Streaming TV -> PC

Ideas and dreaming about C series TV will go this forum.

majonezz
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Re: Streaming TV -> PC

Post by majonezz » Sun Jan 09, 2011 10:40 am

Hmm, good idea. On my B650 i can record on NAS server. If i open that recording on pc then i can say, i'm watchng near-live strem. Recording can be opened even if it still being recorded, so when i rewind it to near end, the delay between air and pc is not that much.
But i'm still thinking that would be great to capture for example whole TS of actually watched transponder and push it through via multicast RTP. I don't know if TV can capture whole TS, but if it can, we technically could watch even other channel (on the same transponder), than actually watched on TV.

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Re: Streaming TV -> PC

Post by erdem_ua » Sun Jan 09, 2011 12:44 pm

Majonezz, What is "whole TS" ? If you mention capturing whole cable signal from one tuner, I think it's not possible. You can capture only one channel, that is actually playing TV, nothing more. Limitation on Hardware, not in software. TV's tuner could capture just one channel at a time. (If TV has second tuner, than we could use second tuner for changing/viewing/capturing other channels but I don't know if it's exist on C series or which models support it...)

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Re: Streaming TV -> PC

Post by timoo » Sun Jan 09, 2011 7:39 pm

imho you can capture whole multiplex(http://en.wikipedia.org/wiki/Multiplex_%28TV%29) from one tuner to .ts

majonezz
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Re: Streaming TV -> PC

Post by majonezz » Sun Jan 09, 2011 10:52 pm

Telling "whole TS" i meant transport stream before demultiplexer. PVR application records content after demultiplexer, so only desired one video and one audio track are recorded. But in most times, transport stream before demultiplexer contains more than one audio/video tracks. Just analyze recorded *.ts with VLC. You'll see, that there are more streams, but only one channel is really recorded - others are empty.
For example here in Poland we have mpeg4 video in DVB-T transmission as standard, so there are 6 or even 7 SD channels fitted into one transport stream (so called mux - multiplex).

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Re: Streaming TV -> PC

Post by erdem_ua » Mon Jan 10, 2011 2:11 am

Himm, I thought cable TV send each channel with it's sound and subtitle tracks on a singe TS via OFDM multiplexing for each stream.
There might be special equipments that capture whole spectrum, all OFDM channels at once. But those tuners are too pricey than our TV's.

I don't know flow how stream processed on tuner. Also don't know if companies push more than one channel to a stream really, don't heard of it before... If they make it, than, yes you can capture whole TS but don't know if there is a HW constraint on it. If there is a demux for unpack those streams, it will be HW demux due BW of stream and that means we cannot capture TS.
But if stream demuxed by software, than we could alter the process and could capture whole transport stream.

But here is question arises, where is the CAM decryption cards stands. Does it just decrypt demuxed channel or whole TS stream?
AFAIK that cam modules supports some MPEG conversions that means CAM works on TS after demux. Or I am false?
I think some users know more on this subject. Will be silent on this and try to learn from others knowledge :)

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Re: Streaming TV -> PC

Post by majonezz » Mon Jan 10, 2011 7:32 am

http://en.wikipedia.org/wiki/File:Commo ... ucture.svg
According to this picture from wiki, CI has access to data before demultiplexer. But CI modules usually handle one desired audio/video stream do decrypt it. Host (TV) and CI module are connected to communicate with each oder with special control bus as well, so TV can tell to CAM that user actually watch this or that... In many cases one TS contain mixed content - encrypted and not. But we are going offtopic i guess :)

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Re: Streaming TV -> PC

Post by erdem_ua » Mon Jan 10, 2011 4:44 pm

But in C series there is no CI interface. All of CI+.
Does anyone inspect exeDSP function for mux / demux functions? We might find something useful.

Instead of streaming to PC via NFS/Samba approach, It looks better if we could place server to TV that produces Network stream.
Does VLC work for that? It can stream from DVB-C/S cards at PC. Or any other program could used for the job.
Just diverting recording stream to that program via pipe will allow such a feature.

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Re: Streaming TV -> PC

Post by majonezz » Tue Jan 11, 2011 3:04 pm

VLC is very powerful, but have much more capabilities than we need for streaming purpose. I guess we need smaller solution. I think gstreamer should do.
Gstreamer is very powerful and have modular construction. Checkout at http://www.gstreamer.net/ .

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Re: Streaming TV -> PC

Post by erdem_ua » Tue Jan 11, 2011 3:08 pm

I think gstreamer might require gtk libraries which is problematic. But VLC supports CLI. Does gstreamer support CLI too?
Does anyone knows a arm build of VLC? I don't want to compile it now.

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