CameraRecorder without audio

YenZi

Hi,

in my app running on embedded target (iMX6) I need to record videos. I am trying to use the QML CameraRecorder (using the videoRecorder property of Camera). 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 error CameraBin warning: "Can't record audio fast enough" (which is comming from gstreamer. 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

YenZi

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.mp4

Now the question would be, how I can control these gstreamer pipeline params just by using the QML Camera component ?

GrecKo

Have you tried setting the muted property of your CameraRecorder to true ?

Cleiton Bueno

@GrecKo it's right, see.

QMediaRecord
Camera Recorder QML

Cleiton Bueno

Blog | Linkedin | B2Open

YenZi

Hi @GrecKo ,

yes, I've set muted: true. Makes no difference.

YenZi

Hi @Cleiton-Bueno,

even if I set muted: true the 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.

Cleiton Bueno

@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_intel

Then 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.conf

So the module will not load and the capture will not work.

Cleiton Bueno

Blog | Linkedin | B2Open

YenZi

@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 the videoRecorder property is enabled in the Camera. That means, the audio encoding was not causing this problem at all.

Thx, Jens

Unsolved CameraRecorder without audio