avfilter: add scale_vt for videotoolbox pix_fmt

For example,

./ffmpeg -hwaccel videotoolbox \
	-hwaccel_output_format videotoolbox_vld \
	-i ios-265.mov \
	-c:v hevc_videotoolbox \
	-profile:v main \
	-b:v 3M \
	-vf scale_vt=w=iw/2:h=ih/2:color_matrix=bt709:color_primaries=bt709:color_transfer=bt709 \
	-c:a copy \
	-tag:v hvc1 \
	/tmp/test.mp4

Input: hevc (Main 10) (hvc1 / 0x31637668), yuv420p10le(tv, bt2020nc/bt2020/arib-std-b67), 3840x2160
Output: hevc (Main) (hvc1 / 0x31637668), yuv420p(tv, bt709, progressive), 1920x1080
Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>

4 files changed, 248 insertions, 2 deletions

diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 9b7813575a..ef2c87104f 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -457,6 +457,7 @@ OBJS-$(CONFIG_SCALE_CUDA_FILTER)             += vf_scale_cuda.o scale_eval.o \
 OBJS-$(CONFIG_SCALE_NPP_FILTER)              += vf_scale_npp.o scale_eval.o
 OBJS-$(CONFIG_SCALE_QSV_FILTER)              += vf_vpp_qsv.o
 OBJS-$(CONFIG_SCALE_VAAPI_FILTER)            += vf_scale_vaapi.o scale_eval.o vaapi_vpp.o
+OBJS-$(CONFIG_SCALE_VT_FILTER)               += vf_scale_vt.o scale_eval.o
 OBJS-$(CONFIG_SCALE_VULKAN_FILTER)           += vf_scale_vulkan.o vulkan.o vulkan_filter.o
 OBJS-$(CONFIG_SCALE2REF_FILTER)              += vf_scale.o scale_eval.o
 OBJS-$(CONFIG_SCALE2REF_NPP_FILTER)          += vf_scale_npp.o scale_eval.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 9a7fadc58d..fefaa94d2b 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -427,6 +427,7 @@ extern const AVFilter ff_vf_scale_cuda;
 extern const AVFilter ff_vf_scale_npp;
 extern const AVFilter ff_vf_scale_qsv;
 extern const AVFilter ff_vf_scale_vaapi;
+extern const AVFilter ff_vf_scale_vt;
 extern const AVFilter ff_vf_scale_vulkan;
 extern const AVFilter ff_vf_scale2ref;
 extern const AVFilter ff_vf_scale2ref_npp;
diff --git a/libavfilter/version.h b/libavfilter/version.h
index c001693e3c..77f38cb9b4 100644
--- a/libavfilter/version.h
+++ b/libavfilter/version.h
@@ -31,8 +31,8 @@
 
 #include "version_major.h"
 
-#define LIBAVFILTER_VERSION_MINOR   8
-#define LIBAVFILTER_VERSION_MICRO 102
+#define LIBAVFILTER_VERSION_MINOR   9
+#define LIBAVFILTER_VERSION_MICRO 100
 
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
diff --git a/libavfilter/vf_scale_vt.c b/libavfilter/vf_scale_vt.c
new file mode 100644
index 0000000000..a7f72c8de9
--- /dev/null
+++ b/libavfilter/vf_scale_vt.c
@@ -0,0 +1,244 @@
+/*
+ * Copyright (c) 2023 Zhao Zhili <zhilizhao@tencent.com>
+ *
+ * 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 <VideoToolbox/VideoToolbox.h>
+
+#include "libavutil/hwcontext.h"
+#include "libavutil/hwcontext_videotoolbox.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+#include "internal.h"
+#include "scale_eval.h"
+
+typedef struct ScaleVtContext {
+    AVClass *class;
+
+    VTPixelTransferSessionRef transfer;
+    int output_width;
+    int output_height;
+    char *w_expr;
+    char *h_expr;
+
+    enum AVColorPrimaries colour_primaries;
+    enum AVColorTransferCharacteristic colour_transfer;
+    enum AVColorSpace colour_matrix;
+    char *colour_primaries_string;
+    char *colour_transfer_string;
+    char *colour_matrix_string;
+} ScaleVtContext;
+
+static av_cold int scale_vt_init(AVFilterContext *avctx)
+{
+    ScaleVtContext *s = avctx->priv;
+    int ret;
+    CFStringRef value;
+
+    ret = VTPixelTransferSessionCreate(kCFAllocatorDefault, &s->transfer);
+    if (ret != noErr) {
+        av_log(avctx, AV_LOG_ERROR, "transfer session create failed, %d\n", ret);
+        return AVERROR_EXTERNAL;
+    }
+
+#define STRING_OPTION(var_name, func_name, default_value)                \
+    do {                                                                 \
+        if (s->var_name##_string) {                                      \
+            int var = av_##func_name##_from_name(s->var_name##_string);  \
+            if (var < 0) {                                               \
+                av_log(avctx, AV_LOG_ERROR, "Invalid %s.\n", #var_name); \
+                return AVERROR(EINVAL);                                  \
+            }                                                            \
+            s->var_name = var;                                           \
+        } else {                                                         \
+            s->var_name = default_value;                                 \
+        }                                                                \
+    } while (0)
+
+    STRING_OPTION(colour_primaries, color_primaries, AVCOL_PRI_UNSPECIFIED);
+    STRING_OPTION(colour_transfer,  color_transfer,  AVCOL_TRC_UNSPECIFIED);
+    STRING_OPTION(colour_matrix,    color_space,     AVCOL_SPC_UNSPECIFIED);
+
+    if (s->colour_primaries != AVCOL_PRI_UNSPECIFIED) {
+        value = av_map_videotoolbox_color_primaries_from_av(s->colour_primaries);
+        if (!value) {
+            av_log(avctx, AV_LOG_ERROR,
+                   "Doesn't support converting to colour primaries %s\n",
+                   s->colour_primaries_string);
+            return AVERROR(ENOTSUP);
+        }
+        VTSessionSetProperty(s->transfer, kVTPixelTransferPropertyKey_DestinationColorPrimaries, value);
+    }
+
+    if (s->colour_transfer != AVCOL_TRC_UNSPECIFIED) {
+        value = av_map_videotoolbox_color_trc_from_av(s->colour_transfer);
+        if (!value) {
+            av_log(avctx, AV_LOG_ERROR,
+                   "Doesn't support converting to trc %s\n",
+                   s->colour_transfer_string);
+            return AVERROR(ENOTSUP);
+        }
+        VTSessionSetProperty(s->transfer, kVTPixelTransferPropertyKey_DestinationTransferFunction, value);
+    }
+
+    if (s->colour_matrix != AVCOL_SPC_UNSPECIFIED) {
+        value = av_map_videotoolbox_color_matrix_from_av(s->colour_matrix);
+        if (!value) {
+            av_log(avctx, AV_LOG_ERROR,
+                   "Doesn't support converting to colorspace %s\n",
+                   s->colour_matrix_string);
+            return AVERROR(ENOTSUP);
+        }
+        VTSessionSetProperty(s->transfer, kVTPixelTransferPropertyKey_DestinationYCbCrMatrix, value);
+    }
+
+    return 0;
+}
+
+static av_cold void scale_vt_uninit(AVFilterContext *avctx)
+{
+    ScaleVtContext *s = avctx->priv;
+
+    if (s->transfer) {
+        VTPixelTransferSessionInvalidate(s->transfer);
+        CFRelease(s->transfer);
+        s->transfer = NULL;
+    }
+}
+
+static int scale_vt_filter_frame(AVFilterLink *link, AVFrame *in)
+{
+    int ret;
+    AVFilterContext *ctx = link->dst;
+    ScaleVtContext *s = ctx->priv;
+    AVFilterLink *outlink = ctx->outputs[0];
+    CVPixelBufferRef src;
+    CVPixelBufferRef dst;
+
+    AVFrame *out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+    if (!out) {
+        ret = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    ret = av_frame_copy_props(out, in);
+    if (ret < 0)
+        goto fail;
+
+    av_reduce(&out->sample_aspect_ratio.num, &out->sample_aspect_ratio.den,
+              (int64_t)in->sample_aspect_ratio.num * outlink->h * link->w,
+              (int64_t)in->sample_aspect_ratio.den * outlink->w * link->h,
+              INT_MAX);
+    if (s->colour_primaries != AVCOL_PRI_UNSPECIFIED)
+        out->color_primaries = s->colour_primaries;
+    if (s->colour_transfer != AVCOL_TRC_UNSPECIFIED)
+        out->color_trc = s->colour_transfer;
+    if (s->colour_matrix != AVCOL_SPC_UNSPECIFIED)
+        out->colorspace = s->colour_matrix;
+
+    src = (CVPixelBufferRef)in->data[3];
+    dst = (CVPixelBufferRef)out->data[3];
+    ret = VTPixelTransferSessionTransferImage(s->transfer, src, dst);
+    if (ret != noErr) {
+        av_log(ctx, AV_LOG_ERROR, "transfer image failed, %d\n", ret);
+        ret = AVERROR_EXTERNAL;
+        goto fail;
+    }
+
+    av_frame_free(&in);
+
+    return ff_filter_frame(outlink, out);
+
+fail:
+    av_frame_free(&in);
+    av_frame_free(&out);
+    return ret;
+}
+
+static int scale_vt_config_output(AVFilterLink *outlink)
+{
+    int err;
+    AVFilterContext *avctx = outlink->src;
+    ScaleVtContext *s  = avctx->priv;
+    AVFilterLink *inlink = outlink->src->inputs[0];
+
+    err = ff_scale_eval_dimensions(s, s->w_expr, s->h_expr, inlink, outlink,
+                                   &s->output_width,
+                                   &s->output_height);
+    if (err < 0)
+        return err;
+
+    outlink->w = s->output_width;
+    outlink->h = s->output_height;
+
+    if (inlink->sample_aspect_ratio.num) {
+        AVRational r = {outlink->h * inlink->w, outlink->w * inlink->h};
+        outlink->sample_aspect_ratio = av_mul_q(r, inlink->sample_aspect_ratio);
+    } else {
+        outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
+    }
+
+    return 0;
+}
+
+#define OFFSET(x) offsetof(ScaleVtContext, x)
+#define FLAGS (AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_VIDEO_PARAM)
+static const AVOption scale_vt_options[] = {
+    { "w", "Output video width",
+            OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, .flags = FLAGS },
+    { "h", "Output video height",
+            OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, .flags = FLAGS },
+    { "color_matrix", "Output colour matrix coefficient set",
+            OFFSET(colour_matrix_string), AV_OPT_TYPE_STRING, { .str = NULL }, .flags = FLAGS },
+    { "color_primaries", "Output colour primaries",
+            OFFSET(colour_primaries_string), AV_OPT_TYPE_STRING, { .str = NULL }, .flags = FLAGS },
+    { "color_transfer", "Output colour transfer characteristics",
+            OFFSET(colour_transfer_string),  AV_OPT_TYPE_STRING, { .str = NULL }, .flags = FLAGS },
+    { NULL },
+};
+
+AVFILTER_DEFINE_CLASS(scale_vt);
+
+static const AVFilterPad scale_vt_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .filter_frame = &scale_vt_filter_frame,
+    },
+};
+
+static const AVFilterPad scale_vt_outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+        .config_props = &scale_vt_config_output,
+    },
+};
+
+const AVFilter ff_vf_scale_vt = {
+    .name           = "scale_vt",
+    .description    = NULL_IF_CONFIG_SMALL("Scale Videotoolbox frames"),
+    .priv_size      = sizeof(ScaleVtContext),
+    .init           = scale_vt_init,
+    .uninit         = scale_vt_uninit,
+    FILTER_INPUTS(scale_vt_inputs),
+    FILTER_OUTPUTS(scale_vt_outputs),
+    FILTER_SINGLE_PIXFMT(AV_PIX_FMT_VIDEOTOOLBOX),
+    .priv_class     = &scale_vt_class,
+    .flags          = AVFILTER_FLAG_HWDEVICE,
+};