Recherche avancée

Sur d’autres sites (9407)

• How to deal ffplay being too slow playing iPhone's videos ?

  8 janvier 2020, par Mikhail T.

  Trying to play a 3840x2160 video recorded by an iPhone 7 (@30fps), I get frequent pauses — in the video, music keeps playing.

  



  This happens both in firefox and when ffplay is invoked to play the file directly — from command-line. The CPU is a dual E6700 @3.20GHz — not super fast, but it should be able to play smoothly, shouldn't it ? Video is Intel's "series 4" integrated chipset — again, not a speed-daemon, but it should be adequate... Support for Intel's VA API is included.

  



  I build ffmpeg-4.1 from source using FreeBSD port. As you can see, the port has a maddening amount of options — including several different ones for the 264-codec.

  



  Any suggestions for improving the decoding speed to the point, where it is watchable by a human ? Thank you !

  


• 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.

  


• Alfresco fails to create video thumbnail

  17 octobre 2019, par Deckard

  As error log says : Empty input file ... It turned out that the source image for ImageMagick is zero sized. (/data/was/alfresco/tomcat/temp/Alfresco/ImageMagickContentTransformerWorker_source_8718262212685093199.jpg). When I manually replace the source image to normal image and execute the command again, there’s no error.

  command:    /data/was/alfresco/common/bin/convert /data/was/alfresco/tomcat/temp/Alfresco/ImageMagickContentTransformerWorker_source_8718262212685093199.jpg[0] -auto-orient -resize "100x100>" -strip -quiet /data/was/alfresco/tomcat/temp/Alfresco/ImageMagickContentTransformerWorker_target_7652060684136589026.png

  So I think the source image is maybe made by FFMPEG by capturing some frame of the video.
  And the FFMPEG somehow failed to do it. Not sure my guess is right...

  But my FFMPEG works good as ffmpeg -version shows proper version info. And FFMPEG is run by root and the Alfresco daemon instance is run by root. It seems that there’s nothing wrong.

  Please review it. Here’s the whole Alfresco-share log :

  Caused by: org.alfresco.service.cmr.repository.ContentIOException: 09160037 Content conversion failed:
  
     reader: ContentAccessor[ contentUrl=store:///data/was/alfresco/tomcat/temp/Alfresco/ComplextTransformer_intermediate_mp4_262176879279399174.jpg, mimetype=image/jpeg, size=0, encoding=UTF-8, locale=en_US]
  
     writer: ContentAccessor[ contentUrl=store:///data/was/alfresco/tomcat/temp/Alfresco/FailoverTransformer_intermediate_ComplexContentTransformer_5223852355212570043.png, mimetype=image/png, size=0, encoding=UTF-8, locale=en_US]
  
     options: {use=doclib, contentReaderNodeRef=null, contentWriterNodeRef=null, sourceContentProperty=null, imageAutoOrient=true, targetContentProperty=null, commandOptions=, imageResizeOptions=ImageResizeOptions [width=100, height=100, maintainAspectRatio=true, percentResize=false, resizeToThumbnail=false, allowEnlargement=false], includeEmbedded=null}
  
     limits: {timeoutMs=120000, pageLimit=1}
  
          at org.alfresco.repo.content.transform.AbstractContentTransformer2.transform(AbstractContentTransformer2.java:350)
  
          at org.alfresco.repo.content.transform.ComplexContentTransformer.transformInternal(ComplexContentTransformer.java:492)
  
          at org.alfresco.repo.content.transform.AbstractContentTransformer2.transform(AbstractContentTransformer2.java:272)
  
          ... 32 more
  
  Caused by: org.alfresco.service.cmr.repository.ContentIOException: 09160036 Failed to perform ImageMagick transformation:
  
  Execution result:
  
     os:         Linux
  
     command:    /data/was/alfresco/common/bin/convert /data/was/alfresco/tomcat/temp/Alfresco/ImageMagickContentTransformerWorker_source_8718262212685093199.jpg[0] -auto-orient -resize "100x100>" -strip -quiet /data/was/alfresco/tomcat/temp/Alfresco/ImageMagickContentTransformerWorker_target_7652060684136589026.png
  
     succeeded:  false
  
     exit code:  1
  
     out:
  
     err:        .convert.bin: Empty input file `/data/was/alfresco/tomcat/temp/Alfresco/ImageMagickContentTransformerWorker_source_8718262212685093199.jpg' @ error/jpeg.c/JPEGErrorHandler/331.
  
  .convert.bin: NoImageForProperty "%w" @ warning/property
  
          at org.alfresco.repo.content.transform.magick.ImageMagickContentTransformerWorker.transformInternal(ImageMagickContentTransformerWorker.java:205)
  
          at org.alfresco.repo.content.transform.magick.AbstractImageMagickContentTransformerWorker.transform(AbstractImageMagickContentTransformerWorker.java:284)
  
          at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  
          at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
  
          at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  
          at java.lang.reflect.Method.invoke(Method.java:498)
  
          at org.alfresco.repo.management.subsystems.SubsystemProxyFactory$1.invoke(SubsystemProxyFactory.java:79)
  
          at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
  
          at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
  
          at com.sun.proxy.$Proxy28.transform(Unknown Source)
  
          at org.alfresco.repo.content.transform.ProxyContentTransformer.transformInternal(ProxyContentTransformer.java:107)
  
          at org.alfresco.repo.content.transform.AbstractContentTransformer2.transform(AbstractContentTransformer2.java:272)
  
          ... 34 more

  In alfresco-global.properties : ffmpeg.exe=/usr/local/bin/ffmpeg/ffmpeg

  * Update As Robert suggested, TransFormer log level changed to debug.
  But the log is too long to paste here. There’s 30,000 characters limit of body in SO which github doesn’t have.
  So please refer to github issue, I pasted the log there.
  https://github.com/Alfresco/share/issues/127