[FFmpeg-devel,v6] avfilter: add OpenCL scale filter

Submitted by Gabriel Machado on April 12, 2018, 10:29 p.m.

Details

Message ID RO1PR80MB00596E54B15439F9EBD0121DE7BC0@RO1PR80MB0059.lamprd80.prod.outlook.com
State New
Headers show

Commit Message

Gabriel Machado April 12, 2018, 10:29 p.m.
On 4/8/18 11:37 PM Song, Ruiling wrote:
> > +    float2 src_coord = (convert_float2(dst_pos) + 0.5) / dst_size;
> For the floating point constant, it is better to add suffix 'f' to the number to tell the compiler that this is a single floating point value (like 0.5f).
> The reason is if no suffix provided, floating point constants will be treated as double precision float number.
> OpenCL C language derive this feature from C language. And most GPUs are performance sensitive to single floating point/ double floating point operations.
> If you intentionally need double precision, it is ok to leave it as it is.
> There are also some other places like this in the OpenCL file.

Changed to floating point constants, thanks.

- Gabriel

From b5cbdef9abc3727e1456915e50bbf1d9c87751d7 Mon Sep 17 00:00:00 2001
From: Gabriel Machado <gabriel_machado@live.com>
Date: Sat, 31 Mar 2018 23:03:18 -0300
Subject: [PATCH] avfilter: add OpenCL scale filter

---
 configure                     |   1 +
 libavfilter/Makefile          |   1 +
 libavfilter/allfilters.c      |   1 +
 libavfilter/opencl/scale.cl   |  67 ++++++
 libavfilter/opencl_source.h   |   1 +
 libavfilter/vf_scale_opencl.c | 544 ++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 615 insertions(+)
 create mode 100644 libavfilter/opencl/scale.cl
 create mode 100644 libavfilter/vf_scale_opencl.c

Patch hide | download patch | download mbox

diff --git a/configure b/configure
index 1e192f8..7d0858c 100755
--- a/configure
+++ b/configure
@@ -2879,6 +2879,7 @@  v4l2_m2m_deps_any="linux_videodev2_h"
 
 hwupload_cuda_filter_deps="ffnvcodec"
 scale_npp_filter_deps="ffnvcodec libnpp"
+scale_opencl_filter_deps="opencl"
 scale_cuda_filter_deps="cuda_sdk"
 thumbnail_cuda_filter_deps="cuda_sdk"
 
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index a90ca30..6303cbd 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -302,6 +302,7 @@  OBJS-$(CONFIG_SAB_FILTER)                    += vf_sab.o
 OBJS-$(CONFIG_SCALE_FILTER)                  += vf_scale.o scale.o
 OBJS-$(CONFIG_SCALE_CUDA_FILTER)             += vf_scale_cuda.o vf_scale_cuda.ptx.o
 OBJS-$(CONFIG_SCALE_NPP_FILTER)              += vf_scale_npp.o scale.o
+OBJS-$(CONFIG_SCALE_OPENCL_FILTER)           += vf_scale_opencl.o opencl.o opencl/scale.o
 OBJS-$(CONFIG_SCALE_QSV_FILTER)              += vf_scale_qsv.o
 OBJS-$(CONFIG_SCALE_VAAPI_FILTER)            += vf_scale_vaapi.o scale.o vaapi_vpp.o
 OBJS-$(CONFIG_SCALE2REF_FILTER)              += vf_scale.o scale.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 6eac828..3073881 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -293,6 +293,7 @@  extern AVFilter ff_vf_sab;
 extern AVFilter ff_vf_scale;
 extern AVFilter ff_vf_scale_cuda;
 extern AVFilter ff_vf_scale_npp;
+extern AVFilter ff_vf_scale_opencl;
 extern AVFilter ff_vf_scale_qsv;
 extern AVFilter ff_vf_scale_vaapi;
 extern AVFilter ff_vf_scale2ref;
diff --git a/libavfilter/opencl/scale.cl b/libavfilter/opencl/scale.cl
new file mode 100644
index 0000000..6583bb5
--- /dev/null
+++ b/libavfilter/opencl/scale.cl
@@ -0,0 +1,67 @@ 
+/*
+ * Copyright (c) 2018 Gabriel Machado
+ *
+ * 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 neighbor(__write_only image2d_t dst,
+                       __read_only  image2d_t src)
+{
+    const sampler_t sampler = (CLK_NORMALIZED_COORDS_TRUE |
+                               CLK_ADDRESS_CLAMP_TO_EDGE |
+                               CLK_FILTER_NEAREST);
+
+    int2 dst_pos = {get_global_id(0), get_global_id(1)};
+    float2 dst_size = {get_global_size(0), get_global_size(1)};
+
+    float2 src_coord = (convert_float2(dst_pos) + 0.5f) / dst_size;
+
+    float4 c = read_imagef(src, sampler, src_coord);
+    write_imagef(dst, dst_pos, c);
+}
+
+__kernel void scale(__write_only image2d_t dst,
+                    __read_only  image2d_t src,
+                    __constant   float    *cx,
+                    __constant   float    *cy,
+                                 int2      flt_size)
+{
+    const sampler_t s_img = (CLK_NORMALIZED_COORDS_FALSE |
+                             CLK_ADDRESS_CLAMP_TO_EDGE |
+                             CLK_FILTER_NEAREST);
+
+    int2 dst_pos = {get_global_id(0), get_global_id(1)};
+
+    float2 dst_size = {get_global_size(0), get_global_size(1)};
+    float2 src_size = convert_float2(get_image_dim(src));
+
+    float2 src_coord = (convert_float2(dst_pos) + 0.5f) * src_size / dst_size;
+
+    int2 src_pos = convert_int2(floor(src_coord - 0.5f));
+
+    float4 col = 0.0f;
+    for (int i = 0; i < flt_size.y; ++i) {
+        float4 s = 0.0f;
+        for (int j = 0; j < flt_size.x; ++j) {
+            float4 c = read_imagef(src, s_img, src_pos + (int2){flt_size.x/2 - j, flt_size.y/2 - i});
+            s += c * cx[dst_pos.x * flt_size.x + j];
+        }
+        col += s * cy[dst_pos.y * flt_size.y + i];
+    }
+
+    write_imagef(dst, dst_pos, col);
+}
diff --git a/libavfilter/opencl_source.h b/libavfilter/opencl_source.h
index 4bb9969..e3bb887 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_convolution;
 extern const char *ff_opencl_source_overlay;
+extern const char *ff_opencl_source_scale;
 extern const char *ff_opencl_source_unsharp;
 
 #endif /* AVFILTER_OPENCL_SOURCE_H */
diff --git a/libavfilter/vf_scale_opencl.c b/libavfilter/vf_scale_opencl.c
new file mode 100644
index 0000000..250edc4
--- /dev/null
+++ b/libavfilter/vf_scale_opencl.c
@@ -0,0 +1,544 @@ 
+/*
+ * Copyright (c) 2018 Gabriel Machado
+ *
+ * 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/mem.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+
+#include "avfilter.h"
+#include "internal.h"
+#include "opencl.h"
+#include "opencl_source.h"
+#include "scale.h"
+#include "video.h"
+
+enum filters {
+    F_AREA,
+    F_BICUBIC,
+    F_BILINEAR,
+    F_GAUSSIAN,
+    F_LANCZOS,
+    F_NEIGHBOR,
+    F_SINC,
+    F_SPLINE,
+    F_EXPERIMENTAL
+};
+
+static int filter_radius[] = {
+    [F_AREA]         =  1,
+    [F_BICUBIC]      =  2,
+    [F_BILINEAR]     =  1,
+    [F_GAUSSIAN]     =  4,
+    [F_LANCZOS]      =  3,
+    [F_NEIGHBOR]     = -1,
+    [F_SINC]         =  10,
+    [F_SPLINE]       =  10,
+    [F_EXPERIMENTAL] =  4
+};
+
+typedef struct ScaleOpenCLContext {
+    OpenCLFilterContext ocf;
+
+    cl_command_queue command_queue;
+    cl_mem           cx, cy;
+    cl_kernel        kernel;
+    const char      *kernel_name;
+
+    char *w_expr,  *h_expr;
+    int   dst_w,    dst_h;
+    int   src_w,    src_h;
+    int   algorithm;
+
+    cl_int2   flt_size;
+    int       initialised;
+} ScaleOpenCLContext;
+
+static float netravali(float t, float B, float C)
+{
+    if (t > 2) {
+        return 0;
+    } else {
+        float tt  = t*t;
+        float ttt = t*tt;
+        if (t < 1) {
+            return ((12 -  9 * B - 6 * C) * ttt +
+                   (-18 + 12 * B + 6 * C) * tt  +
+                     (6 -  2 * B)) / 6;
+        } else {
+            return     ((-B -  6 * C) * ttt +
+                     (6 * B + 30 * C) * tt +
+                   (-12 * B - 48 * C) * t +
+                     (8 * B + 24 * C)) / 6;
+        }
+    }
+}
+
+static float sinc(float t)
+{
+    return (t == 0) ? 1.0 : sin(t * M_PI) / (t * M_PI);
+}
+
+static float lanczos(float t, float a)
+{
+    return (t < a) ? sinc(t) * sinc(t / a) : 0;
+}
+
+static double spline(double a, double b, double c, double d, double dist)
+{
+    if (dist <= 1.0)
+        return ((d * dist + c) * dist + b) * dist + a;
+    else
+        return spline(0.0,
+                      b + 2.0 * c + 3.0 * d,
+                      c + 3.0 * d,
+                      -b - 3.0 * c - 6.0 * d,
+                      dist - 1.0);
+}
+
+static float calc_weight(int algorithm, float ratio, float t)
+{
+    t = fabs(t);
+
+    switch (algorithm) {
+        case F_AREA: {
+            float t2 = t - 0.5;
+            if (t2 * ratio < -0.5)
+                return 1;
+            else if (t2 * ratio < 0.5)
+                return -t2 * ratio + 0.5;
+            else
+                return 0;
+        }
+
+        case F_BICUBIC: {
+            const float B = 0, C = 0.6;
+            return netravali(t, B, C);
+        }
+
+        case F_BILINEAR:
+            return t < 1 ? (1 - t) : 0;
+
+        case F_EXPERIMENTAL: {
+            double A = 1.0;
+            double c;
+
+            if (t < 1.0)
+                c = cos(t * M_PI);
+            else
+                c = -1.0;
+            if (c < 0.0)
+                c = -pow(-c, A);
+            else
+                c = pow(c, A);
+            return c * 0.5 + 0.5;
+        }
+
+        case F_GAUSSIAN: {
+            const float p = 3.0;
+            return exp2(-p * t * t);
+        }
+
+        case F_LANCZOS: {
+            return lanczos(t, filter_radius[algorithm]);
+        }
+
+        case F_NEIGHBOR:
+            return 1;
+
+        case F_SINC:
+            return sinc(t);
+
+        case F_SPLINE: {
+            const double p = -2.196152422706632;
+            return spline(1.0, 0.0, p, -p - 1.0, t);
+        }
+    }
+
+    return 0;
+}
+
+static int scale_opencl_init(AVFilterContext *avctx)
+{
+    ScaleOpenCLContext *ctx = avctx->priv;
+    cl_int cle;
+    int err;
+    int i, j;
+    int filterw, filterh;
+    float scalex, scaley;
+    float *cx = NULL, *cy = NULL;
+
+    if (ctx->algorithm == F_NEIGHBOR) {
+        ctx->kernel_name = "neighbor";
+    } else {
+        ctx->kernel_name = "scale";
+
+        scalex = FFMAX((float) ctx->src_w / ctx->dst_w, 1);
+        scaley = FFMAX((float) ctx->src_h / ctx->dst_h, 1);
+        filterw = ceil(2 * filter_radius[ctx->algorithm] * scalex);
+        filterh = ceil(2 * filter_radius[ctx->algorithm] * scaley);
+
+        filterw = FFMIN(filterw, ctx->src_w - 2);
+        filterw = FFMAX(filterw, 1);
+        filterh = FFMIN(filterh, ctx->src_h - 2);
+        filterh = FFMAX(filterh, 1);
+
+        ctx->flt_size.s[0] = filterw;
+        ctx->flt_size.s[1] = filterh;
+
+        av_log(avctx, AV_LOG_INFO, "filter size: %d %d.\n", filterw, filterh);
+
+        cx = av_malloc_array(ctx->dst_w * filterw, sizeof(cl_float));
+        cy = av_malloc_array(ctx->dst_h * filterh, sizeof(cl_float));
+
+        if (!cx || !cy) {
+            err = AVERROR(ENOMEM);
+            goto fail;
+        }
+
+        for (i = 0; i < ctx->dst_w; ++i) {
+            float s_x = (i + 0.5) * ctx->src_w / ctx->dst_w - 0.5;
+            float t = s_x - floor(s_x);  // fract
+
+            float sum = 0;
+            for (j = 0; j < filterw; ++j) {
+                int x = filterw/2 - j;
+                sum += cx[i * filterw + j] = calc_weight(ctx->algorithm,
+                                                         scalex,
+                                                         (x - t) / scalex);
+            }
+
+            for (j = 0; j < filterw; ++j)
+                cx[i * filterw + j] /= sum;
+        }
+
+        for (i = 0; i < ctx->dst_h; ++i) {
+            float s_y = (i + 0.5) * ctx->src_h / ctx->dst_h - 0.5;
+            float t = s_y - floor(s_y);  // fract
+
+            float sum = 0;
+            for (j = 0; j < filterh; ++j) {
+                int y = filterh/2 - j;
+                sum += cy[i * filterh + j] = calc_weight(ctx->algorithm,
+                                                         scaley,
+                                                         (y - t) / scaley);
+            }
+
+            for (j = 0; j < filterh; ++j)
+                cy[i * filterh + j] /= sum;
+        }
+
+        ctx->cx = clCreateBuffer(ctx->ocf.hwctx->context,
+                                 CL_MEM_READ_ONLY     |
+                                 CL_MEM_COPY_HOST_PTR |
+                                 CL_MEM_HOST_NO_ACCESS,
+                                 ctx->dst_w * filterw * sizeof(cl_float),
+                                 cx,
+                                 &cle);
+
+        ctx->cy = clCreateBuffer(ctx->ocf.hwctx->context,
+                                 CL_MEM_READ_ONLY     |
+                                 CL_MEM_COPY_HOST_PTR |
+                                 CL_MEM_HOST_NO_ACCESS,
+                                 ctx->dst_h * filterh * sizeof(cl_float),
+                                 cy,
+                                 &cle);
+        av_free(cx);
+        av_free(cy);
+        if (!ctx->cx || !ctx->cy) {
+            av_log(avctx, AV_LOG_ERROR, "Failed to create weights buffer: %d.\n", cle);
+            err = AVERROR(EIO);
+            goto fail;
+        }
+    }
+
+    err = ff_opencl_filter_load_program(avctx, &ff_opencl_source_scale, 1);
+    if (err < 0)
+        goto fail;
+
+    ctx->command_queue = clCreateCommandQueue(ctx->ocf.hwctx->context,
+                                              ctx->ocf.hwctx->device_id,
+                                              0, &cle);
+    if (!ctx->command_queue) {
+        av_log(avctx, AV_LOG_ERROR, "Failed to create OpenCL command queue: %d.\n", cle);
+        err = AVERROR(EIO);
+        goto fail;
+    }
+
+    ctx->kernel = clCreateKernel(ctx->ocf.program, ctx->kernel_name, &cle);
+    if (!ctx->kernel) {
+        av_log(avctx, AV_LOG_ERROR, "Failed to create kernel: %d.\n", cle);
+        err = AVERROR(EIO);
+        goto fail;
+    }
+
+    ctx->initialised = 1;
+
+    return 0;
+
+fail:
+    if (ctx->command_queue)
+        clReleaseCommandQueue(ctx->command_queue);
+    if (ctx->kernel)
+        clReleaseKernel(ctx->kernel);
+    if (ctx->cx)
+        clReleaseMemObject(ctx->cx);
+    if (ctx->cy)
+        clReleaseMemObject(ctx->cy);
+    if (cx)
+        av_free(cx);
+    if (cy)
+        av_free(cy);
+    return err;
+}
+
+static int config_input_props(AVFilterLink *inlink)
+{
+    AVFilterContext  *avctx = inlink->dst;
+    AVFilterLink   *outlink = avctx->outputs[0];
+    ScaleOpenCLContext *ctx = avctx->priv;
+    int ret;
+
+    if ((ret = ff_scale_eval_dimensions(ctx,
+                                        ctx->w_expr, ctx->h_expr,
+                                        inlink, outlink,
+                                        &ctx->dst_w, &ctx->dst_h)) < 0)
+        return ret;
+
+    if (((int64_t) ctx->dst_h * inlink->w) > INT_MAX  ||
+        ((int64_t) ctx->dst_w * inlink->h) > INT_MAX)
+        av_log(ctx, AV_LOG_ERROR, "Rescaled value for width or height is too big.\n");
+
+    ctx->ocf.output_width  = ctx->dst_w;
+    ctx->ocf.output_height = ctx->dst_h;
+    ctx->src_w = inlink->w;
+    ctx->src_h = inlink->h;
+
+    return ff_opencl_filter_config_input(inlink);
+}
+
+static int scale_opencl_filter_frame(AVFilterLink *inlink, AVFrame *input)
+{
+    AVFilterContext     *avctx = inlink->dst;
+    AVFilterLink      *outlink = avctx->outputs[0];
+    ScaleOpenCLContext    *ctx = avctx->priv;
+    AVHWFramesContext *main_fc = (AVHWFramesContext *) inlink->hw_frames_ctx->data;
+    const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(main_fc->sw_format);
+    AVFrame *output = NULL;
+
+    cl_int cle;
+    size_t global_work[2];
+    cl_mem src, dst;
+    int err, p;
+    int x_subsample = 1 << pix_desc->log2_chroma_w;
+    int y_subsample = 1 << pix_desc->log2_chroma_h;
+
+    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 = scale_opencl_init(avctx);
+        if (err < 0)
+            goto fail;
+    }
+
+    output = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+    if (!output) {
+        err = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    err = av_frame_copy_props(output, input);
+    if (err < 0)
+        goto fail;
+    output->width  = outlink->w;
+    output->height = outlink->h;
+
+    for (p = 0; p < FF_ARRAY_ELEMS(output->data); p++) {
+        src = (cl_mem) input->data[p];
+        dst = (cl_mem)output->data[p];
+
+        if (!dst)
+            break;
+
+        cle = clSetKernelArg(ctx->kernel, 0, sizeof(cl_mem), &dst);
+        if (cle != CL_SUCCESS) {
+            av_log(avctx, AV_LOG_ERROR, "Failed to set kernel "
+                   "destination image argument: %d.\n", cle);
+            goto fail;
+        }
+        cle = clSetKernelArg(ctx->kernel, 1, sizeof(cl_mem), &src);
+        if (cle != CL_SUCCESS) {
+            av_log(avctx, AV_LOG_ERROR, "Failed to set kernel "
+                   "source image argument: %d.\n", cle);
+            goto fail;
+        }
+
+        if (ctx->algorithm != F_NEIGHBOR) {
+            cle = clSetKernelArg(ctx->kernel, 2, sizeof(cl_mem), &ctx->cx);
+            if (cle != CL_SUCCESS) {
+                av_log(avctx, AV_LOG_ERROR, "Failed to set kernel "
+                "cx argument: %d.\n", cle);
+                goto fail;
+            }
+            cle = clSetKernelArg(ctx->kernel, 3, sizeof(cl_mem), &ctx->cy);
+            if (cle != CL_SUCCESS) {
+                av_log(avctx, AV_LOG_ERROR, "Failed to set kernel "
+                "cy argument: %d.\n", cle);
+                goto fail;
+            }
+            cle = clSetKernelArg(ctx->kernel, 4, sizeof(cl_int2), &ctx->flt_size);
+            if (cle != CL_SUCCESS) {
+                av_log(avctx, AV_LOG_ERROR, "Failed to set kernel "
+                "filter size argument: %d.\n", cle);
+                goto fail;
+            }
+        }
+
+        global_work[0] = output->width / (p ? x_subsample : 1);
+        global_work[1] = output->height / (p ? y_subsample : 1);
+
+        av_log(avctx, AV_LOG_DEBUG, "Run kernel on plane %d "
+               "(%"SIZE_SPECIFIER"x%"SIZE_SPECIFIER").\n",
+               p, global_work[0], global_work[1]);
+
+        cle = clEnqueueNDRangeKernel(ctx->command_queue, ctx->kernel, 2, NULL,
+                                     global_work, NULL, 0, NULL, NULL);
+        if (cle != CL_SUCCESS) {
+            av_log(avctx, AV_LOG_ERROR, "Failed to enqueue kernel: %d.\n", cle);
+            err = AVERROR(EIO);
+            goto fail;
+        }
+    }
+
+    cle = clFinish(ctx->command_queue);
+    if (cle != CL_SUCCESS) {
+        av_log(avctx, AV_LOG_ERROR, "Failed to finish command queue: %d.\n", cle);
+        err = AVERROR(EIO);
+        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 scale_opencl_uninit(AVFilterContext *avctx)
+{
+    ScaleOpenCLContext *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);
+    }
+
+    if (ctx->cx) {
+        cle = clReleaseMemObject(ctx->cx);
+        if (cle != CL_SUCCESS)
+            av_log(avctx, AV_LOG_ERROR, "Failed to release "
+            "weights buffer: %d.\n", cle);
+    }
+
+    if (ctx->cy) {
+        cle = clReleaseMemObject(ctx->cy);
+        if (cle != CL_SUCCESS)
+            av_log(avctx, AV_LOG_ERROR, "Failed to release "
+            "weights buffer: %d.\n", cle);
+    }
+
+    ff_opencl_filter_uninit(avctx);
+}
+
+#define OFFSET(x) offsetof(ScaleOpenCLContext, x)
+#define FLAGS (AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_VIDEO_PARAM)
+static const AVOption scale_opencl_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 },
+    { "algorithm",     "Scaling algorithm",   OFFSET(algorithm), AV_OPT_TYPE_INT,    { .i64 = F_BICUBIC      }, INT_MIN, INT_MAX, FLAGS, "algorithm" },
+    { "area",          "area averaging",      0,                 AV_OPT_TYPE_CONST,  { .i64 = F_AREA         }, 0, 0, FLAGS, "algorithm" },
+    { "bicubic",       "bicubic",             0,                 AV_OPT_TYPE_CONST,  { .i64 = F_BICUBIC      }, 0, 0, FLAGS, "algorithm" },
+    { "bilinear",      "bilinear",            0,                 AV_OPT_TYPE_CONST,  { .i64 = F_BILINEAR     }, 0, 0, FLAGS, "algorithm" },
+    { "experimental",  "experimental",        0,                 AV_OPT_TYPE_CONST,  { .i64 = F_EXPERIMENTAL }, 0, 0, FLAGS, "algorithm" },
+    { "gauss",         "Gaussian",            0,                 AV_OPT_TYPE_CONST,  { .i64 = F_GAUSSIAN     }, 0, 0, FLAGS, "algorithm" },
+    { "lanczos",       "Lanczos",             0,                 AV_OPT_TYPE_CONST,  { .i64 = F_LANCZOS      }, 0, 0, FLAGS, "algorithm" },
+    { "neighbor",      "nearest neighbor",    0,                 AV_OPT_TYPE_CONST,  { .i64 = F_NEIGHBOR     }, 0, 0, FLAGS, "algorithm" },
+    { "sinc",          "sinc",                0,                 AV_OPT_TYPE_CONST,  { .i64 = F_SINC         }, 0, 0, FLAGS, "algorithm" },
+    { "spline",        "bicubic spline",      0,                 AV_OPT_TYPE_CONST,  { .i64 = F_SPLINE       }, 0, 0, FLAGS, "algorithm" },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(scale_opencl);
+
+static const AVFilterPad scale_opencl_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .filter_frame = &scale_opencl_filter_frame,
+        .config_props = &config_input_props,
+    },
+    { NULL }
+};
+
+static const AVFilterPad scale_opencl_outputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = &ff_opencl_filter_config_output,
+    },
+    { NULL }
+};
+
+AVFilter ff_vf_scale_opencl = {
+    .name           = "scale_opencl",
+    .description    = NULL_IF_CONFIG_SMALL("Scale the input video size."),
+    .priv_size      = sizeof(ScaleOpenCLContext),
+    .priv_class     = &scale_opencl_class,
+    .init           = &ff_opencl_filter_init,
+    .uninit         = &scale_opencl_uninit,
+    .query_formats  = &ff_opencl_filter_query_formats,
+    .inputs         = scale_opencl_inputs,
+    .outputs        = scale_opencl_outputs,
+    .flags_internal = FF_FILTER_FLAG_HWFRAME_AWARE,
+};