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Video
on the web is still crappy, (uses too much bandwidth) unless you
got ton of money and what to hook everyone up to a T1 line great.
For those who want to do it for free here's how its done.
STEP
1: CAPTURE THE VIDEO FILE
In
order to to encode the RealVideo files, the video must first be
in a format that the RealVideo encoder can use. The video that you
have must be captured in the one of the following formats.
VHS,
Beta or Laser Disc can be the source for the actual video content
to capture. Consult your video capture card documentation on how
to capture video in to AVI or QuickTime formats.
- NOTE:
RealVideo supports any frame size with a height and width that
are multiples of 16. The RealVideo encoder will also accept a
160x120 image size. When creating content, it is recommend to
use a frame size of 176x144. Most video capture cards do not support
this size. Indeo drivers must be installed on your machine for
the encoder to be able to open the AVI. If the AVI file was captured
with the same machine there is usually no problem. You can locate
the INDEO drivers at this location; http://www.intel.com/ial/indeo/index.htm
STEP
2: CREATE THE REALVIDEO FILE
You
must have the RealVideo encoder to encode Video for the RealVideo
server. You can download a copy of the encoder from http://www.real.com/
You
must set three Parameters when encoding the RealVideo file: Audio
codec,
video bit rate, and frame rate. The quality of the video file depends
on these three settings.
-
First
choose the bit rate for the video. See table below.
| Targeted
Modem Rate |
Total Bit Rate |
| 28.8
kbps |
19
|
| 56.0
kbps |
44
|
| 64.0
kbps |
56
|
| 128.0
kbps |
105
|
- Choose
the Audio codec. In order to figure out which codec to use. Follow
this formula.
Video Bit Rate = (Total Bit Rate) - (Bandwidth of Audio Codec)
The RealVideo has discreet bandwidths. The video bit rate will
be the difference between the total bit rate and the bit rate
used by the chosen audio codec:
**Video Bit rate is calculated by the real video encoder automatically.
- Now
choose the Frame Rate for the video. This depends on the content
type of the video. If you have talking head type video The highest
frame rate that can be achieved at 19 kbps, will be 7.5 to 10
frames per second (fps) for talking head type content with decent
quality. A sporting event may only support 1 fps or maybe less.
See the table below for a guidelines.
| Content
type |
Target
Bandwidth |
Total
Bit Rate |
Audio
Codec |
Audio
Bit Rate |
Frame
Rate |
Talking
Heads
28.8 |
28.8 |
19 |
6.5
Kbps voice |
6.5 |
optimize
|
Talking
Heads
56 |
56.0 |
44 |
6.5
Kbps voice |
8.5 |
optimize
|
Music
Video
28.8,
Emphasize
Audio |
28.8 |
20 |
RealMedia
12 kbps |
12 |
.25 |
Music
Video 56,
Emphasize
Audio |
56.0 |
44 |
RealAudio
3.0 -
28.8 Mono, full
response |
16 |
optimize
|
Music
Video
28.8,
Emphasize
Video |
28.8 |
20 |
RealMedia
8
kbps |
8 |
optimize
|
Music
Video 56,
Emphasize
Video |
56 |
44 |
RealMedia
12 kbps |
12 |
optimize
|
| High
Action w/ Voice, 28.8 |
28.8 |
19 |
6.5
Kbps voice |
6.5 |
1 |
| High
Action w/ Voice, 56 |
56 |
44 |
RealAudio
2.0 - 28.8 |
15.2 |
optimize
|
| High
Action w/Music, 28.8 |
28.8 |
19 |
RealMedia
8 kbps |
8 |
1 |
| High
Action w/ Music, 56 |
56 |
44 |
RealAudio
3.0 - 28.8 Mono, full response |
16 |
optimize
|
| High
Action, 56,Fractal |
56 |
44 |
RealAudio
3.0 - 28.8 Mono, full response |
8.5 |
10 |
High
Action,
112, Fractal |
112.0 |
44 |
RealAudio
3.0 - 28.8 Mono, full
response |
8.5 |
10 |
- After
selecting the correct Audio codec, video bit rate, and frame rate
you can now encode the file. If you have the Real Video Player
you can test the video file on your local system. You can download
a copy of the Real Video Player from http://www.real.com/
Now
save the Real Video File.
** Important
**
Do NOT use underscore
("_") characters when naming RM files as they will not be interpreted
correctly by the .ram file.
STEP
3: CREATING THE .RAM FILE
You
need to create a text file with a ".ram" extension. This text file
contains a URL to the RealAudio file in the following format:
pnm://<yourdomain>/~<userid>/audiofilename.rm
Note
the "pnm:" prefix. Substitute your domain name and userid above.
There must be a tilde (~) before the userid. This file can reside
in the root directory of your account. The audio file name must
have a ".rm" extension.
Once
the .ram text file is created, save it and upload it to your web
site in ASCII transfer mode. We suggest using the same file naming
convention. (e.g. "test.ram" will launch the "test.rm"
file)
STEP
4: UPLOAD THE .RM FILE TO YOUR WEB SITE
Upload
the .rm file to the root directory of your web site in binary transfer
mode.
STEP
5: CREATING THE HTML CODE FOR THE REALAUDIO FILE
The
HTML document does NOT reference the .ra file itself; it must call
the .ram file which, in turn, launches the RealAudio file as represented
below.
<a
href="http://(yourdomain.com)/(textfile.ram)">Listen
to Audio</a>
If
you reference the .ra file directly from your HTML code, the audio
file may play, but you will not benefit from the streaming audio
effect.
EXTRA:
TIPS AND TRICKS
More
information for putting RealVideo files on your page is available
at http://service.real.com/.
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