MPEG4, H.264, MJPEG Compression for DVR Recording - What's the Difference?
By Sharon Macdonald
Digital recording devices are becoming popular in the digital world and are
increasingly becoming accessible to the home consumer. Some digital recording features can
already be found in digital cameras while the more advanced recording features are
prominent in HD digital camcorders. However, higher qualities and lengths of digital
videos mean greater file sizes and when it comes to sharing videos online, therefore file
sizes should be reduced to avoid long delays in sending and receiving the entire clip.
Video compression has come a long way, but the main objective still strives to have the
smallest file size possible while still preserving good video and audio quality. MPEG4,
H.264, and MJPEG are three DVR CODECs that aim to compress the videos for transferring
purposes. Each of these formats have their own strengths and weaknesses.
First came MPEG-1 followed by MPEG-2 and now MPEG-4 comes into the picture. MPEG-4 is a
massive upgrade to the MPEG-2 format that focuses more on compression. It is a standard
that can effectively compress both audio and visual data for streaming purposes or to fit
lengthy data on optical media.
Because it incorporates the existing technologies of MPEG-1 and MPEG-2, MPEG-4 is also
good for video conversations and television broadcasts. It can shrink even the largest
video files into small pieces for faster transfers through the internet or over a wireless
network. Other data may be incorporated to the MPEG-4 as well like images or video. MPEG-4
also sports some interactive elements as long as they have the supported player to allow
some layers of the video to be manipulated.
H.264 otherwise known as MPEG-4 Part 10 or AVC (Advanced Video Coding) takes the MPEG-4
format to another level and is advantageous over the older formats as it contains
inter-picture prediction features allowing up to 32 picture references. It focuses on
lossless methods and aims for flexibility on a variety of different systems. Their
lossless methods can also reduce their file sizes even further than MPEG-4 formats making
them ideal for HD video. Still many mobile devices use the more popular MPEG-4 format.
MJPEG is another format that may not be familiar by everyone. MJPEG basically comes
from the JPEG format, which is highly standardized for compressing images. The MJPEG
follows that same process and adds other stuff in streaming each image or frame together.
The end result leads to lower CPU usages compared to the other formats, but higher file
sizes leading to increased bandwidth needed for streaming.
Your choice of DVR compression depends on the specifications of your system and your
intended use of distribution. This is why there is currently no format that rules over
all. If you plan to distribute video clips for slower computers, MJPEG could be the
choice. For better compatibility with mobile devices and standard computers, MPEG-4 could
be a safe choice. If quality must be preserved while keeping the file size small (preferably
on high definition videos), H.264 is the best choice. You can even try compressing the
video in all 3 formats, compare them all, and see what looks best for you.
Sharon Macdonald is a retired teacher and high-tech security specialist. She is an expert in
[a1-hiddencamera.com is currently unavailable] video and audio surveillance systems and techniques.
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