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

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  • 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 ?

          1 Reply Last reply
          0
          • 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
              0
              • 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
                0
                • 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 :(

                        1 Reply Last reply
                        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
                                    0

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