From: Antoine Jacoutot <ajacoutot@bsdfrog.org>
Subject: Re: gstreamer/plugins-good: Reenable the v4l2 plugin
To: Alexandre Ratchov <alex@caoua.org>
Cc: ports@openbsd.org
Date: Mon, 14 Jul 2025 15:55:24 +0200

On Mon, Jul 14, 2025 at 12:18:34PM +0200, Alexandre Ratchov wrote:
> The v4l2 plugin (used for webcam capture) is currently disabled
> because of a compilation error (according to a comment in the
> Makefile).
> 
> The error is a missing "#ifndef __linux__", probably forgotten and
> unnoticed as it doesn't affect Linux. This diff fixes it and reenables
> v4l2, using the libv4l.
> 
> Example of a one-liner to test the plugin with a webcam:
> 
> gst-launch-1.0 v4l2src ! videoconvert ! ximagesink
> 
> OK?

OK

> 
> Off topic, unfortunately this diff is not enough to fix net/dino: now
> it finds a valid video device but the screen is black on the other
> end.
> 
> Index: Makefile
> ===================================================================
> RCS file: /cvs/ports/multimedia/gstreamer1/plugins-good/Makefile,v
> diff -u -p -r1.89 Makefile
> --- Makefile	1 May 2025 06:55:57 -0000	1.89
> +++ Makefile	14 Jul 2025 09:47:45 -0000
> @@ -1,6 +1,7 @@
>  COMMENT=		good elements for GStreamer
>  
>  DISTNAME=		gst-plugins-good-${V}
> +REVISION=		0
>  
>  SITES=			${SITE_GST:=gst-plugins-good/}
>  
> @@ -9,11 +10,12 @@ COMPILER_LANGS=		c c++
>  
>  WANTLIB += ${COMPILER_LIBCXX} FLAC X11 Xdamage Xext Xfixes Xtst
>  WANTLIB += bz2 cairo cairo-gobject gdk-3 gdk_pixbuf-2.0 gio-2.0
> -WANTLIB += glib-2.0 gobject-2.0 gstaudio-1.0 gstbase-1.0 gstfft-1.0
> -WANTLIB += gstgl-1.0 gstnet-1.0 gstpbutils-1.0 gstreamer-1.0 gstriff-1.0
> -WANTLIB += gstrtp-1.0 gstrtsp-1.0 gstsdp-1.0 gsttag-1.0 gstvideo-1.0
> +WANTLIB += glib-2.0 gobject-2.0 gstallocators-1.0 gstaudio-1.0 
> +WANTLIB += gstbase-1.0 gstfft-1.0 gstgl-1.0 gstnet-1.0
> +WANTLIB += gstpbutils-1.0 gstreamer-1.0 gstriff-1.0 gstrtp-1.0
> +WANTLIB += gstrtsp-1.0 gstsdp-1.0 gsttag-1.0 gstvideo-1.0
>  WANTLIB += gtk-3 intl jpeg m mp3lame nettle opencore-amrnb opencore-amrwb
> -WANTLIB += orc-0.4 png shout speex tag twolame vpx wavpack xml2
> +WANTLIB += orc-0.4 png shout speex tag twolame v4l2 vpx wavpack xml2
>  WANTLIB += z
>  
>  LIB_DEPENDS=		multimedia/gstreamer1/plugins-base=${V} \
> @@ -25,6 +27,7 @@ LIB_DEPENDS=		multimedia/gstreamer1/plug
>  			audio/taglib \
>  			audio/twolame \
>  			audio/wavpack \
> +			multimedia/libv4l \
>  			multimedia/libvpx \
>  			net/libshout \
>  			x11/gtk+3
> @@ -52,10 +55,6 @@ CONFIGURE_ARGS=		-Daalib=disabled \
>  			-Dwaveform=disabled \
>  			-Dv4l2-gudev=disabled \
>  			-Drpicamsrc=disabled
> -
> -# XXX
> -# ../gst-plugins-good-1.26.1/sys/v4l2/gstv4l2object.c:601:25: error: use of undeclared identifier 'v4l2_ioctl_wrapper'
> -CONFIGURE_ARGS +=	-Dv4l2=disabled
>  
>  .if ${MACHINE_ARCH} == "amd64"
>  BUILD_DEPENDS +=	devel/nasm
> Index: patches/patch-sys_v4l2_gstv4l2object_c
> ===================================================================
> RCS file: /cvs/ports/multimedia/gstreamer1/plugins-good/patches/patch-sys_v4l2_gstv4l2object_c,v
> diff -u -p -r1.14 patch-sys_v4l2_gstv4l2object_c
> --- patches/patch-sys_v4l2_gstv4l2object_c	27 Jun 2025 10:12:15 -0000	1.14
> +++ patches/patch-sys_v4l2_gstv4l2object_c	14 Jul 2025 09:47:45 -0000
> @@ -1,6 +1,15 @@
>  Index: sys/v4l2/gstv4l2object.c
>  --- sys/v4l2/gstv4l2object.c.orig
>  +++ sys/v4l2/gstv4l2object.c
> +@@ -595,7 +595,7 @@ gst_v4l2_object_new (GstElement * element,
> +     v4l2object->fd_open = v4l2_fd_open;
> +     v4l2object->close = v4l2_close;
> +     v4l2object->dup = v4l2_dup;
> +-#ifdef __GLIBC__
> ++#if !defined(__linux__) || defined( __GLIBC__)
> +     v4l2object->ioctl = v4l2_ioctl;
> + #else
> +     v4l2object->ioctl = v4l2_ioctl_wrapper;
>  @@ -5332,7 +5332,9 @@ gst_v4l2_object_probe_caps (GstV4l2Object * v4l2object
>       if (v4l2object->ioctl (v4l2object->video_fd, VIDIOC_CROPCAP, &cropcap) < 0) {
>   
> Index: pkg/PLIST
> ===================================================================
> RCS file: /cvs/ports/multimedia/gstreamer1/plugins-good/pkg/PLIST,v
> diff -u -p -r1.6 PLIST
> --- pkg/PLIST	1 May 2025 06:55:57 -0000	1.6
> +++ pkg/PLIST	14 Jul 2025 09:47:45 -0000
> @@ -58,6 +58,7 @@
>  @so lib/gstreamer-${API}/libgsttaglib.so
>  @so lib/gstreamer-${API}/libgsttwolame.so
>  @so lib/gstreamer-${API}/libgstudp.so
> +@so lib/gstreamer-${API}/libgstvideo4linux2.so
>  @so lib/gstreamer-${API}/libgstvideobox.so
>  @so lib/gstreamer-${API}/libgstvideocrop.so
>  @so lib/gstreamer-${API}/libgstvideofilter.so
> 

-- 
Antoine