On Fri 10 August 2012 09:16:34 Hans de Goede wrote:
> Hi,
>
> On 08/09/2012 02:14 PM, Hans Verkuil wrote:
> > On Thu August 9 2012 13:58:07 Hans de Goede wrote:
> >> Hi Konke,
> >>
> >> As Gregor already mentioned there is no need to define libv4l2rdssubdir in configure.ac ,
> >> so please drop that.
> >>
> >> Other then that I've some minor remarks (comments inline), with all those
> >> fixed, this one is could to go. So hopefully the next version can be added
> >> to git master!
> >>
> >> On 08/07/2012 05:11 PM, Konke Radlow wrote:
> >>> ---
> >>> Makefile.am | 3 +-
> >>> configure.ac | 7 +-
> >>> lib/include/libv4l2rds.h | 228 ++++++++++
> >>> lib/libv4l2rds/Makefile.am | 11 +
> >>> lib/libv4l2rds/libv4l2rds.c | 953 +++++++++++++++++++++++++++++++++++++++
> >>> lib/libv4l2rds/libv4l2rds.pc.in | 11 +
> >>> 6 files changed, 1211 insertions(+), 2 deletions(-)
> >>> create mode 100644 lib/include/libv4l2rds.h
> >>> create mode 100644 lib/libv4l2rds/Makefile.am
> >>> create mode 100644 lib/libv4l2rds/libv4l2rds.c
> >>> create mode 100644 lib/libv4l2rds/libv4l2rds.pc.in
> >>>
> >>
> >> <snip>
> >>
> >>> diff --git a/lib/include/libv4l2rds.h b/lib/include/libv4l2rds.h
> >>> new file mode 100644
> >>> index 0000000..4aa8593
> >>> --- /dev/null
> >>> +++ b/lib/include/libv4l2rds.h
> >>> @@ -0,0 +1,228 @@
> >>> +/*
> >>> + * Copyright 2012 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
> >>> + * Author: Konke Radlow <koradlow@xxxxxxxxx>
> >>> + *
> >>> + * This program is free software; you can redistribute it and/or modify
> >>> + * it under the terms of the GNU Lesser General Public License as published by
> >>> + * the Free Software Foundation; either version 2.1 of the License, or
> >>> + * (at your option) any later version.
> >>> + *
> >>> + * This program is distributed in the hope that it will be useful,
> >>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> >>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> >>> + * GNU General Public License for more details.
> >>> + *
> >>> + * You should have received a copy of the GNU General Public License
> >>> + * along with this program; if not, write to the Free Software
> >>> + * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA
> >>> + */
> >>> +
> >>> +#ifndef __LIBV4L2RDS
> >>> +#define __LIBV4L2RDS
> >>> +
> >>> +#include <errno.h>
> >>> +#include <stdio.h>
> >>> +#include <stdlib.h>
> >>> +#include <string.h>
> >>> +#include <stdbool.h>
> >>> +#include <unistd.h>
> >>> +#include <stdint.h>
> >>> +#include <time.h>
> >>> +#include <sys/types.h>
> >>> +#include <sys/mman.h>
> >>> +#include <config.h>
> >>
> >> You should never include config.h in a public header, also
> >> are all the headers really needed for the prototypes in this header?
> >>
> >> I don't think so! Please move all the unneeded ones to the libv4l2rds.c
> >> file!
> >>
> >>> +
> >>> +#include <linux/videodev2.h>
> >>> +
> >>> +#ifdef __cplusplus
> >>> +extern "C" {
> >>> +#endif /* __cplusplus */
> >>> +
> >>> +#if HAVE_VISIBILITY
> >>> +#define LIBV4L_PUBLIC __attribute__ ((visibility("default")))
> >>> +#else
> >>> +#define LIBV4L_PUBLIC
> >>> +#endif
> >>> +
> >>> +/* used to define the current version (version field) of the v4l2_rds struct */
> >>> +#define V4L2_RDS_VERSION (1)
> >>> +
> >>
> >> What is the purpose of this field? Once we've released a v4l-utils with this
> >> library we are stuck to the API we've defined, having a version field & changing it,
> >> won't stop us from breaking existing apps, so once we've an official release we
> >> simply cannot make ABI breaking changes, which is why most of my review sofar
> >> has concentrated on the API side :)
> >>
> >> I suggest dropping this define and the version field from the struct.
> >
> > I think it is useful, actually. The v4l2_rds struct is allocated by the v4l2_rds_create
> > so at least in theory it is possible to extend the struct in the future without breaking
> > existing apps, provided you have a version number to check.
>
> I disagree, if it gets extended only, then existing apps will just work, if an apps gets
> compiled against a newer version with the extension then it is safe to assume it will run
> against that newer version. The only reason I can see a version define being useful is
> to make a newer app compile with an older version of the librarry, but that only requires
> a version define, not a version field in the struct.
That's true, you only need the define, not the version field.
So let's keep the define and ditch the version field. I think that
should do it.
Regards,
Hans
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