Rip an old VHS using avconv and video4linux2

vhsrip.sh

#!/bin/bash

# expects filename as first arg

# Using jack highly recommended over alsa
# Make sure you set up real time priorities
pasuspender -- qjackctl &

echo Before pressing play, go into the jack GUI and \
  connect the source to the sink.

# I have a shitty K-world em28xx USB adapter
# This makes sure it complies

# sets the adapter to use the second channel,
# which is component video, 1st is S-Video
v4l2-ctl -i 1

# set to NTSC (or PAL if you want)
v4l2-ctl  -s ntsc

# force resolution
v4l2-ctl -v width=640,height=480,pixelformat=YUYV

avconv \
        -channel 1 \
        -f video4linux2 \
        -i /dev/video0 \
        -f jack \
        -i convertvid \
        -c:v libx264 \
        -pre:v superfast \
        -b:v 800000 \
        -r:v 25 \
        -threads:v 4 \
        -filter:v crop=636:432:4:0,yadif \
        -c:a libmp3lame \
        -b:a 256k \
        ${1}.mp4

# the cropping filter is optional, yadif is recommended.