Encode-Stream

A BASH Script to Encode VHS / Camera / Cassette Streams to MP4 / MP3 / M4A Files

Basics

This script file is designed for use by any-user (no root access required) within a Terminal. It’s principal purpose is to make it easy & reliable to encode a stream from a VHS, Camera or Cassette player to disk. It has been used extensively by myself to transfer all my VHS tapes as MP4 (using a EasyCAP UTV007 USB converter - example below) & cassettes as MP3 (using a USB-powered cassette player) to disc under Devuan (a systemD-free version of Debian). In addition to BASH, the main utility required is FFMPEG. Note that zero efforts are made to test for the presence of FFMPEG before use.

Begin

The following will assume that you have created a dir ~/.local/sbin within which you store the bash-file; this is to set the script as executable for current user only:

$ chmod 0700 ~/.local/sbin/encode_stream
$ la ~/.local/sbin/add_chapters
-rwx------ 1 user user 5846 Dec 21  2021 /home/user/.local/sbin/encode_stream

Help

Attempting to run the bare script with zero parameters shows a Help message:

$ ~/.local/sbin/encode_stream
!Fatal Error! No OUTPUT_NAME in command.

usage: /home/user/.local/sbin/encode_stream OUTPUT_NAME [AUDIO_DEVICE] [VIDEO_DEVICE] [REGION] [PIX_FMT]

Encodes input from a VHS / Camera / Cassette stream to a mp4 video.

   OUTPUT_NAME     filename of mp4 video       (DEFAULT; no need for mp4 suffix                   )
               or, filename of m4a sound file  (needs m4a suffix                                  )
               or, filename of mp3 sound file  (needs mp3 suffix                                  )
   VIDEO_DEVICE    eg '/dev/video0' (try "v4l2-ctl --all"                                         )
   AUDIO_DEVICE    eg 'hw:2,0'      (try "arecord -l" or "arecord -L" or "cat /proc/asound/cards" )
   REGION          eg 'PAL'         (qv4l2 tool (QT v4l2 test utility) will help test for Region  )
   PIX_FMT         eg 'yuv420p'     (v4l2 default is yuyv422; will prevent display on some devices)

Note:
  Only use "q" to quit from the running process in the terminal

Overview

Use the QT V4L2 test Utility (available from menu:Multimedia | QT V4L2 test Utility) whilst a stream is in action. The idea is that if you can see/hear the stream in that window, then encode_stream will also work fine. The only items that you need to know (or to change in the window) are VIDEO_DEVICE, AUDIO_DEVICE + REGION. For myself, the default in the qv4l2 window was NTSC, whilst the video I was playing was encoded under PAL. The window was black & silent until I changed the Region to PAL & then it played fine, as did the script.

The following will help discover the audio device
(below is output from a problematic MacroSilicon MS210x Capture device; the device is card 2, device 0, which means that the hardware is 'hw:2,0'):–

$ arecord -l
**** List of CAPTURE Hardware Devices ****
card 1: Generic [HD-Audio Generic], device 0: ALC887-VD Analog [ALC887-VD Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: Generic [HD-Audio Generic], device 2: ALC887-VD Alt Analog [ALC887-VD Alt Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: MS210x [MS210x], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

Software

You may need to install ffmpeg.
You may need to install Video for Linux (v4l-utils + qv4l2 as a minimum):–

$ apt search v4l
Sorting... Done
Full Text Search... Done
…
dov4l/stable,now 0.9+repack-1+b1 amd64 [installed]
  program to set and query settings of video4linux devices

dv4l/stable,now 1.0-5+b2 amd64 [installed]
  Redirect V4L API to access a camcorder from a V4L program

libv4l-0/stable,now 1.22.1-5+b2 amd64 [installed,automatic]
  Collection of video4linux support libraries

libv4l2rds0/stable,now 1.22.1-5+b2 amd64 [installed,automatic]
  Video4Linux Radio Data System (RDS) decoding library

libv4lconvert0/stable,now 1.22.1-5+b2 amd64 [installed,automatic]
  Video4linux frame format conversion library

qv4l2/stable,now 1.22.1-5+b2 amd64 [installed]
  Test bench application for video4linux devices

v4l-conf/stable,now 3.107-1.1 amd64 [installed]
  tool to configure video4linux drivers

v4l-utils/stable,now 1.22.1-5+b2 amd64 [installed]
  Collection of command line video4linux utilities

Hardware

This may be the hardest part.
I chose EasyCAP UTV007 because others had reported that it was recognised by Linux & did the job (which it did). If you have any problems at this stage I cannot help, but can report on what happens in the background.

Plugging your USB2 capture device into your desktop computer should auto-create video + audio devices via the interaction of V4L with the kernel:–

$ ls -l /dev/video*
crw-rw----+ 1 root video 81, 0 Sep 12 08:34 /dev/video0
crw-rw----+ 1 root video 81, 1 Sep 12 08:34 /dev/video1

With a VHS player the stream outputs through video0 whilst video1 is null. Normally a non-root user gets a video group-id added to their user and that will give permission to receive the stream. id can check for this:–

$ id
uid=1000(alexk) gid=1000(alexk) groups=1000(alexk),24(cdrom),25(floppy),27(sudo),29(audio),30(dip),
44(video),46(plugdev),102(netdev),109(lpadmin),111(scanner)

If things are going south fast, or you simply are curious, make use of V4L
(what follows is output from a problematic MacroSilicon MS210x Capture device; sorry for the length)

What follows gives us the following information:

Type	Value
Model	AV TO USB2.0
Width x Height	640 x 480
fps	30.000 (30/1)

At this moment (15 Sep 2023) the stream-encode script works fine with 25fps PAL input. ffmpeg should be able to take NTSC imput at 30fps & render it OK. I would like to work with someone to check the script for NTSC. However, the user is currently unable to produce a viable stream within qv4l2, so that is not possible.

Launch the following within a terminal to obtain the info as above:–

$ v4l2-ctl --all
Driver Info:
	Driver name      : uvcvideo
	Card type        : AV TO USB2.0
	Bus info         : usb-0000:01:00.0-6
	Driver version   : 6.5.2
	Capabilities     : 0x84a00001
		Video Capture
		Metadata Capture
		Streaming
		Extended Pix Format
		Device Capabilities
	Device Caps      : 0x04200001
		Video Capture
		Streaming
		Extended Pix Format
Media Driver Info:
	Driver name      : uvcvideo
	Model            : AV TO USB2.0
	Serial           : 20150130
	Bus info         : usb-0000:01:00.0-6
	Media version    : 6.5.2
	Hardware revision: 0x00000121 (289)
	Driver version   : 6.5.2
Interface Info:
	ID               : 0x03000002
	Type             : V4L Video
Entity Info:
	ID               : 0x00000001 (1)
	Name             : AV TO USB2.0
	Function         : V4L2 I/O
	Flags            : default
	Pad 0x01000007   : 0: Sink
	  Link 0x0200000d: from remote pad 0x100000a of entity 'Processing 2' (Video Pixel Formatter): Data, Enabled, Immutable
Priority: 2
Video input : 0 (Camera 1: ok)
Format Video Capture:
	Width/Height      : 640/480
	Pixel Format      : 'MJPG' (Motion-JPEG)
	Field             : None
	Bytes per Line    : 0
	Size Image        : 614400
	Colorspace        : sRGB
	Transfer Function : Rec. 709
	YCbCr/HSV Encoding: ITU-R 601
	Quantization      : Default (maps to Full Range)
	Flags             : 
Crop Capability Video Capture:
	Bounds      : Left 0, Top 0, Width 640, Height 480
	Default     : Left 0, Top 0, Width 640, Height 480
	Pixel Aspect: 1/1
Selection Video Capture: crop_default, Left 0, Top 0, Width 640, Height 480, Flags: 
Selection Video Capture: crop_bounds, Left 0, Top 0, Width 640, Height 480, Flags: 
Streaming Parameters Video Capture:
	Capabilities     : timeperframe
	Frames per second: 30.000 (30/1)
	Read buffers     : 0