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• NDK r8c warning for asm objects regarding "Cortex-A8 erratum" - should I be worried ?

  7 décembre 2012, par Alex Cohn

  Question : What is the meaning of this warning ? If there are no real-life consequences, I can live with it for a while... But I am concerned with what will happen if our program gets loaded on one of the faulty chips.

  Background : With NDK r8c, linking of X264 encoder issues warnings :

  cannot scan executable section 1 of libx264.a(dct-a.o) for Cortex-A8 erratum because it has no mapping symbols

  ... same warning for all assembly files in libx264.

  libx264.a itself was cross-compiled on the same machine with the same 4.6 toolchain taken from NDK.

  Here are the instructions to easily reproduce the problem (Ubuntu or MacOS) :

  1. Download x264-snapshot-20121203-2245 from ftp://ftp.videolan.org/pub/x264/snapshots/last_x264.tar.bz2

  2. Run ./configure --enable-pic --enable-strip --enable-static --cross-prefix=~/android-ndk-r8c/toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/bin/arm-linux-androideabi- --sysroot=~/android-ndk-r8c/platforms/android-14/arch-arm --host=arm-linux

  3. Run ~/android-ndk-r8c/prebuilt/linux-x86/bin/make

  It will build the static library, and after that display the Cortex-A8 warning while linking the x265 executable. I am not worried about the compiler warnings, because building libx264.a is done offline, it is not part of our official daily build.

  I have reported this as http://code.google.com/p/android/issues/detail?id=40794.

  I tried to add the mapping symbols manually to dct-a.S following the ARM.com instructions, but this had no effect.

• ffmpeg : transmission problems / artifacts in rtsp screen grab - might be a WiFi problem

  1er décembre 2022, par Jo Kerner

  In short : Is there a way to "force" ffmpeg to not save a grabbed frame if there are transmission problems ? Or any other software that does the same and I just don't know of ?

  


  Long story :

  


  Updating my house surveillance from almost 10 years old DCS-932L cameras to Tapo C100 Cameras, I changed the image delivery method from ftp push to rtsp grab via ffmpeg.

  


  I had written a program in C++ to check for "bad" pictures from the old cameras, where parts of the picture tended to be simply black once every minute or so (I'm grabbing a pic every 2 seconds). The Tapo C100 doesn't feature ftp-push, thus I tried (after a few days trying)

  


  ffmpeg.exe -y -i rtsp://user:pass@10.0.0.%ld:554/stream1 -vframes 1 %scamera\rtsp.jpg -loglevel quiet


  


  This works absolutely perfect in my main house, which features a Fritz !Box 7590 and a set of Fritz !Powerline (510/and two 540e) repeaters, plus one WiFi repeater Fritz 600) as my phone line and the router are in the basement.

  


  In my holiday home, though, it doesn't. The Wifi is managed by a Hybrid DSL/5G - box I have no alternative to, which is a Huawei DN9245W and works as DHCP Server, because this is almost impossible to change. Everything "real" is managed by another Fritz !Box 7590, connected via ethernet, and another set of Fritz !Powerline 510 and two 540e repeaters plus half a dozen Wifi Repeaters, mostly Fritz ! 310, 450E and 600. The house was partially built with local stones, which are very iron-y, and there's a lot of metallized glass. Full set is show in Image

  


  Now, this does produce different artifacts, about two per minute or in every 15th picture, see
Image with artifacts No. 1

  


  Thinking this might be a transmission problem, I tried forcing the streamgrab via TCP, because while rtsp doesn't have error correction, TCP does :

  


  ffmpeg.exe -rtsp_transport tcp -i
rtsp://user:pass@10.0.0.%ld:554/stream1 -y -f image2 -update 1 -r
1 -vframes 1 -qscale:v 30 %scamera\rtsp.jpg -loglevel quiet


  


  Which didn't change the artifacts much, see Image with artifacts No. 2

  


  The house now has a total of 12 Cameras, six of which are each "managed" by an older Dell Optiplex Desktop bought used off ebay with an i3 or i5 processor from about 2015, which goes to about 65% load. My software will check if the grabbed picture is finished saving (to RAMdisk), rename it, check if there are artifacts, if so, drop it, if not, convert to bitmap and then compare it to previous image, guess if there's a change, mark that change with a rhombus and rate it, save that as a jpeg file, and then some other stuff that's not relevant here. See : Image of my program running with six cameras

  


  I did try grabbing keyframes only, but a bunny or deer or burglar hopping through my property doesn't produce a keyframe, so that turned out to be missing the point.

  


  I'm out of ideas here. It does work flawlessly in the main house. It doesn't in the holiday house. I can hardly install more repeaters ; I already tried mesh and not-mesh, and the problem isn't exactly wifi overload, because even with just one camera running, it still persists. In certain places. Some have no problems. Reasons ? No clue. I really hope someone has a good idea.

  


• i am getting when i am trying to run Ffmpegrabberframe on alpine image [closed]

  18 mars 2020, par avinash tiwari

  # # A fatal error has been detected by the Java Runtime Environment :

  # SIGSEGV (0xb) at pc=0x000000000000dc56, pid=446, tid=0x00007fd3c478db20 # # JRE version : OpenJDK Runtime Environment

  (8.0_242-b08) (build 1.8.0_242-b08) # Java VM : OpenJDK 64-Bit Server
  VM (25.242-b08 mixed mode linux-amd64 compressed oops) # Derivative :
  IcedTea 3.15.0 # Distribution : Custom build (Wed Jan 29 10:43:50 UTC
  2020) # Problematic frame : # C 0x000000000000dc56 # # Failed to
  write core dump. Core dumps have been disabled. To enable core
  dumping, try "ulimit -c unlimited" before starting Java again # # An
  error report file with more information is saved as : #
  /builds/had/tip/asset-delivery/firstgen-ingestion---backend/hs_err_pid446.log

  # If you would like to submit a bug report, please include # instructions on how to reproduce the bug and visit : #

  https://icedtea.classpath.org/bugzilla # Exception in thread
  "Thread-8" java.io.EOFException at
  java.io.ObjectInputStream$BlockDataInputStream.peekByte(ObjectInputStream.java:3015)
  at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1576)
  at java.io.ObjectInputStream.readObject(ObjectInputStream.java:465)
  at java.io.ObjectInputStream.readObject(ObjectInputStream.java:423)
  at
  org.scalatest.tools.Framework$ScalaTestRunner$Skeleton$1$React.react(Framework.scala:818)
  at
  org.scalatest.tools.Framework$ScalaTestRunner$Skeleton$1.run(Framework.scala:807)

  def extractAVI(rawDrivePath: String): List[String] = {
  
      var errorList: List[String] = List.empty
  
      FileUtils.listFiles(new File(rawDrivePath), new SuffixFileFilter(".avi"), TrueFileFilter.INSTANCE)
  
        .asScala.toList.foreach(aviFile => {
  
        var grabber: FFmpegFrameGrabber = null
  
        var aviStream: InputStream = null
  
        var isFailedExtraction: Boolean = false
  
        try {
  
          LOGGER.info(s"--------inside try----------${aviFile.getAbsolutePath}")
  
          aviStream = new FileInputStream(aviFile.getAbsolutePath)
  
          LOGGER.info("--------create grabber----------")
  
          grabber = new FFmpegFrameGrabber(aviStream)
  
          LOGGER.info("--------created grabber extraction of drives----------")
  
          grabber.start()
  
          LOGGER.info("--------start grabber of drives----------")
  
          var count: Int = 1
  
          for (frame <- Iterator.continually(grabber.grabImage()).takeWhile(_ != null)) {
  
            ImageIO.write(converter.convert(frame), "jpg", new File(aviFile.getParent, "capture-" + count + ".jpg"))
  
            count += 1
  
          }
  
          grabber.stop()
  
        } catch {
  
          case ex: Exception => {
  
            LOGGER.info(s"Error while extracting images for ${aviFile.getAbsolutePath} {}", ex)
  
            errorList :+= s"${aviFile.getAbsolutePath.replace(rawDrivePath, "")} -> ${ex.getMessage}"
  
            isFailedExtraction = true
  
            LOGGER.info("last inside catch")
  
          }
  
        } finally {
  
          // Close the video file
  
          LOGGER.info(s"inside finally ")
  
          if (grabber != null)
  
            grabber.release()
  
          if (aviStream != null)
  
            aviStream.close()
  
          if (aviFile.exists() && !isFailedExtraction) {
  
            LOGGER.debug(s"Deleting ${aviFile.getAbsolutePath}")
  
            FileUtils.deleteQuietly(aviFile)
  
          }
  
        }
  
      })