[FFmpeg-devel] [PATCH] lavfi: Add OpenCL avgblur filter

Dylan Fernando dylanf123 at gmail.com
Mon Mar 19 04:28:54 EET 2018


On Mon, Mar 19, 2018 at 6:16 AM, Mark Thompson <sw at jkqxz.net> wrote:

> On 18/03/18 12:48, dylanf123 at gmail.com wrote:
> > From: drfer3 <drfer3 at student.monash.edu>
> >
> > Behaves like the existing avgblur filter, except working on OpenCL
> > hardware frames. Takes exactly the same options.
> > ---
> >  configure                       |   1 +
> >  libavfilter/Makefile            |   2 +
> >  libavfilter/allfilters.c        |   1 +
> >  libavfilter/opencl/avgblur.cl   |  60 ++++++++
> >  libavfilter/opencl_source.h     |   1 +
> >  libavfilter/vf_avgblur_opencl.c | 318 ++++++++++++++++++++++++++++++
> ++++++++++
> >  6 files changed, 383 insertions(+)
> >  create mode 100644 libavfilter/opencl/avgblur.cl
> >  create mode 100644 libavfilter/vf_avgblur_opencl.c
> >
> > diff --git a/configure b/configure
> > index 0c5ed07a07..481d338caf 100755
> > --- a/configure
> > +++ b/configure
> > @@ -3202,6 +3202,7 @@ aresample_filter_deps="swresample"
> >  ass_filter_deps="libass"
> >  atempo_filter_deps="avcodec"
> >  atempo_filter_select="rdft"
> > +avgblur_opencl_filter_deps="opencl"
> >  azmq_filter_deps="libzmq"
> >  blackframe_filter_deps="gpl"
> >  boxblur_filter_deps="gpl"
> > diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> > index fc16512e2c..1043b41d80 100644
> > --- a/libavfilter/Makefile
> > +++ b/libavfilter/Makefile
> > @@ -139,6 +139,8 @@ OBJS-$(CONFIG_ALPHAMERGE_FILTER)             +=
> vf_alphamerge.o
> >  OBJS-$(CONFIG_ASS_FILTER)                    += vf_subtitles.o
> >  OBJS-$(CONFIG_ATADENOISE_FILTER)             += vf_atadenoise.o
> >  OBJS-$(CONFIG_AVGBLUR_FILTER)                += vf_avgblur.o
> > +OBJS-$(CONFIG_AVGBLUR_OPENCL_FILTER)         += vf_avgblur_opencl.o
> opencl.o \
> > +                                                opencl/avgblur.o
> >  OBJS-$(CONFIG_BBOX_FILTER)                   += bbox.o vf_bbox.o
> >  OBJS-$(CONFIG_BENCH_FILTER)                  += f_bench.o
> >  OBJS-$(CONFIG_BITPLANENOISE_FILTER)          += vf_bitplanenoise.o
> > diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> > index cc423af738..3f67e321bf 100644
> > --- a/libavfilter/allfilters.c
> > +++ b/libavfilter/allfilters.c
> > @@ -149,6 +149,7 @@ static void register_all(void)
> >      REGISTER_FILTER(ASS,            ass,            vf);
> >      REGISTER_FILTER(ATADENOISE,     atadenoise,     vf);
> >      REGISTER_FILTER(AVGBLUR,        avgblur,        vf);
> > +    REGISTER_FILTER(AVGBLUR_OPENCL, avgblur_opencl, vf);
> >      REGISTER_FILTER(BBOX,           bbox,           vf);
> >      REGISTER_FILTER(BENCH,          bench,          vf);
> >      REGISTER_FILTER(BITPLANENOISE,  bitplanenoise,  vf);
> > diff --git a/libavfilter/opencl/avgblur.cl b/libavfilter/opencl/avgblur.
> cl
> > new file mode 100644
> > index 0000000000..28e0c90d15
> > --- /dev/null
> > +++ b/libavfilter/opencl/avgblur.cl
> > @@ -0,0 +1,60 @@
> > +/*
> > + * Copyright (c) 2018 Dylan Fernando
> > + *
> > + * 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 avgblur_horiz(__write_only image2d_t dst,
> > +                            __read_only  image2d_t src,
> > +                            int rad)
> > +{
> > +    const sampler_t sampler = (CLK_NORMALIZED_COORDS_FALSE |
> > +                               CLK_FILTER_NEAREST);
> > +    int2 loc = (int2)(get_global_id(0), get_global_id(1));
> > +    int2 size = (int2)(get_global_size(0), get_global_size(1));
> > +
> > +    int count = 0;
> > +    float4 acc = (float4)(0,0,0,0);
> > +
> > +    for (int xx = max(0,loc.x-rad); xx < min(loc.x+rad+1,size.x); xx++)
> {
>
> Keep to the same style as the rest of the code - spaces around operators.
>
> > +        count++;
> > +        acc += read_imagef(src, sampler, (int2)(xx, loc.y));
>
> Setting CLK_ADDRESS_CLAMP_TO_EDGE in the sampler would let you read over
> the edges and possibly avoid some of the min/max branching?  (I don't know
> whether that would actually help at all, would need to be measured - feel
> free to ignore this suggestion.)
>
> > +    }
> > +
> > +    write_imagef(dst, loc, acc / count);
> > +}
> > +
> > +__kernel void avgblur_vert(__write_only image2d_t dst,
> > +                           __read_only  image2d_t src,
> > +                           int radv)
> > +{
> > +    const sampler_t sampler = (CLK_NORMALIZED_COORDS_FALSE |
> > +                               CLK_FILTER_NEAREST);
> > +    int2 loc = (int2)(get_global_id(0), get_global_id(1));
> > +    int2 size = (int2)(get_global_size(0), get_global_size(1));
> > +
> > +    int count = 0;
> > +    float4 acc = (float4)(0,0,0,0);
> > +
> > +    for (int yy = max(0,loc.y-radv); yy < min(loc.y+radv+1,size.y);
> yy++) {
> > +        count++;
> > +        acc += read_imagef(src, sampler, (int2)(loc.x, yy));
> > +    }
> > +
> > +    write_imagef(dst, loc, acc / count);
> > +}
> > diff --git a/libavfilter/opencl_source.h b/libavfilter/opencl_source.h
> > index 23cdfc6ac9..02bc1723b0 100644
> > --- a/libavfilter/opencl_source.h
> > +++ b/libavfilter/opencl_source.h
> > @@ -19,6 +19,7 @@
> >  #ifndef AVFILTER_OPENCL_SOURCE_H
> >  #define AVFILTER_OPENCL_SOURCE_H
> >
> > +extern const char *ff_opencl_source_avgblur;
> >  extern const char *ff_opencl_source_overlay;
> >  extern const char *ff_opencl_source_unsharp;
> >
> > diff --git a/libavfilter/vf_avgblur_opencl.c b/libavfilter/vf_avgblur_
> opencl.c
> > new file mode 100644
> > index 0000000000..7e866b462a
> > --- /dev/null
> > +++ b/libavfilter/vf_avgblur_opencl.c
> > @@ -0,0 +1,318 @@
> > +/*
> > + * Copyright (c) 2018 Dylan Fernando
> > + *
> > + * 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 "video.h"
> > +
> > +
> > +typedef struct AverageBlurOpenCLContext {
> > +    OpenCLFilterContext ocf;
> > +
> > +    int              initialised;
> > +    cl_kernel        kernel_horiz;
> > +    cl_kernel        kernel_vert;
> > +    cl_command_queue command_queue;
> > +
> > +    int radius;
> > +    int radiusV;
> > +    int planes;
> > +
> > +} AverageBlurOpenCLContext;
> > +
> > +
> > +static int avgblur_opencl_init(AVFilterContext *avctx)
> > +{
> > +    AverageBlurOpenCLContext *ctx = avctx->priv;
> > +    cl_int cle;
> > +    int err;
> > +
> > +    err = ff_opencl_filter_load_program(avctx,
> &ff_opencl_source_avgblur, 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_horiz = clCreateKernel(ctx->ocf.program,"avgblur_horiz",
> &cle);
> > +    if (!ctx->kernel_horiz) {
> > +        av_log(avctx, AV_LOG_ERROR, "Failed to create kernel: %d.\n",
> cle);
> > +        err = AVERROR(EIO);
> > +        goto fail;
> > +    }
> > +
> > +    ctx->kernel_vert = clCreateKernel(ctx->ocf.program,"avgblur_vert",
> &cle);
> > +    if (!ctx->kernel_vert) {
> > +        av_log(avctx, AV_LOG_ERROR, "Failed to create kernel: %d.\n",
> cle);
> > +        err = AVERROR(EIO);
> > +        goto fail;
> > +    }
> > +
> > +    if (ctx->radiusV <= 0) {
> > +        ctx->radiusV = ctx->radius;
> > +    }
> > +
> > +    ctx->initialised = 1;
> > +    return 0;
> > +
> > +fail:
> > +    if (ctx->command_queue)
> > +        clReleaseCommandQueue(ctx->command_queue);
> > +    if (ctx->kernel_horiz)
> > +        clReleaseKernel(ctx->kernel_horiz);
> > +    if (ctx->kernel_vert)
> > +        clReleaseKernel(ctx->kernel_vert);
> > +    return err;
> > +}
> > +
> > +static int avgblur_opencl_filter_frame(AVFilterLink *inlink, AVFrame
> *input)
> > +{
> > +    AVFilterContext    *avctx = inlink->dst;
> > +    AVFilterLink     *outlink = avctx->outputs[0];
> > +    AverageBlurOpenCLContext *ctx = avctx->priv;
> > +    AVFrame *output = NULL;
> > +    cl_int cle;
> > +    size_t global_work[2];
> > +    cl_mem src, dst;
> > +    int err, p;
> > +
> > +    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 = avgblur_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;
> > +    }
> > +
> > +    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;
> > +
> > +        int radius_x = ctx->radius;
> > +        int radius_y = ctx->radiusV;
> > +
> > +        if (!(ctx->planes & (1 << p))) {
> > +            radius_x = 0;
> > +            radius_y = 0;
> > +        }
> > +
> > +        cle = clSetKernelArg(ctx->kernel_horiz, 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_horiz, 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;
> > +        }
> > +        cle = clSetKernelArg(ctx->kernel_horiz, 2, sizeof(cl_int),
> &radius_x);
> > +        if (cle != CL_SUCCESS) {
> > +            av_log(avctx, AV_LOG_ERROR, "Failed to set kernel "
> > +                   "sizeX argument: %d.\n", cle);
> > +            goto fail;
> > +        }
> > +
> > +        global_work[0] = output->width;
> > +        global_work[1] = output->height;
> > +
> > +        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_horiz, 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 = clSetKernelArg(ctx->kernel_vert, 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_vert, 1, sizeof(cl_mem),
> &dst);
>
> You can't specify the same image multiple times in the kernel to both read
> from and write to it like this.
>
> The problem here is that some workitems can end up writing to locations of
> the image before they have been read by other workitems looking at
> neighbouring pixels.  That means that the output is not consistent (try it,
> the output changes between runs), and pixels can be blurred downwards
> across a much larger distance than the given radius.
>
> To fix that, I think you need to make a temporary image for each plane to
> be an intermediate between the horizontal and vertical filter steps?  If
> you don't want to have a temporary image then I don't think the two steps
> can be done independently.
>
> > +        if (cle != CL_SUCCESS) {
> > +            av_log(avctx, AV_LOG_ERROR, "Failed to set kernel "
> > +                   "source image argument: %d.\n", cle);
> > +            goto fail;
> > +        }
> > +        cle = clSetKernelArg(ctx->kernel_vert, 2, sizeof(cl_int),
> &radius_y);
> > +        if (cle != CL_SUCCESS) {
> > +            av_log(avctx, AV_LOG_ERROR, "Failed to set kernel "
> > +                   "sizeY argument: %d.\n", cle);
> > +            goto fail;
> > +        }
> > +
> > +        global_work[0] = output->width;
> > +        global_work[1] = output->height;
> > +
> > +        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_vert, 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;
> > +    }
> > +
> > +    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 avgblur_opencl_uninit(AVFilterContext *avctx)
> > +{
> > +    AverageBlurOpenCLContext *ctx = avctx->priv;
> > +    cl_int cle;
> > +
> > +
> > +    if (ctx->kernel_horiz) {
> > +        cle = clReleaseKernel(ctx->kernel_horiz);
> > +        if (cle != CL_SUCCESS)
> > +            av_log(avctx, AV_LOG_ERROR, "Failed to release "
> > +                   "kernel: %d.\n", cle);
> > +    }
> > +
> > +    if (ctx->kernel_vert) {
> > +        cle = clReleaseKernel(ctx->kernel_vert);
> > +        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);
> > +}
> > +
> > +#define OFFSET(x) offsetof(AverageBlurOpenCLContext, x)
> > +#define FLAGS (AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_VIDEO_PARAM)
> > +static const AVOption avgblur_opencl_options[] = {
> > +    { "sizeX",  "set horizontal size",  OFFSET(radius),
> AV_OPT_TYPE_INT, {.i64=1},   1, 1024, FLAGS },
> > +    { "planes", "set planes to filter", OFFSET(planes),
> AV_OPT_TYPE_INT, {.i64=0xF}, 0,  0xF, FLAGS },
> > +    { "sizeY",  "set vertical size",    OFFSET(radiusV),
> AV_OPT_TYPE_INT, {.i64=0},   0, 1024, FLAGS },
> > +    { NULL }
> > +};
> > +
> > +AVFILTER_DEFINE_CLASS(avgblur_opencl);
> > +
> > +static const AVFilterPad avgblur_opencl_inputs[] = {
> > +    {
> > +        .name         = "default",
> > +        .type         = AVMEDIA_TYPE_VIDEO,
> > +        .filter_frame = &avgblur_opencl_filter_frame,
> > +        .config_props = &ff_opencl_filter_config_input,
> > +    },
> > +    { NULL }
> > +};
> > +
> > +static const AVFilterPad avgblur_opencl_outputs[] = {
> > +    {
> > +        .name         = "default",
> > +        .type         = AVMEDIA_TYPE_VIDEO,
> > +        .config_props = &ff_opencl_filter_config_output,
> > +    },
> > +    { NULL }
> > +};
> > +
> > +AVFilter ff_vf_avgblur_opencl = {
> > +    .name           = "avgblur_opencl",
> > +    .description    = NULL_IF_CONFIG_SMALL("Apply average blur filter"),
> > +    .priv_size      = sizeof(AverageBlurOpenCLContext),
> > +    .priv_class     = &avgblur_opencl_class,
> > +    .init           = &ff_opencl_filter_init,
> > +    .uninit         = &avgblur_opencl_uninit,
> > +    .query_formats  = &ff_opencl_filter_query_formats,
> > +    .inputs         = avgblur_opencl_inputs,
> > +    .outputs        = avgblur_opencl_outputs,
> > +    .flags_internal = FF_FILTER_FLAG_HWFRAME_AWARE,
> > +};
> >
>
> Rest looks good to me; also tested and works well (ignoring than the
> inconsistent results from the vertical filtering step).
>
> Thanks,
>
> - Mark
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>

Thanks, I'll fix that.


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