Recherche avancée

Sur d’autres sites (9413)

• ffmpeg, live MPEG-TS demux & decode

  8 mai 2017, par NadavRub

  Environment

  • Ubuntu-14
  • C++
  • ffmpeg

  Use-case

  • Live SPTS is received via UDP by a 3rd party module
  • TS Packets are received iteratively
  • The TS Video (ES) should be decoded in minimal latency

  Considered Implementation

  • Upon TS packet reception, immediately push it to the TS demux
  • Once enough packets are received the video format is resolvable, create the video codec
  • Push each video packet into the video decoder
  • Once enough video packets were processed the video codec result a valid output frame

  Problem at-hand

  Can this be done w/ ffmpeg ?!?!, … using “avformat_open_input” mandate a file to read from… I need a way where I can iteratively push packets to the TS demuxer ( w/ minimal latency )…

  Does ffmpeg support the above mentioned use-case ? How ?

• 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.

  


• FFmpeg - feeding output of encode operation to filter

  21 août 2017, par nsp

  I wanted to know if we can feed the output of an encode operation to a "filter_complex" with a command like :

  ffmpeg -i input.mp4 -c:v libx264 -s:v 1920x1080 -b:v 10000k "[encoder-output-1]" \
  
  -c:v libx264 -s:v 1280x720 -b:v 5000k "[encoder-output-2]" \
  
  -c:v libx264 -s:v 640x360 -b:v 2000k "[encoder-output-3]" \
  
  -filter_complex "[encoder-output-1][0:v]psnr" -f null - \
  
  -filter_complex "[encoder-output-2][0:v]psnr" -f null -\
  
  -filter_complex "[encoder-output-3][0:v]psnr" -f null - 

  If we can do something like this, how should one name the output pad of the encoder, so that one can reference/map it in the filter_complex
  If not, please let me know what is the easiest way to achieve something like this.

  Note :

  1. I would be using third party encoders that don’t have the capability to calculate PSNR scores internally. Thus, I would like to compute the PSNR within an FFmpeg filter.