[MPlayer-users] Re: recording from video tapes (a novice question)

Mon Aug 11 23:04:37 CEST 2003

On 11 Aug 2003  Erik Slagter <erik at oldconomy.com> wrote:

[...]

Many thanks for long and detailed answer.

> Keep in mind that your tv capturing card also has a mixer, which is
> accessible via the v4l interface, not via /dev/mixer etc. Xawtv is able
> to manipulate the settings, as the supplied command line util v4lctl.

I had a look at the man pages of v4lctl but don't see its relevance to
my problem.

> 
> Depending on the type of card you need to set up a loop from the tv
> capturing card to an input of your sound card (makes easy testing) or
> read your audio from the corresponding audio device.

This is the first case, as I wrote in my previous posting of 11 Aug
2003:

> My TV card is connected by a cable to Line input
> of the sound card.

On 11 Aug 2003  Erik Slagter <erik at oldconomy.com> wrote:

> To examplify:
> 
> If you have an bt848 card, you only have analogue audio output, so you
> need to connect the audio output to an input on your soundcard. Using
> xawtv you should be able to check if your setup is ok. On xawtv set the
> volume to max and make sure audio is not muted.

I've done this already, as I wrote on 10 Aug 2003:

> Please note I have no problem with sound when just watching TV with
> mplayer, zapping or xawtv.

On 11 Aug 2003  Erik Slagter <erik at oldconomy.com> wrote:

> 
> If your have a philips card, you will want to fetch the audio over the
> pci bus, because the card goes through great lengths to ensure the video
> and audio are deliverd synchronously. In that case also use xawtv to set
> the v4l volume settings, and locate the extra sound and mixer devices.
> Usually they are /dev/dsp1 and /dev/mixer1, but this may vary depending
> on your setup. Now use sox to copy the input from /dev/dsp1 using
> samplerate 32 Khz (!) to /dev/dsp and you should be able to hear the
> audio via the "pcm" output of your soundcard. If that works, you can try
> to record video and audio with e.g. mencoder, making sure that audio is
> grabbed from your "extra" sound device (/dev/dsp1).

My card has a Philips tuner but I guess this is not what you mean.
Moreover I don't use the btaudio driver which, if I understand
correctly, would provide the sound directly from the TV card.

I just noticed that a tvaudio driver is loaded, but I don't know what
is its function.

> Also check the options "forchechans" and "forceaudio", the are required
> on some v4l2 modules.

Do you mean the parameters which are listed by modinfo -p... ?

> If none of this works, try, while running xawtv, "cat -tv /dev/dsp" and
> "cat -tv /dev/dsp1", etc. This will tell you which audio devices are
> available and which actually deliver sound data.

I get some output only from 

        cat -tv /dev/dsp

However, I get it also without running xawtv. Does it explain
anything?

> 
> What capturing card do you have (or better: what chip is on it?)

I wrote already on 10 Aug 2003:

[...]

> I use an on-board sound card and my mainboard is ECS K7S5A. The
> capture card is AverTV Studio 203.

I enclose as attachment (I hope they are allowed on this list):

the output of v4l-info
the output of lsmod
the fragments of dmesg which seemed relevant to me

Best regards

Janusz

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Linux version 2.4.20-xfs (root at Knoppix) (gcc version 2.95.4 20011002 (Debian prerelease)) #1 SMP Mit M?r 26 15:37:36 CET 2003

[...]

Linux video capture interface: v1.00
i2c-core.o: i2c core module
i2c-algo-bit.o: i2c bit algorithm module
bttv: driver version 0.7.96 loaded
bttv: using 4 buffers with 2080k (8320k total) for capture
bttv: Host bridge is Silicon Integrated Systems [SiS] 735 Host
bttv: Bt8xx card found (0).
PCI: Found IRQ 5 for device 00:09.0
PCI: Sharing IRQ 5 with 00:09.1
bttv0: Bt878 (rev 17) at 00:09.0, irq: 5, latency: 64, mmio: 0xcddfe000
bttv0: detected: AVerMedia TVPhone98 [card=41], PCI subsystem ID is 1461:0003
bttv0: using: BT878(AVerMedia TVPhone 98) [card=41,autodetected]
i2c-core.o: adapter bt848 #0 registered as adapter 0.
bttv0: Avermedia eeprom[0x0a99]: tuner=5 radio:yes remote control:yes
bttv0: using tuner=5
bttv0: i2c: checking for MSP34xx @ 0x80... not found
bttv0: i2c: checking for TDA9875 @ 0xb0... found
i2c-core.o: driver i2c tda9875 driver registered.
tda9875: no such chip at 0xb0 (dic=0x11 rev=0x2)
bttv0: i2c: checking for TDA7432 @ 0x8a... not found
tvaudio: TV audio decoder + audio/video mux driver
tvaudio: known chips: tda9840,tda9873h,tda9874h/a,tda9850,tda9855,tea6300,tea6420,tda8425,pic16c54 (PV951)
i2c-core.o: driver generic i2c audio driver registered.
tvaudio: found tda9874h/a
bttv0: i2c attach [client=tda9874h/a,ok]
i2c-core.o: client [tda9874h/a] registered to adapter [bt848 #0](pos. 0).
i2c-core.o: driver i2c TV tuner driver registered.
tuner: probing bt848 #0 i2c adapter [id=0x10005]
tuner: chip found @ 0xc2
bttv0: i2c attach [client=Philips PAL_BG (FI1216 and compa,ok]
i2c-core.o: client [Philips PAL_BG (FI1216 and compa] registered to adapter [bt848 #0](pos. 1).
bttv0: registered device video0
bttv0: registered device vbi0
bttv0: registered device radio0
8139too Fast Ethernet driver 0.9.26
PCI: Found IRQ 11 for device 00:11.0
eth0: RealTek RTL8139 Fast Ethernet at 0xd2890f00, 00:0a:cd:00:cc:d5, IRQ 11
eth0:  Identified 8139 chip type 'RTL-8139C'
Intel 810 + AC97 Audio, version 0.21, 15:49:30 Mar 26 2003
PCI: Found IRQ 11 for device 00:02.7
i810: SiS 7012 found at IO 0xd800 and 0xdc00, IRQ 11
i810_audio: Audio Controller supports 2 channels.
ac97_codec: AC97 Audio codec, id: ALC38(Unknown)
i810_audio: only 48Khz playback available.
i810_audio: AC'97 codec 0 supports AMAP, total channels = 2

[...]

bttv0: PLL: 28636363 => 35468950 ... ok
tuner: TV freq (0.-6) out of range (44-958)
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-- 
                     ,   
dr hab. Janusz S. Bien, prof. UW
Prof. Janusz S. Bien, Warsaw Uniwersity
jsbien at mimuw.edu.pl, jsbien at uw.edu.pl
http://www.orient.uw.edu.pl/~jsbien/
http://www.mimuw.edu.pl/~jsbien/