LinuxQuestions.org - [SOLVED] How to crop a video of its black borders

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How to crop a video of its black borders

You can use HandBrakeCLI to encode a video and it will automatically crop the black borders, works well unless something on screen gets in the way, see the attached image.

The CBS-Justice tag spoils this

So you can use ffmpeg to detect the black borders and to give you the crop parameters

Code:

ffmpeg -hide_banner -loglevel info -ss 10:00 -i CBS_Justice.mts -vframes 2 -vf "cropdetect=24:16:0" -f null -

This will output this

Code:

    Metadata:

      encoder        : Lavc58.54.100 pcm_s16le

[Parsed_cropdetect_0 @ 0x5567e808af80] x1:69 x2:474 y1:0 y2:575 w:400 h:576 x:72 y:0 pts:74772 t:0.830800 crop=400:576:72:0

frame=    2 fps=0.0 q=-0.0 Lsize=N/A time=00:00:00.80 bitrate=N/A speed=69.5x    

video:1kB audio:9kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown

The next step is to extract the crop=400:576:72:0 bit so you can use awk

Code:

/PROC$ awk '/crop=/ {print $14}' CROPDATA.txt 

crop=400:576:72:0

jonke@charlie:/media/jonke/HITA_500GB/FILES/FUGITIVETEST/PROC$

I saved the output from ffmpeg to CROPDATA.txt

The next step is put this all into a script and this is it

Code:

#!/bin/bash

renice 19 -p $$

# detect the cropping parameters

FFREPORT=file=CROPDATA.txt:level=32 ffmpeg -hide_banner -loglevel quiet -ss 10:00 -i CBS_Justice-10282020-0348.mts  -vframes 2 -vf "cropdetect=24:16:0" -f null -



# Extract the cropping paramaters for the -vf switch

CROP=`awk  '/crop=/ {print $14}' CROPDATA.txt` 



# run ffmpeg using the cropping parameters

FFREPORT=file=cropit.log:level=24 ffmpeg -hide_banner -ss 9:50 -t 10  -i CBS_Justice-10282020-0348.mts -vf $CROP cropit.mp4

# loglevels quiet -8 | fatal 8 | error 16| warning 24 | (info 32) | verbose 40 | debug 48 trace 56

echo "finished okay"

I'll be making the start point of the cropdetect, and the input video file an argument to the script, but what I would like is a critique on the script, could it be improved or is there an entirely different way of cropping out black borders?

Instead of relying on a fragile detection algorithm, I'd simply take a screenshot of the video (assuming that the black borders remain unchanged throughout the video), calculate the pixel dimensions I need to crop, and crop it with ffmpeg.

Quote:

Originally Posted by GPGAgent (Post 6198212)

Code:

ffmpeg -hide_banner -loglevel info -ss 10:00 -i CBS_Justice.mts -vframes 2 -vf "cropdetect=24:16:0" -f null -

This will output this

Code:

    Metadata:

      encoder        : Lavc58.54.100 pcm_s16le

[Parsed_cropdetect_0 @ 0x5567e808af80] x1:69 x2:474 y1:0 y2:575 w:400 h:576 x:72 y:0 pts:74772 t:0.830800 crop=400:576:72:0

frame=    2 fps=0.0 q=-0.0 Lsize=N/A time=00:00:00.80 bitrate=N/A speed=69.5x    

video:1kB audio:9kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown

The next step is to extract the crop=400:576:72:0 bit so you can use awk

Code:

/PROC$ awk '/crop=/ {print $14}' CROPDATA.txt 

crop=400:576:72:0

jonke@charlie:/media/jonke/HITA_500GB/FILES/FUGITIVETEST/PROC$

I saved the output from ffmpeg to CROPDATA.txt

The next step is put this all into a script and this is it

Code:

#!/bin/bash

renice 19 -p $$

# detect the cropping parameters

FFREPORT=file=CROPDATA.txt:level=32 ffmpeg -hide_banner -loglevel quiet -ss 10:00 -i CBS_Justice-10282020-0348.mts  -vframes 2 -vf "cropdetect=24:16:0" -f null -



# Extract the cropping paramaters for the -vf switch

CROP=`awk  '/crop=/ {print $14}' CROPDATA.txt` 



# run ffmpeg using the cropping parameters

FFREPORT=file=cropit.log:level=24 ffmpeg -hide_banner -ss 9:50 -t 10  -i CBS_Justice-10282020-0348.mts -vf $CROP cropit.mp4

# loglevels quiet -8 | fatal 8 | error 16| warning 24 | (info 32) | verbose 40 | debug 48 trace 56

echo "finished okay"

The latest version of devedeng will do this for you. It uses ffmpeg as a back end and handles it seamlessly.

Quote:

ffmpeg -hide_banner -ss 9:50 -t 10 -i CBS_Justice-10282020-0348.mts -vf $CROP cropit.mp4

I have a couple of questions.
What is the output of:

Code:

ffprobe CBS_Justice-10282020-0348.mts

If that transport stream is an mpeg2, and you are making a .mp4 out of it, ffmpeg will reencode it. Is that what you want? Every time you reencode you loose quality. You did not specify -c:a copy -c:v copy

This will reencode the video. Look at what ffmpeg's defaults are.

Code:

ffmpeg -i file.ts -vf crop=700:400:0:2 out.mp4

I would specify the parameters for the reencode. I would find the crop manually, Auto crop will remove part of the video probably, I've never found that to work as good.

Do you want to crop without reencoding or resizing?

Code:

ffmpeg -i Input.ts -c copy -bsf:v h264_metadata=crop_left=20:crop_right=20:crop_top=10:crop_bottom=10 output.ts

Quote:

Originally Posted by ondoho (Post 6198240)

That's what I've done in the past, bit tedious if you have 20+ videos to crop tho', and I'm a believer of getting the 'puter to do the work.

Things that an go wrong:
1 You detect the wrong bit of video
2 The crop=nn:nn:nn:nn isn't the 14th column
3 There are multiple crop= sequences in the data output file
4 Many things I havn't thought of

BTW I do assume the black borders remain the same throughout the video

Quote:

Originally Posted by computersavvy (Post 6198257)

The latest version of devedeng will do this for you. It uses ffmpeg as a back end and handles it seamlessly.

Looks interesting, but it isn't command line is it? I'll try it out tho', not had time at the moment.

I do need a script I can the just loop through my collection of videos and just leave it to run.

Quote:

Originally Posted by teckk (Post 6198294)

I have a couple of questions.
What is the output of:

Code:

ffprobe CBS_Justice-10282020-0348.mts

Code:

$ ffprobe CBS_Justice-10282020-0348.mts

ffprobe version 4.2.4-1ubuntu0.1 Copyright (c) 2007-2020 the FFmpeg developers

  built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)

  configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared

  WARNING: library configuration mismatch

  avcodec    configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared --enable-version3 --disable-doc --disable-programs --enable-libaribb24 --enable-liblensfun --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libtesseract --enable-libvo_amrwbenc

  libavutil      56. 31.100 / 56. 31.100

  libavcodec    58. 54.100 / 58. 54.100

  libavformat    58. 29.100 / 58. 29.100

  libavdevice    58.  8.100 / 58.  8.100

  libavfilter    7. 57.100 /  7. 57.100

  libavresample  4.  0.  0 /  4.  0.  0

  libswscale      5.  5.100 /  5.  5.100

  libswresample  3.  5.100 /  3.  5.100

  libpostproc    55.  5.100 / 55.  5.100

[mpeg2video @ 0x55bbb31e2940] Invalid frame dimensions 0x0.

    Last message repeated 1 times

[mpegts @ 0x55bbb3177240] PES packet size mismatch

Input #0, mpegts, from 'CBS_Justice-10282020-0348.mts':

  Duration: 00:54:00.75, start: 45829.134400, bitrate: 2536 kb/s

  Program 25792 

  Program 25920 

  Program 26176 

  Program 26240 

  Program 26304 

  Program 26368 

  Program 26560 

  Program 26624 

  Program 26752 

  Program 27040 

  Program 27200 

  Program 27424 

  Program 27456 

  Program 27584 

  Program 27616 

  Program 27680 

  Program 27712 

  Program 27744 

    Stream #0:0[0xb7d]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p(tv, top first), 544x576 [SAR 32:17 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc

    Stream #0:1[0xb7e](eng): Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz, stereo, fltp, 128 kb/s

  Program 27776 

  Program 27872 

  Program 27904 

  Program 27968 

  Program 28000 

  Program 28096 

  Program 28160 

  Program 28224 

  Program 28256 

  Program 28288

Code:

ffmpeg -i file.ts -vf crop=700:400:0:2 out.mp4

Code:

ffmpeg -i Input.ts -c copy -bsf:v h264_metadata=crop_left=20:crop_right=20:crop_top=10:crop_bottom=10 output.ts

You're dead right I should have used -acodec copy, I just rushed the last bit - my evening meal was waiting for me and the missus would have been upset if I was late - know what I mean?

Quote:

Originally Posted by teckk (Post 6198294)

I have a couple of questions.
What is the output of:

Code:

ffprobe CBS_Justice-10282020-0348.mts

Input file is mts and I want mp4 files out so yes I do re-encode these files, and yes I may lose (not loose) a bit of quality, but that's acceptable.

And you cannot use copy when re-encoding - here's the error message

Code:

Filtergraph 'crop=400:576:72:0' was defined for video output stream 0:0 but codec copy was selected.

Filtering and streamcopy cannot be used together.

Filtering requires the input video to be fully decoded into raw video, then the raw video is processed by the filter(s), then it is encoded.

It does take time but I run this through a driver script that will process about 20 or 30 videos - takes a little while which is why I do it this way.

Setting up the driver script only takes 5 mins or so then the 'puter does all the work - neat innit!

Code:

And you cannot use copy when re-encoding

No you can't, but you can crop without reencoding. If you have a .mp4 file that is x264 for example. You can make that a transport stream, crop it, and put it back into a .mp4 container without doing any reencoding. You seem to already know that. Good deal.

Okay folks, I've added this autodetect feature into my script, it's pretty ugly and I'm sure I could improve it but it works and does what I want

Basically I user a driver script

Code:

#!/bin/bash

#                        $1      $2    $3  $4    $5    $6    $7    8-9 10-11 12-13

#                      detect  file    preset CRF  st1  en1  st2  en2 - up to five cuts

# ./CutAndEncode-v2.sh 10:00  MAH.mts faster  26  10:00  41:14 53:53 57:42 1:09:17

# -preset  ultrafast superfast veryfast faster fast medium (default) slow veryslow

# 

#

#                      detect file                          preset crf  s1    e1

../CropCutAndEncode-V2.sh 19:00 CBS_Justice-12022020-0348.mts veryfast 26  11:50 26:49 30:32 40:30 44:45 52:17

which calls CropCutAndEncode-V2.sh

Code:

#!/bin/bash

renice 19 -p $$

# detect black borders automatically

# ffmpeg -ss 90 -i input.mp4 -vframes 10 -vf cropdetect -f null -

#

#                        $1      $2      $3  $4    $5    $6    7  8-9 10-11 12-13 14-15  

#                  detect file    preset crf  st1  en1  st2  en2 - up to five cuts

# ./CutAndEncode.sh 10:00 MAH.mts faster 26    41:14 53:53 57:42 1:09:17

# -preset  ultrafast superfast veryfast faster fast medium (default) slow veryslow





# presets are ultrafast, superfast, veryfast, faster, fast, medium, slow, slower, veryslow



LOGFILE="00CropCutAndEncode-V2.log"



# detect the cropping parameters

FFREPORT=file=CROPDATA.txt:level=32 ffmpeg -hide_banner -loglevel quiet -ss $1 -i $2  -vframes 2 -vf "cropdetect=24:16:0" -f null -



shift 1 # remove the detect time from the argument list and continue processing as usual



# Extract the cropping paramaters for the -vf switch

CROP=`awk  '/crop=/ {print $14}' CROPDATA.txt`

VF="$CROP,yadif" 



# run ffmpeg using the cropping parameters

#FFREPORT=file=cropit.log:level=24 ffmpeg -hide_banner -ss 9:50 -t 10  -i CBS_Justice-10282020-0348.mts -vf $CROP  -c:a copy -c:v copy cropit2.mp4

# loglevels quiet -8 | fatal 8 | error 16| warning 24 | (info 32) | verbose 40 | debug 48 trace 56

echo "finished okay"



echo "CropCutAndEncode-V2.sh" > ${LOGFILE}

echo "======================" >> ${LOGFILE}

echot() {

            echo “$*” | tee -a ${LOGFILE}

}



rm 00Tmp*.mp4

cnt=1

for P in "$@"

do

case $cnt in

    1) FN=$P;;          # file name CBS_Justice-10282020-0348.mts

    2) PRESET=$P;;      # superfast

    3) CRF=$P;;        # crf value 26

#  4) VF=${P};;        # crop=400:576:72:0,scale=576:400 or just crop=400:576:72:0

    4) ST=$P;;          # start point of first clip

    5) EN=$P            #  end point of first clip

      echot "Cut $cnt of $FN start at $ST and end at $EN"

      ffmpeg -ss $ST -to $EN -i "$FN" -vf ${VF} -c:v libx265 -crf $CRF -preset $PRESET  00Tmp-01.mp4

      echot "ffmpeg -ss $ST -to $EN -i "$FN" -vf ${VF} -c:v libx265 -crf $CRF -preset $PRESET  00Tmp-01.mp4";;



    6) ST=$P;;

    7) EN=$P

      echot "Cut $cnt of $FN start at $ST and end at $EN"

      ffmpeg -ss $ST -to $EN -i "$FN" -vf  ${VF} -c:v libx265  -crf $CRF  -preset $PRESET  00Tmp-02.mp4

      echot "ffmpeg -ss $ST -to $EN -i "$FN" -vf  ${VF} -c:v libx265  -crf $CRF  -preset $PRESET  00Tmp-02.mp4";;

 

    8)  ST=$P;;

    9)  EN=$P

      echot "Cut $cnt of $FN start at $ST and end at $EN"

    ffmpeg -ss $ST -to $EN -i "$FN" -vf  ${VF} -c:v libx265  -crf $CRF -preset $PRESET  00Tmp-03.mp4

    echot "ffmpeg -ss $ST -to $EN -i "$FN" -vf  ${VF} -c:v libx265  -crf $CRF -preset $PRESET  00Tmp-03.mp4";;



    10) ST=$P;;

    11) EN=$P

      echo "Cut $cnt of $FN start at $ST and end at $EN"

    ffmpeg -ss $ST -to $EN -i "$FN" -vf  ${VF} -c:v libx265  -crf $CRF  -preset $PRESET  00Tmp-04.mp4

    echot "ffmpeg -ss $ST -to $EN -i "$FN" -vf  ${VF} -c:v libx265  -crf $CRF  -preset $PRESET  00Tmp-04.mp4";;



    12) ST=$P;;

    13) EN=$P

      echo "Cut $cnt of $FN start at $ST and end at $EN"

    ffmpeg -ss $ST -to $EN -i "$FN" -vf  ${VF} -c:v libx265  -crf $CRF -preset $PRESET  00Tmp-05.mp4

    echot "ffmpeg -ss $ST -to $EN -i "$FN" -vf  ${VF} -c:v libx265  -crf $CRF -preset $PRESET  00Tmp-05.mp4";;



    14) ST=$P;;

    15) EN=$P

      echot "Cut $cnt of $FN start at $ST and end at $EN"

    ffmpeg -ss $ST -to $EN -i "$FN" -vf  ${VF} -c:v libx265  -crf $CRF -preset $PRESET  00Tmp-06.mp4

    echot "ffmpeg -ss $ST -to $EN -i "$FN" -vf  ${VF} -c:v libx265  -crf $CRF -preset $PRESET  Tmp-06.mp4";;



 esac

 cnt=$((cnt + 1))

done

echot "Now join the cuts"



ls 00Tmp*.mp4 | perl -ne 'print "file $_"' | ffmpeg -protocol_whitelist "file,pipe" -safe 0 -y -f concat -i - -codec copy PROC/$FN-$PRESET-$CRF.mp4

echot "Now delete the temp files"

mv $FN PROC

#rm Tmp*.mp4

Works just fine

1) Detect the crop values however you prefer to.
2) Dynamically construct AviSynth script that utilizes Crop() and splicing.
3) Encode the singular, output-ready script with FFmpeg.

No extraneous encodes and after-the-fact concatting.

Quote:

Originally Posted by antithesis85 (Post 6198791)

Cheers, could you expand your comments please, not entirely sure what you mean

And those links are empty!

Quote:

Originally Posted by teckk (Post 6198547)

Code:

And you cannot use copy when re-encoding

The input is an mts file and I want to re-encode it to mp4 so I'm not copying.

I could just re-encoe the entie video, then rop and copy the resulting mp4 file, it may be quicker, but I don't think there will be much in it, worth trying tho,

Quote:

Originally Posted by GPGAgent (Post 6198868)

Cheers, could you expand your comments please, not entirely sure what you mean

And those links are empty!

The links aren't empty, I just had a look.
You are asking a lot of video editing questions, AVSynth might be very helpful to you.

You did not answer post #4. I think that you have not started at the start. The first thing to do it find out what audio/video is in that transport stream. Then you will know what your options are with ffmpeg, and how to reencode it.