CameraRecorder without audio
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wrote on 12 Jul 2018, 08:37 last edited by
Hi,
in my app running on embedded target (iMX6) I need to record videos. I am trying to use the QML
CameraRecorder(using thevideoRecorderproperty ofCamera). The problem I am facing is, that the camera output is slowed down extremely as soon as I enable the videoRecorder. On the console I can see the errorCameraBin warning: "Can't record audio fast enough"(which is comming fromgstreamer. As I don't need any audio recorded in the video at all, I am looking for a way to set things up so that I can record only the video without any audio. I have searched for a solution for 2 days now and I couldn't find any answer. So maybe someone here on the forum can help out.Thx, YenZi
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wrote on 12 Jul 2018, 13:28 last edited by
So, I just found out that this gstreamer pipeline on the commandline works just fine and records the camera capture to a file :
gst-launch-1.0 -e imxv4l2videosrc ! imxvpuenc_h264 bitrate=4096 ! h264parse ! mp4mux ! filesink location=video.mp4Now the question would be, how I can control these gstreamer pipeline params just by using the QML Camera component ?
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Have you tried setting the
mutedproperty of yourCameraRecordertotrue? -
wrote on 12 Jul 2018, 18:29 last edited by
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wrote on 13 Jul 2018, 05:40 last edited by
Hi @Cleiton-Bueno,
even if I set
muted: truethe gstreamer pipeline still seems to have audio encoding included. The biggest problem is, that I don't have control over the gstreamer pipeline working as the backend for QtMultimedia elements. -
Hi @Cleiton-Bueno,
even if I set
muted: truethe gstreamer pipeline still seems to have audio encoding included. The biggest problem is, that I don't have control over the gstreamer pipeline working as the backend for QtMultimedia elements.wrote on 13 Jul 2018, 13:53 last edited by@YenZi An alternative so you do not have to change QtMultimedia source-code, create patches and everything else is to block the kernel module regarding the mic part of the webcam, for example:
Listing the drivers/modules for the audio interfaces:
$ cat /proc/asound/modules 0 snd_hda_intelThen add in the blacklist this module, be careful that more than one can identify the WebCamera/Camera:
# echo "blacklist snd_hda_intel" >> /etc/modprobe.d/blacklist.confSo the module will not load and the capture will not work.
Cleiton Bueno
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@YenZi An alternative so you do not have to change QtMultimedia source-code, create patches and everything else is to block the kernel module regarding the mic part of the webcam, for example:
Listing the drivers/modules for the audio interfaces:
$ cat /proc/asound/modules 0 snd_hda_intelThen add in the blacklist this module, be careful that more than one can identify the WebCamera/Camera:
# echo "blacklist snd_hda_intel" >> /etc/modprobe.d/blacklist.confSo the module will not load and the capture will not work.
Cleiton Bueno
wrote on 19 Jul 2018, 13:27 last edited by@Cleiton-Bueno thanks for your suggestion. I have disabled audio in my kernel completely now. Now I get the message
CameraBin warning: "Could not open audio device for recording."which shows, that I really removed audio support.
Unfortunately, this still doesn't solve my basic issue, which is a extremely sluggish video output when thevideoRecorderproperty is enabled in theCamera. That means, the audio encoding was not causing this problem at all.Thx, Jens
6/8