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Discussion Starter · #1 ·
Using MyHD I recorded something off PBS and the transport file contains both the standard def program and a separate HD program. What's funny is that when you play back the file thru MyHD it plays the SD subchannel by default even though the HD subchannel was selected to record. At first this gave me the impression that MyHD did not capture the HD program until you switch the subchannel during playback.


So given that MyHD records the entire stream, is their a way to strip off the SD subchannel so that when I play back I get only the HD program I'm interested in?


Also would probably benefit from a one subchannel TP for WM9 encoding as I understand it can be problematic with the Elecard filters, although I have not tried encoding programs with subchannels yet.
 

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Discussion Starter · #2 ·
What's also strange is that HDTVtoMPEG2 v.10 shows 4 subchannels in the TP stream. Two SD and two HD with each having different audio PID's. But there are only two subchannel selections via MyHD app. I suspect that they me be different audio tracks (language or DD2.0 vs 5.1?) but not sure how to access the alternate audio via MyHD.
 

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The way I do it is to use bbtools and epid. Epid was written by jacob balazer http://www-personal.engin.umich.edu/...id/readme.html

and it will remove the sub channel. Usually I find in the SF bay area most channels have the SD channel on 0x0021 and 0x0024. However, you can check this by getting bbdmux.exe from the bbtools package. Not sure of the official home page but http://www.google.com/search?sourcei...bbtools+bbdmux has a list of places where you can download it.

Basically I run bbdmux on one of the ts files. It spits out the list of PIDs (sub channels) and I look for the 2nd biggest one. The biggest one will be the HD video (and there will be a seperate PID for the audio) and the 2nd biggest will be the SD video (and it will have an accompanying audio channel)


So:

bbdmux "[2003-04-06 09.00pm Alias].0000.ts"

epid *.ts 0x0021 0x0024


At this point the file will be the same size but the SD channel will have been overwritten with NULL values. This makes the file much more compressible.
 
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