[FFmpeg-devel] [PATCH V1 1/2] lavfi/vf_scale_vaapi: add scaling mode setting support.

[Li, Zhong]

> -----Original Message-----
> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On Behalf
> Of Li, Zhong
> Sent: Tuesday, January 15, 2019 5:58 PM
> To: FFmpeg development discussions and patches
> <ffmpeg-devel at ffmpeg.org>
> Subject: Re: [FFmpeg-devel] [PATCH V1 1/2] lavfi/vf_scale_vaapi: add scaling
> mode setting support.
> 
> 
> 
> > -----Original Message-----
> > From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On
> Behalf
> > Of Mark Thompson
> > Sent: Monday, December 10, 2018 2:26 AM
> > To: ffmpeg-devel at ffmpeg.org
> > Subject: Re: [FFmpeg-devel] [PATCH V1 1/2] lavfi/vf_scale_vaapi: add
> > scaling mode setting support.
> >
> > On 06/12/2018 10:39, Jun Zhao wrote:
> > > before this change, scale_vaapi hard coding the scaling mode, add a
> > > new option "mode" to setting the scaling mode, it can be use to
> > > change scaling algorithm for performance/quality trade off.
> > >
> > > Signed-off-by: Jun Zhao <mypopydev at gmail.com>
> > > ---
> > >  libavfilter/vf_scale_vaapi.c |   33
> > ++++++++++++++++++++++++++++++---
> > >  1 files changed, 30 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/libavfilter/vf_scale_vaapi.c
> > > b/libavfilter/vf_scale_vaapi.c index d6529d5..ad222e6 100644
> > > --- a/libavfilter/vf_scale_vaapi.c
> > > +++ b/libavfilter/vf_scale_vaapi.c
> > > @@ -35,10 +35,26 @@ typedef struct ScaleVAAPIContext {
> > >
> > >      char *output_format_string;
> > >
> > > +    int   mode;
> > > +
> > >      char *w_expr;      // width expression string
> > >      char *h_expr;      // height expression string
> > >  } ScaleVAAPIContext;
> > >
> > > +static const char *scale_vaapi_mode_name(int mode) {
> > > +    switch (mode) {
> > > +#define D(name) case VA_FILTER_SCALING_ ## name: return #name
> > > +        D(DEFAULT);
> > > +        D(FAST);
> > > +        D(HQ);
> > > +#undef D
> > > +    default:
> > > +        return "Invalid";
> > > +    }
> > > +}
> > > +
> > > +
> > >  static int scale_vaapi_config_output(AVFilterLink *outlink)  {
> > >      AVFilterLink *inlink     = outlink->src->inputs[0];
> > > @@ -70,6 +86,7 @@ static int scale_vaapi_filter_frame(AVFilterLink
> > *inlink, AVFrame *input_frame)
> > >      AVFilterContext *avctx   = inlink->dst;
> > >      AVFilterLink *outlink    = avctx->outputs[0];
> > >      VAAPIVPPContext *vpp_ctx = avctx->priv;
> > > +    ScaleVAAPIContext *ctx   = avctx->priv;
> > >      AVFrame *output_frame    = NULL;
> > >      VASurfaceID input_surface, output_surface;
> > >      VAProcPipelineParameterBuffer params; @@ -119,7 +136,7 @@
> > static
> > > int scale_vaapi_filter_frame(AVFilterLink *inlink, AVFrame *input_frame)
> > >      params.output_color_standard = params.surface_color_standard;
> > >
> > >      params.pipeline_flags = 0;
> > > -    params.filter_flags = VA_FILTER_SCALING_HQ;
> > > +    params.filter_flags |= ctx->mode;
> >
> > "=" would feel safer - "|=" implies something else might have been
> > setting it as well.
> >
> > >
> > >      err = ff_vaapi_vpp_render_picture(avctx, &params,
> > output_surface);
> > >      if (err < 0)
> > > @@ -131,9 +148,10 @@ static int
> > > scale_vaapi_filter_frame(AVFilterLink
> > > *inlink, AVFrame *input_frame)
> > >
> > >      av_frame_free(&input_frame);
> > >
> > > -    av_log(avctx, AV_LOG_DEBUG, "Filter output: %s, %ux%u
> > (%"PRId64").\n",
> > > +    av_log(avctx, AV_LOG_DEBUG, "Filter output: %s, %ux%u
> > > + (%"PRId64"), mode: %s.\n",
> > >             av_get_pix_fmt_name(output_frame->format),
> > > -           output_frame->width, output_frame->height,
> > output_frame->pts);
> > > +           output_frame->width, output_frame->height,
> > output_frame->pts,
> > > +           scale_vaapi_mode_name(ctx->mode));
> > >
> > >      return ff_filter_frame(outlink, output_frame);
> > >
> > > @@ -174,6 +192,15 @@ static const AVOption scale_vaapi_options[] = {
> > >        OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, .flags =
> > FLAGS },
> > >      { "format", "Output video format (software format of hardware
> > frames)",
> > >        OFFSET(output_format_string), AV_OPT_TYPE_STRING, .flags =
> > > FLAGS },
> > > +    { "mode", "Scaling mode",
> > > +      OFFSET(mode), AV_OPT_TYPE_INT, { .i64 =
> > VA_FILTER_SCALING_HQ },
> > > +      0, VA_FILTER_SCALING_NL_ANAMORPHIC, FLAGS, "mode" },
> >
> > NL_ANAMORPHIC mentioned in this limit but not offered as an option?
> >
> > > +    { "default", "Use the default (depend on the driver) scaling
> > algorithm",
> > > +      0, AV_OPT_TYPE_CONST, { .i64 =
> VA_FILTER_SCALING_DEFAULT },
> > 0, 0, FLAGS, "mode" },
> > > +    { "fast", "Use fast scaling algorithm",
> > > +      0, AV_OPT_TYPE_CONST, { .i64 = VA_FILTER_SCALING_FAST }, 0,
> > > + 0,
> > FLAGS, "mode" },
> > > +    { "hq", "Use high quality scaling algorithm",
> > > +      0, AV_OPT_TYPE_CONST, { .i64 = VA_FILTER_SCALING_HQ }, 0,
> 0,
> > > + FLAGS,  "mode" },
> > >      { NULL },
> > >  };
> > >
> > >
> >
> > LGTM in any case.
> >
> > (Ack on keeping the HQ default - IIRC the reason for choosing HQ as
> > the mode when this was written was that the default/fast mode was not
> > faster and had much worse quality on some of the older Intel platforms
> > (I would guess Bay Trail based on what I probably had available at the
> > time).  Might be worth investigating further if you have such machines
> > available to test.)
> 
> Current implementation is to set VA_FILTER_SCALING_HQ as default (if
> mode unset), but setting "mode=default" means
> VA_FILTER_SCALING_DEFAULT.
> Thus looks like a conflict and it is confusing.
> 
> I think would better to set the default mode to be
> VA_FILTER_SCALING_DEFAULT, and then driver will choose an appropriate
> mode.
> E.g: If SVC (Enabled started from Skylake:
> https://01.org/sites/default/files/documentation/intel-gfx-prm-osrc-skl-vol
> 15-sfc.pdf ) is supported by HW , SVC will be the scaling mode.

Sorry for the typo, it is SFC, not SVC.