[mythtv-users] VIDIOCMCAPTURE0: Device or resource busy

[David Madsen]

On Tue, Sep 2, 2008 at 9:52 AM, David Madsen <david.madsen at gmail.com> wrote:
>> I have a bttv card and experienced the problem with kernel 2.6.25 and
>> 2.6.26 which stopped me using them with MythTV.  Because of this I
>> switched back to 2.6.24 which was fine.  When this patch came out I
>> tried it and at first it seemed to work; I could upgrade to kernel
>> 2.6.26 and record with MythTV.
>>
>> After a while though I realised that the recordings were poor quality.
>> During playback there were frames displayed at the wrong time, these
>> are most easily seen when editing a recording.  For example I saw that
>> one interlaced field in a frame should actually have been about 7
>> frames earlier (estimating from a fast moving picture).  This occurs
>> every second or so (it isn't regular) and only causes a visual
>> disturbance with fast moving scenes.  The problem was definitely in
>> the recorded data, not playback.
>>
>> Since switching back to kernel 2.6.24 and backing out the patch
>> everything seems to be back to normal.
>
> Interesting.  I haven't noticed anything like that and have made more
> than a few recordings with the bttv card since upgrading to 2.6.26.
> What encoding options are you using for the bttv recordings?  I admit
> I haven't taken a close look at any of the recordings, but I haven't
> noticed any glitches in typical playback.  Long ago I do remember
> turning some of the more CPU demanding options on in the mpeg4
> recording profile when I initially set up the card, so its possible
> that may affect this.  I'll take a closer look at some of my
> recordings and see if there is anything similar.

I took a closer look at a few of a few of my most recent recording
from the bttv tuner and didn't see anything similar to what you
mentioned.  Do you see these misplaced frames regularly?  I
singlestepped frames through about 1 minute blocks in several
different places throughout the recordings and didn't find anything
like what you described.

My recording profile details:
Mpeg4
Resolution: 640x480
Bitrate: 3300
Max quality: 2
Min quality: 15
Quality diff between frames: 3
+Scale bitrate to frame size
+Enable high quality encoding
+Enable 4MV encoding
-Enable interlaced DCT encoding
-Enable interlaced motion estimation
Num threads: 1

As far as the tuner itself:


05:00.0 Multimedia video controller [0400]: Brooktree Corporation
Bt878 Video Capture [109e:036e] (rev 02)
05:00.1 Multimedia controller [0480]: Brooktree Corporation Bt878
Audio Capture [109e:0878] (rev 02)



bttv: driver version 0.9.17 loaded
bttv: using 8 buffers with 2080k (520 pages) each for capture
bttv: Bt8xx card found (0).
ACPI: PCI Interrupt 0000:05:00.0[A] -> GSI 20 (level, low) -> IRQ 20
bttv0: Bt878 (rev 2) at 0000:05:00.0, irq: 20, latency: 32, mmio: 0xf2100000
bttv0: detected: Hauppauge WinTV [card=10], PCI subsystem ID is 0070:13eb
bttv0: using: Hauppauge (bt878) [card=10,autodetected]
bttv0: gpio: en=00000000, out=00000000 in=0002001b [init]
bttv0: Hauppauge/Voodoo msp34xx: reset line init [5]
tveeprom 1-0050: Hauppauge model 37381, rev B123, serial# 205xxxx
tveeprom 1-0050: tuner model is Philips FM1236 (idx 23, type 2)
tveeprom 1-0050: TV standards NTSC(M) (eeprom 0x08)
tveeprom 1-0050: audio processor is MSP3430 (idx 7)
tveeprom 1-0050: has radio
bttv0: Hauppauge eeprom indicates model#37381
bttv0: tuner type=2
bttv0: i2c: checking for MSP34xx @ 0x80... found
msp3400' 1-0040: MSP3430G-A1 found @ 0x80 (bt878 #0 [sw])
msp3400' 1-0040: msp3400 supports radio, mode is autodetect and autoselect
bttv0: i2c: checking for TDA9875 @ 0xb0... not found
bttv0: i2c: checking for TDA7432 @ 0x8a... not found
tuner' 1-0042: chip found @ 0x84 (bt878 #0 [sw])
tda9887 1-0042: creating new instance
tda9887 1-0042: tda988[5/6/7] found
tuner' 1-0061: chip found @ 0xc2 (bt878 #0 [sw])
tuner-simple 1-0061: creating new instance
tuner-simple 1-0061: type set to 2 (Philips NTSC (FI1236,FM1236 and
compatibles))
bttv0: registered device video0
bttv0: registered device vbi0
bttv0: registered device radio0
bttv0: PLL: 28636363 => 35468950 .. ok

--David Madsen