Android 11.0 根据Camera的YUYV和MJPG两种格式做特殊处理

Posted 2022-05-27 王睿丶

Camera的格式，只能在Native层先获取，然后使用__system_property_set（key,value）设置属性值。来到Java层后通过SystemProperties.get(key)获取属性值就可以了。

hardware/interfaces/camera/device/3.4/default/ExternalCameraDevice.cpp

    struct v4l2_fmtdesc fmtdesc;
    fmtdesc.index = 0;
    if (capability.device_caps & V4L2_CAP_VIDEO_CAPTURE_MPLANE)
        fmtdesc.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
    else
        fmtdesc.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

    int ret = 0;
    while (ret == 0) 
++	char m = (char)fmtdesc.pixelformat & 0xFF;
++	if(m == 'M')
++		ALOGV("Recognize MJPG - %c = ",fmtdesc.pixelformat & 0xFF);
++		 __system_property_set("media.audio.xxx.format_type", "MJPG");
++	
        ret = TEMP_FAILURE_RETRY(ioctl(fd, VIDIOC_ENUM_FMT, &fmtdesc));
        ALOGV("index:%d,ret:%d, format:%c%c%c%c", fmtdesc.index, ret,
                fmtdesc.pixelformat & 0xFF,
                (fmtdesc.pixelformat >> 8) & 0xFF,
                (fmtdesc.pixelformat >> 16) & 0xFF,
                (fmtdesc.pixelformat >> 24) & 0xFF);
        if (ret == 0 && !(fmtdesc.flags & V4L2_FMT_FLAG_EMULATED)) 
            auto it = std::find (

packages/apps/Camera2/src/com/android/camera/settings/SettingsUtil.java

    public static Size sizeFromSettingString(String sizeSettingString) 
        if (sizeSettingString == null) 
            return null;
        
        String[] parts = sizeSettingString.split(SIZE_SETTING_STRING_DIMENSION_DELIMITER);
        if (parts.length != 2) 
            return null;
        

++        // wangrui Read Camera resolution format value, non-empty value is MJPG, empty value is YUYVav
++        String s =  SystemProperties.get("media.audio.xxx.format_type");
        try 
            int width = Integer.parseInt(parts[0]);
            int height = Integer.parseInt(parts[1]);
++            if ("MJPG".equals(s))
++                android.util.Log.d("SettingsUtil","MJPG 摄像头");
++            else
++                if (width == 1600 && height == 1200)
++                     width = 1280;
++                     height = 720;
++                
++                android.util.Log.d("SettingsUtil","YUYV 摄像头");
++            
            return new Size(width, height);
         catch (NumberFormatException ex) 
            return null;
        
    

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