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• opencv cannot read MP4 file from sony camcorder

  7 juin 2016, par Jundong

  The sony camcorder recorded video in MP4 format. I am reading the file by

  import cv2
  
  vid = cv2.VideoCapture('sample.MP4')

  my OpenCV version is 2.4.8, as a Python module.

  The codec of the ’sample.MP4’ is H.264, Linear PCM.

  ffprobe sample.MP4

  returns :

  > Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'C0004.mp4':   Metadata:
  
  >     major_brand     : XAVC
  
  >     minor_version   : 16785407
  
  >     compatible_brands: XAVCmp42iso2
  
  >     creation_time   : 2016-06-06 13:41:51   Duration: 00:00:15.02, start: 0.000000, bitrate: 50439 kb/s
  
  >     Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709/bt709/iec61966-2-4), 1920x1080 [SAR 1:1 DAR 16:9],
  
  > 48655 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
  
  >     Metadata:
  
  >       creation_time   : 2016-06-06 13:41:51
  
  >       handler_name    : Video Media Handler
  
  >       encoder         : AVC Coding
  
  >     Stream #0:1(und): Audio: pcm_s16be (twos / 0x736F7774), 48000 Hz, 2 channels, s16, 1536 kb/s (default)
  
  >     Metadata:
  
  >       creation_time   : 2016-06-06 13:41:51
  
  >       handler_name    : Sound Media Handler
  
  >     Stream #0:2(und): Data: none (rtmd / 0x646D7472), 245 kb/s (default)
  
  >     Metadata:
  
  >       creation_time   : 2016-06-06 13:41:51
  
  >       handler_name    : Timed Metadata Media Handler 
  
  > Unsupported codec with id 0 for input stream 2

  It seems that the codec for h.264 is missing. The version of my FFmpeg is 3.0.

  I tried avconv -i sample.MP4 -c:a copy -c:v copy sample_converted.mp4 to convert the sample.MP4 to sample_converted.mp4, this command line did not work. The command ffmpeg -i sample.mp4 sample_converted.mp4 worked ; however, it compromised the video quality badly.I used an online video converter : http://www.online-convert.com/ (which output nice quality video in mp4 format, but it has size limitation for free users)
  to convert the MP4 to mp4, the command in Terminal as below :

  ffprobe 'sample_converted.mp4'

  returns

  > Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'C0001_converted.mp4':  
  
  > Metadata:
  
  >     major_brand     : isom
  
  >     minor_version   : 512
  
  >     compatible_brands: isomiso2avc1mp41
  
  >     encoder         : Lavf57.36.100   Duration: 00:00:02.02, start: 0.000000, bitrate: 16777 kb/s
  
  >     Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 16801 kb/s, 59.94
  
  > fps, 59.94 tbr, 60k tbn, 119.88 tbc (default)
  
  >     Metadata:
  
  >       handler_name    : VideoHandler
  
  >     Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 127 kb/s (default)
  
  >     Metadata:
  
  >       handler_name    : SoundHandler

  Obviously, the encoders, handler_names etc. of the sample.MP4 and sample_converted.mp4 are different. Any idea using FFmpeg or OpenCV to convert this raw video from camcorder to the readable format without compromising the video quality ?

• How can I make sure trimming in ffmpeg with -c:v copy is accurate

  9 avril 2020, par Angelo

  I looked at many things online and I understand it's better to re-encode if you want precision.

  



  But for instance, I have the following command :

  



  -ss 00:00:09 -i "input.mp4" -c:v copy -c:a copy -vframes 600 "output.mp4


  



  Where 600 is calculated using the video's FPS and duration, in this case 10 seconds from an 60FPS video. Can I expect to get something accurate with this all the time ? I tested many variants but this seems to be doing ok for the couple videos I tested for.. And if not, can I really ever get complete ACCURACY with copying, or must I stick to H264 for instance ?

  


• DiscordJS Music Bot Connects and Then Immediately Disconnects From Voice Channel

  23 janvier 2020, par კΙбthebraɨɴs

  I see that questions similar to this one have been asked, and after following their solutions I still end up the same as I started. Below I have listed my code, a link to test it with a sample bot I created, and the modules you will need to test it using a self-hosted instance.

  My problem is that upon connecting to the specified voice channel, the bot immediately leaves afterwards without any signs of errors or exceptions. I’m not sure if it is a problem with my code, or with one of the libraries I am using. The only console output I receive is as follows :

  Bot Ready For Use
  
  joined channel
  
  left channel

  Thanks !

  My Code

  var voiceChannel = message.member.voiceChannel;
  
  
  
  if (!message.member.voiceChannel) return message.channel.send(`You do realize you have to be in a voice channel to do that, right ${message.author.username}?`)
  
  
  
  if (!message.member.voiceConnection) voiceChannel.join().then(async connection => {
  
  
  
      let streamURL = args.slice(1).join(" ")
  
      let streamTitle = "";
  
      let streamThumb = "";
  
      let streamAuth = "";
  
      let streamAuthThumb = "";
  
  
  
      if (streamURL.includes("https://www.youtube.com") || streamURL.includes("https://youtu.be/") && !streamURL.includes(' ')) {
  
          let results = await youtube.getVideo(streamURL)
  
  
  
          let {
  
              body
  
          } = await snekfetch.get(`https://www.googleapis.com/youtube/v3/channels?part=snippet&id=${results.channel.id}&fields=items%2Fsnippet%2Fthumbnails&key=${ytapikey}`).query({
  
              limit: 800
  
          })
  
  
  
          streamTitle = results.title
  
          streamThumb = results.thumbnails.medium.url
  
          streamAuth = results.channel.title
  
          streamAuthThumb = body.items[0].snippet.thumbnails.medium.url
  
  
  
      } else if (!streamURL.includes("https://www.youtube.com") || !streamURL.includes("https://youtu.be/")) {
  
  
  
          let results = await youtube.searchVideos(streamURL)
  
  
  
          let {
  
              body
  
          } = await snekfetch.get(`https://www.googleapis.com/youtube/v3/channels?part=snippet&id=${results[0].channel.id}&fields=items%2Fsnippet%2Fthumbnails&key=${ytapikey}`).query({
  
              limit: 800
  
          })
  
  
  
          streamURL = results[0].url
  
          streamTitle = results[0].title
  
          streamThumb = results[0].thumbnails.medium.url
  
          streamAuth = results[0].channel.title
  
          streamAuthThumb = body.items[0].snippet.thumbnails.medium.url
  
  
  
      } else {
  
          return message.reply("I can only play videos from YouTube (#NotSponsored).")
  
      }
  
  
  
      console.log("joined channel");
  
      const stream = ytdl('https://www.youtube.com/watch?v=gOMhN-hfMtY', {
  
          filter: 'audioonly'
  
      });
  
      const dispatcher = connection.playStream(stream, {
  
          seek: 0,
  
          volume: 1
  
      });
  
      dispatcher.on("end", end => {
  
          console.log("left channel");
  
          voiceChannel.leave();
  
      });
  
  
  
      let musicEmbed = new Discord.RichEmbed()
  
          .setAuthor(streamAuth, streamAuthThumb)
  
          .setTitle(`Now Playing:`)
  
          .addField(`${streamAuth}`, `${streamTitle}`)
  
          .setImage(streamThumb)
  
          .setColor(embedRed)
  
          .setFooter(`${streamAuth} - ${streamTitle} (${streamURL}`)
  
  
  
      message.channel.send(musicEmbed)
  
  
  
  }).catch(console.error);
  
  break

  List of Modules

  discord.js
  
  simple-youtube-api
  
  node-opus
  
  ffmpeg
  
  ffbinaries
  
  ffmpeg-binaries
  
  opusscript
  
  snekfetch
  
  node-fetch
  
  ytdl-core

  Click here to use my sample bot through repl.it.

  Thanks Again !