2012-02 Digitise Video tapes

I've had a few goes at this. always a bit half-hearted but I'd like to get rid of the tapes lying around and I have a gruntier system then when I last tried so I'll give it another shot.

# ***** Done: *****
# size is good.
# deinterlace is acceptable.
# cropping - could be better.
# Selects the correct video input (instead of the TV tuner) Check the size and rate settings.
# output to file. - works without fram dropping on video only - test with audio.
# audio capture. - need to set the capture channel via alsalmixer.
# sync to keep sound in sync - no noticable drift in 10 min tests
# A format better: 10min = 270meg. Try audio compression too ? Great - tiny now.
# Cropping top and bottom looks a bit out too. - Better, good enough for now.
# ***** Needs: *****
# nothing really - some good long tests.
# find out why the grab is sometimes textured and a restart fixes it.
mencoder -tv driver=v4l2:input=3:alsa:adevice=default:width=768:height=576 -vf pp=lb,crop=768:560 tv:// -oac mp3lame -lameopts preset=medium -ovc x264 -x264encopts pass=1 qp=40 -o deathrace2000.avi

# Result:
# Works very well indeed with 927M for a full length video that looks as good as the original and can be viewed close to real time with mplayer so you can record as you watch.
# Outstanding issue:
# find out why the grab is sometimes oddly textured and a restart fixes it.
# Workaround:
# Check recording with mplayer after a few seconds. Restart if not right.

mencoder -tv driver=v4l2:input=3:alsa:adevice=default:width=768:height=576 -vf pp=lb,crop=768:560 tv:// -oac mp3lame -lameopts preset=medium -ovc x264 -x264encopts pass=1 qp=40 -o deathrace2000.avi

# Trim and crop:
# ***** Needs: *****
# Needs to be sped up
# Needs to preseve quality.
# ***** Done: *****
# Start time: -ss hh:mm:ss.xx
# End time: - t seconds or hh:mm:ss.xx
# Crop: -vf crop=width:height:x:y
# the -vcodec copy overrides any -vf - fix quality: Use another codec.

ffmpeg -i deathrace2000.avi -ss 00:00:50.00 -t 20 -vcodec libx264 -vf "crop=656:560:54:0" dr2000-02.avi

That's all a bit sucky: Just trim instead and use the player to crop if needed. So I can just go:

ffmpeg -i deathrace2000.avi -ss 00:00:50.00 -t 20 -vcodec copy dr2000-02.avi

Which is blindingly fast and preserves quality.

2012-01 Low Noise Phono System

I've always had a little hum on the record player. So low though that even quiet music obscures it.
However it is there and I recently got a copy of Tibetan Bells. TB is very quiet indeed, with long passages where a single bell note fades completely before the next is struck.

[1] Check the amp.
[2] Check the cables.
[3] Check the record player.

Amp:
Found the Tuner input on the amp, which I had been using had some hum. Checked them all: The Tape input is quietest by far.

Cables:
OK.

Record player:
Both check out fine.



OK, the pre-amp in the amp is noisy so I got a general preamp kit from jcar (http://www.jaycar.co.nz/productView.asp?ID=KC5159) to try. Cheap enough to discard if not good enough.
It sounds great. Housed it in an old power supply case and it goes directly to a spare input on the PC sound card.
I can easily hear the original tape noise kick in as the cutting engineer switches it in when mastering the LP on Tibetan Bells so the total noise in the system here is less then in the original studio (1970's analog) and there's no discernible hum at all. An added advantage here is there is no need to use any mechanical switches any more. I just use alsa mixer to directly control the sound-card input level and switch between inputs on the sound card.

Here's a photo of the finished pre-amp disguised as a pedestal.

2010-10 IR Menus system

The OSD tools I'd used for the IR control menu have bit rotted, are too slow and not good looking.
Get a simple, fast image based menu going. Theme-ability is a bonus.

2008-06 PC Infra-red Remote

After last months project burn-out I wanted a simple P.T.O.M. this time. I've started using the TV card on the PC and watching vcds etc on my PC. The TV card(s) both came with remotes and in these cold winter nights lying on the sofa these could be useful.
So how hard can it be? and the IR can control all sorts eh? oxine looked great for example so that was it. Get IR control going in the POTM.

LIRC seems to be the main project here. It looks like it supports both of the TV cards I have, One SAA7134 based and one BT878 based.

It goes: A Real Quick Run-down for fedora 9.

• Set up the remote: Install the IR drivers and lirc. Use irrecord to create a config file for your remote control and copy it to /etc/lircd.conf.
  
• Get lircd running. Configure /etc/sysconfig/lirc to use the right driver for you and then lircd to start on system boot like any daemon. (use the /dev/input/by-path device if you use devinput as the device driver. Don't use /dev/input/eventX as X can change on reboot)
  
• edit (and create if necessary) ~/.lircrc. Check the application you want to control for details on lirc commands and match the commands to the keys in ~/.lircrc
  
• use irexec if needed. It will trigger things if the app you wan't to control isn't looking at lircd for events itself. For example; tvtime needs irexec but gnome-radio does not. I use gnomes session management to run this.

OK What happened in detail:
First it had to track down the parts; The remote controls and the IR sensors. Found the remotes. Now check that they remotes both work aftre years in storage.
I recall a note in Silcon Chips serviceman pages saying you can check IR by looking for the IR led in a CCD device.

IE by looking at them with a web cam or digital camera and that works: Off and On.
Both remotes are good and so are their batteries.
Kinda ghostly seeing one thing in the view finder and another with your eyes.

Now find the IR sensors. Both found (yeah for my pack-rat self) and the different plugs mean it's clear that which sensor is for which card.

OK plug in the sensor and let's try to get IR control going on the existing card in my desktop PC.

Nothing. OK, check the module options for the card; I was never that sure they were right even thought the seemed to work OK with BT878 card. Check the PCI ID and find it could be one of three so try them all:

options bttv card=30 #Seems OK. No IR. The value I have been using.
options bttv card=39 #Video OK. No sound, no IR, snd_BT87x won't help with sound.
options bttv card=52 #Video OK. No sound, no IR, snd_BT87x won't help with sound.

OK that's not getting me anywhere, lets try the SAA7134 card from gnabgib. I think that was more upmarket and I've bumped into reassuring references to them while checking the LIRC docs.

Fire up gnabgib which is the machine that the card had last been used in (mothballed right now) and check the existing config (from memory it worked OK, never tried the IR though, only really used the FM card for the Concert and National stations):

relevant Modules loaded on gnabgib:
saa7134 110741 0
video_buf 23365 1 saa7134
v4l2_common 5825 1 saa7134
v4l1_compat 13125 1 saa7134
i2c_core 21825 2 tuner,saa7134
ir_common 7493 1 saa7134
videodev 9537 1 saa7134
soundcore 10529 2 saa7134,snd

relevant modprobe.conf line from gnabgib:
alias char-major-81 saa7134

Log from gnabgib of saa7134 loading:
kernel: saa7130/34: v4l2 driver version 0.2.12 loaded
kernel: saa7134[0]: quirk: PCIPCI_TRITON
kernel: saa7134[0]: found at 0000:00:04.0, rev: 1, irq: 11, latency: 66, mmio: 0x41080000
kernel: saa7134[0]: subsystem: 5168:0138, board: LifeView FlyVIDEO3000 [card=2,autodetected]
kernel: saa7134[0]: board init: gpio is 39000
kernel: saa7134[0]: there are different flyvideo cards with different tuners
kernel: saa7134[0]: out there, you might have to use the tuner= insmod
kernel: saa7134[0]: option to override the default value.
kernel: saa7134[0]: registered input device for IR
kernel: saa7134[0]: i2c eeprom 00: 68 51 38 01 10 28 ff ff ff ff ff ff ff ff ff ff
kernel: tuner 0-0061: chip found @ 0xc2 (saa7134[0])
kernel: tuner 0-0061: type set to 5 (Philips PAL_BG (FI1216 and compatibles))
kernel: saa7134[0]: registered device video0 [v4l2]
kernel: saa7134[0]: registered device vbi0
kernel: saa7134[0]: registered device radio0
kernel: saa7134[0]/audio: audio carrier scan failed, using 5.500 MHz [default]

OK, pull the card out.

Card label info:
DSE PCI TV Tuner Card XH6765

Well, that just worked. No config nothing: I thought I'd just try the remote to see and the volume and channel numbers worked on both remotes.

(Later I understood that this is becase lirc creates a fake keyboard that sends keystrokes matching keycodes of a real keyboard so numbers, enter key and volume all worked as though the keystroke came from the keyboard. I think the vol worked becase it emulates those odd-arsed mutlimedia keys )

Events are commint in on /dev/input/event7 so I'll look at irc now and see if I
can get things going more generally.

After reboot it was event6. Then on the next reboot event7 again . Himmm...

OK: Created a profile for the remote with irrecord - painless - and moved it to
/etc/lircd so that the keys are recognised and have names that mean something.

Set up /etc/sysconf/lirc.conf to tell it to use event7.

Got stuck then. Created a test ~/.lircrc for tvtime but nothing.
read read read...
OK tvtime is not a client itself. Run irexec as a daemon which connects to lirc as a client and then ~/.lircrc will be used by it and any revient lines executed.
NOTE it seems that as soon as a vaild client connects the fake keystrokes are no
longer available.

Beaut mate.

2008-02 Digitize VHS cassettes.

I have a lot of old SciFi films I'd like to get onto my media server and then a friend had some old tapes he wanted converted too so that made it a good project of the month.