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Transport Stream Analyzer for HDTV standard

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4.87/5 (34 votes)

May 8, 2004

2 min read

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A program that analyzes a transport stream.

Intro

This program deals with Transport Stream files. Basically, Transport Stream means one or more streams (usually, MPEG-2 files) multiplexed into a single stream. That's what the HDTV is using (the digital television).

The concept:

A Transport Stream consists of fixed length packets. There can be more sizes but the standard one is 188 bytes. A packet can contain info from a Program Stream, can be a null packet, a Program Association Table or a Conditional Access Table. The PID is the field deciding the packet.

Mainly, the TS packets transport data from Program Streams at a fixed bit rate which must be greater than the sum of Program Streams bit rate. For example, if a standard MPEG-2 is encoded at a few Mbits per second, the Transport Stream usually has bigger bit rate values.

To better understand the composition of a Transport Stream, take a look at the picture below:

Sample screenshot

The program:

TS_Analyzer reads each packet from the input stream and analyzed it. You can view the packets as a graphical display of fields, or use the "write to file" option to list individual packets info or statistics.

I know that a Transport Stream is not so easy to find as a MPEG-2 file, so I've included a sample at the downloads section above. If you'll play this sample with Media Player, you'll hear about 1s of sound, and if you have the appropriate codec, you'll also see an image. It's a small part (4000 packs) of a larger transport stream (about 400,000 packs) but can give you an idea about the concept. Another player you can use is DVD2AVI.

If you would like to try a real transport stream, download mp2tsmpdex.exe from here. This is a Transport Stream Demo producer that will give you a 10s transport stream that can be analyzed by my program.

To use the program, just read the readme file included.

Main window:

Sample screenshot

This is how the program looks when you start it.

Browse window:

Sample screenshot

This is the browse window used to change the current directory.

Analyzer window:

Sample screenshot

That's how the analyzer window looks.

Output text file "tsinfo.txt":

That's what you'll see in the output text file after processing a Transport Stream:

Sample screenshot

Output text file "ts_stats.txt":

These are statistics about your input Transport Stream:

Sample screenshot

Author notes:

I don't really know of how much interest this subject really is. It's not a very known one and might not be the thing you're looking for. Still, the HDTV standard uses it and some VPN networks also. It's fun to see how digital TV signal is formed, and surely this is not an obsolete subject.

For impressions regarding this program or discussions related to this subject, feel free to contact me by e-mail (ro_angel_bv@hotmail.com or ro_angel_bv@fastmail.fm).