Hi and welcome back to my blog, this week I looked at practical digital media production and how media compression works, and why it is important for the quality and delivery of your video. Compressing media is a method of reducing the amount of storage space needed to save a file. There are a variety of compression techniques that are used. The advantage of compression is the file will take less time to upload, download and transfer from a USB flash drive, a website, or a digital camera.
I knew a small bit about compression before watching the
videos, but I didn’t know there was that much to it. I knew about how the gigabyte
gets its size and higher storage means more storage but I didn’t know exactly how
much information it can store.
I learned from computer skills – BIT – Binary Digit
Computer Skills Course: Bits, Bytes, Kilobytes, Megabytes, Gigabytes, Terabytes
- 8 bits = 1 Byte which is enough space for a single letter
- 1,000 Bytes = 1 Kilobyte (KB)
- 1,000 Kilobytes = 1 Megabyte (MB) which is enough space for one book or one photograph or one minute of music.
- 1,000 Megabytes = 1 Gigabyte (GB) which is enough space for 1,000 books, or 1,000 photos, or 16 hours of music.
- 1,000 Gigabytes = 1 Terabyte (TB) which is enough space for 1,000,000 books, or 1,000,000 photos or 2 years of continuous music.
I learned that the higher the compression rate is the lower
the quality of the media. I understand that 2160p is very low compression but
good quality, whereas 144p is very high
compression with low quality.
I also learned there are four ways that data size can be reduced
using compression which are;
- Frame – lowering the frames per second (fps)
- Colour- how bright the image needs to be, you could remove colours if the human eye is not sensitive to those colours.
- Picture- inter-frame compression looks at each frame and removes information that is duplicated across. Reduces overall size.
- Sound- in theory, eliminating high or low frequencies may not be noticeable to the human eye.
Two Compression types ;
Lossy – which is information removed or lost, but still can
retain a lot of quality.
Lossless – Compression is used in cases where no information must be lost or changed. For this reason, lossless
compression is not a very effective way of making the file size smaller.
The only formats and codecs I knew before watching the videos was, Mp3, but after watching the videos I have learned interesting information that there is a lot of different ones that are used for different reasons.
Video Compression as Fast as Possible
What You Lose When You Compress Music to MP3, MP4, WMA, etc.
I found out there are
Video Codecs such as;
H.264/AVC – good quality.
H.265/HEVC- better quality, high efficiency video coding,
half bitrate of H.264, and good for live streams.
VP9 – open source and more consistent and reliable.
AV1 – which is in development and is an open source.
The Audio Codecs;
MP3 is one of the most popular codecs and gives you
barely any quality loss, but is a limited function for video.
AAC – advanced audio coding, limited on audio channels.
AC-3 – Dolby Digital Audio Codec 3
The file format is a standardized set of rules for storing containers, codecs, metadata, and folder structure including all the information such as time of creation, bitrate, resolution, and subtitles.
A codec is a piece of software needed for audio and video compression, which is used to compress and decompress and it contains containers for a video stream, audio stream, and metadata.
Video Formats, Codecs, and Containers Explained
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