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• Streaming MP4 frames to HTML5, what am I doing wrong ?

  5 septembre 2014, par mczarnek

  Currently I am generating a MP4 Bitstream using Intel’s Media SDK library, which uses ffmpeg underneath the covers. I can generate a mp4 file, and play it and it works.

  However, when I try to stream that mp4 across the network, it doesn’t play within the HTML5 video player, as tested within Chrome, Firefox, or IE.

  This much is sent back and forth across the network :

  Sent by Chrome:
  
  GET / HTTP/1.1
  
  Host: localhost:8085
  
  Connection: keep-alive
  
  User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/32.0.1700.102 Safari/537.36
  
  Accept-Encoding: identity;q=1, *;q=0
  
  Accept: */*
  
  Accept-Language: en-US,en;q=0.8
  
  Range: bytes=0-
  
  
  
  From my video player:
  
  HTTP/1.1 200 OK
  
  Server: Microsoft-HTTPAPI/2.0
  
  Date: Thu, 09 Jan 2014 17:28:14 GMT
  
  Content-type: video/mp4

  After this, I send a newline, and all the video frames, one after another, while listening to see if I receive anything back from the browser.

  Then nothing happens. Any suggestions to get this playing video ? Thank you !

• Estimate time of transcoding video FFMPEG [on hold]

  9 mars 2019, par Anh Vo Nguyen Nhat

  Currently, I want to assign a video transcoding task to a computer in my distributed network. The computer are heterogeneous, so I have to check whether that computing can handle the task fast enough (during a specified deadline). My approach for this is to run many experiments and then based on the statistics I will try to estimate the time when running another task.

  I am trying to predict beforehand the time it takes when transcoding a video (e.g. transcoding 1920x1080 H264 video to 1280x720 VP9) using FFMPEG tool.
  I have used the following features to build a simple neural network to predict the time :
   Video Resolution (Input + Output)
   Video Duration
   Video Codec (Input + Output)
   Video Bitrate
   Video Framerate
   Number of B, I, P frames

  However, the result is not really promising. I want to ask if there is any other way to estimate/predict the time it takes when transcoding a video ? Are there any other features beside the listed that affects the transcoding time ?

• Efficiently streaming a remote file into ffmpeg

  17 janvier 2016, par YZats

  My use case requires transcoding a remote MOV file that can’t be stored locally. I was hoping to use http protocol to stream the file into ffmpeg. This works, but I’m observing this to be a very expensive operation with (seemingly) redundant network traffic, so am looking for suggestions.

  What I see is that ffmpeg starts out with a Range request “0-“ (which brings in the entire file), followed by a number of open-ended requests (no ending offset) at different positions, each of which makes the http server return large chunks of the file again and again, from the starting position to the very end.

  For example, http range requests for a short 10MB file look like this :

  bytes=0-   
  
  bytes=10947419-
  
  bytes=36-
  
  bytes=3153008-
  
  bytes=5876422-

  Is there another input method that would be more network-efficient for my use case ? I control the server where the video file resides, so I’m flexible in what code runs there.

  Any help is greatly appreciated