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• How to take screenshots of streamers using the Twitch API

  10 décembre 2020, par oo92

  My goal is to create a dataset of gameplays on Twitch using the API. How I want to do it is this :

  


  

  1. Get a list of live streams using the API.

  


  2. Use streamlink and ffmpeg on Python to take the screenshots through the Stream source

  


  


  To get the streams, I have the following code thanks to a SO user :

  


  from twitch import TwitchClient&#xA;&#xA;client = TwitchClient(client_id=&#x27;<my client="client">&#x27;)&#xA;streams = client.streams.get_live_streams(limit=100)&#xA;&#xA;print(streams)&#xA;</my>

  


  The output is this. Its a lot larger, I just made it shorter... :

  


  [{'id': 40889579422, 'game': 'Among Us', 'broadcast_platform': 'live', 'community_id': '', 'community_ids': [], 'viewers': 74594, 'video_height': 1080, 'average_fps': 60, 'delay': 0, 'created_at': datetime.datetime(2020, 12, 9, 23, 53, 34), 'is_playlist': False, 'stream_type': 'live', 'preview': {'small': 'https://static-cdn.jtvnw.net/previews-ttv/live_user_sykkuno-80x45.jpg', 'medium': 'https://static-cdn.jtvnw.net/previews-ttv/live_user_sykkuno-320x180.jpg', 'large': 'https://static-cdn.jtvnw.net/previews-ttv/live_user_sykkuno-640x360.jpg', 'template': 'https://static-cdn.jtvnw.net/previews-ttv/live_user_sykkuno-{width}x{height}.jpg'}, 'channel': {'mature': False, 'status': 'amongus at 4 !!', 'broadcaster_language': 'en', 'broadcaster_software': '', 'display_name': 'Sykkuno', 'game': 'Among Us', 'language': 'en', 'id': 26154978, 'name': 'sykkuno', 'created_at': datetime.datetime(2011, 11, 15, 1, 29, 29, 140794), 'updated_at': datetime.datetime(2020, 12, 10, 0, 35, 50, 916363), 'partner': True, 'logo': 'https://static-cdn.jtvnw.net/jtv_user_pictures/sykkuno-profile_image-6ab1e70e07e29e9b-300x300.jpeg', 'video_banner': 'https://static-cdn.jtvnw.net/jtv_user_pictures/4b654ce5-58dc-4fa6-b77c-7250bb2d5269-channel_offline_image-1920x1080.png', 'profile_banner': 'https://static-cdn.jtvnw.net/jtv_user_pictures/1caee146-3323-4d45-9907-96c20c224d3e-profile_banner-480.png', 'profile_banner_background_color': '', 'url': 'https://www.twitch.tv/sykkuno', 'views': 23590965, 'followers': 1928724, 'broadcaster_type': '', 'description': 'Hi ! ', 'private_video': False, 'privacy_options_enabled': False}}, ... 


  


  First, I want to know how I can iterate through the JSON to get the channel name using the id. I tried to do it on my own but it said that it isn't subscriptable.

  


  Second, I have the following code that tries to use ffmpeg to get a screenshot of the stream through its source :

  


  import streamlink, os

# This code connects to the streamer's source
# Get the Twitch API to work so you can add the streamer's name at the end of the link
username = 'Sykkuno'
streams = streamlink.streams('http://twitch.tv/' + username)

# Stream source
stream = streams["best"].url

# Directory where the screenshots will be saved
dir_path = os.getcwd() + '/' + username

# number of streamers
streamers = 1

os.system('ffmpeg -i ' + stream +' -r 0.5 -f image2 ${dir}/output_%09d.jpg')


  


  But that is throwing the following error :

  


  ffmpeg version 4.1.3-0ppa1~18.04 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 7 (Ubuntu 7.3.0-27ubuntu1~18.04)
  configuration: --prefix=/usr --extra-version='0ppa1~18.04' --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-opengl --enable-sdl2 --enable-nonfree --enable-libfdk-aac --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 22.100 / 56. 22.100
  libavcodec     58. 35.100 / 58. 35.100
  libavformat    58. 20.100 / 58. 20.100
  libavdevice    58.  5.100 / 58.  5.100
  libavfilter     7. 40.101 /  7. 40.101
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  3.100 /  5.  3.100
  libswresample   3.  3.100 /  3.  3.100
  libpostproc    55.  3.100 / 55.  3.100
[hls,applehttp @ 0x557212854940] Opening 'https://video-edge-c2a360.yto01.abs.hls.ttvnw.net/v1/segment/CuAErHgNDEVK3cqjkRZLcz4El99YD2ZSy9tgtjc3ZTrPuN4584-GY3DKYO3MFCBt9M3v8_7IfHAlLvHeUn2wq4d-VC7u4Zv2-k1Bee9IPmIXbFQLZFKrYiT98OTzFMDaElsEZ9Sr4MXz6FoAC1yXhhZ0MYahZVnZa1Tuqnn217nN_rN8wr7kdScBIir_Uo1s2C_I8_54mi2uzdgxB9AYj0a0kG2UtdPkUVA6Qc7XIZ0nUhEeObEf80N0uW9ZU6WHpO3V6G9RD0VkmwUexDWk9MaLy1NJuvLSzRaMfOmKxhrzn3UDoY4CrQN11KOnHYCiCOfvhZmMKzSqtiA8YP0Q9iS03eZZhPQ3WxBHWhd6VeZ0btNeeoudGX73EBIj4ujZnKWKfPiN8K_HLj5FZWqQ5m_4Q1llQlnSAfmhzXR9PHAkz8nxRVcFR-tFokGzFEfkZGHngPNz9boLmo4KHx6404rocPUcXbTHkYsWXZwFC356AhfrNn6x0JYHGfcDpRsEFebLQljEpCyhnNOHFEf9b7Ipeiy521cCupzoEz1uMrzW77h9FJwn0GwvY3jp2KwRXJMvArYwiUHccBmfW7ZDLO9vH7eJGUnAzoy586KMSPLVeLxWMWRDfKkAcI8vYXOIuxNb_MZKm2O_dcoFrDDta5TZn-MLjFquT47P9NbXxlTTJfimlYyMG17SPoW3KJVtAJmjoj0GZ1ehftLJWz1Qgd8zmg40u4g8fz867eCHW_Tiv65yd6qJZD-_bD3G916fm3KeA9bPyhalTD99CWhQL7f0apCfX_6IiQElgPT6kOrFI-ISEG4GdhIpFi4ubzSx29pm7H4aDIXx6BAI5ziHVMPbrg.ts' for reading
[hls,applehttp @ 0x557212854940] Opening 'https://video-edge-c2a360.yto01.abs.hls.ttvnw.net/v1/segment/CuIECWLarz2I5hNCtGLSTDXbCIgahI91KOHXVmPHddzZediyiVbcicZpGakO99CJp1cK_6OnmOKBzZ3sn3KogNyPVRqSy32IpanlyPPUTz23TojfR5DTmJa3zampOzVMfETvvPEpj58-kGhQeQQGtK1zLV2h465RElCLkmc7SeWbXEZ5j6IQ38OVFZ0vdcMHVTNPtJaY7509bE196-9-5YYFiET_-kdkS2X6_lhVQBZrq45PBxApTzeLkDx9ZtGQx78dLr_tZepww_uVnJTwxI_TA3tU8z5_w8ml6rh0GK1W6lTlvuDkPKAwIDLvG736MtbPGz9cFPoRAFQxD3QSwAM-bO1grvWlNsOUDUYLXLNjuejmz8xmRpeE0pqJYxUboRZpxrPXTi52HcX8lpGT4Lx2z6hJcoi9npQttK58HDSHQ3cYH3rlNsYV_RlZ3F-u-fZSn8Em67-vAYeXAMaBe9xxv0Zu2n1TrdPICMyGmk-VgLK788IeDhxqM441GONGLxo6AF8RE5_OawTf9n_MVzImsX4LMn0oN8e8w6mjk7YDuNdA4mEl99Erg8xMdX6Q3fDYTdStaC-zQwXgMctfGpIsUpp91BtRBPMynFCxZ8fZB7NvGFNZTYWDvCZjisiwzs0N1pDdDM_Fkj3i46_Ou105z348PLHRA28Dt1qgn_NjzwRNoaowFx7PxQ-X2zRpAhwNcqaTOHYh5NYZHToVE16WiOe9HzVs_I_3Wqu44bypEsGrhxYhgXSGfvO757iTbErZHmkidsBF2BET5j3JeIifr4fJooalAKc_5uiSPMCGSTtV9hIQX5mQWJudg9UsMRp1AWVrnBoMQPAhy1UwBDtAOrBs.ts' for reading
Input #0, hls,applehttp, from 'https://video-weaver.yto01.hls.ttvnw.net/v1/playlist/CvADco9ZO_szpL7RVLVI3U6zl4IMo2uaUBvZTWAyEOKETN-SxI3m3hLLxpmCfz06rlyCGCPimEbk28kKPSbVYtMThiZFRtLxnrdpLr5DWBQwbpIStPQwMetU4Z04Mkm3nEWplL8hpn69Cmd_eWSdI1yHubK_sRL-n1ml5akAEWWGkS0OgVRQTTsYv4RpkbeWc8wrr3DsDBDfyrxciGSZevnStZOLwg-tNuNu3VNugLigNG1HMsNdxoJGO6wLyO-6FL5EQidOiSw2THSibAvADAWMVOxNX2z39d-nJwbVprbWFnox_lDlh-y88uhjj_MpU6OwkXP9vgrBDEmKjtRbYsIN5N94-8pDFEB3yIYk10vUiuod1yfqztVCqWo5m9r48uINP1CD-Bwgybo6K7Oko-TUjMj43GqAu0mmPtkgPFO69LpQQMifZTn_XbVQ5UUfoCwyl-ljObfRE51aCvZP_dOTsUyqi_JRE8h-C3306aW1ISXwCs3YpnjDxJv6yKyWTktBvsN5NWMVzJg-_-MAtTmoy-w2ppbbOozLzyrGF4zfCetaHLmHtbsKe1Ed1nndJg9b6T7v-87ExrI0eQwRjH3gmBTgqu_peS5oQGBaDOe4QSGMNFgf8lQfuqvFH-miXgpk8RytdorzT7wB05iX7c3bhBIQ3FvvjNIal3IgvyxKatZs4BoMW_P_CuyZOUJs2_Yr.m3u8':
  Duration: N/A, start: 60.000000, bitrate: N/A
  Program 0 
    Metadata:
      variant_bitrate : 0
    Stream #0:0: Audio: aac (LC) ([15][0][0][0] / 0x000F), 44100 Hz, stereo, fltp
    Metadata:
      variant_bitrate : 0
    Stream #0:1: Video: h264 (Main) ([27][0][0][0] / 0x001B), yuv420p(tv, unknown/bt709/unknown), 1920x1080, 29.97 tbr, 90k tbn, 2k tbc
    Metadata:
      variant_bitrate : 0
    Stream #0:2: Data: timed_id3 (ID3  / 0x20334449)
    Metadata:
      variant_bitrate : 0
Stream mapping:
  Stream #0:1 -> #0:0 (h264 (native) -> mjpeg (native))
Press [q] to stop, [?] for help
[swscaler @ 0x557213e262c0] deprecated pixel format used, make sure you did set range correctly
Output #0, image2, to '/output_%09d.jpg':
  Metadata:
    encoder         : Lavf58.20.100
    Stream #0:0: Video: mjpeg, yuvj420p(pc), 1920x1080, q=2-31, 200 kb/s, 0.50 fps, 0.50 tbn, 0.50 tbc
    Metadata:
      variant_bitrate : 0
      encoder         : Lavc58.35.100 mjpeg
    Side data:
      cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: -1
[image2 @ 0x557213012040] Could not open file : /output_000000001.jpg
av_interleaved_write_frame(): Input/output error
frame=    1 fps=0.0 q=7.5 Lsize=N/A time=00:00:02.00 bitrate=N/A speed=27.7x    
video:46kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
Conversion failed!


  


• Haskell - Turning multiple image-files into one video-file using the ffmpeg-light package

  25 avril 2021, par oRole

  Background
  
I wrote an application for image-processing which uses the ffmpeg-light package to fetch all the frames of a given video-file so that the program afterwards is able to apply grayscaling, as well as edge detection alogrithms to each of the frames.
  

  


  Now I'm trying to put all of the frames back into a single video-file.

  


  Used Libs
  
ffmpeg-light-0.12.0
  
JuicyPixels-3.2.8.3
  
...

  


  What have I tried ?
  
I have to be honest, I didn't really try anything because I'm kinda clueless where and how to start. I saw that there is a package called Command which allows running processes/commands using the command line. With that I could use ffmpeg (not ffmpeg-light) to create a video out of image-files which I would have to save to the hard drive first but that would be kinda hacky.

  
Within the documentation of ffmpeg-light on hackage (ffmpeg-light docu) I found the frameWriter function which sounds promising.

  


  frameWriter :: EncodingParams -> FilePath -> IO (Maybe (AVPixelFormat, V2 CInt, Vector CUChar) -> IO ()) 


  


  I guess FilePath would be the location where the video file gets stored but I can't really imagine how to apply the frames as EncodingParams to this function.

  


  Others
  
I can access :
  

  


  

  • r, g, b, a as well asy. a values
    

  


  • image width / height / format

  


  


  Question
  
Is there a way to achieve this using the ffmpeg-light package ?

  


  As the ffmpeg-light package lacks of documentation when it comes to conversion from images to video, I really would appreciate your help. (I do not expect a fully working solution.)

  


  Code
  
The code that reads the frames :

  


  -- Gets and returns all frames that a given video contains
getAllFrames :: String -> IO [(Double, DynamicImage)]
getAllFrames vidPath = do 
  result <- try (imageReaderTime $ File vidPath) :: IO (Either SomeException (IO (Maybe (Image PixelRGB8, Double)), IO()))
  case result of 
    Left ex -> do 
                 printStatus "Invalid video-path or invalid video-format detected." "Video" 
                 return []
    Right (getFrame, _) -> addNextFrame getFrame [] 

-- Adds up all available frames to a video.
addNextFrame :: IO (Maybe (Image PixelRGB8, Double)) -> [(Double, DynamicImage)] -> IO [(Double, DynamicImage)]
addNextFrame getFrame frames = do
  frame <- getFrame
  case frame of 
    Nothing -> do 
                 printStatus "No more frames found." "Video"
                 return frames
    _       -> do                             
                 newFrameData <- fmap ImageRGB8 . swap . fromJust <$> getFrame 
                 printStatus ("Frame: " ++ (show $ length frames) ++ " added.") "Video"
                 addNextFrame getFrame (frames ++ [newFrameData]) 


  


  Where I am stuck / The code that should convert images to video :

  


  -- Converts from several images to video
juicyToFFmpeg :: [Image PixelYA8] -> ?
juicyToFFmpeg imgs = undefined


  


• Script to cut video by silence part with FFMPEG

  11 février 2020, par fricadelle

  This is a question that is raised here How to split video or audio by silent parts or here How can I split an mp4 video with ffmpeg every time the volume is zero ?

  So I was able to come up with a straightforward bash script that works on my Mac.

  Here it is (only argument is the name of the video to be cut, it will generate a file start_timestamps.txt with the list of silence starts if the file does not exist and reuse it otherwise) :

  #!/bin/bash
  
  
  
  INPUT=$1
  
  
  
  filename=$(basename -- "$INPUT")
  
  extension="${filename##*.}"
  
  filename="${filename%.*}"
  
  
  
  SILENCE_DETECT="silence_detect_logs.txt"
  
  TIMESTAMPS="start_timestamps.txt"
  
  
  
  if [ ! -f $TIMESTAMPS ]; then
  
      echo "Probing start timestamps"
  
      ffmpeg -i "$INPUT" -af "silencedetect=n=-50dB:d=3" -f null - 2> "$SILENCE_DETECT"
  
      cat "$SILENCE_DETECT"| grep "silence_start: [0-9.]*" -o| grep -E '[0-9]+(?:\.[0-9]*)?' -o > "$TIMESTAMPS"
  
  fi
  
  
  
  PREV=0.0
  
  number=0
  
  
  
  cat "$TIMESTAMPS"| ( while read ts
  
  do
  
      printf -v fname -- "$filename-%02d.$extension" "$(( ++number ))"
  
      DURATION=$( bc <<< "$ts - $PREV")
  
      ffmpeg -y -ss "$PREV" -i "$INPUT" -t "$DURATION" -c copy "$fname"
  
      PREV=$ts
  
  done
  
  printf -v fname -- "$filename-%02d.$extension" "$(( ++number ))"
  
  ffmpeg -y -ss "$PREV" -i "$INPUT" -c copy "$fname" )

  Unfortunately it does not seem to work :

  I have a video that is basically a collection of clips, each clip being introduced by a 5 second silence with a static frame with a title on it. So I want to cut the original video so that each chunk is the 5 seconds "introduction" + video until the next introduction. Hope it’s clear.

  Anyway, in my script I first find all silence_start using ffmpeg silencedetect plugin. I get a start_timestamps.txt that read :

  141.126
  
  350.107
  
  1016.07
  
  etc.

  Then for example I would call (I don’t need to transcode again the video), knowing that (1016.07 - 350.107) = 665.963

  ffmpeg -ss 350.107 -i Some_video.mp4 -t 665.963 -c copy "Some_video02.mp4"

  The edge cases being the first chunk that has to go from 0 to 141.126 and the last chunk that has to go from last timestamp to end of the video.

  Anyway the start_timestamps seem legit. But my output chunks are completely wrong. Sometimes the video does not even play anymore in Quicktime. I don’t even have my static frame with the title in any of the videos...

  Hope someone can help. Thanks.

  EDIT Ok as explained in the comments, if I echo $PREV while commenting out the ffmpeg command I get a perfectly legit list of values :

  0.0
  
  141.126
  
  350.107
  
  1016.07
  
  etc.

  With the ffmpeg command I get :

  0.0
  
  141.126
  
  50.107
  
  016.07
  
  etc.

  bash variable changes in loop with ffmpeg shows why.

  I just need to append < /dev/null to the ffmpeg command or add -nostdin argument. Thanks everybody.