Play deinterlaced video with sound from a video capture card with minimal lag, on GNU/Linux, saveable as raw video and audio in a Matroska container.

capplay

#!/bin/sh

# Copyright (c) 2014 Scott Zeid.
# Released under the X11 License <https://tldrlegal.com/license/x11-license>.

cap() {
 local video=$1
 local audio=$2
 ffmpeg \
  -f v4l2 -i "$video" \
  -f alsa -i "$audio" \
  -vcodec rawvideo -acodec copy \
  -vf kerndeint \
  -f matroska -
}

save() {
 local out=$1
 [ x"$out" != x"" ] && tee "$out" || cat
}

play() {
 local title=$1
 ffplay -window_title "$title" -
}

capplay() {
 if [ x"$1" = x"" ] || [ x"$1" = x"-h" ] || [ x"$1" = x"--help" ]; then
  echo "Usage: $0 <video-file> hw:<card>,<device> [title] [-o|--output output-file.mkv]"
  ([ x"$1" = x"-h" ] || [ x"$1" = x"--help" ]) && return 0 || return 2
  return 0
 fi
 
 local video=$1; shift
 local audio=$1; shift
 
 if [ x"$1" != x"-o" ] && [ x"$1" != x"--output" ]; then
  local title=$1; shift
 else
  local title=
 fi
 
 if [ x"$1" = x"-o" ] || [ x"$1" = x"--output" ]; then
  shift
  local out=$1; shift
 else
  local out=
 fi
 
 cap "$video" "$audio" | save "$out" | play "$title"
}

main() { capplay "$@"; }

main "$@"

otg102

#!/bin/sh

# Copyright (c) 2014 Scott Zeid.
# Released under the X11 License <https://tldrlegal.com/license/x11-license>.

first() { printf '%s' "$1"; }

TITLE="OTG102"
VIDEO=`first /dev/v4l/by-id/usb-Geniatech_Inc._Video_Capture_20090456-video-index*`
AUDIO=hw:`( pacmd list-sources; echo index: ) | awk 'BEGIN { want = 0; card = "" } /alsa.card / { card = $0 } /alsa.long_card_name.* cx231xx/ { want = 1 } /index:/ { if (want == 1) { print card; exit } }' | sed -e 's/[^"]*"\([^"]*\)".*/\1/g' -e 's/:/./g'`,0

main() {
 if [ x"$1" = x"-h" ] || [ x"$1" = x"--help" ]; then
  echo "Usage: $0 [title] [-o|--output output-file.mkv]"
  return 0
 fi
 
 if [ x"$1" != x"-o" ] && [ x"$1" != x"--output" ]; then
  local title=$1; shift
 else
  local title=
 fi
 title=${title:-$TITLE}
 
 if [ x"$1" = x"-o" ] || [ x"$1" = x"--output" ]; then
  shift
  local out=$1; shift
 else
  local out=
 fi
 
 if [ x"$out" = x"" ]; then
  capplay "$VIDEO" "$AUDIO" "$title"
 else
  capplay "$VIDEO" "$AUDIO" "$title" -o "$out"
 fi
}

main "$@"