[Spice-devel] [spice-server v6 7/9] reds: drop sscanf() in favour of g_strsplit()

[Victor Toso]

Hi,

On Thu, Feb 02, 2017 at 04:45:28AM -0500, Frediano Ziglio wrote:
> >
> > On Wed, Feb 01, 2017 at 01:39:26PM +0100, Victor Toso wrote:
> > > Hi,
> > >
> > > On Tue, Jan 31, 2017 at 03:54:01PM +0100, Christophe Fergeau wrote:
> > > > On Tue, Jan 31, 2017 at 07:16:04AM -0500, Frediano Ziglio wrote:
> > > > > >
> > > > > > From: Victor Toso <me at victortoso.com>
> > > > > >
> > > > > > As there is a need to iterate over every encoder:codec pair and we
> > > > > > do a check for every encoder and every codec, g_strsplit() is less
> > > > > > complex and easier to follow.
> > > > > >
> > > > > > This change makes much easier to extend the input which is
> > > > > > currently a list of tuples encoder:video-codec.
> > > > > >
> > > > > > Signed-off-by: Victor Toso <victortoso at redhat.com>
> > > > >
> > > > > I had a though this morning about the syntax.
> > > > >
> > > > > We are moving from a set or "encoder:codec" separated with ";" to a
> > > > > set of "encoder:codec:priority". All this to allow same priority in
> > > > > the list. Why not having a "light" separator, something like
> > > > >
> > > > > "gstreamer:vp8 gstreamer:h264;gstreamer:h264;spice:mjpeg"
> > > > >
> > > > > (not the space). So the first 2 will have same "priority" while the
> > > > > others less (but different) ?
> > > >
> > > > Do we need to have an extra-smart string-based syntax like this? Or
> > > > can we side-step this problem by having a higher-level API?
> > >
> > > Indeed, if it gets too complex, an extra API would be better.
> > > If we agree in having an extra API, we can drop this patch but
> > > suggestions for the API are welcome :)
> >
> > My plan was all along to figure out the API while adding support for
> > this in QEMU/libvirt, but I never got to it. So no idea :)
> >
> > Christophe
> >
>
> Something like
>
> typedef struct SpiceCodec {
>    const char *encoder;
>    const char *codec;
>    uint8_t priority;
> } SpiceCodec;
>
> int spice_server_set_video_codecs(SpiceServer *reds,
>                                   const SpiceCodecs *codecs, unsigned num_codecs);
>
>
> Qemu is quite command line friendly so having a string as Victor
> proposed is not that terrible.
>
> libvirt is building Qemu command line from an XML file so it could be not
> a string but a structure like
>
>    <video-codecs>
>      <video-codec>
>        <encoder>gstreamer</encoder>
>        <codec>mjpeg</codec>
>        <priority>1</priority>
>      </video-codec>
>    </video-codecs>
>
> but still would have to build something for Qemu, maybe a multiple argument like
>   -qxl-video-codec gstreamer:vp8:1 -qxl-video-codec gstreamer:mjpeg:1
> (or some options for qxl)

Something like this looks good to me.

I'll drop this g_strsplit() patch and also some other patches from spicy
and resend later today. My goal is to keep the bare minimal around
preferred-video-codec message which is already upstream.

Cheers,

>
> Recently I was working on OpenSSL and the cipher suite string, the
> string is flexible but the parsing/filtering/ordering is possibly
> quite complicated (https://linux.die.net/man/1/ciphers).
>
> Frediano
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