youtube-dl: Support decoding Coub videos (was: Downloaded Coub video file broken)

I found something interesting inside their js:

MediaElementStrategy.prototype.decode = function(buf) {
      var x;
      x = new Uint16Array(buf, 0, 2);
      if (x[0] === 19392) {
        return x[0] = 0;
      }
    };

And indeed, zeroing out the first two bytes with a hex editor makes the files playable.

Here is simple script to construct videos that should looks similar to the ones played on the site. I didn’t try to make it fancy, just the minimal proof of concept.

#!/usr/bin/env bash
set -e
youtube-dl -o 1.mp4 "$1"
youtube-dl -f html5-audio-high -o 1.mp3 "$1"
printf '\x00\x00' | dd of=1.mp4 bs=1 count=2 conv=notrunc
for i in `seq 1 100`; do echo "file '1.mp4'" >> 1.txt; done
ffmpeg -hide_banner -f concat -i 1.txt -i 1.mp3 -c copy -shortest -movflags faststart out.mp4
rm 1.mp4 1.mp3 1.txt

FWIW, I just tested this again and it is still not working with the latest version of youtube-dl. Dunno, maybe either incorporate a fix along those examples listed here, or take Coub off of the list of supported sites in the meantime.

@ozburo @arisboch @catdog2 If you guys still have problem, try this: curl -wL $(youtube-dl -g 'http://coub.com/view/uilvc') | grep -o "http.*mp4" | sed 's/muted_//g'

@niranjanshr13 Don’t use /usr/bin/env to find a program (or shell)… you should know exactly where the program (or shell) is on your system and it should be in a safe directory. I’m sure you can find other advice, but quite simply, don’t use /usr/bin/env … EVER.

@arisboch here is the code without any loop.

#!/bin/bash
url="http://coub.com/view/g8j3b"
youtube-dl $url -o 1.mp4
printf '\x00\x00' | dd of=1.mp4 bs=1 count=2 conv=notrunc

#!/usr/bin/env bash
[ -z "$1" ] && exit 88
URL=$1
[ -e "$(youtube-dl --restrict-filenames -f 'html5-video-med[ext=mp4]' --get-filename -o "%(title)s-%(id)s.%(ext)s" "$URL")" ] && echo -e "Already downloaded $URL" &&  exit 0
if youtube-dl --list-formats "${URL}" | /bin/grep html5-audio &>/dev/null; then
    youtube-dl -q --restrict-filenames -f 'html5-video-med[ext=mp4]+html5-audio-high[ext=mp3]' --merge-output-format FAKE -o "%(title)s-%(id)s.%(ext)s" "$URL" &>/dev/null
    printf '\x00\x00' | dd of=$(youtube-dl --restrict-filenames -f 'html5-video-med[ext=mp4]' --get-filename -o "%(title)s-%(id)s.f%(format_id)s.%(ext)s" "$URL") bs=1 count=2 conv=notrunc &>/dev/null
    youtube-dl  --restrict-filenames --prefer-ffmpeg --postprocessor-args '-shortest' -f 'html5-video-med[ext=mp4]+html5-audio-high[ext=mp3]' --exec 'touch {}' -o "%(title)s-%(id)s.%(ext)s" "$URL" &>/dev/null
else
    youtube-dl -q --restrict-filenames --prefer-ffmpeg -f 'html5-video-med[ext=mp4]' --exec "printf '\x00\x00' | dd of={} bs=1 count=2 conv=notrunc" -o "%(title)s-%(id)s.%(ext)s"  "$URL" &>/dev/null
fi

re-edited because if the coub is video only it will only get the fragment. now it gets the video correctly with or without audio.

the first -e is because if you try to download the same url it will create fragments and then say it already made the file and exit. I use FAKE to force an error, but it would fail anyway, so it’s probably irrelevant, still… and the --exec touch is something I do cause I don’t want the date to be the video’s but I want now.

that’s the smallest I could do, I did it this way because if I download the pieces separately then you don’t have the name and you’re still going to need to call --get-filename for each “fragment”

if --exec would really run after download this could be 1 line 😦

youtube-dl --restrict-filenames --ffmpeg-location /root/bin/ -f 'html5-video-med[ext=mp4]+html5-audio-high[ext=mp3]' --exec "[[ {} =~ \.mp4$ ]] && printf '\x00\x00' | dd of={} bs=1 count=2 conv=notrunc || true" --merge-output-format mp4 -o "%(title)s-%(id)s.%(ext)s" <URL>

but it doesn’t work cause it will try to execute on the post-processed, but it doesn’t reach it as ffmpeg won’t recognize the video as a video.

for the python user.

#!/usr/bin/python3
import youtube_dl
import requests
link='http://coub.com/view/zoxf2'
ytdl = youtube_dl.YoutubeDL({'outtmpl': '%(id)s%(ext)s'})
result = ytdl.extract_info(link, download=False)
r = requests.get(result['url'])
with open( result['title'] + '.mp4','wb') as f:
    f.write(b'\x00\x00' + r.content[2:])

Okay, here’s my take on that shell script:

#!/bin/bash

set -e

TMPFILE=$(mktemp 'XXXXXXXX.mp4')

filename_format+='%(upload_date)s'
filename_format+='_%(title)s'
filename_format+='_%(id)s'

FILE_NAME=$(
	youtube-dl --get-filename \
		--restrict-filenames -o "${filename_format}" "${1}"
)

youtube-dl -f html5-video-high -o "${FILE_NAME}.mp4" "$1"
youtube-dl -f html5-audio-high -o "${FILE_NAME}.mp3" "$1"
printf '\x00\x00' | dd of="${FILE_NAME}.mp4" bs=1 count=2 conv=notrunc
i=0;export i
for i in {1..100}
do
	echo "file '${FILE_NAME}.mp4'" >> "${FILE_NAME}.txt"
done
ffmpeg -y -hide_banner -f concat -i "${FILE_NAME}.txt" \
	-i "${FILE_NAME}.mp3" -c copy -shortest -movflags faststart "${TMPFILE}"
rm "${FILE_NAME}"*
mv "${TMPFILE}" "${FILE_NAME}.mp4"