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• Android : Recording and Streaming at the same time

  29 mars 2016, par Bruno Siqueira

  This is not really a question as much as it is a presentation of all my attempts to solve one of the most challenging functionalities I was faced with.

  I use libstreaming library to stream realtime videos to Wowza Server and I need to record it at the same time inside the SD card. I am presenting below all my attempts in order to collect new ideias from the community.

  Copy bytes from libstreaming stream to a mp4 file

  Development

  We created an interception in libstreaming library to copy all the sent bytes to a mp4 file. Libstreaming sends the bytes to Wowza server through a LocalSocket. It users MediaRecorder to access the camera and the mic of the device and sets the output file as the LocalSocket’s input stream. What we do is create a wrapper around this input stream extending from InputStream and create a File output stream inside it. So, every time libstreaming executes a reading over the LocaSocket’s input stream, we copy all the data to the output stream, trying to create a valid MP4 file.

  Impediment

  When we tried to read the file, it is corrupted. We realized that there are meta information missing from the MP4 file. Specifically the moov atom. We tried to delay the closing of the streaming in order to give time to send this header (this was still a guessing) but it didn’t work. To test the coherence of this data, we used a paid software to try to recover the video, including the header. It became playable, but it was mostly green screen. So this became an not trustable solution. We also tried using "untrunc", a free open source command line program and it couldn’t even start the recovery, since there was no moov atom.

  Use ffmpeg compiled to android to access the camera

  Development

  FFMPEG has a gradle plugin with a java interface to use it inside Android apps. We thought we could access the camera via command line (it is probably in "/dev/video0") and sent it to the media server.

  Impediment

  We got the error "Permission Denied" when trying to access the camera. The workaround would be to root the device to have access to it, but it make the phones loose their warranty and could brick them.

  Use ffmpeg compiled to android combined with MediaRecorder

  Development

  We tried to make FFMPEG stream a mp4 file being recorded inside the phone via MediaRecorder

  Impediment

  FFMPEG can not stream MP4 files that are not yet done with the recording.

  Use ffmpeg compiled to android with libstreaming

  Development

  Libstreaming uses LocalServerSocket as the connection between the app and the server, so we thought that we could use ffmpeg connected with LocalServerSocket local address to copy the streaming directly to a local file inside the SD card. Right after the streaming started, we also ran the ffmpeg command to start recording the data to a file. Using ffmpeg, we believed that it would create a MP4 file in the proper way, which means with the moov atom header included.

  Impediment

  The "address" created is not readable via command line, as a local address inside the phone. So the copy is not possible.

  Use OpenCV

  Development

  OpenCV is an open-source, cross-platform library that provides building blocks for computer vision experiments and applications. It offers high-level interfaces for capturing, processing, and presenting image data. It has their own APIs to connect with the device camera so we started studding it to see if it had the necessary functionalities to stream and record at the same time.

  Impediment

  We found out that the library is not really defined to do this, but more as image mathematical manipulation. We got even the recommendation to use libstreaming (which we do already).

  Use Kickflip SDK

  Development

  Kickflip is a media streaming service that provides their own SDK for development in android and IOS. It also uses HLS instead of RTMP, which is a newer protocol.

  Impediment

  Their SDK requires that we create a Activity with camera view that occupies the entire screen of the device, breaking the usability of our app.

  Use Adobe Air

  Development

  We started consulting other developers of app’s already available in the Play Store, that stream to servers already.

  Impediment

  Getting in touch with those developers, they reassured that would not be possible to record and stream at the same time using this technology. What’s more, we would have to redo the entire app from scratch using Adobe Air.

  UPDATE

  Webrtc

  Development

  We started using WebRTC following this great project. We included the signaling server in our NODEJS server and started doing the standard handshake via socket. We were still toggling between local recording and streaming via webrtc.

  Impediment

  Webrtc does not work in every network configuration. Other than that, the camera acquirement is all native code, which makes a lot harder to try to copy the bytes or intercept it.

• AWS Lambda and Fluent FFMPEG error "cannot read property "isStream" of undefined"

  29 mai 2021, par Travis Lee

  so here's the goal : convert a .webm file hosted in an S3 into a gif and upload that to a new bucket. This all works fine when run locally, but when trying to translate it into a lambda, fluent-ffmpeg throws errors when it runs the command.

  


  Here's the code snippet :

  


  ffmpeg(new URL(vid))
  .outputOptions("-vf", "scale=320:-1:flags=lanczos,fps=14")
  .on('progress', () => {
      console.log('progress');
  })
  .on('end', () => {
     //Do stuff with the result when it is done
  })
  .output(newKey)
  .run(newKey);


  


  in this snippet, "vid" is a presigned GET url for an S3 bucket containing the .webm video file, and "newKey" is the name of the new bucket (and a temporary writeStream/File that is created in the lambda to store the new .gif file until we upload it to S3 - not super relevant to this issue).

  


  What should happen (and does locally) is that a new output is created containing the converted .gif file

  


  What happens when it is deployed in a lambda is that it reaches the .outputOptions call and throws a type error saying that it cannot read property isStream of undefined.

  


  At first glance, this seems like I simply don't have FFMPEG installed in the lambda, but I do. I have tried with the prebuilt layer using NodeJS 10 found here : https://serverlessrepo.aws.amazon.com/applications/us-east-1/145266761615/ffmpeg-lambda-layer ,
with a NodeJS 12 layer that was built by some engineers here previously, and tried building a NodeJS 14 FFMPEG layer myself and using that. I tried for all three using no configuration and letting it call the PATH ffmpeg, using the FFMPEG_PATH and FFPROBE_PATH environment variables set to either what was specified in the previous layers, or what I made it in the newly built one, and even manually setting the path to the executables using the setFfmpegPath and setFfprobePath functions found on the fluent-ffmpeg object.

  


  Lastly, I even tried bundling the executables in with the actual lambda code itself and uploading it through an S3, trying all three above methods of getting it to point to the correct paths once again to no avail.

  


  I'm seriously in need of help if anyone else has encountered something similar or just might know what is going on. I'm at wit's end here trying to figure this out.

  


• How to send ffmpeg based HTTP stream to CloudFront [on hold]

  5 octobre 2017, par Tarun Maheshwari

  I have a live streaming server, where media is available as HTTP / RTMP / HLS format.
  I am able to access it and play from my desktop using following links.

   rtmp://52.xx.xx.192/live/tarun1 (RTMP)
  
   http://52.xx.xx.192:8080/hls/movie.m3u8 (HLS)
  
   http://52.xx.xx.190:7090/stream (HTTP)

  I want to forward any of the above streams to CloudFront with these steps.