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• lavfi : add a new filtergraph parsing API

  16 janvier 2023, par Anton Khirnov

  lavfi : add a new filtergraph parsing API
  Callers currently have two ways of adding filters to a graph - they can
  
  either
  
   create, initialize, and link them manually
  
   use one of the avfilter_graph_parse*() functions, which take a
  
    (typically end-user-written) string, split it into individual filter
  
    definitions+options, then create filters, apply options, initialize
  
    filters, and finally link them - all based on information from this
  
    string.
  A major problem with the second approach is that it performs many
  
  actions as a single atomic unit, leaving the caller no space to
  
  intervene in between. Such intervention would be useful e.g. to
  
   modify filter options ;
  
   supply hardware device contexts ;
  
  both of which typically must be done before the filter is initialized.
  Callers who need such intervention are then forced to invent their own
  
  filtergraph parsing, which is clearly suboptimal.
  This commit aims to address this problem by adding a new modular
  
  filtergraph parsing API. It adds a new  avfilter_graph_segment_parse()
  
  function to parse a string filtergraph description into an intermediate
  
  tree-like representation (AVFilterGraphSegment and its children).
  This intermediate form may then be applied step by step using further
  
  new avfilter_graph_segment*() functions, with user intervention possible
  
  between each step.
  

  • [DH] doc/APIchanges
  • [DH] libavfilter/avfilter.h
  • [DH] libavfilter/graphparser.c
  • [DH] libavfilter/version.h

• build : Fine-grained link-time dependency settings

  22 janvier 2017, par Diego Biurrun

  build : Fine-grained link-time dependency settings
  Previously, all link-time dependencies were added for all libraries,
  
  resulting in bogus link-time dependencies since not all dependencies
  
  are shared across libraries. Also, in some cases like libavutil, not
  
  all dependencies were taken into account, resulting in some cases of
  
  underlinking.
  To address all this mess a machinery is added for tracking which
  
  dependency belongs to which library component and then leveraged
  
  to determine correct dependencies for all individual libraries.
  

  • [DBH] Makefile
  • [DBH] avbuild/common.mak
  • [DBH] avbuild/library.mak
  • [DBH] configure
  • [DBH] tests/checkasm/Makefile

• Error in Splitting Educational Videos into Segments Using Python (ffmpeg issue) [closed]

  28 décembre 2024, par Yahia Mohamed Hanbal

  I created a Python project to split long educational videos into smaller segments, each focused on a single question. The program uses OCR to detect text on video frames, identifies the word "Question," extracts the number following it, and splits the video whenever the number increases.

  


  here is the video i am tring to split ((video))

  


  Here’s an example of the program’s output :

  


  Video loaded: 14071 frames at 60 FPS, duration: 234.52s  
Frame 480, Time 8.00s, Question: 6  
...  
Frame 12360, Time 206.00s, Question: 7  
Creating segment 1: 8.00s to 206.00s  
Error: module 'ffmpeg' has no attribute 'Error'


  


  I’ve shared the full code in a GitHub repository for reference : Automated Video Scene Cutting.

  


  What the Program Does

  


  

  • Input : A long educational video.

  


  • Processing :

    

    • Detects text in each frame using OCR.

    


    • Searches for the word "Question" followed by a number.

    


    • Monitors when the number increases to identify segment boundaries.

    


    


  


  • Output : Creates video segments corresponding to individual questions.

  


  


  The Problem

  


  The program detects the questions and timestamps correctly, but when it tries to create the segments, I encounter the following error :

  


  Error: module 'ffmpeg' has no attribute 'Error'


  


  What I’ve Tried

  


  

  • Verified the ffmpeg-python library is installed (pip show ffmpeg-python confirms the installation).

  


  • Ensured the ffmpeg binary is accessible from the command line.

  


  • Reviewed the library documentation to ensure the correct usage of ffmpeg.

  


  • Tested with different video files to rule out input-specific issues.

  


  


  Environment Details

  


  

  • OS : Windows 11

  


  • Python Version : 3.9.13

  


  • Key Libraries : ffmpeg-python

  


  


  If anyone has insights into resolving this issue or suggestions for alternative approaches to handle this use case, I’d greatly appreciate your help.

  


  Thank you !