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702 Posts
Discussion Starter · #1 ·
I recorded Apollo 13 OTA last week from KGO the ABC affiliate here in the bay area. Looking at the recording it seems to be very low quality. So I surmise that I'm watching the SD feed.

I want to edit the .ch and .pid files so that it will play back the HD sub channel.

When I look at the transport stream with bbdmux it reports the following about the first minute:

F:\ emp\\bb>bbdmux j:\\hdtv\\apollo13\\apollo13.ts.0000

bbDMUX - version 1.9, by Brent Beyeler ([email protected])

speed increases by, Apachez and Christian Vogelgsang

Scanning for PID's, press control-c to quit ...

File j:\\hdtv\\apollo13\\apollo13.ts.0000 is an MPEG-2 Transport Stream

Found PID 0x0021, Other Stream

Found PID 0x0011, Other Stream

Found PID 0x1FFF, Null Packet Stream

Found PID 0x0024, Other Stream

Found PID 0x0014, Other Stream

Found PID 0x0000, Program Association Table Stream

Found PID 0x0020, Other Stream

Found PID 0x0010, Other Stream

Found PID 0x1FFB, Other Stream

Found PID 0x1D03, Other Stream

Found PID 0x1D01, Other Stream

Found PID 0x1D02, Other Stream

Found PID 0x1E80, Other Stream

Found PID 0x1D00, Other Stream


MPEG Transport Packets = 766464

PID 0x0000, Program Association Table packets = 595, total bytes = 109480

PID 0x0010, Other packets = 594, total bytes = 109296

PID 0x0011, Video stream 0 packets = 497712, total bytes = 91494622

PID 0x0014, Private Stream 1 packets = 16718, total bytes = 2853152

PID 0x0020, Other packets = 594, total bytes = 109296

PID 0x0021, Video stream 0 packets = 176651, total bytes = 32467196

PID 0x0024, Private Stream 1 packets = 16718, total bytes = 2853258

PID 0x1D00, Other packets = 105, total bytes = 19320

PID 0x1D01, Other packets = 425, total bytes = 78200

PID 0x1D02, Other packets = 213, total bytes = 39192

PID 0x1D03, Other packets = 143, total bytes = 26312

PID 0x1E80, Other packets = 213, total bytes = 39192

PID 0x1FFB, Other packets = 953, total bytes = 175352

PID 0x1FFF, Null packets = 54830, total bytes = 10088720

F:\ emp\\bb>

My .ch file as recorded reads:


and my .pid file as recorded reads:


I noticed that 0017 = 0x0011 (decimal vs. hexadecimal)

and the 0020 = 0x0014 corresponding to a fairly large stream that would seem to be the audio.

So I tried modifying the.ch file to read:


(KGO comes in as channel 7, and I'm assuming the second number is the sub channel)

and I modified the .pid file to read

0033,0036 to correspond with the other two big streams that bbdmux reported.

Watching that, it seems a little higher quality but not being able to see them side by side, it's hard to tell if there's a difference.

Am I doing the correct thing? Am I missing anything?

Did anybody watch the HD feed and could tell me whether it was soft and noisy?

TitanTV and HDTVgalaxy disagreed on whether this was really in HD, so are there just two SD streams here?

Thanks all.

PS I did try and search the forum for editing subchannel files but I couldn't find anything.

3,772 Posts
I didn't watch it so I can't say for sure, but

I think there were reports that it was a

"sub-optimal" broadcast... Perhaps only

an upconvert.

KGO does send two sub-channels at once.

I think 24-1 is the 720p version

and 24-2 is the 480p version.

It sounds like you are learning alot about

picking apart the streams and figuring out

how to get HiPix to play the ones you want.

Perhaps you could record another program

in known 720p, and try the same thing

again to check your results.

619 Posts
The ability to select subchannels easily on playback is a glaring omission from the current HiPix software. Hopefully it will be corrected on the next release.

Can any beta testers comment on this? If HiPix can't give us an easy selection (e.g., a pop-up window showing which sub-channels are active) I hope they'll at least publish a comprehensive guide to selecting it so we don't have to figure the system out by hit-or-miss means.


9,884 Posts
I don't have a HiPix but I've read the PID file is just the video & audio pid numbers in decimal.

But even though you didn't like it you would think the higher quality video would be the bigger stream, the one you started with. So there is maybe something else wrong.

- Tom

3,325 Posts
Your procedure for selecting the different subchannels from a recording is correct. I've done the same thing myself.

Just make sure that you select the subchannel [the .ch file] based on what the HiPix uses, not hearsay. [e.g., 7.1 and 7.2]
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