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QT's QMediaRecorder not working - Unable to record from camera

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  • J jack1998

    @JonB ok thank you for your reply but have you please any idea about the recording please ?

    J Offline
    J Offline
    jack1998
    wrote on last edited by
    #4

    any idea please :(

    1 Reply Last reply
    0
    • SGaistS Offline
      SGaistS Offline
      SGaist
      Lifetime Qt Champion
      wrote on last edited by
      #5

      Hi,

      Did you check that "filerecord" points to a valid location ?
      Did you connect any of the error signals to know if something wrong happened ?

      Interested in AI ? www.idiap.ch
      Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

      J 2 Replies Last reply
      0
      • SGaistS SGaist

        Hi,

        Did you check that "filerecord" points to a valid location ?
        Did you connect any of the error signals to know if something wrong happened ?

        J Offline
        J Offline
        jack1998
        wrote on last edited by jack1998
        #6

        @SGaist thank you for your reply, yes i can find the file video.PNG
        but i can't open it
        the error :
        AL lib: (EE) ALCcaptureAlsa_open: Could not open capture device 'default': Aucun fichier ou dossier de ce type
        QMediaRecorder::RecordingState
        QMediaRecorder::RecordingStatus
        QMediaRecorder::NoError
        CameraBin error: "Could not open device."
        CameraBin error: "Internal data stream error."

        J 1 Reply Last reply
        0
        • J jack1998

          @SGaist thank you for your reply, yes i can find the file video.PNG
          but i can't open it
          the error :
          AL lib: (EE) ALCcaptureAlsa_open: Could not open capture device 'default': Aucun fichier ou dossier de ce type
          QMediaRecorder::RecordingState
          QMediaRecorder::RecordingStatus
          QMediaRecorder::NoError
          CameraBin error: "Could not open device."
          CameraBin error: "Internal data stream error."

          J Offline
          J Offline
          jack1998
          wrote on last edited by
          #7
          This post is deleted!
          1 Reply Last reply
          0
          • SGaistS SGaist

            Hi,

            Did you check that "filerecord" points to a valid location ?
            Did you connect any of the error signals to know if something wrong happened ?

            J Offline
            J Offline
            jack1998
            wrote on last edited by
            #8

            @SGaist what does that mean please AL lib: (EE) ALCcaptureAlsa_open: Could not open capture device 'default' please ?

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            • SGaistS Offline
              SGaistS Offline
              SGaist
              Lifetime Qt Champion
              wrote on last edited by
              #9

              Did you check that you have access to the device(s) you are trying to use for recording ?

              Interested in AI ? www.idiap.ch
              Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

              J 1 Reply Last reply
              0
              • SGaistS SGaist

                Did you check that you have access to the device(s) you are trying to use for recording ?

                J Offline
                J Offline
                jack1998
                wrote on last edited by
                #10

                @SGaist how can i check them please ?

                jsulmJ 1 Reply Last reply
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                • J jack1998

                  @SGaist how can i check them please ?

                  jsulmJ Offline
                  jsulmJ Offline
                  jsulm
                  Lifetime Qt Champion
                  wrote on last edited by
                  #11

                  @jack1998

                  ls -lh /dev/video4
                  

                  and see what user and groupd are set and also the access rights.

                  https://forum.qt.io/topic/113070/qt-code-of-conduct

                  J 1 Reply Last reply
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                  • jsulmJ jsulm

                    @jack1998

                    ls -lh /dev/video4
                    

                    and see what user and groupd are set and also the access rights.

                    J Offline
                    J Offline
                    jack1998
                    wrote on last edited by
                    #12

                    @jsulm hello thank you for your replay, i find this result with the terminal in raspberry: crw-rw----+ 1 root video 81, 17 mai 4 12:01 /dev/video4

                    jsulmJ 1 Reply Last reply
                    0
                    • J jack1998

                      @jsulm hello thank you for your replay, i find this result with the terminal in raspberry: crw-rw----+ 1 root video 81, 17 mai 4 12:01 /dev/video4

                      jsulmJ Offline
                      jsulmJ Offline
                      jsulm
                      Lifetime Qt Champion
                      wrote on last edited by
                      #13

                      @jack1998 So, only root user and users which are member of the "video" group have access to /dev/video4
                      Is your user member of that group (enter this command in terminal to check: groups).

                      https://forum.qt.io/topic/113070/qt-code-of-conduct

                      J 1 Reply Last reply
                      0
                      • jsulmJ jsulm

                        @jack1998 So, only root user and users which are member of the "video" group have access to /dev/video4
                        Is your user member of that group (enter this command in terminal to check: groups).

                        J Offline
                        J Offline
                        jack1998
                        wrote on last edited by jack1998
                        #14

                        @jsulm thank you for your reply, i check it and i have access
                        it is not a problem with the code please?

                        J 1 Reply Last reply
                        0
                        • J jack1998

                          @jsulm thank you for your reply, i check it and i have access
                          it is not a problem with the code please?

                          J Offline
                          J Offline
                          jack1998
                          wrote on last edited by
                          #15

                          what does that mean please ?
                          GStreamer-CRITICAL **: 12:40:27.463:
                          Trying to dispose element camera_source, but it is in PAUSED instead of the NULL state.
                          You need to explicitly set elements to the NULL state before
                          dropping the final reference, to allow them to clean up.
                          This problem may also be caused by a refcounting bug in the
                          application or some element.
                          i m new with the qt :(

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                          0
                          • SGaistS Offline
                            SGaistS Offline
                            SGaist
                            Lifetime Qt Champion
                            wrote on last edited by
                            #16

                            Are you able to use that device from GStreamer directly ?
                            Are there other applications trying to access it ?

                            Interested in AI ? www.idiap.ch
                            Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                            J 1 Reply Last reply
                            0
                            • SGaistS SGaist

                              Are you able to use that device from GStreamer directly ?
                              Are there other applications trying to access it ?

                              J Offline
                              J Offline
                              jack1998
                              wrote on last edited by jack1998
                              #17

                              @SGaist AL lib: (EE) ALCcaptureAlsa_open: Could not open capture device 'default': no such file or folder

                              jsulmJ 1 Reply Last reply
                              0
                              • J jack1998

                                @SGaist AL lib: (EE) ALCcaptureAlsa_open: Could not open capture device 'default': no such file or folder

                                jsulmJ Offline
                                jsulmJ Offline
                                jsulm
                                Lifetime Qt Champion
                                wrote on last edited by
                                #18

                                @jack1998 said in QT's QMediaRecorder not working - Unable to record from camera:

                                AL lib: (EE) ALCcaptureAlsa_open: Could not open capture device 'default': no such file or folder

                                Is this coming when you try to access the device directly using GStreamer?

                                https://forum.qt.io/topic/113070/qt-code-of-conduct

                                J 1 Reply Last reply
                                0
                                • jsulmJ jsulm

                                  @jack1998 said in QT's QMediaRecorder not working - Unable to record from camera:

                                  AL lib: (EE) ALCcaptureAlsa_open: Could not open capture device 'default': no such file or folder

                                  Is this coming when you try to access the device directly using GStreamer?

                                  J Offline
                                  J Offline
                                  jack1998
                                  wrote on last edited by
                                  #19

                                  @jsulm yes

                                  J 1 Reply Last reply
                                  0
                                  • J jack1998

                                    @jsulm yes

                                    J Offline
                                    J Offline
                                    jack1998
                                    wrote on last edited by
                                    #20

                                    when I run the code in pi it works well however in root it does not work

                                    1 Reply Last reply
                                    0
                                    • SGaistS Offline
                                      SGaistS Offline
                                      SGaist
                                      Lifetime Qt Champion
                                      wrote on last edited by
                                      #21

                                      What do you mean by "in root" ?

                                      Interested in AI ? www.idiap.ch
                                      Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                                      1 Reply Last reply
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