[FFmpeg-devel] [PATCH v4] avfilter: add pu21 filter
Frank Plowman
post at frankplowman.com
Sat Aug 31 20:20:38 EEST 2024
Hi,
Thanks for your patch.
On 23/08/2024 20:15, Rajiv Harlalka wrote:
> Adds the PU21 encoding filter for high dynamic range images and video
> quality assessment
> Mantiuk, R., & Azimi, M. PU21: A novel perceptually uniform encoding
> for adapting existing quality metrics for HDR
> https://github.com/gfxdisp/pu21
>
> Signed-off-by: Rajiv Harlalka <rajivharlalka009 at gmail.com>
> ---
> Changelog | 1 +
> libavfilter/Makefile | 1 +
> libavfilter/allfilters.c | 1 +
> libavfilter/version.h | 4 +-
> libavfilter/vf_pu21.c | 175 +++++++++++++++++++++++++++++++++++++++
> 5 files changed, 180 insertions(+), 2 deletions(-)
> create mode 100644 libavfilter/vf_pu21.c
>
> diff --git a/Changelog b/Changelog
> index 571b27ad98..552aa6028a 100644
> --- a/Changelog
> +++ b/Changelog
> @@ -18,6 +18,7 @@ version <next>:
> - D3D12VA HEVC encoder
> - Cropping metadata parsing and writing in Matroska and MP4/MOV de/muxers
> - Intel QSV-accelerated VVC decoding
> +- Addition of vf_pu21 encoding filter
>
>
> version 7.0:
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index 63088e9286..102315f5bf 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -121,6 +121,7 @@ OBJS-$(CONFIG_AXCORRELATE_FILTER) += af_axcorrelate.o
> OBJS-$(CONFIG_AZMQ_FILTER) += f_zmq.o
> OBJS-$(CONFIG_BANDPASS_FILTER) += af_biquads.o
> OBJS-$(CONFIG_BANDREJECT_FILTER) += af_biquads.o
> +OBJS-$(CONFIG_PU21_FILTER) += vf_pu21.o
This line should be inserted such that the list is in alphabetical order.
> OBJS-$(CONFIG_BASS_FILTER) += af_biquads.o
> OBJS-$(CONFIG_BIQUAD_FILTER) += af_biquads.o
> OBJS-$(CONFIG_BS2B_FILTER) += af_bs2b.o
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index 63600e9b58..ced076626c 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -231,6 +231,7 @@ extern const AVFilter ff_vf_convolution_opencl;
> extern const AVFilter ff_vf_convolve;
> extern const AVFilter ff_vf_copy;
> extern const AVFilter ff_vf_coreimage;
> +extern const AVFilter ff_vf_pu21;
This line should be inserted such that the list is in alphabetical order.
> extern const AVFilter ff_vf_corr;
> extern const AVFilter ff_vf_cover_rect;
> extern const AVFilter ff_vf_crop;
> diff --git a/libavfilter/version.h b/libavfilter/version.h
> index d8cd8a2cfb..7e0eb9af97 100644
> --- a/libavfilter/version.h
> +++ b/libavfilter/version.h
> @@ -31,8 +31,8 @@
>
> #include "version_major.h"
>
> -#define LIBAVFILTER_VERSION_MINOR 2
> -#define LIBAVFILTER_VERSION_MICRO 102
> +#define LIBAVFILTER_VERSION_MINOR 3
> +#define LIBAVFILTER_VERSION_MICRO 100
>
>
> #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
> diff --git a/libavfilter/vf_pu21.c b/libavfilter/vf_pu21.c
> new file mode 100644
> index 0000000000..64804ce60b
> --- /dev/null
> +++ b/libavfilter/vf_pu21.c
> @@ -0,0 +1,175 @@
> +/*
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg 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.
> + *
> + * FFmpeg 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
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +#include "libavfilter/avfilter.h"
> +#include "libavutil/opt.h"
> +#include "libavutil/pixdesc.h"
> +#include "libavutil/mem.h"
> +#include "libavutil/imgutils.h"
> +#include "libavfilter/formats.h"
> +#include "libavutil/internal.h"
> +#include "video.h"
> +#include "libavutil/libm.h"
I think some of these includes are unused.
> +
> +enum {
> + BANDING,
> + BANDING_GLARE,
> + PEAKS,
> + PEAKS_GLARE
> +};
> +
> +typedef struct PU21Context {
> + const AVClass* class;
> + double L_min, L_max;
L_min and L_max are unused
> + int multiplier;
> + int mode;
> +
> + int depth;
> + int nb_planes;
> +} PU21Context;
> +
> +const float pu21_params[4][7] = {
> + // Reference: "PU21: A novel perceptually uniform encoding for adapting existing quality metrics for HDR"
> + // Rafał K. Mantiuk and M. Azimi, Picture Coding Symposium 2021
> + // https://github.com/gfxdisp/pu21
> + {1.070275272f, 0.4088273932f, 0.153224308f, 0.2520326168f, 1.063512885f, 1.14115047f, 521.4527484f}, // BANDING
> + {0.353487901f, 0.3734658629f, 8.277049286e-05f, 0.9062562627f, 0.09150303166f, 0.9099517204f, 596.3148142f}, // BANDING_GLARE
> + {1.043882782f, 0.6459495343f, 0.3194584211f, 0.374025247f, 1.114783422f, 1.095360363f, 384.9217577f}, // PEAKS
> + {816.885024f, 1479.463946f, 0.001253215609f, 0.9329636822f, 0.06746643971f, 1.573435413f, 419.6006374f} // PEAKS_GLARE
> +};
This variable should be marked static.
> +
> +
> +#define OFFSET(x) offsetof(PU21Context, x)
> +#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
> +static const AVOption pu21_options[] = {
> + { "multiplier", "multiplier for increasing the pixel value based on the screen display model", OFFSET(multiplier), AV_OPT_TYPE_INT, {.i64 = 1}, 1, 10000, FLAGS},
> + { "mode", "Set the mode of the PU21 encoding", OFFSET(mode), AV_OPT_TYPE_INT, {.i64 = BANDING_GLARE}, BANDING, PEAKS_GLARE, FLAGS},
> + { NULL }
> +};
> +
> +AVFILTER_DEFINE_CLASS(pu21);
> +
> +static av_cold int pu21_init(AVFilterContext* ctx) {
> + PU21Context* pu21 = ctx->priv;
> + pu21->mode = BANDING_GLARE;
> + pu21->multiplier = 1;
> + return 0;
> +}
> +
> +static float apply_pu21(float pixel_val, PU21Context* pu21) {
> + float Y, V;
> + const float* pu21_param = pu21_params[pu21->mode];
> + Y = pixel_val * (pu21->multiplier);
> + V = fmax(pu21_param[6] * (powf((pu21_param[0] + pu21_param[1] * powf(Y, pu21_param[3])) / (1 + pu21_param[2] * powf(Y, pu21_param[3])), pu21_param[4]) - pu21_param[5]), 0);
fmax acts on doubles so the result is being needlessly up-casted to a
double then immediately back down to a float. This could be avoided
with fmaxf.
Nit: This line is still very long, could you further break it up and/or
wrap it? Ideally giving names to some of the intermediate results to
aid readability.
> + return V;
> +}
> +
> +#define DEFINE_PU21_FILTER(name, type, div) \
> +static void pu21_encode_##name(AVFilterContext* ctx, AVFrame* in, AVFrame* out) \
> +{ \
> + PU21Context* pu21 = ctx->priv; \
> + const int height = in->height; \
> + const int width = in->width; \
> + \
> + int plane; \
> + for (plane = 0; plane < pu21->nb_planes; plane++) { \
> + const type* src = (const type *)in->data[plane]; \
> + type* dst = (type *)out->data[plane]; \
> + int linesize = in->linesize[plane] / div; \
Nit: extra space between int and linesize
> + type pixel_val; \
> + for (int y = 0; y < height; y++) { \
> + for (int x = 0; x < width; x++) { \
> + pixel_val = src[y * linesize + x]; \
> + dst[y * linesize + x] = (type)apply_pu21(pixel_val, pu21); \
This naive cast to/from floats might result in some floating-point
precision issues, particularly for u16 inputs. You could probably get a
better result by scaling to/from a more suitable range for the floats
(e.g. [0,1]) before/after calling apply_pu21. This is just a hunch
though, I imagine you will be better able than me to assess the impact
of such a change.
> + } \
> + } \
> + } \
> +}
> +
> +DEFINE_PU21_FILTER(8, uint8_t, 1)
> +DEFINE_PU21_FILTER(16, uint16_t, 2)
> +DEFINE_PU21_FILTER(32, float, 4)
The final parameter could be removed and replaced with sizeof(type) in
the macro body. This would be easier to follow and eliminate a
potential cause of a bug in future.
> +
> +static int filter_frame(AVFilterLink* inlink, AVFrame* input) {
Nit: As mentioned in my review of v2, FFmpeg uses K&R style where
opening and closing braces of function definitions are on their own
line, just like above for the pu21_encode_* functions.
> + AVFilterContext* ctx = inlink->dst;
> + PU21Context* pu21 = ctx->priv;
> +
> + AVFilterLink* outlink = ctx->outputs[0];
> + AVFrame* out;
> +
> + if (av_frame_is_writable(input)) {
> + out = input;
> + } else {
> + out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
> + if (!out) {
> + av_frame_free(&input);
> + return AVERROR(ENOMEM);
> + }
> + av_frame_copy_props(out, input);
> + }
> +
> + if (pu21->depth <= 8) {
> + pu21_encode_8(ctx, input, out);
> + } else if (pu21->depth <= 16) {
> + pu21_encode_16(ctx, input, out);
> + } else {
> + pu21_encode_32(ctx, input, out);
> + }
> +
> + if (out != input)
> + av_frame_free(&input);
> + return ff_filter_frame(outlink, out);
> +}
> +
> +
> +static int config_input(AVFilterLink* inlink) {
> + const AVPixFmtDescriptor* desc = av_pix_fmt_desc_get(inlink->format);
> + PU21Context* s = inlink->dst->priv;
> +
> + s->depth = desc->comp[0].depth;
> + s->nb_planes = av_pix_fmt_count_planes(inlink->format);
> +
> + return 0;
> +}
> +
> +static const AVFilterPad pu21_inputs[] = {
> + {
> + .name = "default",
> + .type = AVMEDIA_TYPE_VIDEO,
> + .config_props = config_input,
> + .filter_frame = filter_frame,
> + }
> +};
> +
> +static const AVFilterPad pu21_outputs[] = {
> + {
> + .name = "default",
> + .type = AVMEDIA_TYPE_VIDEO,
> + }
> +};
> +
> +const AVFilter ff_vf_pu21 = {
> + .name = "pu21",
> + .description = NULL_IF_CONFIG_SMALL("Convert HDR linear values to PU values using PU21 transform"),
> + .priv_size = sizeof(PU21Context),
> + .init = pu21_init,
> + FILTER_INPUTS(pu21_inputs),
> + FILTER_OUTPUTS(pu21_outputs),
> + .priv_class = &pu21_class,
> + .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
> +};
--
Cheers,
Frank
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