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zvbi-atsc-cc device node conflict

DISCUSSION David Liontooth 3 participants 7 messages Apr 16, 2010 – Apr 17, 2010 Media (V4L/DVB)

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#0 lore raw

I'm using a HVR-1850 in digital mode and get good picture and sound using

mplayer -autosync 30 -cache 2048 dvb://KCAL-DT

Closed captioning works flawlessly with this command:

zvbi-atsc-cc -C test-cc.txt KCAL-DT

However, if I try to run both at the same time, I get a device node conflict:

zvbi-atsc-cc: Cannot open '/dev/dvb/adapter0/frontend0': Device or
resource busy.

How do I get video and closed captioning at the same time?

Cheers,
Dave

#1 lore raw
Quoted 8 lines · David Liontooth

I'm using a HVR-1850 in digital mode and get good picture and sound using

 mplayer -autosync 30 -cache 2048 dvb://KCAL-DT

Closed captioning works flawlessly with this command:

zvbi-atsc-cc -C test-cc.txt KCAL-DT

Quoted 7 lines

However, if I try to run both at the same time, I get a device node conflict:

 zvbi-atsc-cc: Cannot open '/dev/dvb/adapter0/frontend0': Device or resource busy.

How do I get video and closed captioning at the same time?

To my knowledge, you cannot run two userland apps streaming from the frontend at the same time. Generally, when people need to do this sort of thing they write a userland daemon that multiplexes. Alternatively, you can cat the frontend to disk and then have both mplayer and your cc parser reading the resulting file.

Devin

Signature · 2 lines
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com
#2 lore raw

2010/4/17 Devin Heitmueller <[email protected]>:

Quoted 15 lines · David Liontooth
Quoted 14 lines

I'm using a HVR-1850 in digital mode and get good picture and sound using

 mplayer -autosync 30 -cache 2048 dvb://KCAL-DT

Closed captioning works flawlessly with this command:

zvbi-atsc-cc -C test-cc.txt KCAL-DT

However, if I try to run both at the same time, I get a device node conflict:

 zvbi-atsc-cc: Cannot open '/dev/dvb/adapter0/frontend0': Device or resource busy.

Quoted 8 lines
Quoted 1 line

How do I get video and closed captioning at the same time?

To my knowledge, you cannot run two userland apps streaming from the frontend at the same time.  Generally, when people need to do this sort of thing they write a userland daemon that multiplexes. Alternatively, you can cat the frontend to disk and then have both mplayer and your cc parser reading the resulting file.

Usually there is some way, for ex. command line option, how to say to "second" app that frondend is already locked. Then second app simply skips tuning at all.

Rest processing is made using demux and dvr devices, so there is not reason why 2 apps should tune in same time.

/Honza

#3 lore raw
Quoted 32 lines · HoP

2010/4/17 Devin Heitmueller <[email protected]>:

Quoted 16 lines · David Liontooth
Quoted 15 lines

I'm using a HVR-1850 in digital mode and get good picture and sound using

mplayer -autosync 30 -cache 2048 dvb://KCAL-DT

Closed captioning works flawlessly with this command:

zvbi-atsc-cc -C test-cc.txt KCAL-DT

However, if I try to run both at the same time, I get a device node conflict:

zvbi-atsc-cc: Cannot open '/dev/dvb/adapter0/frontend0': Device or resource
busy.

Quoted 9 lines
Quoted 2 lines

How do I get video and closed captioning at the same time?

To my knowledge, you cannot run two userland apps streaming from the frontend at the same time. Generally, when people need to do this sort of thing they write a userland daemon that multiplexes. Alternatively, you can cat the frontend to disk and then have both mplayer and your cc parser reading the resulting file.

Usually there is some way, for ex. command line option, how to say to "second" app that frondend is already locked. Then second app simply skips tuning at all.

Quoted 6 lines

Rest processing is made using demux and dvr devices, so there is not reason why 2 apps should tune in same time.

/Honza

Thanks! I'm trying to create separate recordings of the video/audio file on the one hand and the closed captioning on the other.

In one console, I issue

azap -r KOCE-HD

In a second, I issue

cat /dev/dvb/adapter0/dvr0 > test-cat3.mpeg

I cannot at the same time run this in a third:

zvbi-atsc-cc -C test-cc.txt KOCE-HD

because of resource conflict.

Using cat works, but how do I get closed captioning from the resulting mpeg file?

If I can get that to work, that would be great -- but not particularly elegant. Does someone have an example of a multiplexing userland daemon that allows me to spit out video to one file and text to another?

Cheers,
Dave

#4 lore raw

2010/4/17 David Liontooth <[email protected]>:

Quoted 58 lines
Quoted 39 lines · HoP

2010/4/17 Devin Heitmueller <[email protected]>:

Quoted 21 lines
Quoted 17 lines · David Liontooth

I'm using a HVR-1850 in digital mode and get good picture and sound using

 mplayer -autosync 30 -cache 2048 dvb://KCAL-DT

Closed captioning works flawlessly with this command:

zvbi-atsc-cc -C test-cc.txt KCAL-DT

However, if I try to run both at the same time, I get a device node conflict:

 zvbi-atsc-cc: Cannot open '/dev/dvb/adapter0/frontend0': Device or resource
busy.

Quoted 10 lines
Quoted 2 lines

How do I get video and closed captioning at the same time?

To my knowledge, you cannot run two userland apps streaming from the frontend at the same time.  Generally, when people need to do this sort of thing they write a userland daemon that multiplexes. Alternatively, you can cat the frontend to disk and then have both mplayer and your cc parser reading the resulting file.

Usually there is some way, for ex. command line option, how to say to "second" app that frondend is already locked. Then second app simply skips tuning at all.

Quoted 6 lines

Rest processing is made using demux and dvr devices, so there is not reason why 2 apps should tune in same time.

/Honza

Thanks! I'm trying to create separate recordings of the video/audio file on the one hand and the closed captioning on the other.

In one console, I issue

 azap -r KOCE-HD

In a second, I issue

 cat /dev/dvb/adapter0/dvr0 > test-cat3.mpeg

Quoted 9 lines

I cannot at the same time run this in a third:

 zvbi-atsc-cc -C test-cc.txt KOCE-HD

because of resource conflict.

Using cat works, but how do I get closed captioning from the resulting mpeg file?

Very dump way is simply feed zvbi with resulting test-cat3.mpeg. If this page is correct: http://www.digipedia.pl/man/doc/view/zvbi-atsc-cc.1/
using -t command line option you can get CC by issuing something like "cat test-cat3.mpeg > zvbi-atsc-cc -ts -C test-cc.txt"

Of course I'm assuming that CC pid is included in recording. But dunno if azap is demuxing pids others then A/V.

/Honza

#5 lore raw
Quoted 76 lines · HoP

2010/4/17 David Liontooth <[email protected]>:

Quoted 58 lines
Quoted 38 lines · HoP

2010/4/17 Devin Heitmueller <[email protected]>:

Quoted 20 lines
Quoted 16 lines · David Liontooth

I'm using a HVR-1850 in digital mode and get good picture and sound using

mplayer -autosync 30 -cache 2048 dvb://KCAL-DT

Closed captioning works flawlessly with this command:

zvbi-atsc-cc -C test-cc.txt KCAL-DT

However, if I try to run both at the same time, I get a device node conflict:

zvbi-atsc-cc: Cannot open '/dev/dvb/adapter0/frontend0': Device or
resource
busy.

Quoted 11 lines
Quoted 3 lines

How do I get video and closed captioning at the same time?

To my knowledge, you cannot run two userland apps streaming from the frontend at the same time. Generally, when people need to do this sort of thing they write a userland daemon that multiplexes. Alternatively, you can cat the frontend to disk and then have both mplayer and your cc parser reading the resulting file.

Usually there is some way, for ex. command line option, how to say to "second" app that frondend is already locked. Then second app simply skips tuning at all.

Quoted 7 lines

Rest processing is made using demux and dvr devices, so there is not reason why 2 apps should tune in same time.

/Honza

Thanks! I'm trying to create separate recordings of the video/audio file on the one hand and the closed captioning on the other.

In one console, I issue

azap -r KOCE-HD

In a second, I issue

cat /dev/dvb/adapter0/dvr0 > test-cat3.mpeg

Quoted 10 lines

I cannot at the same time run this in a third:

zvbi-atsc-cc -C test-cc.txt KOCE-HD

because of resource conflict.

Using cat works, but how do I get closed captioning from the resulting mpeg file?

Very dump way is simply feed zvbi with resulting test-cat3.mpeg. If this page is correct: http://www.digipedia.pl/man/doc/view/zvbi-atsc-cc.1/
using -t command line option you can get CC by issuing something like "cat test-cat3.mpeg > zvbi-atsc-cc -ts -C test-cc.txt"

Quoted 6 lines

Of course I'm assuming that CC pid is included in recording. But dunno if azap is demuxing pids others then A/V.

/Honza

That's promising but no cigar:

cat test-cat3.mpeg > zvbi-atsc-cc --ts

just feeds the output of the cat into a file called zvbi-atsc-cc (not surprisingly).

cat test-cat3.mpeg | zvbi-atsc-cc --ts

also doesn't work. zvbi-atsc-cc's --ts switch is designed to "Decode a DVB Transport Stream on stdin", so if the file created with

cat /dev/dvb/adapter0/dvr0 > test-cat3.mpeg

qualifies as a DVB Transport Stream, then there's a way to pipe it to zvbi-atsc-cc. How do we get the syntax for this?

I'm also wondering if zvbid, the zvbi daemon, could be used to get a text file output from zvbi-atsc-cc. This would seem the more elegant solution.

Cheers,
Dave

#6 lore raw
Quoted 6 lines

That's promising but no cigar:

cat test-cat3.mpeg > zvbi-atsc-cc --ts

just feeds the output of the cat into a file called zvbi-atsc-cc (not surprisingly).

Hehe. Sure, it was my mistake. Piping syntax what you tried later is exactly what I thought :-)

Quoted 11 lines

cat test-cat3.mpeg | zvbi-atsc-cc --ts

also doesn't work. zvbi-atsc-cc's --ts switch is designed to "Decode a DVB Transport Stream on stdin", so if the file created with

cat /dev/dvb/adapter0/dvr0 > test-cat3.mpeg

qualifies as a DVB Transport Stream, then there's a way to pipe it to zvbi-atsc-cc. How do we get the syntax for this?

Of course I can be wrong as I have exactly zero experiences of using zvbi tool, but I think command line option --ts should tell that data are not comming from dvr device but from stdin. Dunno why it not works for you. May be it needs some additional options?

/Honza