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• Android - Adding Effects to Videos like Instagram

  7 novembre 2017, par San

  I am in need of a idea to apply filters to video like Instagram, video trimming and fetching images from the video. I have researched a lot and all I can come up with is the following ways to achieve what I want :

  1. FFMPEG
  2. Open CV
  3. Camera2 API

  FFMPEG :

  As far as FFMPEG is considered, majority of the average level droid devs feel that its a pain cause it involves NDK and compiling the FFMPEG commands.The above mentioned link is self-explanatory and it saves me the pain of setting up the NDK but the biggest drawback in this is that its not stable and its REALLY slow.
  My query on this topic is that how do I compile FFMPEG into my project. I have gone through several links to integrate FFMPEG as follows :

  One

  Two

  Three

  The third link seemed to make sense but ultimately I couldn’t understand completely and go where,do what after following those steps.

  Question 1 :

  Is there is a solid Android - FFMPEG Integration Document that can help a beginner like me ?

  Open CV

  Question 2 :

  I haven’t tried Open CV yet but will it be worth it ?

  Camera2 API

  Question 3 :

  As far as I researched, I can see that the Camera2 API can help us shoot videos and images with effects added to it but will it be useful for me to process the already existing videos and images ? I don’t have the requirement to add effects to the camera while its captured, its aftermath is where I want to add my effects.

  If someone is kind enough to accept my stupidity and help me out, I am thankful to them.

  Will going ahead with FFMPEG be good or OpenCV or Camera2 API will be better ?

• How to compres a image size to a desired file size in KBs using ffmpeg or python or Ubuntu Command line ?

  16 octobre 2017, par yash17

  I’m using ffmpeg to take a screenshot from a udp stream.
  Due to varying bit rates while transmission, the captured screenshot has different file size everytime.400KB,500KB..Eventhough it is screenshot of a same static page.

  Is there a way to get a specific file size everytime,in ffmpeg ?

  Or is there a command to convert a captured file to the desired KB using Python or through Ubuntu terminal ?

  Here is the command I’m using.

  ffmpeg -i udp://@XXX.XX.XX.XX:XXXX -vframes 1 -q:v 1 test.png

  I also tried the following commands in terminal,but it did nothing.

  convert -define jpeg:extent=100kb test.png output.png

• MediaRecorder - FFMPEG - RTMP issue

  5 octobre 2017, par Bear10

  Currently I’m working on streaming Audio and Video from a video captured in Chrome 61.0.3163.100 with the MediaRecorder API.

  The backend is running on node and it spawns a child process which runs ffmpeg :

  ffmpeg -threads 4 -i udp://127.0.0.1:41234 -t 5400 -ar 44100
  
  -b:a 128k -c:v libx264 -c:a libfdk_aac -pix_fmt yuv420p -r 30 -g 60 -vb 2048k -preset slow -minrate 2000k -maxrate 4000k test.mp4

  On the client side I send the raw Blob from Chrome to the Node server via web socket :

   var mediaStream = new MediaStream([videoOutput.getVideoTracks()[0], audioOutput.getAudioTracks()[0]]),
  
              recorder = new MediaRecorder(mediaStream, {
  
                  mimeType: 'video/webm;codecs=vp8'
  
              });
  
  
  
          socket = io('http://localhost:' + port);
  
  
  
          recorder.addEventListener('dataavailable', function (evt) {
  
              socket.emit('video:data', evt.data);
  
          });

  And in Node we simply resend via udp to the ffmpeg process :

  let client = dgram.createSocket('udp4'),
  
  
  
  client.send(chunk, 0, chunk.length, 41234, '127.0.0.1', function (err, bytes) {
  
              if (err) {
  
                  throw err;
  
              }
  
          });

  The resulting mp4 is viewable on VLC without any issues, despite many of the following warnings showing up in the FFMPEG console :

  stderr: frame= 1751 fps= 31 q=17.0 size=   15997kB time=00:00:58.39 bitrate=2244.3kbits/s dup=449 drop=32 speed=1.03x
  
  stderr: [mp4 @ 0x7fefe6019000] Non-monotonous DTS in output stream 0:1; previous: 2573919, current: 2573792; changing to 2573920. This may result in incorrect timestamps in the output file.
  
  
  
  stderr: frame= 1767 fps= 31 q=17.0 size=   16166kB time=00:00:58.90 bitrate=2248.4kbits/s dup=452 drop=32 speed=1.03x
  
  stderr: [libmp3lame @ 0x7fefe7004c00] Queue input is backward in time
  
  
  
  stderr: [mp4 @ 0x7fefe6019000] Non-monotonous DTS in output stream 0:1; previous: 2614768, current: 2614686; changing to 2614769. This may result in incorrect timestamps in the output file.

  However when I try to re stream this specific video on Youtube or any other RTMP platform (ex : Facebook) the audio is choppy, the command I use :

  ffmpeg -i ./test.mp4 -f flv rtmp://a.rtmp.youtube.com/live2/MYAPIKEY

  On the other hand any other "good" video not made from the aforementioned process re streams just fine and I suspect it might be from the warnings I’m getting.

  As an added bit of information streaming directly from my PC with avfoundation to youtube also works fine, and writing from avfoundation to a file and then streaming to youtube also works ok.

  The goal is to stream from my browser to the node server and directly to the Youtube RTMP without the choppy audio issue.

  If someone knows how to get rid of the warning to ensure ffmpeg isn’t the issue or can point me in the direction to achieve the desired result that’d be great.