Recherche avancée

Sur d’autres sites (6212)

• 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.

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

  25 avril 2021, par oRole

  Background
  &#xA;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.
  

  &#xA;

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

  &#xA;

  Used Libs
  &#xA;ffmpeg-light-0.12.0
  &#xA;JuicyPixels-3.2.8.3
  &#xA;...

  &#xA;

  What have I tried ?
  &#xA;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.

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

  &#xA;

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


  &#xA;

  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.

  &#xA;

  Others
  &#xA;I can access :
  

  &#xA;

  &#xA;
  • r, g, b, a as well asy. a values
    

  &#xA;

  • image width / height / format

  &#xA;

  &#xA;

  Question
  &#xA;Is there a way to achieve this using the ffmpeg-light package ?

  &#xA;

  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.)

  &#xA;

  Code
  &#xA;The code that reads the frames :

  &#xA;

  -- 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]) 


  &#xA;

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

  &#xA;

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


  &#xA;

• 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 :

  &#xA;

  &#xA;
  1. Get a list of live streams using the API.

  &#xA;

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

  &#xA;

  &#xA;

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

  &#xA;

  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>

  &#xA;

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

  &#xA;

  [{'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}}, ... 


  &#xA;

  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.

  &#xA;

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

  &#xA;

  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')


  &#xA;

  But that is throwing the following error :

  &#xA;

  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!


  &#xA;