[FFmpeg-devel] lavfi: add lumakey_opencl filter

diff --git a/configure b/configure
index 5783407..9816ebb 100755
--- a/configure
+++ b/configure
@@ -3356,6 +3356,7 @@  interlace_filter_deps="gpl"
 kerndeint_filter_deps="gpl"
 ladspa_filter_deps="ladspa libdl"
 lensfun_filter_deps="liblensfun version3"
+lumakey_opencl_filter_deps="opencl"
 lv2_filter_deps="lv2"
 mcdeint_filter_deps="avcodec gpl"
 movie_filter_deps="avcodec avformat"
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 5d4549e..2a01bf3 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -253,6 +253,8 @@  OBJS-$(CONFIG_LIBVMAF_FILTER)                += vf_libvmaf.o framesync.o
 OBJS-$(CONFIG_LIMITER_FILTER)                += vf_limiter.o
 OBJS-$(CONFIG_LOOP_FILTER)                   += f_loop.o
 OBJS-$(CONFIG_LUMAKEY_FILTER)                += vf_lumakey.o
+OBJS-$(CONFIG_LUMAKEY_OPENCL_FILTER)         += vf_lumakey_opencl.o opencl.o \
+                                                opencl/lumakey.o
 OBJS-$(CONFIG_LUT_FILTER)                    += vf_lut.o
 OBJS-$(CONFIG_LUT2_FILTER)                   += vf_lut2.o framesync.o
 OBJS-$(CONFIG_LUT3D_FILTER)                  += vf_lut3d.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 521bc53..065ad9f 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -242,6 +242,7 @@  extern AVFilter ff_vf_libvmaf;
 extern AVFilter ff_vf_limiter;
 extern AVFilter ff_vf_loop;
 extern AVFilter ff_vf_lumakey;
+extern AVFilter ff_vf_lumakey_opencl;
 extern AVFilter ff_vf_lut;
 extern AVFilter ff_vf_lut2;
 extern AVFilter ff_vf_lut3d;
diff --git a/libavfilter/opencl/lumakey.cl b/libavfilter/opencl/lumakey.cl
new file mode 100644
index 0000000..dbee63e
--- /dev/null
+++ b/libavfilter/opencl/lumakey.cl
@@ -0,0 +1,43 @@ 
+/*
+ * Copyright (c) 2018 Danil Iashchenko
+ *
+ * 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
+ */
+
+__kernel void lumakey_global(__write_only image2d_t dstAlpha,
+                             __read_only  image2d_t srcLuma,
+                             float w,
+                             float b,
+                             int so)
+{
+    const sampler_t sampler = (CLK_NORMALIZED_COORDS_FALSE |
+                               CLK_ADDRESS_CLAMP_TO_EDGE   |
+                               CLK_FILTER_NEAREST);
+
+    int2 loc = (int2)(get_global_id(0), get_global_id(1));
+    float4 lumaPix = read_imagef(srcLuma,  sampler, loc) * 255;
+
+    if (lumaPix.x >= b && lumaPix.x <= w) {
+        write_imagef(dstAlpha, loc, (float4)(0.0f));
+    } else if (lumaPix.x > b - so && lumaPix.x < w + so) {
+        if (lumaPix.x < b) {
+            write_imagef(dstAlpha, loc, (float4)((1 - (lumaPix.x - b + so) / so)));
+        } else {
+            write_imagef(dstAlpha, loc, (float4)(((lumaPix.x - w) / so)));
+        }
+    }
+}
diff --git a/libavfilter/opencl_source.h b/libavfilter/opencl_source.h
index de4e66e..dba701e 100644
--- a/libavfilter/opencl_source.h
+++ b/libavfilter/opencl_source.h
@@ -22,6 +22,7 @@ 
 extern const char *ff_opencl_source_avgblur;
 extern const char *ff_opencl_source_colorspace_common;
 extern const char *ff_opencl_source_convolution;
+extern const char *ff_opencl_source_lumakey;
 extern const char *ff_opencl_source_overlay;
 extern const char *ff_opencl_source_tonemap;
 extern const char *ff_opencl_source_unsharp;
diff --git a/libavfilter/vf_lumakey_opencl.c b/libavfilter/vf_lumakey_opencl.c
new file mode 100644
index 0000000..8879a88
--- /dev/null
+++ b/libavfilter/vf_lumakey_opencl.c
@@ -0,0 +1,243 @@ 
+/*
+ * Copyright (c) 2018 Danil Iashchenko
+ *
+ * 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 "libavutil/common.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/opt.h"
+
+
+#include "avfilter.h"
+#include "internal.h"
+#include "opencl.h"
+#include "opencl_source.h"
+#include "video.h"
+
+typedef struct LumakeyOpenCLContext {
+    OpenCLFilterContext ocf;
+
+    int              initialised;
+    cl_kernel        kernel;
+    cl_command_queue command_queue;
+
+    cl_int threshold;
+    cl_int tolerance;
+    cl_int softness;
+
+    cl_float black;
+    cl_float white;
+
+} LumakeyOpenCLContext;
+
+static int lumakey_opencl_init(AVFilterContext *avctx)
+{
+    LumakeyOpenCLContext *ctx = avctx->priv;
+    cl_int cle;
+    int err;
+
+    err = ff_opencl_filter_load_program(avctx, &ff_opencl_source_lumakey, 1);
+    if (err < 0)
+        goto fail;
+
+    ctx->command_queue = clCreateCommandQueue(ctx->ocf.hwctx->context,
+                                              ctx->ocf.hwctx->device_id,
+                                              0, &cle);
+    CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to create OpenCL "
+                     "command queue %d.\n", cle);
+
+    ctx->kernel = clCreateKernel(ctx->ocf.program, "lumakey_global", &cle);
+    CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to create "
+                     "kernel %d.\n", cle);
+
+    ctx->initialised = 1;
+    return 0;
+
+fail:
+    if (ctx->command_queue)
+        clReleaseCommandQueue(ctx->command_queue);
+    if (ctx->kernel)
+        clReleaseKernel(ctx->kernel);
+    return err;
+}
+
+
+static int lumakey_opencl_filter_frame(AVFilterLink *inlink, AVFrame *input)
+{
+    AVFilterContext *avctx = inlink->dst;
+    AVFilterLink *outlink = avctx->outputs[0];
+    LumakeyOpenCLContext *ctx = avctx->priv;
+    AVFrame *output = NULL;
+    cl_int cle;
+    size_t global_work[2];
+    cl_mem src, dst;
+    int err, i;
+    size_t origin[3] = {0, 0, 0};
+    size_t region[3] = {0, 0, 1};
+
+    av_log(ctx, AV_LOG_DEBUG, "Filter input: %s, %ux%u (%"PRId64").\n",
+           av_get_pix_fmt_name(input->format),
+           input->width, input->height, input->pts);
+
+    if (!input->hw_frames_ctx)
+        return AVERROR(EINVAL);
+
+    if (!ctx->initialised) {
+        err = lumakey_opencl_init(avctx);
+        if (err < 0)
+            goto fail;
+
+        ctx->white = ctx->threshold + ctx->tolerance;
+        ctx->black = ctx->threshold - ctx->tolerance;
+    }
+
+    output = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+    if (!output) {
+        err = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    for (i = 0; i < FF_ARRAY_ELEMS(output->data) - 1; i++) {
+        src  = (cl_mem) input->data[i];
+        dst  = (cl_mem)output->data[i];
+
+        if (!dst)
+            break;
+
+        err = ff_opencl_filter_work_size_from_image(avctx, region, output, i, 0);
+        if (err < 0)
+            goto fail;
+
+        cle = clEnqueueCopyImage(ctx->command_queue, src, dst,
+                                 origin, origin, region, 0, NULL, NULL);
+        CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to copy plane %d: %d.\n",
+                         i, cle);
+    }
+
+    src = (cl_mem) input->data[0];
+    dst = (cl_mem)output->data[3];
+
+    CL_SET_KERNEL_ARG(ctx->kernel, 0, cl_mem,   &dst);
+    CL_SET_KERNEL_ARG(ctx->kernel, 1, cl_mem,   &src);
+    CL_SET_KERNEL_ARG(ctx->kernel, 2, cl_float, &ctx->white);
+    CL_SET_KERNEL_ARG(ctx->kernel, 3, cl_float, &ctx->black);
+    CL_SET_KERNEL_ARG(ctx->kernel, 4, cl_int,   &ctx->softness);
+
+    err = ff_opencl_filter_work_size_from_image(avctx, global_work, output, 0, 0);
+    if (err < 0)
+        goto fail;
+
+    av_log(avctx, AV_LOG_DEBUG, "Run kernel on plane %d"
+           "(%"SIZE_SPECIFIER"x%"SIZE_SPECIFIER").\n",
+           0, global_work[0], global_work[1]);
+
+    cle = clEnqueueNDRangeKernel(ctx->command_queue, ctx->kernel, 2, NULL,
+                                 global_work, NULL,
+                                 0, NULL, NULL);
+    CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to enqueue "
+                     "kernel: %d.\n", cle);
+
+
+    cle = clFinish(ctx->command_queue);
+    CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to finish command queue: %d.\n", cle);
+
+    err = av_frame_copy_props(output, input);
+    if (err < 0)
+        goto fail;
+
+    av_frame_free(&input);
+
+    av_log(ctx, AV_LOG_DEBUG, "Filter output: %s, %ux%u (%"PRId64").\n",
+           av_get_pix_fmt_name(output->format),
+           output->width, output->height, output->pts);
+
+    return ff_filter_frame(outlink, output);
+
+fail:
+    clFinish(ctx->command_queue);
+    av_frame_free(&input);
+    av_frame_free(&output);
+    return err;
+}
+
+
+static av_cold void lumakey_opencl_uninit(AVFilterContext *avctx)
+{
+    LumakeyOpenCLContext *ctx = avctx->priv;
+    cl_int cle;
+
+    if (ctx->kernel) {
+        cle = clReleaseKernel(ctx->kernel);
+        if (cle != CL_SUCCESS)
+            av_log(avctx, AV_LOG_ERROR, "Failed to release "
+                   "kernel: %d.\n", cle);
+    }
+
+    if (ctx->command_queue) {
+        cle = clReleaseCommandQueue(ctx->command_queue);
+        if (cle != CL_SUCCESS)
+            av_log(avctx, AV_LOG_ERROR, "Failed to release "
+                   "command queue: %d.\n", cle);
+    }
+
+    ff_opencl_filter_uninit(avctx);
+}
+
+static const AVFilterPad lumakey_opencl_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .filter_frame = &lumakey_opencl_filter_frame,
+        .config_props = &ff_opencl_filter_config_input,
+    },
+    { NULL }
+};
+
+static const AVFilterPad lumakey_opencl_outputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = &ff_opencl_filter_config_output,
+    },
+    { NULL }
+};
+
+#define OFFSET(x) offsetof(LumakeyOpenCLContext, x)
+#define FLAGS (AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_VIDEO_PARAM)
+
+static const AVOption lumakey_opencl_options[] = {
+    { "threshold", "set the threshold value", OFFSET(threshold), AV_OPT_TYPE_INT, {.i64=0}, 0, UINT16_MAX, FLAGS },
+    { "tolerance", "set the tolerance value", OFFSET(tolerance), AV_OPT_TYPE_INT, {.i64=1}, 0, UINT16_MAX, FLAGS },
+    { "softness",  "set the softness value",  OFFSET(softness),  AV_OPT_TYPE_INT, {.i64=0}, 0, UINT16_MAX, FLAGS },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(lumakey_opencl);
+
+AVFilter ff_vf_lumakey_opencl = {
+    .name           = "lumakey_opencl",
+    .description    = NULL_IF_CONFIG_SMALL("Apply convolution mask to input video"),
+    .priv_size      = sizeof(LumakeyOpenCLContext),
+    .priv_class     = &lumakey_opencl_class,
+    .init           = &ff_opencl_filter_init,
+    .uninit         = &lumakey_opencl_uninit,
+    .query_formats  = &ff_opencl_filter_query_formats,
+    .inputs         = lumakey_opencl_inputs,
+    .outputs        = lumakey_opencl_outputs,
+    .flags_internal = FF_FILTER_FLAG_HWFRAME_AWARE,
+};