[FFmpeg-devel] [PATCH] lavfi: add nlmeans_opencl filter

Mark Thompson sw at jkqxz.net
Mon Apr 8 23:25:48 EEST 2019


On 01/04/2019 08:52, Ruiling Song wrote:
> Signed-off-by: Ruiling Song <ruiling.song at intel.com>
> ---
> This filter runs about 2x faster on integrated GPU than nlmeans on my Skylake CPU.
> Anybody like to give some comments?

Nice!

>  configure                       |   1 +
>  doc/filters.texi                |   4 +
>  libavfilter/Makefile            |   1 +
>  libavfilter/allfilters.c        |   1 +
>  libavfilter/opencl/nlmeans.cl   | 108 +++++++++
>  libavfilter/opencl_source.h     |   1 +
>  libavfilter/vf_nlmeans_opencl.c | 390 ++++++++++++++++++++++++++++++++
>  7 files changed, 506 insertions(+)
>  create mode 100644 libavfilter/opencl/nlmeans.cl
>  create mode 100644 libavfilter/vf_nlmeans_opencl.c
> 
> diff --git a/configure b/configure
> index f6123f53e5..a233512491 100755
> --- a/configure
> +++ b/configure
> @@ -3460,6 +3460,7 @@ mpdecimate_filter_select="pixelutils"
>  minterpolate_filter_select="scene_sad"
>  mptestsrc_filter_deps="gpl"
>  negate_filter_deps="lut_filter"
> +nlmeans_opencl_filter_deps="opencl"
>  nnedi_filter_deps="gpl"
>  ocr_filter_deps="libtesseract"
>  ocv_filter_deps="libopencv"
> diff --git a/doc/filters.texi b/doc/filters.texi
> index 867607d870..21c2c1a4b5 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -19030,6 +19030,10 @@ Apply erosion filter with threshold0 set to 30, threshold1 set 40, threshold2 se
>  @end example
>  @end itemize
>  
> + at section nlmeans_opencl
> +
> +Non-local Means denoise filter through OpenCL, this filter accepts same options as @ref{nlmeans}.
> +
>  @section overlay_opencl
>  
>  Overlay one video on top of another.
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index fef6ec5c55..92039bfdcf 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -291,6 +291,7 @@ OBJS-$(CONFIG_MIX_FILTER)                    += vf_mix.o
>  OBJS-$(CONFIG_MPDECIMATE_FILTER)             += vf_mpdecimate.o
>  OBJS-$(CONFIG_NEGATE_FILTER)                 += vf_lut.o
>  OBJS-$(CONFIG_NLMEANS_FILTER)                += vf_nlmeans.o
> +OBJS-$(CONFIG_NLMEANS_OPENCL_FILTER)         += vf_nlmeans_opencl.o opencl.o opencl/nlmeans.o
>  OBJS-$(CONFIG_NNEDI_FILTER)                  += vf_nnedi.o
>  OBJS-$(CONFIG_NOFORMAT_FILTER)               += vf_format.o
>  OBJS-$(CONFIG_NOISE_FILTER)                  += vf_noise.o
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index c51ae0f3c7..2a6390c92d 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -277,6 +277,7 @@ extern AVFilter ff_vf_mix;
>  extern AVFilter ff_vf_mpdecimate;
>  extern AVFilter ff_vf_negate;
>  extern AVFilter ff_vf_nlmeans;
> +extern AVFilter ff_vf_nlmeans_opencl;
>  extern AVFilter ff_vf_nnedi;
>  extern AVFilter ff_vf_noformat;
>  extern AVFilter ff_vf_noise;
> diff --git a/libavfilter/opencl/nlmeans.cl b/libavfilter/opencl/nlmeans.cl
> new file mode 100644
> index 0000000000..dcb04834ca
> --- /dev/null
> +++ b/libavfilter/opencl/nlmeans.cl
> @@ -0,0 +1,108 @@
> +/*
> + * 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
> + */
> +
> +const sampler_t sampler = (CLK_NORMALIZED_COORDS_FALSE |
> +                           CLK_ADDRESS_CLAMP_TO_EDGE   |
> +                           CLK_FILTER_NEAREST);
> +
> +kernel void horiz_sum(__global uint4 *ii,
> +                      __read_only image2d_t src,
> +                      int width,
> +                      int height,
> +                      int4 dx,
> +                      int4 dy)
> +{
> +
> +    int y = get_global_id(0);
> +    int work_size = get_global_size(0);
> +
> +    uint4 sum = (uint4)(0);
> +    float4 s2;
> +    for (int i = 0; i < width; i++) {
> +        float s1 = read_imagef(src, sampler, (int2)(i, y)).x;
> +        s2.x = read_imagef(src, sampler, (int2)(i+dx.x, y+dy.x)).x;
> +        s2.y = read_imagef(src, sampler, (int2)(i+dx.y, y+dy.y)).x;
> +        s2.z = read_imagef(src, sampler, (int2)(i+dx.z, y+dy.z)).x;
> +        s2.w = read_imagef(src, sampler, (int2)(i+dx.w, y+dy.w)).x;
> +        sum += convert_uint4((s1-s2)*(s1-s2) * 255*255);
> +        ii[y * width + i] = sum;
> +    }
> +}
> +
> +kernel void vert_sum(__global uint4 *ii,
> +                     int width,
> +                     int height)
> +{
> +    int x = get_global_id(0);
> +    uint4 sum = 0;
> +    for (int i = 0; i < height; i++) {
> +        ii[i * width + x] += sum;
> +        sum = ii[i * width + x];

This looks like it might be able to overflow in extreme cases?

3840 * 2160 * (1 - 0)^2 * 255 * 255 = 539,343,360,000 which is a long way out of range for a 32-bit int.  That requires impossible input (all pixels differing by the most extreme value), but something like a chequerboard might be of the same order?

> +    }
> +}
> +
> +kernel void weight_accum(global float *sum, global float *weight,
> +                         global uint4 *ii, __read_only image2d_t src,
> +                         int width, int height, int p, float h,
> +                         int4 dx, int4 dy)
> +{
> +    // w(x) = ii(x-p, y-p) + ii(x+p, y+p) - ii(x+p, y-p) - ii(x-p, y+p)
> +    // total_sum[x] += w(x, y) * src(x+dx, y+dy)
> +    // total_weight += w(x, y)
> +    int x = get_global_id(0);
> +    int y = get_global_id(1);
> +    int4 xoff = x+dx;
> +    int4 yoff = y+dy;
> +    uint4 a = 0, b = 0, c = 0, d = 0;
> +    uint4 src_pix = 0;
> +
> +    // out-of-bounding-box?
> +    int oobb = (x-p) < 0 || (y-p) < 0 || (y+p) >= height || (x+p) >= width;
> +
> +    src_pix.x = (int)(255 * read_imagef(src, sampler, (int2)(xoff.x, yoff.x)).x);
> +    src_pix.y = (int)(255 * read_imagef(src, sampler, (int2)(xoff.y, yoff.y)).x);
> +    src_pix.z = (int)(255 * read_imagef(src, sampler, (int2)(xoff.z, yoff.z)).x);
> +    src_pix.w = (int)(255 * read_imagef(src, sampler, (int2)(xoff.w, yoff.w)).x);
> +    if (!oobb) {
> +        a = ii[(y-p) * width + x - p];
> +        b = ii[(y + p) * width + x - p];
> +        c = ii[(y-p) * width + x + p];
> +        d = ii[(y + p) * width + x + p];
> +    }
> +
> +    float4 patch_diff = convert_float4(d + a - c - b);
> +    float4 w = native_exp(-patch_diff/(h*h));
> +    float w_sum = w.x + w.y + w.z + w.w;
> +    weight[y*width + x] += w_sum;
> +    sum[y*width + x] += dot(w, convert_float4(src_pix));
> +}

I feel like the global ii buffer in all of these functions could be given a clearer name based on what it's doing in that function.

> +
> +kernel void average(__write_only image2d_t dst,
> +                    __read_only image2d_t src,
> +                    global float *sum, global float *weight) {
> +    int x = get_global_id(0);
> +    int y = get_global_id(1);
> +    int2 dim = get_image_dim(dst);
> +
> +    float w = weight[y * dim.x + x];
> +    float s = sum[y*dim.x + x];
> +    float src_pix = read_imagef(src, sampler, (int2)(x, y)).x;
> +    float r = (s + src_pix * 255) / (1.0f + w) / 255.0f;
> +    if (x < dim.x && y < dim.y)
> +        write_imagef(dst, (int2)(x, y), (float4)(r, 0.0f, 0.0f, 1.0f));
> +}
> diff --git a/libavfilter/opencl_source.h b/libavfilter/opencl_source.h
> index 4118138c30..fd40fd7dca 100644
> --- a/libavfilter/opencl_source.h
> +++ b/libavfilter/opencl_source.h
> @@ -23,6 +23,7 @@ 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_neighbor;
> +extern const char *ff_opencl_source_nlmeans;
>  extern const char *ff_opencl_source_overlay;
>  extern const char *ff_opencl_source_tonemap;
>  extern const char *ff_opencl_source_transpose;
> diff --git a/libavfilter/vf_nlmeans_opencl.c b/libavfilter/vf_nlmeans_opencl.c
> new file mode 100644
> index 0000000000..0cc9af10da
> --- /dev/null
> +++ b/libavfilter/vf_nlmeans_opencl.c
> @@ -0,0 +1,390 @@
> +/*
> + * 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 <float.h>
> +
> +#include "libavutil/avassert.h"
> +#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 "video.h"
> +
> +static const enum AVPixelFormat supported_formats[] = {
> +    AV_PIX_FMT_YUV420P,
> +    AV_PIX_FMT_YUV444P,
> +    AV_PIX_FMT_GBRP,

YUV420P16, YUV444P16, GBRP16 probably also work with no change?

> +};
> +
> +static int is_format_supported(enum AVPixelFormat fmt)
> +{
> +    int i;
> +
> +    for (i = 0; i < FF_ARRAY_ELEMS(supported_formats); i++)
> +        if (supported_formats[i] == fmt)
> +            return 1;
> +    return 0;
> +}
> +
> +typedef struct NLMeansOpenCLContext {
> +    OpenCLFilterContext   ocf;
> +    int                   initialised;
> +    cl_kernel             vert_kernel;
> +    cl_kernel             horiz_kernel;
> +    cl_kernel             accum_kernel;
> +    cl_kernel             average_kernel;
> +    double                sigma;
> +    float                 h;
> +    int                   chroma_w;
> +    int                   chroma_h;
> +    int                   patch_size;
> +    int                   patch_size_uv;
> +    int                   research_size;
> +    int                   research_size_uv;
> +    cl_command_queue      command_queue;
> +} NLMeansOpenCLContext;
> +
> +static int nlmeans_opencl_init(AVFilterContext *avctx)
> +{
> +    NLMeansOpenCLContext *ctx = avctx->priv;
> +    cl_int cle;
> +    int err;
> +
> +    ctx->h = ctx->sigma * 10;
> +    if (!ctx->research_size_uv)
> +        ctx->research_size_uv = ctx->research_size;
> +    if (!ctx->patch_size_uv)
> +        ctx->patch_size_uv = ctx->patch_size;
> +
> +    err = ff_opencl_filter_load_program(avctx, &ff_opencl_source_nlmeans, 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->vert_kernel = clCreateKernel(ctx->ocf.program, "vert_sum", &cle);
> +    CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to create vert_sum kernel %d.\n", cle);
> +
> +    ctx->horiz_kernel = clCreateKernel(ctx->ocf.program, "horiz_sum", &cle);
> +    CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to create horiz_sum kernel %d.\n", cle);
> +
> +    ctx->accum_kernel = clCreateKernel(ctx->ocf.program, "weight_accum", &cle);
> +    CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to create accum kernel %d.\n", cle);
> +
> +    ctx->average_kernel = clCreateKernel(ctx->ocf.program, "average", &cle);
> +    CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to create average kernel %d.\n", cle);
> +
> +    ctx->initialised = 1;
> +    return 0;
> +
> +fail:
> +    if (ctx->command_queue)
> +        clReleaseCommandQueue(ctx->command_queue);
> +    if (ctx->vert_kernel)
> +        clReleaseKernel(ctx->vert_kernel);
> +    if (ctx->horiz_kernel)
> +        clReleaseKernel(ctx->horiz_kernel);
> +    if (ctx->accum_kernel)
> +        clReleaseKernel(ctx->accum_kernel);
> +    if (ctx->average_kernel)
> +        clReleaseKernel(ctx->average_kernel);
> +    return err;
> +}
> +
> +static int nlmeans_plane(AVFilterContext *avctx, cl_mem dst, cl_mem src,
> +                         int w, int h, int p, int r)
> +{
> +    NLMeansOpenCLContext *ctx = avctx->priv;
> +    const float zero = 0.0f;
> +    const size_t worksize1[] = {h};
> +    const size_t worksize2[] = {w};
> +    const size_t worksize3[2] = {w, h};
> +    int dx, dy, err = 0, weight_buf_size;
> +    cl_mem ii, weight, sum;
> +    cl_int cle;
> +    int nb_pixel, *tmp, *dxdy, idx = 0;

I think some of these should be cl_int since they are going to be used on the device side.

> +
> +    weight_buf_size = w * h * sizeof(int);

sizeof(cl_int)

> +    ii = clCreateBuffer(ctx->ocf.hwctx->context, 0, 4 * weight_buf_size,
> +                               NULL, &cle);
> +    weight = clCreateBuffer(ctx->ocf.hwctx->context, 0, weight_buf_size,
> +                               NULL, &cle);
> +    sum = clCreateBuffer(ctx->ocf.hwctx->context, 0, weight_buf_size,
> +                               NULL, &cle);

These allocations are unchecked.

The sizes shouldn't vary - is there any benefit to allocating the buffers once and them keeping them across iterations?  (Maybe it's swamped by other operations being slow anyway.)

> +    cle = clEnqueueFillBuffer(ctx->command_queue, weight, &zero, sizeof(float),
> +                              0, weight_buf_size, 0, NULL, NULL);
> +    CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to fill weight buffer: %d.\n",
> +                     cle);
> +    cle = clEnqueueFillBuffer(ctx->command_queue, sum, &zero, sizeof(float),
> +                              0, weight_buf_size, 0, NULL, NULL);
> +    CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to fill sum buffer: %d.\n",
> +                     cle);
> +
> +    nb_pixel = (2*r+1) *(2*r+1)-1;

Spaces around binary operators, please.  (Also in some places below.)

> +    dxdy = av_malloc(nb_pixel * 2 * sizeof(int));
> +    tmp = av_malloc(nb_pixel * 2 * sizeof(int));
> +
> +    if (!dxdy || !tmp)
> +        goto fail;
> +
> +    for (dx = -r; dx <= r; dx++) {
> +        for (dy = -r; dy <= r; dy++) {
> +            if (dx || dy) {
> +                tmp[idx++] = dx;
> +                tmp[idx++] = dy;
> +            }
> +        }
> +    }
> +    // repack dx/dy seperately, as we want to do four pairs of dx/dy in a batch
> +    for (int i = 0; i < nb_pixel/4;i++) {
> +        dxdy[i * 8] = tmp[i * 8];         // dx0
> +        dxdy[i * 8 + 1] = tmp[i * 8 + 2]; // dx1
> +        dxdy[i * 8 + 2] = tmp[i * 8 + 4]; // dx2
> +        dxdy[i * 8 + 3] = tmp[i * 8 + 6]; // dx3
> +        dxdy[i * 8 + 4] = tmp[i * 8 + 1]; // dy0
> +        dxdy[i * 8 + 5] = tmp[i * 8 + 3]; // dy1
> +        dxdy[i * 8 + 6] = tmp[i * 8 + 5]; // dy2
> +        dxdy[i * 8 + 7] = tmp[i * 8 + 7]; // dy3
> +    }
> +    av_freep(&tmp);
> +
> +    for (int i = 0; i < nb_pixel / 4; i++) {
> +        int *dx_cur = dxdy + 8 * i;
> +        int *dy_cur = dxdy + 8 * i + 4;
> +
> +        // ii(x,y) = sum of [u(i,y) - u(i+dx,y+dy)]^2 for all i < x
> +        CL_SET_KERNEL_ARG(ctx->horiz_kernel, 0, cl_mem, &ii);
> +        CL_SET_KERNEL_ARG(ctx->horiz_kernel, 1, cl_mem, &src);
> +        CL_SET_KERNEL_ARG(ctx->horiz_kernel, 2, cl_int, &w);
> +        CL_SET_KERNEL_ARG(ctx->horiz_kernel, 3, cl_int, &h);
> +        CL_SET_KERNEL_ARG(ctx->horiz_kernel, 4, cl_int4, dx_cur);
> +        CL_SET_KERNEL_ARG(ctx->horiz_kernel, 5, cl_int4, dy_cur);
> +        cle = clEnqueueNDRangeKernel(ctx->command_queue, ctx->horiz_kernel, 1,
> +                               NULL, worksize1, NULL, 0, NULL, NULL);
> +        CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to enqueue horiz_kernel: %d.\n",
> +                         cle);
> +
> +        // ii(x,y) = ii(x,0) + ii(x,1) +...+ ii(x,y-1)
> +        CL_SET_KERNEL_ARG(ctx->vert_kernel, 0, cl_mem, &ii);
> +        CL_SET_KERNEL_ARG(ctx->vert_kernel, 1, cl_int, &w);
> +        CL_SET_KERNEL_ARG(ctx->vert_kernel, 2, cl_int, &h);
> +        cle = clEnqueueNDRangeKernel(ctx->command_queue, ctx->vert_kernel,
> +                                     1, NULL, worksize2, NULL, 0, NULL, NULL);
> +        CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to enqueue vert_kernel: %d.\n",
> +                         cle);
> +
> +        // accumlate weights
> +        CL_SET_KERNEL_ARG(ctx->accum_kernel, 0, cl_mem, &sum);
> +        CL_SET_KERNEL_ARG(ctx->accum_kernel, 1, cl_mem, &weight);
> +        CL_SET_KERNEL_ARG(ctx->accum_kernel, 2, cl_mem, &ii);
> +        CL_SET_KERNEL_ARG(ctx->accum_kernel, 3, cl_mem, &src);
> +        CL_SET_KERNEL_ARG(ctx->accum_kernel, 4, cl_int, &w);
> +        CL_SET_KERNEL_ARG(ctx->accum_kernel, 5, cl_int, &h);
> +        CL_SET_KERNEL_ARG(ctx->accum_kernel, 6, cl_int, &p);
> +        CL_SET_KERNEL_ARG(ctx->accum_kernel, 7, cl_float, &ctx->h);
> +        CL_SET_KERNEL_ARG(ctx->accum_kernel, 8, cl_int4, dx_cur);
> +        CL_SET_KERNEL_ARG(ctx->accum_kernel, 9, cl_int4, dy_cur);
> +        cle = clEnqueueNDRangeKernel(ctx->command_queue, ctx->accum_kernel,
> +                                     2, NULL, worksize3, NULL, 0, NULL, NULL);
> +        CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to enqueue kernel: %d.\n", cle);
> +    }
> +    av_freep(&dxdy);
> +
> +    // average
> +    CL_SET_KERNEL_ARG(ctx->average_kernel, 0, cl_mem, &dst);
> +    CL_SET_KERNEL_ARG(ctx->average_kernel, 1, cl_mem, &src);
> +    CL_SET_KERNEL_ARG(ctx->average_kernel, 2, cl_mem, &sum);
> +    CL_SET_KERNEL_ARG(ctx->average_kernel, 3, cl_mem, &weight);
> +    cle = clEnqueueNDRangeKernel(ctx->command_queue, ctx->average_kernel, 2,
> +                                 NULL, worksize3, NULL, 0, NULL, NULL);
> +    CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to enqueue average kernel: %d.\n",
> +                     cle);
> +    cle = clFinish(ctx->command_queue);

Excepting the destruction of the memory objects, is there any reason it needs the clFinish() here rather than once all planes have been processed?

(More generally, it feels like there should be some more parallelism extractable here.)

> +    CL_FAIL_ON_ERROR(AVERROR(EIO), "Failed to finish kernel: %d.\n", cle);
> +fail:
> +    if (tmp)
> +      av_freep(&tmp);
> +    if (dxdy)
> +      av_freep(&dxdy);
> +    clFinish(ctx->command_queue);
> +    clReleaseMemObject(ii);
> +    clReleaseMemObject(weight);
> +    clReleaseMemObject(sum);
> +    return err;
> +}
> +
> +static int nlmeans_opencl_filter_frame(AVFilterLink *inlink, AVFrame *input)
> +{
> +    AVFilterContext    *avctx = inlink->dst;
> +    AVFilterLink     *outlink = avctx->outputs[0];
> +    NLMeansOpenCLContext *ctx = avctx->priv;
> +    AVFrame *output = NULL;
> +    AVHWFramesContext *input_frames_ctx;
> +    const AVPixFmtDescriptor *desc;
> +    enum AVPixelFormat in_format;
> +    cl_mem src, dst;
> +    int w, h, err, p, patch, research;
> +
> +    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);
> +    input_frames_ctx = (AVHWFramesContext*)input->hw_frames_ctx->data;
> +    in_format = input_frames_ctx->sw_format;
> +
> +    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;
> +
> +    if (!ctx->initialised) {
> +        desc = av_pix_fmt_desc_get(in_format);
> +        if (!is_format_supported(in_format)) {
> +            err = AVERROR(EINVAL);
> +            av_log(avctx, AV_LOG_ERROR, "input format %s not supported\n",
> +                   av_get_pix_fmt_name(in_format));
> +            goto fail;
> +        }
> +        ctx->chroma_w = AV_CEIL_RSHIFT(inlink->w, desc->log2_chroma_w);
> +        ctx->chroma_h = AV_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
> +
> +        err = nlmeans_opencl_init(avctx);
> +        if (err < 0)
> +            goto fail;
> +    }
> +
> +    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;
> +        w = p ? ctx->chroma_w : inlink->w;
> +        h = p ? ctx->chroma_h : inlink->h;
> +        patch = (p ? ctx->patch_size_uv : ctx->patch_size) / 2;
> +        research = (p ? ctx->research_size_uv : ctx->research_size) / 2;
> +        err = nlmeans_plane(avctx, dst, src, w, h, patch, research);
> +        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;
> +}
> +
> +#define RELEASE_KERNEL(k)                                    \
> +do {                                                         \
> +    if (k) {                                                 \
> +        cle = clReleaseKernel(k);                            \
> +        if (cle != CL_SUCCESS)                               \
> +            av_log(avctx, AV_LOG_ERROR, "Failed to release " \
> +                   "kernel: %d.\n", cle);                    \
> +    }                                                        \
> +} while(0)

This appears multiple times here and also in other filters.  Maybe it should be a macro in opencl.h like CL_SET_KERNEL_ARG?

> +
> +static av_cold void nlmeans_opencl_uninit(AVFilterContext *avctx)
> +{
> +    NLMeansOpenCLContext *ctx = avctx->priv;
> +    cl_int cle;
> +
> +    RELEASE_KERNEL(ctx->vert_kernel);
> +    RELEASE_KERNEL(ctx->horiz_kernel);
> +    RELEASE_KERNEL(ctx->accum_kernel);
> +    RELEASE_KERNEL(ctx->average_kernel);
> +
> +    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);
> +}
> +
> +#define OFFSET(x) offsetof(NLMeansOpenCLContext, x)
> +#define FLAGS (AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_VIDEO_PARAM)
> +static const AVOption nlmeans_opencl_options[] = {
> +    { "s",  "denoising strength", OFFSET(sigma), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 1.0, 30.0, FLAGS },
> +    { "p",  "patch size",                   OFFSET(patch_size),    AV_OPT_TYPE_INT, { .i64 = 2*3+1 }, 0, 99, FLAGS },
> +    { "pc", "patch size for chroma planes", OFFSET(patch_size_uv), AV_OPT_TYPE_INT, { .i64 = 0 },     0, 99, FLAGS },
> +    { "r",  "research window",                   OFFSET(research_size),    AV_OPT_TYPE_INT, { .i64 = 7*2+1 }, 0, 99, FLAGS },
> +    { "rc", "research window for chroma planes", OFFSET(research_size_uv), AV_OPT_TYPE_INT, { .i64 = 0 },     0, 99, FLAGS },

There is an assumption that the size arguments are odd integers, but it isn't checked anywhere.

> +    { NULL }
> +};
> +
> +AVFILTER_DEFINE_CLASS(nlmeans_opencl);
> +
> +static const AVFilterPad nlmeans_opencl_inputs[] = {
> +    {
> +        .name         = "default",
> +        .type         = AVMEDIA_TYPE_VIDEO,
> +        .filter_frame = &nlmeans_opencl_filter_frame,
> +        .config_props = &ff_opencl_filter_config_input,
> +    },
> +    { NULL }
> +};
> +
> +static const AVFilterPad nlmeans_opencl_outputs[] = {
> +    {
> +        .name         = "default",
> +        .type         = AVMEDIA_TYPE_VIDEO,
> +        .config_props = &ff_opencl_filter_config_output,
> +    },
> +    { NULL }
> +};
> +
> +AVFilter ff_vf_nlmeans_opencl = {
> +    .name           = "nlmeans_opencl",
> +    .description    = NULL_IF_CONFIG_SMALL("Non-local means denoiser through OpenCL"),
> +    .priv_size      = sizeof(NLMeansOpenCLContext),
> +    .priv_class     = &nlmeans_opencl_class,
> +    .init           = &ff_opencl_filter_init,
> +    .uninit         = &nlmeans_opencl_uninit,
> +    .query_formats  = &ff_opencl_filter_query_formats,
> +    .inputs         = nlmeans_opencl_inputs,
> +    .outputs        = nlmeans_opencl_outputs,
> +    .flags_internal = FF_FILTER_FLAG_HWFRAME_AWARE,
> +};
> 

I got good results compared to CPU nlmeans (1.4x speedup) on the GPU vs. CPU of a CFL 8700 with Beignet, even including the upload/download overhead.  Have you tried it on any larger GPU?  Can it get much faster with more processing power, or does something else limit it?

Thanks,

- Mark


More information about the ffmpeg-devel mailing list