UD230

Creating WWW Pages with RealAudio / RealVideo

By following the procedures in this user document, departmental Webmasters can create multimediaWeb page with RealAudio / RealVideo. This document contains two sections: 

1. How to create RealAudio Web page
2. How to create RealVideo Web page.

1. How to create RealAudio Web page

1.1 Pre-requisites for creating a web page with RealAudio files

1. A departmental webmaster account on the HKU WWW Server.
2. Knowledge of web page authoring in HTML (e.g. use of Netscape Gold).
3. Knowledge of using FTP (File Transfer Program) and Telnet (remote login program).
4. Pentium PC (running Windows 95) or PowerMac or Unix Workstation with sound recording device, e.g., SoundBlaster Card.
5. Audio input device (with respect to the PC), e.g., tape or CDROM Player.
6. An audio cable connecting the audio input device to the sound recording device of your computer.
7. RealAudio Encoder program.
8. RealPlayer is required for testing the Real Audio contents.
   click here to download RealPlayer for Windows 95
   click here to download RealPlayer for other platform


1.2 Download and install the RealAudio Encoder program 

1. Click here to download the RealAudio Encoder for Windows 95.
2. Click here to download the RealAudio Encoder for PowerMac.
3. Click http://www.real.com/products/encoder/realaudio/index.html to download the RealAudio Encoder for other platforms , e.g. (Solaris, AIX, Windows NT, etc.)
4. In your PC's file manager or the like, double click on the downloaded file to start the installation program.
5. Follow the instruction of the installation program to install the RealAudio Encoder Program.

1.3 Record or convert to RealAudio (RA) files 

Users can directly record from an audio input device (e.g. tape or CDROM player) or convert from an existing sound clip file (e.g. file.wav, file.au, etc.) to RA format..

1. Connect your audio input device to the sound recording device of your computer.
2. Start the "RealAudio Encoder" program. (The following uses the Windows 95 version for illustration).

1. At the "Source" section on the left pane of the RealAudio Encoder window:
• If you want to convert a pre-recorded sound file to a RA file, click on the "File" tab.
• If you want to record directly from an audio input device to a RA file, click on the "Live Stream" tab.
2. For most purposes, it is recommended at the present stage to record RA files in "RA2.0 -14.4kbps" compressed format rather than RA3.0 format, because files in RA2.0 format are ready to be played by most of the existing RealPlayer v2 and v3 programs, while files in RA3.0 format can only be played by RealPlayer v3 programs.
3. At the "Destination" section on the right pane of the RealAudio Encoder window:
• Click on the "File" tab, and optionally the "Browse..." button, to select a folder to store the destination file. You should use "14_4.ra" as the output file name for the "RealAudio 2.0 - 14.4kbps" compress format. It is because the RA Encoder does not allow file name extension other than ".ra".  After the recording finished, you MUST rename this file as "14_4.18" for the RA Server to recognize the file. If you choose other compression format, please rename the recorded file according to the corresponding filename given in the table below.
• Don't click on the tab "RealAudio Server", because one cannot directly put the output of the Encoder up on the HKU WWW Server.
4. Click on the "Start Encoding" button to start the recording or conversion.
5. You can record the same sound source using a different compression format by choosing a different destination file name.

Note: RA files with different compression formats are identified by different file names. You should use the proper file names according to the following table.

Encoding Compression format	Filename	Suggested Usage
RealAudio 2.0 14.4 Mono	14_4.18	speech, talks
RealAudio 2.0 28.8 Mono	28_8.36	speech, talks
RealAudio 3.0 - 28.8 Mono, narrow response  RealAudio 3.0 - 28.8 Mono, medium response,  RealAudio 3.0 - 28.8 Mono, ful response	dnet.20	good quality broadcast, speech, talks
RealAudio 3.0 - 28.8 Stereo	dnet.25	good quality musical recording
RealAudio 3.0 - ISDN Mono,  RealAudio 3.0 - ISDN Stereo	dnet.50	high quality musical recording
RealAudio 3.0 - Dual ISDN Mono  RealAudio 3.0 - Dual ISDN Stereo	dnet.100	highest quality musical recording

1.4 Upload the RA files to the HKU WWW Server and create an HTML file 

1. Use FTP to upload the RA file(s) produced by the encoder to the HKU WWW server.
2. Change the destination directory to /web/docs/account where account is the name of the WebMaster account.
3. Create a new directory, say ratest, under the directory /web/docs/account/. (You can use any other directory name.)
4. Put the RA files (e.g., 14_4.18, 28_8.36, .... or dnet.100) under the directory /web/docs/account/ratest/.
   Note:
• RA files with different compression methods from the same sound source should be stored under a single directory and the sound source is identified by the name of the directory.
• RA Server and RA Player will automatically determine the best match of RA files to download, based on the speed of network connection, for playback.
5. Create a file under /web/docs/account/ratest with name test.ram which contains only one statement:

pnm://www.hku.hk/account/ratest

Change the permission of the file to be readable by others using the following command:
chmod 644 test.ram

6. Create an HTML file which contains a pointer to the above ".ram" file. For example, you can create the file test.htm under the same directory /web/docs/account/ratest/. This file should at least contain the following statement which references the .ram file:

<a href="test.ram">RealAudio Testing</a>

Change the permission of the file to be readable by others using the following command:
chmod 644 test.htm

1.5 Test the newly created web page

Start your Netscape browser (with RA Player installed) to visit the web page http://www.hku.hk/account/test.htm, and then click on the link to listen to the audio file. You should have RealPlayer installed, and it would start automatically to play the audio file.

1.6 Further reference on RealAudio

• Click here to download the "Real Audio Server Administration and Content Creation Guide". This file is in PDF format and requires Acrobat Reader for reading.

2. How to create RealVideo Web page

2.1 Pre-requisites for creating web page with RealVideo

A departmental webmaster account on the HKU WWW Server.

Knowledge of web page authoring in HTML (e.g. use of Netscape Gold).

Knowledge of using FTP (File Transfer Program) and Telnet (remote login program).

Pentium PC (running Windows 95) or PowerMac or Unix Workstation with video capture device, e.g., VideoBlaster Card.

Video input device, e.g., VCR, Camcorder, LD Player.

A video cable connecting the video input device to the video capture device of your computer.

RealVideo Encoder program.

If the video was captured in AVI format, the RealVideo Encoder program can convert it to RealVideo Format.

RealPlayer is required for testing the RealVideo contents.
click here to download RealPlayer for Windows 95
click here to download RealPlayer for other platform

Note: When this article is written, the RealPlayer capable of playing RealVideo file is a beta version, i.e., it is only a test version and will expire after some date. The user will be informed to download a newer version when the expiration date is passed.


2.2 Download and install the RealVideo Encoder program 

Click here to download the RealVideo Encoder for Windows 95.

Click http://www.real.com/products/encoder/realvideo/index.html to download the RealVideo Encoder for other platforms , e.g. (Solaris, AIX, Windows NT, etc.)

In your PC's file manager or the like, double click on the downloaded file to start the installation program.

Follow the instruction of the installation program to install the RealVideo Encoder Program.

2.3 Record or convert to RealVideo (RV) files 

Users can directly record from a video input device (e.g VCR, LD Player, Camcorder) or convert from an existing video clip file (e.g. file.avi, file.mov) to RV format..

1. Connect your video input device to the video capture device of your computer.
2. Start the "RealVideo Encoder" program. (The following uses the Windows 95 version for illustration).



 

3. Click on the "File" menu and select "Open Session"
• If you want to record directly from an video input device, click on the "Capture Device" and select "Video Capture" and "Audio Capture" from the "Source box".
• If you want to convert a pre-recorded video file (e.g. file.avi or file.mov), click on the "File" checkbox, then click on the "Add" button and select the pre-recorded file from the "Source box".
• Click on the "Realmedia" check box, then click on the "Select" button and select a destination path and filename.
5. Selection of "templates"
   "Templates" with higher bandwidth results in higher output quality at the expense of longer download time and the possibility of frame dropping during playback in slow connection client RealPlayer programs. It is recommended to record using the "template" "High Action 56 with Music". However it is common to record more than one RV file for different bandwidth, since the RealPlayer program will automatically select the best file to match the client PC's bandwidth.
   
6. You can name the destination file as file.rm when recording, however you MUST rename it in accordance to the table below, e.g. "High Action 56 with Music" renamed as "prnv.70".

Note: RV files with different compression formats are identified by different file names. You should use the proper file names according to the following table.

Encoding Templates	Filename	Suggested Usage
Total Bandwidth 14.4kbps	pnrv.18	Nearly static video
Total Bandwidth 19.2kbps	pnrv.24
High Action 28.8 with voice High Action 28.8 with music Music Video 28.8 emphasize video Music Video 28.8 emphasize video	pnrv.36	low quality video
High Action 56 with voice High Action 56 with music Music Video 56 emphasize video Music Video 56 emphasize video	pnrv.70	middle quality video
Single ISDN 56 (total bandwidth 56kbps)	pnrv.70	middle quality video
Dual ISDN 56 (total bandwidth 115kbps	pnrv.144	above middle quality video
T1 (total bandwidth 1544kbps)	pnrv.1930	high quality video

2.4 Upload the RV files to the HKU WWW Server and create an HTML file 

• Use FTP to upload the RV file(s) produced by the encoder to the HKU WWW server.
• Change the destination directory to /web/docs/account where account is the name of the WebMaster account.
• Create a new directory, say rvtest, under the directory /web/docs/account/. (You can use any other directory name.)
• Put the RV files (e.g., pnrv.70, pnrv.36, ... or pnrv.1930) under the directory /web/docs/account/rvtest/.
  Note:
1. RV files encoded with different templates from the same video source should be stored under a single directory and the video source is identified by the name of the directory.
2. RV Server and RV Player will automatically determine the best match of RV files to download, based on the speed of network connection, for playback.
• Create a file under /web/docs/account/rvtest with name test.ram which contains only one statement:

pnm://www.hku.hk:7060/account/rvtest

Make sure the string ":7060" is included in the statement.

Change the permission of the file to be readable by others using the following command:
chmod 644 test.ram

• Create an HTML file which contains a pointer to the above ".ram" file. For example, you can create the file test.htm under the same directory /web/docs/account/rvtest/. This file should at least contain the following statement which references the .ram file:

<a href="test.ram">RealVideo Testing</a>

Change the permission of the file to be readable by others using the following command:
chmod 644 test.htm

2.5 Test the newly created web page

Start your Netscape browser (with RealPlayer installed) to visit the web page http://www.hku.hk/account/test.htm, and then click on the link to view the video file. You should have RealPlayer installed, and it would start automatically to play the video file.

2.6 Remarks for RealVideo Encoding

It is recommended to record video clips in AVI format first by using Adobe Primer, then use the RV Encoder to convert it to RealVideo rather than directly recording it using the RealVideo Encoder.

It is noted that the use of the "RealVideo Fractal" in the "Advanced" Template option menu takes at least 5 times longer than the default "RealVideo Standard" to compress a video clip, and the output will only be slightly better.

It is recommended to use a PC with Pentium 166 MHz or above CPU to record directly from a video playback source.

It is recommended to use a PC with Pentium 166 MHz or above CPU to convert from AVI or MOV file to RV file.

2.7 Examples of RealVideo Encoded files

Four examples RV files are encoded via different compression methods for the same (71 secs) AVI file, using a PC with Pentium Pro 200MHz CPU running RV Encoder as a background job.You can view each RV file by clicking on the appropriate links below. The time to finish the compression ranges from a few minutes to several hours, depending on which compression format is used. The subjective visual quality of the four files has some differences. As a producer of RV files, you have to trade off between quality, compressed file size, and time to compress.

Example	Compress Method & Option	Compressed File Size	Time to compress
Example 1	"High action 28.8 with music" option with RealVideo Standard compression.	230 K byte	40 sec
Example 2	"High action 56 with music" options with RealVideo Standard compression.	839 K byte	7minutes
Example 3	Customized settings -Total bandwidth 112Kbps with RealVideo Standard compression.	0.99M byte	8 minutes
Example 4	customized settings -Total bandwidth 256Kbps with RealVideo Standard compression.	2.43M byte	9 minutes

Note: RV files created for 300Kbps bandwidth, on playback on a shared Ethernet, may have severe dropping of video frames and the video may appear jerky, depending on how busy the overall network traffic is.

2.8 Further reference on RealVideo

• Click here to download the "RealVideo Content Creation Guide". This file is in PDF format requires Acrobat reader for reading.

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