2008-05-16

Storage Format

The HF100 compresses video to the very efficient MPEG-4 AVC/H.264 compression format. AVC stands for Advanced Video Codec.

AVCHD on the other hand is just a strict recording format specification for high definition (HD) digital video cameras to ensure compatibility with editing software.

AVCHD Format Specifications1
Video Signal 1080/60i, 1080/50i, 1080/24p
Pixels 1920x1080, 1440x1080
Aspect ratio 16:9
Video compression MPEG-4 AVC/H.264
Sampling structure 4:2:0
Audio compression Dolby Digital (AC3)
Audio bit rate 64 to 640 kbits/s, ?
Audio channels 1, 2, 3, 4, 5.1 channels
System MPEG-2 Transport Stream
System bit rate up to 24 Mbits/s (17 Mbits/s)

1I only included the specifications that apply to the HF100. Specifications of the HF100 PAL model are in bold. The full format specification overview can be found at http://www.avchd-info.org/format/index.html

The HF100 uses only 60% of the maximal allowed AVCHD system bitrate of 24 Mbits/s. As you can see there's no 25p in the specification. In fact the "progressive" frames of the "PF25" mode are converted and stored in interlaced 50i format. This camera doesn't store real progressive frames!

1 comment:

Wayne said...

I'm confused how this works - how are "progressive frames" stored in 50i format?