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• Architecture of video-based service for mobile phones

  27 juin 2015, par David Azar

  I guess this is more of a conceptual question than a technical one.

  I’m trying to figure out the best way to upload short videos to a server and also be able to download them and watch them on both Android and iOS.

  Lets focus on Android for the moment.

  I’ve done some experiments, and my results have been :

  • I’m able to compress 12-14MB video down to 500KB using FFMPEG lib with pretty good results in quality, but it takes about 12 seconds.

  • Next, im uploading those videos to my Parse backend as ParseFile to store them.

  • Finally, i can download them and watch them with no problem using a VideoView widget.

  Now, for the tests i’ve been running, these are great results. But i want to see if there is a better way to manage and scale all of this.

  My questions are :

  • Is there a better, lighter way to compress video ?

  • Is Parse the right way to go ?

  • How can i stream videos instead of downloading them and storing the on local storage before playing them ? i know this will cause my app to use significant space on disk and i dont want that.

  • How do big companies do this kind of tasks ?

  I’ve heard Amazon S3 is a cool thing for projects like this one, also Google Cloud Platform. I want to understand the best approach before building everything so i can do it the right way and also, provide the absolute best user experience for watching these videos.

• Stream Recorder Using FFmpeg Fails on AWS Lambda

  10 mai, par user30495567

  I am trying to stream audio from URLs and save them to a file in S3 using AWS Lambda with FFmpeg. Here is an example FFmpeg command I'm using :

  


  ffmpeg -hide_banner -loglevel error -t 10 -i http://playerservices.streamtheworld.com/api/livestream-redirect/KTOOFMAAC_SC -ar 16000 -b:a 64k -ac 2 output.mp3


  


  

  • The FFmpeg command is getting called in a python script using subprocess.Popen()

  


  • The command works as expected on local, but does not work in an AWS Lambda python environment using a custom FFMPEG layer configured with these instructions.

  


  • When run on Lambda, I get the following error : FileNotFoundError : [Errno 2] No such file or directory : '/tmp/output.mp3'

  


  


  Note : I've also tried a version where I use python requests to stream chunks and pipe them into ffmpeg. This works for some stream URLs, but for others, such as the streamtheworld URL above, it only saves 5 seconds of audio from the stream or results in a Broken Pipe error.

  


• Streaming without Content-Length in response

  29 août 2011, par kain

  I'm using Node.js, Express (and connect), and fluent-ffmpeg.

  We want to stream audio files that are stored on Amazon S3 through http.

  We have all working, except that we would like to add a feature, the on-the-fly conversion of the stream through ffmpeg.

  This is working well, the problem is that some browsers checks in advance before actually getting the file.

  Incoming requests containing the Range header, for which we reply with a 206 with all the info from S3, have a fundamental problem : we need to know in advance the content-length of the file.

  We don't know that since it is going through ffmpeg.

  One solution might be to write out the resulting content-length directly on S3 when storing the file (in a special header), but this means we have to go through the pain of having queues to encode after upload just to know the size for future requests.
  It also means that if we change compressor or preset we have to go through all this over again, so it is not a viable solution.

  We also noticed big differencies in the way Chrome and Safari request the audio tag src, but this may be discussion for another topic.

  Fact is that without a proper content-length header in response everything seems to break or browsers goes in an infinite loop or restart the stream at pleasure.

  Ideas ?