The following is a comparison of encoding video clips at alternate bitrates, sizes
and frame rates. The video is encoded using MPEG-4 Simple Profile.
NOTES:
The video clips are played in pop-up windows so you can do comparisons
easily. If this doesn't seem to work you may be using a pop-up window eliminator.
The playback performance is dependent on the your device. A large video with
a high frame rate and bit rate, for example, requires a fast capable personal computer.
Content
Modem 34kbps
ISDN 84kbps
384K DSL 268kbps
768K DSL 536kbps
Cable modem 872kbps
176x120
10fps
15fps
30fps
352x240
10fps
15fps
30fps
704x480
10fps
15fps
30fps
The player can scale the video on the client. To see the video scaled select a scale factor, 2x or 4x the selected video.
A 176x120 video can be scaled by a factor 2x to be seen at a 352x240 size.
A 704x480 video can be scaled by a factor 4x to be seen at a 2816x1920 size.
Content details
The original video was an MPEG-2 interlaced video at 704x480 pixels and 30 fps.
The video was deinterlaced for streaming across the web.
The bit rates are suitable for modem, ISDN, DSL, cable and LAN topologies. The bit
rates accommodate an additional audio clip of 16kbps at the low bit rates to 128kbps at the highest
bitrate.
Connection Speed
Total bit rate
Reserve for audio
Result video
56K Modem
50kbps
16kbps
34kbps
128K ISDN
100kbps
16kbps
84kbps
384K DSL
300kbps
32kbps
268kbps
768K DSL
600kbps
64kbps
536kbps
1.5M Cable modem
1000kbps
128kbps
872kbps
The alternate sizes of the video were arrived at by halving and quartering the
original video. This yields roughly QCIF, CIF and 4CIF video sizes.
The 10, 15 and 30fps frame rates are common standard frame rates.
