How to add audio inside or outside a loop?

[amaipaipai]

I'm trying to mimic my 20+ year test pattern tape that I've use to do electronic maintenance, my tapes are all busted, worth nothing anymore, so I'm willing to create new ones. This tapes has a loop of 10s B&W screen followed by 10s color bar with a stereo, non intermittent, background sound of a 440 Hz sine. With the help of Inkscape I was able to draw this iconic RCA Indian Test Pattern

I borrow the avisynth code from here to create my own.

x1=ImageSource("J:\monoscope.png")
x2=ImageSource("J:\cbar.png")
edit=x1.Trim(0,240).Grayscale() + x2.Trim(0,240)
return edit.loop()

I've tried to use the ColorBar function, it doesn't work in this script. The Tone also doesn't work inside or outside the loop.

Tone(frequency=440, samplerate=48000, channels=2, type="sine", level=0.5)

I thought I could import the script and latter add the tone, also without success.

Import("pattern.avs")
Tone(frequency=440, samplerate=48000, channels=2, type="sine", level=0.5)
Trim(0,43200).info()

Another thing I couldn't figure it out by my self is how to make this work like this professional pattern tapes I had, the B&W screen is true B&W or grayscale, it has no color information on it, is possible to confirm this with a oscilloscope. I've converted this to different file formats, created a DVD and I could not get rid of the color signal from this screen.

The Color Bars works great.


The monosco is another history, can't get rid of the chroma signal.


The original monosco test pattern test generates a signal like this that I use this to align the tape guides.


How to create a B&W video of this pattern?
I've looked in this forum, doom9 and other forums, there are tons of information about grayscale images, ffmpeg, but didn't find anything practical that really works.

Any suggestions?
Thanks.

[jagabo]

B&W: GreyScale(), Tweak(sat=0.0), or ColorYUV(cont_u=-256, cont_v=-256) -- the latter two require YUV.

Add audio:

video=Import("pattern.avs")
audio=Tone(frequency=440, samplerate=48000, channels=2, type="sine", level=0.5)
AudioDub(video, audio)
Trim(0,43200).info()

[amaipaipai]

B&W: GreyScale(), Tweak(sat=0.0), or ColorYUV(cont_u=-256, cont_v=-256) -- the latter two require YUV.

I'm using GreyScale(), you can check at my script, but still it has this info.

This was using tmpgenc.

ID                                       : 224 (0xE0)
Format                                   : MPEG Video
Format version                           : Version 2
Format profile                           : Main@High
Format settings                          : BVOP
Format settings, BVOP                    : Yes
Format settings, Matrix                  : Default
Format settings, GOP                     : M=3, N=18
Duration                                 : 30 min 0 s
Bit rate mode                            : Variable
Bit rate                                 : 2 337 kb/s
Maximum bit rate                         : 7 000 kb/s
Width                                    : 720 pixels
Height                                   : 480 pixels
Display aspect ratio                     : 4:3
Frame rate                               : 24.000 FPS
Standard                                 : Component
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Compression mode                         : Lossy
Bits/(Pixel*Frame)                       : 0.282
Time code of first frame                 : 00:00:00:00
Time code source                         : Group of pictures header
GOP, Open/Closed                         : Open
GOP, Open/Closed of first frame          : Closed
Stream size                              : 501 MiB (84%)
Writing library                          : TMPGEnc 2.521.58.169
Color primaries                          : BT.601 PAL
Transfer characteristics                 : BT.470 System B, BT.470 System G
Matrix coefficients                      : FCC 73.682

This ffmpeg (DVD Styler)

ID                                       : 224 (0xE0)
Format                                   : MPEG Video
Format version                           : Version 2
Format profile                           : Main@Main
Format settings, BVOP                    : No
Format settings, Matrix                  : Default
Duration                                 : 467 ms
Bit rate mode                            : Variable
Maximum bit rate                         : 9 000 kb/s
Width                                    : 720 pixels
Height                                   : 480 pixels
Display aspect ratio                     : 4:3
Frame rate                               : 29.970 (30000/1001) FPS
Standard                                 : NTSC
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Compression mode                         : Lossy

ffmpeg -i pattern.avs -vf format=gray -pix_fmt yuv420p output.mp4

ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L3
Format settings                          : CABAC / 4 Ref Frames
Format settings, CABAC                   : Yes
Format settings, RefFrames               : 4 frames
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 30 min 0 s
Bit rate                                 : 41.7 kb/s
Width                                    : 720 pixels
Height                                   : 480 pixels
Display aspect ratio                     : 3:2
Frame rate mode                          : Constant
Frame rate                               : 24.000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.005
Stream size                              : 8.96 MiB (24%)
Writing library                          : x264 core 146 r2538 121396c
Encoding settings                        : cabac=1 / ref=3 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=7 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=12 / lookahead_threads=2 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=24 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=crf / mbtree=1 / crf=23.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00

At the end, it will not be a true gray or B&W file.

[sneaker]

What is a "true gray or B&W file"? And why do you think you need one?

[amaipaipai]

About the late edition to Audio, the script makes the screen swap from 2 files (a monoscope and colorbar) used as video back and forth in loop, the AudioDub is useless in this case.

[jagabo]

At the end, it will not be a true gray or B&W file.

I'm not sure what you mean. All the functions I gave you reduce the chroma channels to flat 128, meaning there is no color. Are you looking to remove the chroma channels altogether? Use ConvertToY8(). What your encoder does with that is another issue.

[amaipaipai]

What is a "true gray or B&W file"? And why do you think you need one?

A true gray or B&W is a file without any color (chroma) information.

I need one to do mechanism alignment, is a necessary visual cue, like this:


A file with color information returns a different pattern on the oscilloscope, making it impossible to align the tape guides. In the past many manufactures sold this special tapes, VHS, DV, minDV, etc. Since we are talking about a old technology, they don't sell it anymore.

[amaipaipai]

At the end, it will not be a true gray or B&W file.

I'm not sure what you mean. All the functions I gave you reduce the chroma channels to flat 128, meaning there is no color. Are you looking to remove the chroma channels altogether? Use ConvertToY8().

Yes, I need a video without any chroma information, just luma. After that, I need it to stay like that, if I convert the file to DVD it converts to another color format.

What your encoder does with that is another issue.

Well, that is the main issue.

[jagabo]

I'm pretty sure DVD only supports YV12. But if the chroma channels are flat 128 you will get no color in the output.

[sneaker]

If you use Greyscale() and encode to e.g. x264 (4:2:0) there will technically be chroma planes but they will be completely 0. Since chroma and luma planes are encoded separately there is no kind of color information present. If you still "get"/measure color during playback it has nothing to do with the encoding but only your playback/measuring equipment.

[jagabo]

About the late edition to Audio, the script makes the screen swap from 2 files (a monoscope and colorbar) used as video back and forth in loop, the AudioDub is useless in this case.

Again, it's not clear what you're asking for. You want different audio for the two patterns? Then use two AudioDubs in the script that builds the pattern videos.

[amaipaipai]

Again, it's not clear what you're asking for. You want different audio for the two patterns? Then use two AudioDubs in the script that builds the pattern videos.

I need a test pattern that swap between 2 different screens 10s apart from each other with a default 440 Hz tone as a default audio, I've already done the script to swap the patterns. The script just fail to add the audio.

I'm attaching a sample video with the swapping patterns.

[sneaker]

x1=ImageSource("J:\monoscope.png")
x2=ImageSource("J:\cbar.png")
edit=x1.Trim(0,240).Grayscale() + x2.Trim(0,240)
loop = edit.loop()

audio=Tone(frequency=440, samplerate=48000, channels=2, type="sine", level=0.5)

AudioDub(loop, audio)

Not what you want?

(Of course you could just put the tone in a completely separate script, encode that to audio and mux with the H.264 video at the end. It's not mandatory to have them in a single script.)

[amaipaipai]

x1=ImageSource("J:\monoscope.png")
x2=ImageSource("J:\cbar.png")
edit=x1.Trim(0,240).Grayscale() + x2.Trim(0,240)
loop = edit.loop()

audio=Tone(frequency=440, samplerate=48000, channels=2, type="sine", level=0.5)

AudioDub(loop, audio)

Not what you want?

(Of course you could just put the tone in a completely separate script, encode that to audio and mux with the H.264 video at the end. It's not mandatory to have them in a single script.)

Yes, thats it.
With a few changes for a 30min loop.

x1=ImageSource("J:\monoscope.png")
x2=ImageSource("J:\cbar.png")
edit=x1.Trim(0,240).Grayscale() + x2.Trim(0,240)
loop = edit.loop()

audio=Tone(length=1800, frequency=440, samplerate=48000, channels=2, type="sine", level=0.5)

AudioDub(loop, audio)
Trim(0,43200)

It would be nice to create a DVD without YV12 and the B&W part to stay B&W.
How the industry creates this B&W movies?
On my equipment a B&W movie is B&W, do I need to encode this in a different standard?

Than you for fixing the script!

[sneaker]

Does this make a difference?

x1=ImageSource("J:\monoscope.png").ConvertToYV12().Grayscale()
x2=ImageSource("J:\cbar.png").ConvertToYV12()
edit=x1.Trim(0,240) + x2.Trim(0,240)
loop = edit.loop()

audio=Tone(length=1800, frequency=440, samplerate=48000, channels=2, type="sine", level=0.5)

AudioDub(loop, audio)
Trim(0,43200)

[amaipaipai]

This is the DVD I have, Elvis Presley Jailhouse Rock, the Japanese release is B&W
https://www.amazon.co.jp/監獄ロック-DVD-エルビス・プレスリー/dp/B00005I1PL/ref=sr_1_1?ie=UTF8&qid=151...=4988135516350

The US release is NTSC B&W.
https://www.amazon.com/Jailhouse-Rock-Deluxe-Elvis-Presley/dp/B000QUUD5G/ref=sr_1_1?ie...house+rock+dvd

Do I need to do something special to convert this to B&W instead of NTSC B&W?

[amaipaipai]

Does this make a difference?

x1=ImageSource("J:\monoscope.png").ConvertToYV12().Grayscale()
x2=ImageSource("J:\cbar.png").ConvertToYV12()
edit=x1.Trim(0,240) + x2.Trim(0,240)
loop = edit.loop()

audio=Tone(length=1800, frequency=440, samplerate=48000, channels=2, type="sine", level=0.5)

AudioDub(loop, audio)
Trim(0,43200)

Yes, it mess up the colors, I'm not a big fan of YV12.
YV12 (4:2:0)


I rather prefer YV24 or any other 4:4:4 like RGB for storage, this is YV24

[sneaker]

If your goal is DVD you have to use 4:2:0. No way around it. Even UltraHD Blu-Ray uses 4:2:0.

(And 4:2:0 doesn't mess up large, single-color areas, anyways.)

[amaipaipai]

If your goal is DVD you have to use 4:2:0. No way around it. Even UltraHD Blu-Ray uses 4:2:0.
(And 4:2:0 doesn't mess up large, single-color areas, anyways.)

Yes, for DVD looks like there is no way around it.

I'm attaching the monosco file, don't know what a person will do with it outside a maintenance bench but... Just in case some one need it, fell free to use it. The colorbar file is a copy from the colorbar function from avisynth.


Anyway, I can figure things up from now on, thank you both @sneaker and @jagabo for helping out.