptual quality too much.
Temporal compression is a method of video compression that reduces the number of bits needed to represent the changes or motion between successive frames or images of a video. Temporal compression works by exploiting the temporal coherence or continuity of a video sequence. For example, temporal compression can use techniques such as interframe coding, motion estimation, or motion compensation to encode only the differences or motion vectors between frames, rather than the entire frames. Temporal compression can also use techniques such as frame skipping, frame dropping, or frame interpolation to adjust the frame rate or timing of a video without affecting its perceptual quality too much.
Lossy and lossless compression are two types of video compression that differ in the amount of information or quality that is preserved or lost during the compression process. Lossy compression is a type of video compression that discards some information or quality that is deemed less important or less noticeable by human perception, in order to achieve higher compression ratios. Lossy compression can result in artifacts or distortions in the compressed video, such as blurring, blocking, ringing, or noise. Lossless compression is a type of video compression that preserves all the information or quality of the original video, without any loss or degradation. Lossless compression can achieve lower compression ratios than lossy compression, but can ensure exact reproduction of the original video.
La compresión con pérdida descarta información menos perceptible para la percepción humana, permitiendo relaciones de compresión más altas. Sin embargo, esto puede causar artefactos como desenfoque o bloqueo. En contraste, la compresión sin pérdidas conserva toda la información y calidad del vídeo original, evitando la degradación. Aunque logra relaciones de compresión más bajas, garantiza una reproducción exacta del vídeo original sin distorsiones perceptibles. Explorar estas diferencias ayuda a comprender cómo se equilibran la eficiencia y la fidelidad en el proceso de compresión de vídeo.
Video compression performance can be measured by using different metrics or criteria, such as compression ratio, bit rate, quality, and complexity. Compression ratio is the ratio between the size of the original video and the size of the compressed video. Bit rate is the number of bits per second that are used to encode or transmit the compressed video. Quality is the degree of similarity or difference between the original video and the compressed video, in terms of visual or auditory perception. Complexity is the amount of computational or algorithmic resources that are required to perform or implement the video compression process. Video compression performance can vary depending on the characteristics of the video, the compression method, the compression parameters, and the quality requirements.