User manual

Bitrate view

This bitrate view is based on the assumption that a complete constant bitrate transport stream is analyzed. When used on a partial transport stream with variable bitrate the results will have no meaning.

Bar view

Also the bar chart view is based on the assumption that a complete constant bit rate transport stream is analyzed. When used on a partial transport stream with variable bit rate the results will have no meaning.

Grid view

The grid view shows individual packets of the transport stream, using the same colors as the bitrate chart. When the mouse is placed over a box, the mouse over show packet number and PID of that packet.

For most transport streams the picture will show very little structure, but for example a DVB-H stream will clearly show the time slicing.

This is part of the DVB-H service. The time slices are easy to see.

Filter

Select View -> Filter to display this filter. It can be used to customize the bit rate, the bar and the grid view.

With the sliders at the top the start and end moment can be changed. This makes it possible to zoom in on a small interval. This control is not idiot proof, it is possible to set a later start moment than the end moment. However, the result will be without meaning.

The "steps" drop down changes the number of steps used to draw the chart, and calculate minimum and maximum values.

The PID filter section determines which PID are used in the charts. PIDs in the left list are not used, PIDs in the right list are. It is also possible to change the order of the PIDs.

Examples

video only PIDs

When you are interested in only the video bit rates remove all other PIDs from the right list. (Easiest is to use "swap" to remove all, than add only the MPEG2 Video PIDs back to the right list)

The bit rate chart showing only the video PIDs. When putting the mouse over the chart, exact values are shown for that PID at that moment.

The bar chart showing only the video PIDs. When putting the mouse over a bar, exact values are shown.

DVB-H Zoom

This is the default bit rate display for a 31 second capture of the DVB-H (Handheld)service of KPN. It looks 'weird' on first impression.

We use the filter to zoom in on the first part (8.458 TS packets, or about 2 seconds).

Now this chart makes much more sense, it clearly shows the time slicing used by DVB-H. On DVB-H large pieces of data are transmitted in bursts, allowing the receiver to be switched off in inactive periods. This saves energy for the mostly battery operated devices.

Grid Filter

When we filter the example stream to show only the PMT fields, we see these are closely grouped together at almost constant distances.

This page was last modified on 15/05/2012