[FFmpeg-devel] [PATCH 3/3][RFC] avfilter/vf_chromakey: Add OpenCL acceleration

Timo Rothenpieler timo at rothenpieler.org
Tue Sep 29 21:45:38 CEST 2015


> Signed-off-by: Timo Rothenpieler <timo at rothenpieler.org>
> ---
>  doc/filters.texi                      |   5 +
>  libavfilter/chromakey_opencl_kernel.h |  98 +++++++++++++++++++
>  libavfilter/opencl_allkernels.c       |   2 +
>  libavfilter/vf_chromakey.c            | 179 +++++++++++++++++++++++++++++++++-
>  4 files changed, 283 insertions(+), 1 deletion(-)
>  create mode 100644 libavfilter/chromakey_opencl_kernel.h
> 
> diff --git a/doc/filters.texi b/doc/filters.texi
> index 044876c..4faf4b9 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -3734,6 +3734,11 @@ Signals that the color passed is already in YUV instead of RGB.
>  
>  Litteral colors like "green" or "red" don't make sense with this enabled anymore.
>  This can be used to pass exact YUV values as hexadecimal numbers.
> +
> + at item opencl
> +If set to 1, specify using OpenCL capabilities, only available if
> +FFmpeg was configured with @code{--enable-opencl}. Default value is 0.
> +
>  @end table
>  
>  @subsection Examples
> diff --git a/libavfilter/chromakey_opencl_kernel.h b/libavfilter/chromakey_opencl_kernel.h
> new file mode 100644
> index 0000000..56bbc79
> --- /dev/null
> +++ b/libavfilter/chromakey_opencl_kernel.h
> @@ -0,0 +1,98 @@
> +/*
> + * Copyright (c) 2015 Timo Rothenpieler <timo at rothenpieler.org>
> + *
> + * 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
> + */
> +
> +#ifndef AVFILTER_CHROMAKEY_OPENCL_KERNEL_H
> +#define AVFILTER_CHROMAKEY_OPENCL_KERNEL_H
> +
> +#include "libavutil/opencl.h"
> +
> +const char *ff_kernel_chromakey_opencl = AV_OPENCL_KERNEL(
> +
> +inline unsigned char get_pixel(global unsigned char *src,
> +                               int x,
> +                               int y,
> +                               int w,
> +                               int h,
> +                               int linesize,
> +                               int hsub_log2,
> +                               int vsub_log2,
> +                               unsigned char def)
> +{
> +    if (x < 0 || x >= w || y < 0 || x >= w)
> +        return def;
> +
> +    x >>= hsub_log2;
> +    y >>= vsub_log2;
> +
> +    return src[linesize * y + x];
> +}
> +
> +kernel void chromakey(global unsigned char *src_u,
> +                      global unsigned char *src_v,
> +                      global unsigned char *dst,
> +                      int linesize_u,
> +                      int linesize_v,
> +                      int linesize_a,
> +                      int height,
> +                      int width,
> +                      int hsub_log2,
> +                      int vsub_log2,
> +                      unsigned char chromakey_u,
> +                      unsigned char chromakey_v,
> +                      float similarity,
> +                      float blend
> +                     )
> +{
> +    int x = get_global_id(0);
> +    int y = get_global_id(1);
> +    unsigned char res;
> +
> +    int xo, yo, du, dv;
> +    double diff = 0.0;
> +
> +    if (x >= width || y >= height)
> +        return;
> +
> +    for (yo = 0; yo < 3; yo++) {
> +        for (xo = 0; xo < 3; xo++) {
> +            du = get_pixel(src_u, x + xo - 1, y + yo - 1, width, height, linesize_u, hsub_log2, vsub_log2, chromakey_u);
> +            dv = get_pixel(src_v, x + xo - 1, y + yo - 1, width, height, linesize_v, hsub_log2, vsub_log2, chromakey_v);
> +
> +            du -= chromakey_u;
> +            dv -= chromakey_v;
> +
> +            diff += sqrt((du * du + dv * dv) / (double)(255.0 * 255.0));
> +        }
> +    }
> +
> +    diff /= 9.0;
> +
> +    if (blend > 0.0001) {
> +        res = clamp((diff - similarity) / blend, 0.0, 1.0) * 255.0;
> +    } else {
> +        res = (diff > similarity) ? 255 : 0;
> +    }
> +
> +    dst[linesize_a * y + x] = res;
> +}
> +
> +);
> +
> +#endif /* AVFILTER_CHROMAKEY_OPENCL_KERNEL_H */
> diff --git a/libavfilter/opencl_allkernels.c b/libavfilter/opencl_allkernels.c
> index 6d80fa8..fc05e66 100644
> --- a/libavfilter/opencl_allkernels.c
> +++ b/libavfilter/opencl_allkernels.c
> @@ -23,6 +23,7 @@
>  #include "libavutil/opencl.h"
>  #include "deshake_opencl_kernel.h"
>  #include "unsharp_opencl_kernel.h"
> +#include "chromakey_opencl_kernel.h"
>  #endif
>  
>  #define OPENCL_REGISTER_KERNEL_CODE(X, x)                                              \
> @@ -37,5 +38,6 @@ void ff_opencl_register_filter_kernel_code_all(void)
>   #if CONFIG_OPENCL
>     OPENCL_REGISTER_KERNEL_CODE(DESHAKE,     deshake);
>     OPENCL_REGISTER_KERNEL_CODE(UNSHARP,     unsharp);
> +   OPENCL_REGISTER_KERNEL_CODE(CHROMAKEY,   chromakey);
>   #endif
>  }
> diff --git a/libavfilter/vf_chromakey.c b/libavfilter/vf_chromakey.c
> index 47fdea631..8f15f3e 100644
> --- a/libavfilter/vf_chromakey.c
> +++ b/libavfilter/vf_chromakey.c
> @@ -25,6 +25,10 @@
>  #include "internal.h"
>  #include "video.h"
>  
> +#if CONFIG_OPENCL
> +#include "libavutil/opencl_internal.h"
> +#endif
> +
>  typedef struct ChromakeyContext {
>      const AVClass *class;
>  
> @@ -35,8 +39,152 @@ typedef struct ChromakeyContext {
>      float blend;
>  
>      int is_yuv;
> +
> +    int opencl;
> +
> +#if CONFIG_OPENCL
> +    cl_command_queue command_queue;
> +    cl_program program;
> +    cl_kernel kernel;
> +
> +    cl_mem cl_inbuf_u;
> +    size_t cl_inbuf_u_size;
> +    cl_mem cl_inbuf_v;
> +    size_t cl_inbuf_v_size;
> +    cl_mem cl_outbuf;
> +    size_t cl_outbuf_size;
> +#endif
>  } ChromakeyContext;
>  
> +#if CONFIG_OPENCL
> +#define ROUND_TO_16(a) (((((a) - 1)/16)+1)*16)
> +
> +static av_cold int opencl_chromakey_init(AVFilterContext *avctx)
> +{
> +    int res = 0;
> +    ChromakeyContext *ctx = avctx->priv;
> +
> +    if (res = av_opencl_init(NULL))
> +        return res;
> +
> +    ctx->command_queue = av_opencl_get_command_queue();
> +    if (!ctx->command_queue) {
> +        av_log(ctx, AV_LOG_ERROR, "Unable to get OpenCL command queue in filter 'chromakey'\n");
> +        return AVERROR(EINVAL);
> +    }
> +
> +    ctx->program = av_opencl_compile("chromakey", NULL);
> +    if (!ctx->program) {
> +        av_log(ctx, AV_LOG_ERROR, "OpenCL failed to compile program 'chromakey'\n");
> +        return AVERROR(EINVAL);
> +    }
> +
> +    ctx->kernel = clCreateKernel(ctx->program, "chromakey", &res);
> +    if (res != CL_SUCCESS) {
> +        av_log(ctx, AV_LOG_ERROR, "OpenCL failed to create kernel 'chromakey'\n");
> +        return AVERROR(EINVAL);
> +    }
> +
> +    return res;
> +}
> +
> +static av_cold void opencl_chromakey_uninit(AVFilterContext *avctx)
> +{
> +    ChromakeyContext *ctx = avctx->priv;
> +
> +    if (ctx->cl_inbuf_u)
> +        av_opencl_buffer_release(&ctx->cl_inbuf_u);
> +    if (ctx->cl_inbuf_v)
> +        av_opencl_buffer_release(&ctx->cl_inbuf_v);
> +    if (ctx->cl_outbuf)
> +        av_opencl_buffer_release(&ctx->cl_outbuf);
> +    if (ctx->kernel)
> +        clReleaseKernel(ctx->kernel);
> +    if (ctx->program)
> +        clReleaseProgram(ctx->program);
> +
> +    ctx->command_queue = NULL;
> +
> +    av_opencl_uninit();
> +}
> +
> +static int opencl_chromakey_frame(AVFilterContext *avctx, AVFrame *frame)
> +{
> +    ChromakeyContext *ctx = avctx->priv;
> +    int res = 0;
> +    int hsub_log2 = 0, vsub_log2 = 0;
> +
> +    size_t global_work_size[2] = { (size_t)ROUND_TO_16(frame->width), (size_t)ROUND_TO_16(frame->height) };
> +
> +    FFOpenclParam param = { 0 };
> +    param.ctx = avctx;
> +    param.kernel = ctx->kernel;
> +
> +    if (frame->format == AV_PIX_FMT_YUVA420P || frame->format == AV_PIX_FMT_YUVA422P)
> +        hsub_log2 = 1;
> +
> +    if (frame->format == AV_PIX_FMT_YUVA420P)
> +        vsub_log2 = 1;
> +
> +    if (!ctx->cl_inbuf_u || !ctx->cl_inbuf_v || !ctx->cl_outbuf) {
> +        ctx->cl_inbuf_u_size = frame->linesize[1] * (frame->height >> vsub_log2);
> +        ctx->cl_inbuf_v_size = frame->linesize[2] * (frame->height >> vsub_log2);
> +        ctx->cl_outbuf_size = frame->linesize[3] * frame->height;
> +
> +        res = av_opencl_buffer_create(&ctx->cl_inbuf_u, ctx->cl_inbuf_u_size, CL_MEM_READ_ONLY, NULL);
> +        if (res)
> +            return res;
> +
> +        res = av_opencl_buffer_create(&ctx->cl_inbuf_v, ctx->cl_inbuf_v_size, CL_MEM_READ_ONLY, NULL);
> +        if (res)
> +            return res;
> +
> +        res = av_opencl_buffer_create(&ctx->cl_outbuf, ctx->cl_outbuf_size, CL_MEM_READ_WRITE, NULL);
> +        if (res)
> +            return res;
> +    }
> +
> +    res = av_opencl_buffer_write(ctx->cl_inbuf_u, frame->data[1], ctx->cl_inbuf_u_size);
> +    if (res)
> +        return res;
> +
> +    res = av_opencl_buffer_write(ctx->cl_inbuf_v, frame->data[2], ctx->cl_inbuf_v_size);
> +    if (res)
> +        return res;
> +
> +    res = avpriv_opencl_set_parameter(&param,
> +                                      FF_OPENCL_PARAM_INFO(ctx->cl_inbuf_u),
> +                                      FF_OPENCL_PARAM_INFO(ctx->cl_inbuf_v),
> +                                      FF_OPENCL_PARAM_INFO(ctx->cl_outbuf),
> +                                      FF_OPENCL_PARAM_INFO(frame->linesize[1]),
> +                                      FF_OPENCL_PARAM_INFO(frame->linesize[2]),
> +                                      FF_OPENCL_PARAM_INFO(frame->linesize[3]),
> +                                      FF_OPENCL_PARAM_INFO(frame->height),
> +                                      FF_OPENCL_PARAM_INFO(frame->width),
> +                                      FF_OPENCL_PARAM_INFO(hsub_log2),
> +                                      FF_OPENCL_PARAM_INFO(vsub_log2),
> +                                      FF_OPENCL_PARAM_INFO(ctx->chromakey_uv[0]),
> +                                      FF_OPENCL_PARAM_INFO(ctx->chromakey_uv[1]),
> +                                      FF_OPENCL_PARAM_INFO(ctx->similarity),
> +                                      FF_OPENCL_PARAM_INFO(ctx->blend),
> +                                      NULL);
> +    if (res)
> +        return res;
> +
> +    res = clEnqueueNDRangeKernel(ctx->command_queue, ctx->kernel, 2, NULL, global_work_size, NULL, 0, NULL, NULL);
> +    if (res != CL_SUCCESS) {
> +        av_log(ctx, AV_LOG_ERROR, "OpenCL run kernel error occurred: %s\n", av_opencl_errstr(res));
> +        return AVERROR_EXTERNAL;
> +    }
> +
> +    res = av_opencl_buffer_read(frame->data[3], ctx->cl_outbuf, ctx->cl_outbuf_size);
> +    if (res)
> +        return res;
> +
> +    return res;
> +}
> +#endif
> +
>  static uint8_t do_chromakey_pixel(ChromakeyContext *ctx, uint8_t u[9], uint8_t v[9])
>  {
>      double diff = 0.0;
> @@ -110,10 +258,18 @@ static int do_chromakey_slice(AVFilterContext *avctx, void *arg, int jobnr, int
>  static int filter_frame(AVFilterLink *link, AVFrame *frame)
>  {
>      AVFilterContext *avctx = link->dst;
> +    ChromakeyContext *ctx = avctx->priv;
>      int res;
>  
> -    if (res = avctx->internal->execute(avctx, do_chromakey_slice, frame, NULL, FFMIN(frame->height, avctx->graph->nb_threads)))
> +    if (CONFIG_OPENCL && ctx->opencl) {
> +#if CONFIG_OPENCL
> +        if (res = opencl_chromakey_frame(avctx, frame)) {
> +            return res;
> +        }
> +#endif
> +    } else if (res = avctx->internal->execute(avctx, do_chromakey_slice, frame, NULL, FFMIN(frame->height, avctx->graph->nb_threads))) {
>          return res;
> +    }
>  
>      return ff_filter_frame(avctx->outputs[0], frame);
>  }
> @@ -134,9 +290,28 @@ static av_cold int initialize_chromakey(AVFilterContext *avctx)
>          ctx->chromakey_uv[1] = RGB_TO_V(ctx->chromakey_rgba);
>      }
>  
> +    if (ctx->opencl) {
> +#if CONFIG_OPENCL
> +        return opencl_chromakey_init(avctx);
> +#else
> +        av_log(ctx, AV_LOG_ERROR, "OpenCL support was not enabled in this build, cannot be selected\n");
> +        return AVERROR(EINVAL);
> +#endif
> +    }
> +
>      return 0;
>  }
>  
> +static av_cold void uninitialize_chromakey(AVFilterContext *avctx)
> +{
> +#if CONFIG_OPENCL
> +    ChromakeyContext *ctx = avctx->priv;
> +
> +    if (ctx->opencl)
> +        opencl_chromakey_uninit(avctx);
> +#endif
> +}
> +
>  static av_cold int query_formats(AVFilterContext *avctx)
>  {
>      static const enum AVPixelFormat pixel_fmts[] = {
> @@ -181,6 +356,7 @@ static const AVOption chromakey_options[] = {
>      { "similarity", "set the chromakey similarity value", OFFSET(similarity), AV_OPT_TYPE_FLOAT, { .dbl = 0.01 }, 0.01, 1.0, FLAGS },
>      { "blend", "set the chromakey key blend value", OFFSET(blend), AV_OPT_TYPE_FLOAT, { .dbl = 0.0 }, 0.0, 1.0, FLAGS },
>      { "yuv", "color parameter is in yuv instead of rgb", OFFSET(is_yuv), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS },
> +    { "opencl", "use OpenCL filtering capabilities", OFFSET(opencl), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS },
>      { NULL }
>  };
>  
> @@ -192,6 +368,7 @@ AVFilter ff_vf_chromakey = {
>      .priv_size     = sizeof(ChromakeyContext),
>      .priv_class    = &chromakey_class,
>      .init          = initialize_chromakey,
> +    .uninit        = uninitialize_chromakey,
>      .query_formats = query_formats,
>      .inputs        = chromakey_inputs,
>      .outputs       = chromakey_outputs,
> 

ping once again

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 473 bytes
Desc: OpenPGP digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20150929/1c7bf1f6/attachment.sig>


More information about the ffmpeg-devel mailing list