While H.264 is often considered a single format, there are many different types of H.264 formats. Each of these different types of formats has performance advantages and disadvantages. In recent years, most IP camera manufacturers have supported only the most basic type of format – the basic line profile. Now, manufacturers are increasingly supporting the more ‘advanced’ format types, including high profile and main. In this article, we share the results of the baseline profile tests against the largest profile differences in bandwidth and hardware (CPU) usage.
H.264 background
Manufacturers of IP cameras have widely standardized H.264 codec as the selected video surveillance codec. Because virtually all video surveillance systems need compression, codecs are indispensable. Previously, MJPEG and MPEG-4 were the most widely used. Today, the most widely used is H.264. In the last few years there has been a hot debate over the use of MJPEG or H.264, but H.264 certainly offers very interesting bandwidth savings.
Basic vs. Main line H.264 profile
Of the many H.264 profiles, the two most commonly used for video surveillance are the basic and main line. The baseline profile is generally considered the least effective of the H.264 profiles, but also the least demanding in terms of hardware resources. In contrast, the main profile is considered effective in bandwidth consumption, but also more demanding.
Increasingly, newer IP cameras use the main profile by default, while the generation 2-3 years ago would be more likely to use the basic profile.
Questions to be solved with the tests with h.264
IPVM performed a test in 3 different scenarios – during the day, at night and in high traffic complexity. For measuring the differences in bandwidth usage and hardware utilization (CPU) for base and main line H.264 profiles.
The questions they asked were the following:
How much bandwidth savings, if any, would you have with the main profile compared to the baseline?
How much bandwidth savings would you have depending on the stage type?
What is the increase in hardware consumption (CPU) when using the main profile instead of the basic line profile?
Should we prefer a main profile camera rather than a basic line profile camera?
Main conclusions and answers
The bandwidth limitation is modest. The main profile reduced bandwidth consumption by 10-30% in all three tests.
In all three tests, no noticeable difference in hardware consumption (CPU) was observed between the base profile and the main profile.
The tests were also performed using MJPEG. Bandwidth usage was 10 to 100 times more than the main profile.
Furthermore, it was also very interesting that the hardware consumption (CPU) was generally significantly higher than any of the H.264 sequences.
