Real Media Files

Real Media Extraction Files

• The Code
  Real Media file extraction procs written in TCL
  http://www.bmrc.berkeley.edu/people/shailen/realmedia/realmedia_procs.tcl

• How To Use The Code
  To analyse any real media file run a tcl shell, source the file above, then type
  analyse_rm_headers filename
  where you fill in an actual file for filename
  EXAMPLE
  > tclsh
  % source realmedia_procs.tcl
  % analyse_rm_headers firstrun.rm

• Demonstration Tclet
  You can run the following tclet at the command prompt: analyse_rm_file.tcl filename
  EXAMPLE
  > analyse_rm_file.tcl firstrun.rm

  You might want to cat the output to a file for easier viewing (i.e. analyse_rm_file.tcl firstrun.rm > output.txt )

  You can copy the code to a local directory if you do not have access to /n/plateau/project/vods2/tclets/realmedia/realmedia_procs.tcl

• Demonstration Real Media File
  Download this file to try out the demonstration tclet firstrun.rm
  http://www.bmrc.berkeley.edu/people/shailen/realmedia/firstrun.rm

• Sample Output
  Output from the file firstrun.rm (see #2 in Important Links for a description of extracted fields)
  http://www.bmrc.berkeley.edu/people/shailen/realmedia/output.txt
  

In question answer format

Q. What information can you get from the header files?
A.

• media title
• duration of the media
• file version
• author
• description
• copyright
• mime type
• maximum and average bit rate required to deliver the file over the network
• maximum and average packet size
• number of packets
• pre-buffer time
• number of media streams
• name of the stream
• enable/disable - copy to disk, extra buffering
• live broadcast
The title, duration, file version, author, and description can be used when checking a Real Media file into VODS.

Q. What is the height and width of the files being sent?
A. From what I have read, it is cannot be found in the header files. The Real Player can play the video files at many different sizes.

Q. What file types does the Real Networks support?
A.

Type	Extension
RealMedia File	*.ra *.rm
RAM Meta File	*.ram *.rmm
SMIL File Format	*.smi *.smil
Shockwave Flash	*.swf
Real Text File Format	*.rt
Real Pix	*.rp

Q. What headers are in a Real Media file?
A.

1. File
2. Properties
3. Media
4. Content
5. Data Chunk
6. Data Packet
7. Index Section
8. Index Record

 

Important Links

1. The Real Homepage
   http://www.real.com
2. RealMedia File Format (RMFF)
   http://www.real.com/devzone/library/creating/rmsdk/doc/rmff.htm
3. RealSystem Developer's Guide
   http://www.real.com/devzone/library/creating/rmsdk
4. Real Time Streaming Protocol (RTSP)   [ Text ]
   http://www.real.com/devzone/library/creating/rmsdk/doc/rtsp.pdf
5. White Papers from Real
   http://www.real.com/devzone/library/whitepapers
6. References from Real
   http://www.real.com/devzone/library/reference
7. Real Forum - Great Place for Frequently Asked Questions
   http://realforum.real.com/realforum/index.html
8. Knowledge Base - Enter your Query
   http://service.real.com/kb/default.htm

 

People I Talked To About Real Media Files

• José María González
  chema@cs.berkeley.edu

 

Email : shailen@cs.berkeley.edu | Last Updated November 1998