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• h264_mp4toannexb : Stop reallocating the output buffer

  14 décembre 2019, par Andreas Rheinhardt

  h264_mp4toannexb : Stop reallocating the output buffer
  Up until now, h264_mp4toannexb would grow the output packet's buffer by
  
  the desired amount every time another NAL unit of the input packet has
  
  been read ; this commit changes this : The input buffer is now essentially
  
  parsed twice, once to determine the final size of the output packet and
  
  once to write the output packet's data.
  Fixes : Timeout
  
  Fixes : 19322/clusterfuzz-testcase-minimized-ffmpeg_BSF_H264_MP4TOANNEXB_fuzzer-5688407821123584
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
  
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavcodec/h264_mp4toannexb_bsf.c

• Non stop stream to rtmp with FFMPEG

  13 février 2020, par Надежда Перемен

  I want to stream to RTMP with FFMPEG. I need to dynamically change next play file, for that i use web urls for my localhost.

  I have PHP file located : http://127.0.0.1/mp3.php

  $file = '1.mp3';
  
  
  
  $mime_type = "audio/mpeg, audio/x-mpeg, audio/x-mpeg-3, audio/mpeg3";
  
  
  
  if(file_exists($file)){
  
      header('Content-type: {$mime_type}');
  
      header('Content-length: ' . filesize($file));
  
      header('Content-Disposition: filename="' . $file);
  
      header('X-Pad: avoid browser bug');
  
      header('Cache-Control: no-cache');
  
      readfile($file);
  
  }else{
  
      header("HTTP/1.0 404 Not Found");
  
  }

  And i run ffmpeg with this command line :

  ffmpeg -re -stream_loop -1 -i logo.png -stream_loop -1 -i http://127.0.0.1/mp3.php -ab 320k -c:v libx264 -f flv "rtmp://ms......."

  This works, but it playing only once time and FFMPEG returns an error :

  Seek to start failed
http://127.0.0.1/mp3.php: Function not implemented

  How can i fix it ?

• How to start and stop saving video frames according to a trigger with OpenCV VideoWriter

  11 août 2021, par Jacob nighFor

  I am building an app that records frames from IP camera through RTSP.

  



  My engine is in charge to save a video in mp4 with Opencv VideoWriter working well.
What I am looking for is to create a startRecord and a stopRecord class method that will respectively start and stop recording according to a trigger (it could be an argument that I pass to the thread).
Is anyone know what the best way to do that kind of stuff ?

  



  Here is my class :

  



  from threading import Thread
import cv2
import time
import multiprocessing
import threading
class RTSPVideoWriterObject(object):
    def __init__(self, src=0):
        # Create a VideoCapture object
        self.capture = cv2.VideoCapture(src)

        # Start the thread to read frames from the video stream
        self.thread = Thread(target=self.update, args=())
        self.thread.daemon = True
        self.thread.start()

    def update(self):
        # Read the next frame from the stream in a different thread
        while True:
            if self.capture.isOpened():
                (self.status, self.frame) = self.capture.read()

    def endRecord(self):
        self.capture.release()
        self.output_video.release()
        exit(1)

    def startRecord(self,endRec):

        self.frame_width = int(self.capture.get(3))
        self.frame_height = int(self.capture.get(4))
        self.codec = cv2.VideoWriter_fourcc(*'mp4v')
        self.output_video = cv2.VideoWriter('fileOutput.mp4', self.codec, 30, (self.frame_width, self.frame_height))
        while True:          
            try:
                self.output_video.write(self.frame)
                if endRec:
                    self.endRecord()
            except AttributeError:
                pass




if __name__ == '__main__':

    rtsp_stream_link = 'rtsp://foo:192.5545....'
    video_stream_widget = RTSPVideoWriterObject(rtsp_stream_link)

    stop_threads = False
    t1 = threading.Thread(target = video_stream_widget.startRecord, args =[stop_threads]) 
    t1.start() 
    time.sleep(15)
    stop_threads = True



  



  As you can see in the main I reading frames and store them in a separate thread. Then I am starting to record (record method is with an infinite loop so blocking) and then after 15 sec, I am trying to pass a 'stop_record' argument to stop recording properly.

  



  A part of the code comes from Storing RTSP stream as video file with OpenCV VideoWriter

  



  Is someone have an idea ?
I read a lot that OpenCV can be very tricky for multithreading

  



  N.