User manual

PCR/PTS/DTS - TEMI - SCTE-35 Graph

Populating this view can take much memory, for long TS streams. That is why it can be disabled in the settings menu.

The PCR/PTS/DTS Graph shows the relation between the different time stamps of the components of a single service.

The service to be analyzed should not be encrypted. When a service is encrypted the PCR is not encrypted, but the PTS and DTS time stamps are part of the pay load and are encrypted.

This view uses the range selected in the filter. It does not use the PID-filtering of the filter. To toggle which time stamps / SCTE-35 markers are displayed in this graph use the check boxes on top of the window.

Zoom

Initially this view shows the entire length of the stream. To see more detail it is necessary to zoom in. This can be done by right-clicking in the graph and using the pop-up menu. Or you can click mouse the button (left, middle or right) and select area of interest by dragging from top-left to bottom-right. Reset to original view by clicking mouse button and dragging from right to left, or bottom to top.

Another way to zoom is using the left-mouse button to 'draw' the area you want to zoom into.

The last option for zooming is to point at area of interest, and scroll mouse wheel up. Zoom out by scrolling mouse wheel down.

Panning

When zoomed in you can pan to another part of the graph by holding the CTRL-button and moving the mouse.

View

This is a 'normal' view of the components of a single service. Notice all the PTS/DTS marks are 'above' the PCR-line. This means all PES-packets have arrived before they should be presented. If any component is below the PCR-line, there is a serious sync-problem.

For most components the PTS-marks will show a ascending line. The exception to this rule are the video-frames. Because of the structure of I,P and B frames a P frame has to be decoded before the preceding B-frames can be decoded. So the the P frame is broadcast out-of-order, before the preceding B-frames. The decoder then has to decode it first (indicated by the DTS time), before decoding the B-frames.After the B-frames are decoded and presented the P-frame is presented.

This graph shows how the distance between PCR and video PTS varies over time. This means the video buffer is growing and shrinking. ISO/IEC 13818-1 specifies the buffering must not exceed one second.

Mouse Over

When the mouse pointer is over one of the time stamps in the graph a hover item will display the exact values of this PCR/PTS.

Switching service

With the drop down at the top-left a different service can be selected for analyzing.

Packet numbers

The radio button at the top-right the x-axis can be used to switch the x-axis between time and packet number display. The hover will then also display the packet number.

TEMI

When one or more of the PIDs in the service contain "Timed External Media Information"(TEMI) data (the adaptation field contains temi_timeline_descriptors) the check-box "TEMI-display" becomes enabled. By checking this box an extra y-axis will be added to the right of the graph, and all temi_timeline_descriptors in the PIDs will be marked.

When the mouse pointer is over one of the temi markers in the graph a hover item will display the exact values of this descriptor.

Experimental

This TEMI feature is still very experimental. Any suggestions for improvements are welcome. Also test streams are welcome. If you have any streams available, or suggestions/remarks please contact me to help improve DVB Inspector.

SCTE-35 splice_insert and time_signal

When SCTE-35 splice_inserts and/or time_signals are present in the selected program they are displayed in this graph.

This page was last modified on 13/04/2019