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• Scaling Application for video decoding using ffmpeg

  6 juillet 2020, par jasoos

  I am building an application to read multiple IP camera streams (rtsp) and run different Machine Learning Algorithms over it in real time. For each camera stream,

  


  

  1. I spawn an ffmpeg process which continuously break the rtsp streams
into frames and store them as images (JPEG). The streams use H.264
encoding. I am taking 1 frame every second as output.

  


  2. Message queues corresponding to models are given the message
containing location of the file.

  


  3. Models keep on picking up the file and drawing inferences

  


  


  The problem I am facing is the CPU usage by ffmpeg decoding process. For real time inference without any loss of frames, I have to beef up my server by a core for every 2 camera streams. Is there any optimization I am missing for ffmpeg ?

  


  I am using Intel Xeon Gold processor with Ubuntu 18.04 OS

  


• Adding ffmpeg library to Python Kivy App and Buildozer for Android

  15 août 2023, par Chris-Yoon

  I am working on a Python Kivy App, in which I have to manipulate audio files such as joining audio files or converting them into aac format. In order to achieve this I use the ffmpeg library. Everything works fine on my Linux machine, however, I couldn't make it run on the Android device. I build my apk/aab file by using Buildozer. I built a variety of cross-platform apps for Windows or Linux or for the web, but I am not really an experienced Android developer.

  


  Can someone give me a high-level explanation or even a detailed description on how I can add this third party library to the apk/aab file and define it as environment variable using buildozer, so that other modules such as ffmpeg-python or pydub can find it ? I am also open to alternatives if there are any.

  


  I tried ffmpegkit, adding prebuilt libraries, defining the path to the converter in PyDub.

  


• Best way to stream FFMPEG conversion to HTML5 video element ?

  4 août 2021, par SamTheFam

  Context

  


  Me and my friend are currently working on a media player desktop application using Electron (which implements website code into a desktop application). For the video element we are using the HTML5 video element, and loading a video from the user's local machine. Most browsers only support MP4, OGG, and WebM (Mozilla Specification), but we would like to support more formats to make it applicable to more users. For this reason, we decided to use the FFMPEG video converter. As FFMPEG takes some time to convert videos, we would like to have a streaming implementation that converts the video while playing the HTML5 video.

  


  The Problem

  


  The problem is that we cannot figure out the best way to stream our video whilst it is converting to another format. The primary issue is that we are unsure how we can implement skipping in the video, where we convert that specfic point if skipped to.

  


  For further clarification of the issue, if a user provided a .mkv file, we would start the FFMPEG conversion to .mp4, and would convert enough for the video to start playing. While the video is being watched, FFMPEG would continue converting before the user has reached that point in the video. If a user wanted to skip through the video, we would need a way to fast-forward the conversion to a specific point in the video, thus allowing the user to watch that section of the video, if it has not already been converted.

  


  Ideally we would like the conversion to be faster than the playback of the video, but if this has a cost in quality, we would prefer to make it optional to the end user.

  


  The first solution that came to our heads was to convert small sections of the video, and produce many small (3-5 second) videos, that would be loaded into the video element respectively. The issue here is that the video element takes quite a lot of time to load new source files and as a result make an awful user experience, with the video going black every x seconds.

  


  Another possible solution we stumbled accross was mentioned here. If we were to implement this, we would start a HTTP server on the user's local machine. The issue we had with this is that it could be a rather bloated solution and could be tedious to maintain. Along with this, it would likely slow down the start time for the application, and the runtime as well.

  


  Thank you in advance, we look forward to your responses.