On Thu, 2021-08-19 at 04:44 +0000, Xiang, Haihao wrote:
> On Wed, 2021-08-04 at 05:17 +0000, Soft Works wrote:
> > > -----Original Message-----
> > > From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
> > > Haihao Xiang
> > > Sent: Tuesday, 29 June 2021 03:46
> > > To: ffmpeg-devel at ffmpeg.org
> > > Cc: Haihao Xiang <haihao.xiang at intel.com>
> > > Subject: [FFmpeg-devel] [PATCH] ffmpeg_hw: make hardware selection for
> > > filters more user friendly
> > >
> > > When a device is derived from a source device, there are at least 2
> > > devices,
> > > and usually the derived device is the expected device, so let's pick the
> > > last
> > > device if user doesn't specify the filter device with filter_hw_device
> > > option
> > >
> > > After applying this patch, the command below can work:
> > >
> > > $> ffmpeg -init_hw_device vaapi=va:/dev/dri/renderD128 -init_hw_device
> > > qsv=hw at va -f lavfi -i yuvtestsrc -vf
> > > format=nv12,hwupload=extra_hw_frames=64 -c:v h264_qsv -y out.h264
> > > ---
> > > fftools/ffmpeg_hw.c | 20 +++++++++++++-------
> > > 1 file changed, 13 insertions(+), 7 deletions(-)
> > >
> > > diff --git a/fftools/ffmpeg_hw.c b/fftools/ffmpeg_hw.c index
> > > fc4a5d31d6..14e2cb0177 100644
> > > --- a/fftools/ffmpeg_hw.c
> > > +++ b/fftools/ffmpeg_hw.c
> > > @@ -527,15 +527,21 @@ int hw_device_setup_for_filter(FilterGraph *fg)
> > > HWDevice *dev;
> > > int i;
> > >
> > > - // If the user has supplied exactly one hardware device then just
> > > - // give it straight to every filter for convenience. If more than
> > > - // one device is available then the user needs to pick one explcitly
> > > - // with the filter_hw_device option.
> > > + // Pick the last hardware device if the user doesn't pick the device
> > > for
> > > + // filters explicitly with the filter_hw_device option.
> > > if (filter_hw_device)
> > > dev = filter_hw_device;
> > > - else if (nb_hw_devices == 1)
> > > - dev = hw_devices[0];
> > > - else
> > > + else if (nb_hw_devices > 0) {
> > > + dev = hw_devices[nb_hw_devices - 1];
> > > +
> > > + if (nb_hw_devices > 1)
> > > + av_log(NULL, AV_LOG_WARNING, "There are %d hardware devices.
> > > device "
> > > + "%s of type %s is picked for filters by default. Set
> > > hardware "
> > > + "device explicitly with the filter_hw_device option if
> > > device "
> > > + "%s is not usable for filters.\n",
> > > + nb_hw_devices, dev->name,
> > > + av_hwdevice_get_type_name(dev->type), dev->name);
> > > + } else
> > > dev = NULL;
> > >
> > > if (dev) {
> > > --
> >
> > Haihao,
> >
> > Thanks for the patch, I hadn't seen it. Due to working off an older baseline
> > version, I wasn't actually aware of the current code which had been added
> > by
> > Mark Thompson in April 2020:
> >
> > - when a single hw device is initialized, all filters are automatically set
> > to
> > that device context
> > - when more than one device is initialized, it silently does nothing
> >
> > This leads to the following behavior: you have a working command line with a
> > single device. Then you add initialization for a second device and the
> > command
> > line stops working.
> >
> > @mark - would you mind to comment?
> > I suppose the idea was that when there's more than a single device, the user
> > needs to set filter_hw_device explicitly. But IMO, this doesn't go well
> > together with making an automatic selection: either there's always an
> > automatic selection or never, but the current behavior is confusing.
> >
> > Now, that there's already an automatic selection for cases with a single
> > device, the "never" option is practically off the table. For those reasons,
> > Haihao's patch would LGTM.
> >
>
> Could someone help to merge this patch if no more comment ?
Ping again.
Thanks
Haihao