Recherche avancée

Sur d’autres sites (6316)

• VideoCapture on RTSP target takes a second to open a stream

  8 novembre 2022, par QBRT

  I am trying to write rtsp player using Opencv FFmpeg. When I open stream using cap.open(url, CAP_FFMPEG), program just freezes for about 1s and then opens stream with similar delay.

  


  Code :

  


  vector<int> a;&#xA;a.push_back(CAP_PROP_OPEN_TIMEOUT_MSEC);&#xA;a.push_back(2000);&#xA;cap.open(url, CAP_FFMPEG, a);&#xA;</int>

  


  What can I do to reduce that delay ?

  


  I have tried using cap.grab(), using threads, using for(int i = 0; i<5; i++) cap>>frame; after opening - all is not working. What else can I do ?

  


  Edit : When I using ffplay directly with nobuffer and low_latency flags, I have good latency. (about 2 times less)

  


• avcodec/vc1dec : Don't open and close decoder during init

  30 octobre 2022, par Andreas Rheinhardt

  avcodec/vc1dec : Don't open and close decoder during init
  This is done since 16af29a7a6deff3f6081fca1e36ad96cf8fec77d
  
  (and is actually unnecessary, because the tables initialized
  
  in ff_msmpeg4_decode_init() are only ever used in vc1_block.c
  
  which is only entered after a call to ff_msmpeg4_decode_init())
  
  in a very ugly manner ; said manner had the byproduct of
  
  involving lots of unnecessary allocations and even opening
  
  and closing a hwaccel in case one is used.
  This commit achieves the aim of 16af29a7a6deff3f6081fca1e36ad96cf8fec77d
  
  by initializing the VLCs used by VC-1 in ff_vc1_init_common().
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] libavcodec/vc1dec.c

• How to supply mufti filter_complex values using ffmpeg

  11 octobre 2022, par Mohammed Hamdan

  for single image being merged to video i use the following command to supply values for -filter_complex

  


  String comand = '-y -i $videoPath -i $imagePath -filter_complex "[1:v]scale=300:300[ovrl];[0:v][ovrl]overlay=100:100" $outPutPath';


  


  but what if i want merge more than one image (input) ?

  


  How do we make a certain distinction for each input except $videoPath ?

  


  String comand = '-y -i $videoPath -i $imagePath1 i $imagePath2 i $imagePath3  $outPutPath4';


  


  How could i supply difference scale overlay rotate values for each input which is for $imagePath1 $imagePath2 $imagePath3 $imagePath4

  


  in other word : evry input has it's own filter values ?

  


  to be honest i have no idea what does [1:v] means but After several attempts, I was able to get successful command (my first command in my qwestion) to give values for one entry, and this was successful , but couldn't do it for many inputs