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Mapping frontends to demuxes

DISCUSSION Rémi Denis-Courmont 2 participants 4 messages Mar 11, 2012 Media (V4L/DVB)

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Hello linux-media folks,

With the new multi-system frontend capability API, how are frontend and demux/dvr devices paired? Should userspace assume that frontendX corresponds to demuxX and dvrX (and caX and netX?) within a multifrontend adaptor?

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Rémi Denis-Courmont
http://www.remlab.net/
http://fi.linkedin.com/in/remidenis
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By the way, the bt8xx driver exposes ATSC but not ITU J.83 annex B. This is contrary to all other ATSC frontends. Is this correct?

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Rémi Denis-Courmont
http://www.remlab.net/
http://fi.linkedin.com/in/remidenis
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2012/3/11 Rémi Denis-Courmont <[email protected]>:

Quoted 2 lines

By the way, the bt8xx driver exposes ATSC but not ITU J.83 annex B. This is contrary to all other ATSC frontends. Is this correct?

Many of the older cards didn't support J.83 annex B (i.e. ClearQAM). Whether the device supports ClearQAM or not is actually controlled by the demodulator driver, not the bridge driver.

If you provide specifically which product you are talking about (the product name and PCI ID), it's easy enough to confirm by taking a quick look at the source.

Devin

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Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com
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Le dimanche 11 mars 2012 17:34:50 Devin Heitmueller, vous avez écrit :

Quoted 7 lines

2012/3/11 Rémi Denis-Courmont <[email protected]>:

Quoted 2 lines

By the way, the bt8xx driver exposes ATSC but not ITU J.83 annex B. This is contrary to all other ATSC frontends. Is this correct?

Many of the older cards didn't support J.83 annex B (i.e. ClearQAM). Whether the device supports ClearQAM or not is actually controlled by the demodulator driver, not the bridge driver.

Ah ok, thanks.

On the topic of J.83, what's the intended difference between SYS_ISDBC and SYS_DVBC_ANNEX_C ? (I cannot find any driver with SYS_ISDBC.)

Signature · 3 lines
Rémi Denis-Courmont
http://www.remlab.net/
http://fi.linkedin.com/in/remidenis