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Transport Stream Editing
PostPosted: Wed Jul 14, 2004 2:34 pm Reply with quote
crow
 
Joined: 15 Jan 2004
Posts: 22




My understanding is that the ATSC transport stream contains redundancy to compensate for limited packet loss. Is there some tool that can post-process a transport stream and clean it up to only have the minimum required data? Similarly, is there a tool to split out the subchannels?

Am I correct that, in theory, I could write a program that would take a transport stream and generate one mpeg file for each subchannel where the total space used by the mpeg file(s) would be less than the original.
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Re: Transport Stream Editing
PostPosted: Fri Jul 16, 2004 12:04 am Reply with quote
mk500
 
Joined: 11 Jan 2004
Posts: 51
Location: San Francisco, CA




I think dtvstream will do a lot of what you want:

http://www.pchdtv.com/forum/viewtopic.php?t=157

crow wrote:
My understanding is that the ATSC transport stream contains redundancy to compensate for limited packet loss. Is there some tool that can post-process a transport stream and clean it up to only have the minimum required data? Similarly, is there a tool to split out the subchannels?

Am I correct that, in theory, I could write a program that would take a transport stream and generate one mpeg file for each subchannel where the total space used by the mpeg file(s) would be less than the original.
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MPEG conversions
PostPosted: Thu Jul 22, 2004 5:25 pm Reply with quote
inkling
 
Joined: 05 Feb 2004
Posts: 342




There is a tool called DVB Replex that will remove the redundant information from the stream and attempt to generate a regular MPEG, i.e. non-transport-stream.

It needs some work on the front end to make it more robust for the occasional dropouts, and needs some work in the buffer allocation code to handle the larger frame size of HDTV.

If you're inclined to write some code, and this does what you're looking for, you might want to see what you can do with this program.

I've puzzled over it for a little while but so far haven't gotten it to work except on 704x480 only streams.

I would provide a sample of stream to the metzler bros so they could fix it, but I haven't the bandwidth to do such a thing.

http://www.metzlerbros.org/dvb/index.html

If you're wanting to do stream-redistribution, you probably want to keep it as transport stream to feed to the other computers in your house.

dtvstream may be able to help you reduce the bandwidth somewhat.

Actually trying to do that scenario here with khttpd and xine, but khttpd is acting somewhat broken and refuses to serve the transport files.

Haven't figured out how to make it NOT go to a user land http server. Want it to serve the file or give a 404 instead of kernel oops.

Should be able to drive about 3 computers on 100bt, no telling how many on 1000bt. Switches intead of hubs will help too.

I'll be happy enough if it just handles 1.
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correction: khttpd is dead
PostPosted: Tue Jul 27, 2004 1:18 pm Reply with quote
inkling
 
Joined: 05 Feb 2004
Posts: 342




[quote="inkling"]
Actually trying to do that scenario here with khttpd and xine, but khttpd is acting somewhat broken and refuses to serve the transport files.
[/quote]

khttpd is dead, Jim. From what I can tell, no one ever got it to work right.

A server that lets you set the position in the stream would be needed anyway, if you want to skip around in xine and have it be truly useful.

That's what I figured out after investigating.
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Transport Stream Editing
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