PRB: EPG Does Not Clear the Channel List After a New Virtual Channel Table ID Is Sent (319199)

SYMPTOMS

When you send a new Virtual Channel Configuration message that has the setting VCT ID=FFFF, and no channel map is included, the electronic program guide (EPG) still contains a list of channels and information from the previous map. The DCT5000 can tune through this list (however, there is no audio or video present on the channels).

CAUSE

When the DCT5000 set-top box (STB) receives a new Virtual Channel Table (VCT) channel map, the MSGLoader is signaled to process the channel map. For each signal, the loader calls GetVCTData,which is a GITV routine.

In this case, GetVCTData returns with a successful status code, but the pointer to the VCT data table out parameter is still set to null. This status code condition is skipped because it is a wrong result, and the MSG service records that were processed previously are used. If this routine passes a VCT table structure that has zero entries, the table is processed and the routine returns an empty channel list.

RESOLUTION

Update the STB with a VCT that contains at least one channel.

NOTE: You cannot update the client with an empty channel map by sending an empty VCT to the STB.

MORE INFORMATION

The Virtual Channel Table (VCT) contains the following information: service types, analog, digital, data, audio, multiple audio, multiple major, maximum channels, multiple sections, and current/next transitions.

VCT gives a list of the virtual channels in the transport stream and gives information about each channel that includes the channel name, the logical channel number, and a list of the program elements of the channel (the video stream, the audio stream, and/or the data stream).