[FFmpeg-user] Video filtering for chroma dot crawl and rainbow effect

[Christian Johannesen]

Looked through all the documentation for FFMPEG and I can't seem to find
any video filters that deal with chroma dot crawl & rainbow artifacts in
files captured from analog tape formats. I have a feeling that I am going
to need to immerse myself in AVISynth, but if anyone has any leads I would
appreciate any info.

Thanks,
Chris

[Paul B Mahol]

Post by Christian Johannesen
Looked through all the documentation for FFMPEG and I can't seem to find
any video filters that deal with chroma dot crawl & rainbow artifacts in
files captured from analog tape formats. I have a feeling that I am going
to need to immerse myself in AVISynth, but if anyone has any leads I would
appreciate any info.

Could you provide short samples that exibit such artifacts?

Post by Christian Johannesen
Thanks,
Chris
_______________________________________________
ffmpeg-user mailing list
http://ffmpeg.org/mailman/listinfo/ffmpeg-user

[Christian Johannesen]

Post by Paul B Mahol

Post by Christian Johannesen
Looked through all the documentation for FFMPEG and I can't seem to find
any video filters that deal with chroma dot crawl & rainbow artifacts in
files captured from analog tape formats. I have a feeling that I am going
to need to immerse myself in AVISynth, but if anyone has any leads I

would

Post by Christian Johannesen
appreciate any info.

Could you provide short samples that exibit such artifacts?

Post by Christian Johannesen
Thanks,
Chris

Sure, I uploaded two short samples to upload.ffmpeg.org
as test_720x486i_dotcrawl.mov & test_720x486i_dotcrawl2.mov

[Carl Eugen Hoyos]

Post by Christian Johannesen
Looked through all the documentation for FFMPEG and I can't
seem to find any video filters that deal with chroma dot
crawl & rainbow artifacts in files captured from analog
tape formats.

One of the reasons we always ask for command line including
complete, uncut console output is that it often helps
understanding the original issue.

I am not convinced I understand your issue but maybe you
are searching for the interl option of the scale filter?
$ ffmpeg -i test_720x486i_dotcrawl.mov -vf scale=interl=1,fieldmatch

I opened ticket #5187 because of the green lines fieldmatch
produces.

Carl Eugen

[Christian Johannesen]

Post by Carl Eugen Hoyos

Post by Christian Johannesen
Looked through all the documentation for FFMPEG and I can't
seem to find any video filters that deal with chroma dot
crawl & rainbow artifacts in files captured from analog
tape formats.

One of the reasons we always ask for command line including
complete, uncut console output is that it often helps
understanding the original issue.
I am not convinced I understand your issue but maybe you
are searching for the interl option of the scale filter?
$ ffmpeg -i test_720x486i_dotcrawl.mov -vf scale=interl=1,fieldmatch
I opened ticket #5187 because of the green lines fieldmatch
produces.
Carl Eugen
My goal was to remove some of the video artifacts before compressing to

x264. Sort of like this
http://home.earthlink.net/~tacosalad/video/dotcrawl.html

I think I named my files more generally when I uploaded them.
test_720x486i_dotcrawl.mov shows more of the rainbow effect in some of the
detail areas than the dot crawl. I tested processing that clip to 23.98 in
this command line example.

ffmpeg.exe -r 30000/1001 -i D:\media\test_720x486i_dotcrawl.mov
-filter_complex
[0:0]crop=704:480:8:6,pullup,dejudder,idet,yadif=mode=1:deint=interlaced,atadenoise,scale=640x480,setsar=sar=1/1,setfield=prog[v_0];[0:1][0:2]amerge=inputs=2[amerge_0_0];"[amerge_0_0]pan=2c|c0=c0|c1=c1[pan_0_0]"
-map "[v_0]" -map "[pan_0_0]" -r 24000/1001 -c:v libx264 -crf 19 -r
24000/1001 -c:a aac -movflags +faststart -shortest
D:\media\test_640x480.mp4
ffmpeg version N-77547-g2893dbf Copyright (c) 2000-2015 the FFmpeg
developers
built with gcc 5.2.0 (GCC)
configuration: --enable-gpl --enable-nonfree --enable-libx264
--enable-libx265 --enable-libfdk_aac --enable-static --disable-shared
--enable-libfreetype --enable-libfontconfig
libavutil 55. 11.100 / 55. 11.100
libavcodec 57. 20.100 / 57. 20.100
libavformat 57. 21.100 / 57. 21.100
libavdevice 57. 0.100 / 57. 0.100
libavfilter 6. 22.100 / 6. 22.100
libswscale 4. 0.100 / 4. 0.100
libswresample 2. 0.101 / 2. 0.101
libpostproc 54. 0.100 / 54. 0.100
Guessed Channel Layout for Input Stream #0.1 : mono
Guessed Channel Layout for Input Stream #0.2 : mono
Guessed Channel Layout for Input Stream #0.3 : mono
Guessed Channel Layout for Input Stream #0.4 : mono
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from
'D:\media\test_720x486i_dotcrawl.mov':
Metadata:
major_brand : qt
minor_version : 537199360
compatible_brands: qt
creation_time : 2016-01-22 21:27:58
com.apple.quicktime.player.movie.audio.gain: 1.000000
com.apple.quicktime.player.movie.audio.treble: 0.000000
com.apple.quicktime.player.movie.audio.bass: 0.000000
com.apple.quicktime.player.movie.audio.balance: 0.000000
com.apple.quicktime.player.movie.audio.pitchshift: 0.000000
com.apple.quicktime.player.movie.audio.mute:
com.apple.quicktime.player.movie.visual.brightness: 0.000000
com.apple.quicktime.player.movie.visual.color: 1.000000
com.apple.quicktime.player.movie.visual.tint: 0.000000
com.apple.quicktime.player.movie.visual.contrast: 1.000000
com.apple.quicktime.player.version: 7.6.6 (7.6.6)
com.apple.quicktime.version: 7.7.3 (2943) 0x7738000 (Mac OS X, 10.11.3,
15D21)
Duration: 00:00:19.35, start: 0.000000, bitrate: 33131 kb/s
Stream #0:0(und): Video: prores (apcs / 0x73637061),
yuv422p10le(bt470bg/smpte240m/bt709), 720x486, 28517 kb/s, SAR 10:11 DAR
400:297, 29.97 fps, 29.97 tbr, 30k tbn, 30k tbc (default)
Metadata:
creation_time : 2016-01-22 21:27:58
handler_name : Apple Alias Data Handler
encoder : ProRes 422 (LT)
timecode : 00:59:20;00
Stream #0:1(und): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, 1
channels, s32 (24 bit), 1152 kb/s (default)
Metadata:
creation_time : 2016-01-22 21:27:58
handler_name : Apple Alias Data Handler
Stream #0:2(und): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, 1
channels, s32 (24 bit), 1152 kb/s (default)
Metadata:
creation_time : 2016-01-22 21:27:58
handler_name : Apple Alias Data Handler
Stream #0:3(und): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, 1
channels, s32 (24 bit), 1152 kb/s (default)
Metadata:
creation_time : 2016-01-22 21:27:58
handler_name : Apple Alias Data Handler
Stream #0:4(und): Audio: pcm_s24le (in24 / 0x34326E69), 48000 Hz, 1
channels, s32 (24 bit), 1152 kb/s (default)
Metadata:
creation_time : 2016-01-22 21:27:58
handler_name : Apple Alias Data Handler
Stream #0:5(und): Data: none (tmcd / 0x64636D74) (default)
Metadata:
creation_time : 2016-01-22 21:27:58
handler_name : Apple Alias Data Handler
timecode : 00:59:20;00
[Parsed_idet_3 @ 00000051505b2e80] Repeated Fields: Neither: 0 Top:
0 Bottom: 0
[Parsed_idet_3 @ 00000051505b2e80] Single frame detection: TFF: 0 BFF:
0 Progressive: 0 Undetermined: 0
[Parsed_idet_3 @ 00000051505b2e80] Multi frame detection: TFF: 0 BFF:
0 Progressive: 0 Undetermined: 0
[Parsed_amerge_9 @ 00000051505ca3e0] No channel layout for input 1
[Parsed_amerge_9 @ 00000051505ca3e0] Input channel layouts overlap: output
layout will be determined by the number of distinct input channels
[Parsed_pan_10 @ 00000051505ca0e0] Pure channel mapping detected: 0 1
No pixel format specified, yuv422p for H.264 encoding chosen.
Use -pix_fmt yuv420p for compatibility with outdated media players.
[libx264 @ 00000051505bef60] using SAR=1/1
[libx264 @ 00000051505bef60] using cpu capabilities: MMX2 SSE2Fast SSSE3
SSE4.2 AVX
[libx264 @ 00000051505bef60] profile High 4:2:2, level 3.0, 4:2:2 8-bit
[libx264 @ 00000051505bef60] 264 - core 148 - H.264/MPEG-4 AVC codec -
Copyleft 2003-2015 - http://www.videolan.org/x264.html - options: 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=15 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=23 scenecut=40
intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=19.0 qcomp=0.60 qpmin=0
qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to 'D:\media\test_640x480.mp4':
Metadata:
major_brand : qt
minor_version : 537199360
compatible_brands: qt
com.apple.quicktime.version: 7.7.3 (2943) 0x7738000 (Mac OS X, 10.11.3,
15D21)
com.apple.quicktime.player.movie.audio.gain: 1.000000
com.apple.quicktime.player.movie.audio.treble: 0.000000
com.apple.quicktime.player.movie.audio.bass: 0.000000
com.apple.quicktime.player.movie.audio.balance: 0.000000
com.apple.quicktime.player.movie.audio.pitchshift: 0.000000
com.apple.quicktime.player.movie.audio.mute:
com.apple.quicktime.player.movie.visual.brightness: 0.000000
com.apple.quicktime.player.movie.visual.color: 1.000000
com.apple.quicktime.player.movie.visual.tint: 0.000000
com.apple.quicktime.player.movie.visual.contrast: 1.000000
com.apple.quicktime.player.version: 7.6.6 (7.6.6)
encoder : Lavf57.21.100
Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv422p,
640x480 [SAR 1:1 DAR 4:3], q=-1--1, 23.98 fps, 24k tbn, 23.98 tbc (default)
Metadata:
encoder : Lavc57.20.100 libx264
Side data:
unknown side data type 10 (24 bytes)
Stream #0:1: Audio: aac ([64][0][0][0] / 0x0040), 48000 Hz, stereo,
fltp, 128 kb/s (default)
Metadata:
encoder : Lavc57.20.100 aac
Stream mapping:
Stream #0:0 (prores) -> crop
Stream #0:1 (pcm_s24le) -> amerge:in0
Stream #0:2 (pcm_s24le) -> amerge:in1
setfield -> Stream #0:0 (libx264)
pan -> Stream #0:1 (aac)
Press [q] to stop, [?] for help
[mp4 @ 00000051505b47c0] Starting second pass: moving the moov atom to the
beginning of the filespeed=1.84x
frame= 464 fps= 43 q=-1.0 Lsize= 8515kB time=00:00:19.37
bitrate=3601.1kbits/s dup=1 drop=46 speed=1.79x
video:8195kB audio:306kB subtitle:0kB other streams:0kB global headers:0kB
muxing overhead: 0.164892%
[Parsed_idet_3 @ 00000051505ca9e0] Repeated Fields: Neither: 481 Top:
0 Bottom: 0
[Parsed_idet_3 @ 00000051505ca9e0] Single frame detection: TFF: 20 BFF:
14 Progressive: 72 Undetermined: 375
[Parsed_idet_3 @ 00000051505ca9e0] Multi frame detection: TFF: 28 BFF:
0 Progressive: 453 Undetermined: 0
[libx264 @ 00000051505bef60] frame I:3 Avg QP:18.73 size: 51198
[libx264 @ 00000051505bef60] frame P:233 Avg QP:20.90 size: 26067
[libx264 @ 00000051505bef60] frame B:228 Avg QP:22.59 size: 9490
[libx264 @ 00000051505bef60] consecutive B-frames: 12.9% 59.1% 16.8% 11.2%
[libx264 @ 00000051505bef60] mb I I16..4: 4.9% 81.2% 13.8%
[libx264 @ 00000051505bef60] mb P I16..4: 0.2% 4.1% 1.6% P16..4: 42.4%
28.5% 20.2% 0.0% 0.0% skip: 3.0%
[libx264 @ 00000051505bef60] mb B I16..4: 0.0% 0.2% 0.3% B16..8: 43.1%
6.8% 2.6% direct:14.7% skip:32.3% L0:42.5% L1:45.7% BI:11.7%
[libx264 @ 00000051505bef60] 8x8 transform intra:69.3% inter:49.1%
[libx264 @ 00000051505bef60] coded y,uvDC,uvAC intra: 96.9% 97.1% 85.5%
inter: 45.9% 63.2% 21.5%
[libx264 @ 00000051505bef60] i16 v,h,dc,p: 5% 25% 19% 51%
[libx264 @ 00000051505bef60] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 10% 10% 37% 7%
7% 6% 7% 8% 10%
[libx264 @ 00000051505bef60] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 9% 18% 15% 8%
11% 7% 12% 7% 12%
[libx264 @ 00000051505bef60] i8c dc,h,v,p: 57% 13% 16% 13%
[libx264 @ 00000051505bef60] Weighted P-Frames: Y:20.6% UV:3.0%
[libx264 @ 00000051505bef60] ref P L0: 56.0% 16.5% 16.4% 9.4% 1.7%
[libx264 @ 00000051505bef60] ref B L0: 65.2% 32.9% 1.9%
[libx264 @ 00000051505bef60] ref B L1: 95.1% 4.9%
[libx264 @ 00000051505bef60] kb/s:3468.61
[aac @ 00000051505c0060] Qavg: 434.865

[Carl Eugen Hoyos]

Post by Christian Johannesen
ffmpeg.exe -r 30000/1001 -i D:\media\test_720x486i_dotcrawl.mov

Please remove the input option -r unless you know exactly
what you are doing.

Post by Christian Johannesen
-filter_complex [0:0]crop=704:480:8:6,pullup

As already written, you have to tell the (automatically
inserted) scale filter that your input is not progressive
to avoid artefacts.

But the real issue is that detelecine's start_frame
option does not work;-(

Carl Eugen

[Andy Furniss]

Post by Christian Johannesen
ffmpeg.exe -r 30000/1001 -i D:\media\test_720x486i_dotcrawl.mov

Please remove the input option -r unless you know exactly what you
are doing.

Post by Christian Johannesen
-filter_complex [0:0]crop=704:480:8:6,pullup

Input on ticket is 4:2:0 and you can't crop vertically interlaced 4:2:0
by 6 without messing up the chroma. AFAIK you need to crop 4 lines at a
time.

Maybe you could crop 6 if you converted (interlace aware) to 4:2:2 crop
and then interlace aware back to 4:2:0 (untested!).

[Andy Furniss]

Post by Andy Furniss

Post by Christian Johannesen
ffmpeg.exe -r 30000/1001 -i D:\media\test_720x486i_dotcrawl.mov

Please remove the input option -r unless you know exactly what you
are doing.

Post by Christian Johannesen
-filter_complex [0:0]crop=704:480:8:6,pullup

Input on ticket is 4:2:0 and you can't crop vertically interlaced
4:2:0 by 6 without messing up the chroma. AFAIK you need to crop 4
lines at a time.
Maybe you could crop 6 if you converted (interlace aware) to 4:2:2
crop and then interlace aware back to 4:2:0 (untested!).

Hmm, after looking at the trac sample I think the chroma has already
been scaled progressive = broken sample.

I may be wrong! only looked quickly.

[Andy Furniss]

Post by Andy Furniss

Post by Andy Furniss

Post by Christian Johannesen
ffmpeg.exe -r 30000/1001 -i
D:\media\test_720x486i_dotcrawl.mov

Please remove the input option -r unless you know exactly what
you are doing.

Post by Christian Johannesen
-filter_complex [0:0]crop=704:480:8:6,pullup

Input on ticket is 4:2:0 and you can't crop vertically interlaced
4:2:0 by 6 without messing up the chroma. AFAIK you need to crop 4
lines at a time.
Maybe you could crop 6 if you converted (interlace aware) to 4:2:2
crop and then interlace aware back to 4:2:0 (untested!).

Hmm, after looking at the trac sample I think the chroma has already
been scaled progressive = broken sample.
I may be wrong! only looked quickly.

Looked again and I still think the "master" is broken. As noted in the
track it's size may be an issue by its self (as 420 interlaced would
normally be divisible by 4).

Ignoring that it seems that it has been converted/generated incorrectly
for 420 interlaced. The chroma has bled between the fields so even
something simple like yadif=1 alone produces corrupt output.

If you don't have access to better/"real" masters I don't think you can
get good results from this.

What produced this file with height 486?

[Christian Johannesen]

Post by Andy Furniss

Post by Andy Furniss

Post by Andy Furniss

Post by Christian Johannesen
ffmpeg.exe -r 30000/1001 -i

Post by Christian Johannesen
D:\media\test_720x486i_dotcrawl.mov

Please remove the input option -r unless you know exactly what
you are doing.
-filter_complex [0:0]crop=704:480:8:6,pullup

Input on ticket is 4:2:0 and you can't crop vertically interlaced
4:2:0 by 6 without messing up the chroma. AFAIK you need to crop 4
lines at a time.
Maybe you could crop 6 if you converted (interlace aware) to 4:2:2
crop and then interlace aware back to 4:2:0 (untested!).

Hmm, after looking at the trac sample I think the chroma has already
been scaled progressive = broken sample.
I may be wrong! only looked quickly.

Looked again and I still think the "master" is broken. As noted in the
track it's size may be an issue by its self (as 420 interlaced would
normally be divisible by 4).
Ignoring that it seems that it has been converted/generated incorrectly
for 420 interlaced. The chroma has bled between the fields so even
something simple like yadif=1 alone produces corrupt output.
If you don't have access to better/"real" masters I don't think you can
get good results from this.
What produced this file with height 486?

The file was captured as 720x486 29.97 fps interlaced lower field first
ProRes 422 HQ with an EVS OpenCube server from Beta SP tape. The resolution
is used to retain line 21 data that would not be stored with a 720x480
capture.

Post by Andy Furniss
_______________________________________________
ffmpeg-user mailing list
http://ffmpeg.org/mailman/listinfo/ffmpeg-user

[Andy Furniss]

Post by Christian Johannesen

Post by Andy Furniss
If you don't have access to better/"real" masters I don't think
you can get good results from this.
What produced this file with height 486?

The file was captured as 720x486 29.97 fps interlaced lower field
first ProRes 422 HQ with an EVS OpenCube server from Beta SP tape.
The resolution is used to retain line 21 data that would not be
stored with a 720x480 capture.

OK, so you need to crop to 480 while it's still 422 and then do an
interlace aware scale to 420 before processing any further.

That's assuming you want to start with 420. I don't know whether or not
all the filters you need will work with 422.

Of course after yadif then you are progressive so if you did work in 422
then the final conversion wouldn't need to be interlace.

I noticed when testing the trac sample (I don't have access to others)
that I needed to specify bff for yadif - just another potential issue to
look out for.

[Paul B Mahol]

Post by Christian Johannesen

Post by Carl Eugen Hoyos

Post by Christian Johannesen
Looked through all the documentation for FFMPEG and I can't
seem to find any video filters that deal with chroma dot
crawl & rainbow artifacts in files captured from analog
tape formats.

One of the reasons we always ask for command line including
complete, uncut console output is that it often helps
understanding the original issue.
I am not convinced I understand your issue but maybe you
are searching for the interl option of the scale filter?
$ ffmpeg -i test_720x486i_dotcrawl.mov -vf scale=interl=1,fieldmatch
I opened ticket #5187 because of the green lines fieldmatch
produces.
Carl Eugen
My goal was to remove some of the video artifacts before compressing to

x264. Sort of like this
http://home.earthlink.net/~tacosalad/video/dotcrawl.html
I think I named my files more generally when I uploaded them.
test_720x486i_dotcrawl.mov shows more of the rainbow effect in some of the
detail areas than the dot crawl. I tested processing that clip to 23.98 in
this command line example.

There is tcomb avisynth filter for removing dot crawl and rainbows from *static*
parts of videos.