[Buildroot] [PATCH v7 2/7] package/opencv: add gstreamer-1.x support

[Yann E. MORIN]

Samuel, All,

On 2015-07-04 21:06 +0200, Samuel Martin spake thusly:
> Starting with the 2.4.10 release, OpenCV supports both Gstreamer-0.10
> and Gstreamer-1, but only one can be enabled at the same time (OpenCV
> chooses Gstreamer-1 over Gstreamer-0.10 when both are available).
> 
> Signed-off-by: Samuel Martin <s.martin49 at gmail.com>
> Cc: "Yann E. MORIN" <yann.morin.1998 at free.fr>

[--SNIP--]
> diff --git a/package/opencv/Config.in b/package/opencv/Config.in
> index c3b7535..92a1306 100644
> --- a/package/opencv/Config.in
> +++ b/package/opencv/Config.in
> @@ -194,6 +194,19 @@ comment "gstreamer-0.10 support needs a toolchain w/ wchar, threads"
>  	depends on BR2_USE_MMU
>  	depends on !BR2_USE_WCHAR || !BR2_TOOLCHAIN_HAS_THREADS
>  
> +config BR2_PACKAGE_OPENCV_WITH_GSTREAMER1
> +	bool "gstreamer-1.x"
> +	depends on BR2_USE_MMU # libglib2
> +	depends on BR2_USE_WCHAR # libglib2
> +	depends on BR2_TOOLCHAIN_HAS_THREADS # libglib2

I would have used the "gst -> libglib2" trail in the comment because,
again, we're not selecting libglib2, but gst-1, so it's weid to see the
dependency being explained because of libglib2...

[--SNIP--]
> diff --git a/package/opencv/opencv.mk b/package/opencv/opencv.mk
> index 633c2bf..6b1a139 100644
> --- a/package/opencv/opencv.mk
> +++ b/package/opencv/opencv.mk
> @@ -222,11 +222,18 @@ else
>  OPENCV_CONF_OPTS += -DWITH_FFMPEG=OFF
>  endif
>  
> +ifeq ($(BR2_PACKAGE_OPENCV_WITH_GSTREAMER)$(BR2_PACKAGE_OPENCV_WITH_GSTREAMER1),)
> +OPENCV_CONF_OPTS += -DWITH_GSTREAMER=OFF -DWITH_GSTREAMER_0_10=OFF
> +endif

Why do you split this out, rather than have each be defined in the else
clause of each if-block?

AFAICS, GST and GST_0_10 are mutually exclusive (i.e. when one is ON,
the other is OFF) :

>  ifeq ($(BR2_PACKAGE_OPENCV_WITH_GSTREAMER),y)
> -OPENCV_CONF_OPTS += -DWITH_GSTREAMER=ON -DWITH_GSTREAMER_0_10=ON
> +OPENCV_CONF_OPTS += -DWITH_GSTREAMER=OFF -DWITH_GSTREAMER_0_10=ON

... here: GST=OFFF and GST_0_10=ON ...

>  OPENCV_DEPENDENCIES += gstreamer gst-plugins-base
> -else
> -OPENCV_CONF_OPTS += -DWITH_GSTREAMER=OFF -DWITH_GSTREAMER_0_10=OFF
> +endif
> +
> +ifeq ($(BR2_PACKAGE_OPENCV_WITH_GSTREAMER1),y)
> +OPENCV_CONF_OPTS += -DWITH_GSTREAMER=ON -DWITH_GSTREAMER_0_10=OFF

... and here GST=ON and GST_0_10=OFF

> +OPENCV_DEPENDENCIES += gstreamer1 gst1-plugins-base
>  endif

So, I'd have written something like:

    ifeq ($(BR2_PKG_OCV_GST_0_10),y)
    OCV_CONF_OPTS += -DWITH_GST_0_10=ON
    OVC_DEPS += gst gst-plugins-base
    else
    OCV_CONF_OPTS += -DWITH_GST_0_10=OFF
    endif

    ifeq ($(BR2_PKG_OCV_GST),y)
    OCV_CONF_OPTS += -DWITH_GST=ON
    OVC_DEPS += gst-1 gst-1-plugins-base
    else
    OCV_CONF_OPTS += -DWITH_GST=OFF
    endif

(Sorry, I forgot to say so in my previous review... :-( )

Regards,
Yann E. MORIN.

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