What Is It?
A modern container format, used with MPEG-4 and H.264 video.
What Plays It?
QuickTime, VLC, some portable players.
More Information
The MP4 container gets its heritage from the QuickTime .mov container. Its native video
formats are MPEG-4 and H.264 (also known as AVC), with AAC audio.
Easy Settings One-by-One
320 pixels wide
By default, VisualHub will create a MP4
fi
le with the same image size as the original video. By checking this box,
VisualHub will constrain the video to 320 pixels across, scaling proportionally. 320x240 is a standard video resolution for
medium-quality Internet distribution.
Quality
If visual quality isn't as important as just getting the message across, you can set the quality slider to "Low". If the video
demands the absolute best quality possible, choose "High" or "Go Nuts". "Go Nuts" sets a data rate near the maximum
attainable quality of the codec. This setting may take over 5 times as much space as "Standard", but will look nominally
better.
The 56K setting will create a
fi
le that can stream in realtime over a 56K modem.
H.264 Encoding
H.264 is a newer, more advanced video compression type. Videos compressed with H.264 will look better than the
default MPEG-4 counterparts and take up less disk space. Of course, there's a catch. It takes much longer to compress
to H.264 than MPEG-4. H.264 videos compressed under the MP4 tab are "Main Pro
fi
le" with one b-frame.
Hint for streaming
This option may be useful to webmasters looking to post completed videos online. Checking this box will create hinted
tracks in the
fi
nished video. Hinted tracks allow internet streaming of a video via QuickTime/Darwin Streaming Server. By
default, MP4 videos created by VisualHub are "FastStart" and will begin to play as they are downloaded from a web
server, aka, Progressive Download. Hinted streaming videos never get stored on the downloading user's computer - they
download and play back in real time with no option to save.
20
