[FFmpeg-devel] [GSoC'22] Added Chromakey CUDA filter

mohamed Elhadidy mohamedpower_50 at hotmail.com
Thu Jun 30 03:01:53 EEST 2022


From: Mohamed Khaled Mohamed <56936494+MohamedElhadidy0019 at users.noreply.github.com>


GSoC'22 GPU accelerated video filters
Added CUDA chromakeyfilter
libavfilter/vf_chromakey_cuda.cu:the CUDA kernel for the filter
libavfilter/vf_chromakey_cuda.c: the C side that calls the kernel and gets user input
libavfilter/allfilters.c: added the filter to it
libavfilter/Makefile: added the filter to it
cuda/cuda_runtime.h: added two math CUDA functions that are used in the filter
---
 compat/cuda/cuda_runtime.h       |   2 +
 libavfilter/Makefile             |   2 +
 libavfilter/allfilters.c         |   1 +
 libavfilter/vf_chromakey_cuda.c  | 520 +++++++++++++++++++++++++++++++
 libavfilter/vf_chromakey_cuda.cu | 248 +++++++++++++++
 5 files changed, 773 insertions(+)
 create mode 100644 libavfilter/vf_chromakey_cuda.c
 create mode 100644 libavfilter/vf_chromakey_cuda.cu

diff --git a/compat/cuda/cuda_runtime.h b/compat/cuda/cuda_runtime.h
index 30cd085e48..5837c1ad37 100644
--- a/compat/cuda/cuda_runtime.h
+++ b/compat/cuda/cuda_runtime.h
@@ -181,7 +181,9 @@ static inline __device__ double trunc(double a) { return __builtin_trunc(a); }
 static inline __device__ float fabsf(float a) { return __builtin_fabsf(a); }
 static inline __device__ float fabs(float a) { return __builtin_fabsf(a); }
 static inline __device__ double fabs(double a) { return __builtin_fabs(a); }
+static inline __device__ float sqrtf(float a) { return __builtin_sqrtf(a); }
 
+static inline __device__ float __saturatef(float a) { return __nvvm_saturate_f(a); }
 static inline __device__ float __sinf(float a) { return __nvvm_sin_approx_f(a); }
 static inline __device__ float __cosf(float a) { return __nvvm_cos_approx_f(a); }
 static inline __device__ float __expf(float a) { return __nvvm_ex2_approx_f(a * (float)__builtin_log2(__builtin_exp(1))); }
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 22b0a0ca15..8aee10fc76 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -210,6 +210,8 @@ OBJS-$(CONFIG_CAS_FILTER)                    += vf_cas.o
 OBJS-$(CONFIG_CHROMABER_VULKAN_FILTER)       += vf_chromaber_vulkan.o vulkan.o vulkan_filter.o
 OBJS-$(CONFIG_CHROMAHOLD_FILTER)             += vf_chromakey.o
 OBJS-$(CONFIG_CHROMAKEY_FILTER)              += vf_chromakey.o
+OBJS-$(CONFIG_CHROMAKEY_CUDA_FILTER)         += vf_chromakey_cuda.o  vf_chromakey_cuda.ptx.o framesync.o
+
 OBJS-$(CONFIG_CHROMANR_FILTER)               += vf_chromanr.o
 OBJS-$(CONFIG_CHROMASHIFT_FILTER)            += vf_chromashift.o
 OBJS-$(CONFIG_CIESCOPE_FILTER)               += vf_ciescope.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index ec70feef11..da1a96b23c 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -195,6 +195,7 @@ extern const AVFilter ff_vf_cas;
 extern const AVFilter ff_vf_chromaber_vulkan;
 extern const AVFilter ff_vf_chromahold;
 extern const AVFilter ff_vf_chromakey;
+extern const AVFilter ff_vf_chromakey_cuda;
 extern const AVFilter ff_vf_chromanr;
 extern const AVFilter ff_vf_chromashift;
 extern const AVFilter ff_vf_ciescope;
diff --git a/libavfilter/vf_chromakey_cuda.c b/libavfilter/vf_chromakey_cuda.c
new file mode 100644
index 0000000000..822488d436
--- /dev/null
+++ b/libavfilter/vf_chromakey_cuda.c
@@ -0,0 +1,520 @@
+/*
+* Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved.
+*
+* Permission is hereby granted, free of charge, to any person obtaining a
+* copy of this software and associated documentation files (the "Software"),
+* to deal in the Software without restriction, including without limitation
+* the rights to use, copy, modify, merge, publish, distribute, sublicense,
+* and/or sell copies of the Software, and to permit persons to whom the
+* Software is furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included in
+* all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+* DEALINGS IN THE SOFTWARE.
+*/
+
+#include <float.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "libavutil/avstring.h"
+#include "libavutil/common.h"
+#include "libavutil/hwcontext.h"
+#include "libavutil/hwcontext_cuda_internal.h"
+#include "libavutil/cuda_check.h"
+#include "libavutil/internal.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+#include "cuda/load_helper.h"
+
+
+
+#define FIXNUM(x) lrint((x) * (1 << 10))
+#define RGB_TO_U(rgb) (((- FIXNUM(0.16874) * rgb[0] - FIXNUM(0.33126) * rgb[1] + FIXNUM(0.50000) * rgb[2] + (1 << 9) - 1) >> 10) + 128)
+#define RGB_TO_V(rgb) (((  FIXNUM(0.50000) * rgb[0] - FIXNUM(0.41869) * rgb[1] - FIXNUM(0.08131) * rgb[2] + (1 << 9) - 1) >> 10) + 128)
+
+
+static const enum AVPixelFormat supported_formats[] = {
+    AV_PIX_FMT_YUV420P,
+    AV_PIX_FMT_NV12,
+    AV_PIX_FMT_YUV444P,
+    AV_PIX_FMT_YUVA420P
+
+};
+
+#define DIV_UP(a, b) ( ((a) + (b) - 1) / (b) )
+#define BLOCKX 32
+#define BLOCKY 16
+
+#define CHECK_CU(x) FF_CUDA_CHECK_DL(ctx, s->hwctx->internal->cuda_dl, x)
+
+
+typedef struct ChromakeyCUDAContext {
+    const AVClass *class;
+
+    AVCUDADeviceContext *hwctx;
+
+    enum AVPixelFormat in_fmt, out_fmt;
+    const AVPixFmtDescriptor *in_desc, *out_desc;
+    int in_planes, out_planes;
+    int in_plane_depths[4];
+    int in_plane_channels[4];
+
+
+    uint8_t chromakey_rgba[4];
+    uint16_t chromakey_uv[2];
+    int is_yuv;
+    float similarity;
+    float blend;
+
+
+
+    AVBufferRef *frames_ctx;
+    AVFrame     *frame;
+
+    AVFrame *tmp_frame;
+
+    char *w_expr;               ///< width  expression string
+    char *h_expr;               ///< height expression string
+
+    CUcontext   cu_ctx;
+    CUmodule    cu_module;
+    CUfunction  cu_func;
+    CUfunction  cu_func_uv;
+    CUstream    cu_stream;
+} ChromakeyCUDAContext;
+
+static av_cold int cudachromakey_init(AVFilterContext *ctx)
+{
+    ChromakeyCUDAContext *s = ctx->priv;
+
+    s->frame = av_frame_alloc();
+    if (!s->frame)
+        return AVERROR(ENOMEM);
+
+    s->tmp_frame = av_frame_alloc();
+    if (!s->tmp_frame)
+        return AVERROR(ENOMEM);
+
+    return 0;
+}
+
+static av_cold void cudachromakey_uninit(AVFilterContext *ctx)
+{
+    ChromakeyCUDAContext *s = ctx->priv;
+
+    if (s->hwctx && s->cu_module) {
+        CudaFunctions *cu = s->hwctx->internal->cuda_dl;
+        CUcontext context;
+
+        CHECK_CU(cu->cuCtxPushCurrent(s->hwctx->cuda_ctx));
+        CHECK_CU(cu->cuModuleUnload(s->cu_module));
+        s->cu_module = NULL;
+        CHECK_CU(cu->cuCtxPopCurrent(&context));
+    }
+
+    av_frame_free(&s->frame);
+    av_buffer_unref(&s->frames_ctx);
+    av_frame_free(&s->tmp_frame);
+}
+
+static av_cold int init_hwframe_ctx(ChromakeyCUDAContext *s, AVBufferRef *device_ctx, int width, int height)
+{
+    AVBufferRef *out_ref = NULL;
+    AVHWFramesContext *out_ctx;
+    int ret;
+
+    out_ref = av_hwframe_ctx_alloc(device_ctx);
+    if (!out_ref)
+        return AVERROR(ENOMEM);
+    out_ctx = (AVHWFramesContext*)out_ref->data;
+
+    out_ctx->format    = AV_PIX_FMT_CUDA;
+    out_ctx->sw_format = s->out_fmt;
+    out_ctx->width     = width;
+    out_ctx->height    = height;
+
+    ret = av_hwframe_ctx_init(out_ref);
+    if (ret < 0)
+        goto fail;
+
+    av_frame_unref(s->frame);
+    ret = av_hwframe_get_buffer(out_ref, s->frame, 0);
+    if (ret < 0)
+        goto fail;
+
+    av_buffer_unref(&s->frames_ctx);
+    s->frames_ctx = out_ref;
+
+    return 0;
+fail:
+    av_buffer_unref(&out_ref);
+    return ret;
+}
+
+static int format_is_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;
+}
+
+static av_cold void set_format_info(AVFilterContext *ctx, enum AVPixelFormat in_format, enum AVPixelFormat out_format)
+{
+    ChromakeyCUDAContext *s = ctx->priv;
+    int i, p, d;
+
+    s->in_fmt = in_format;
+    s->out_fmt = out_format;
+
+    s->in_desc  = av_pix_fmt_desc_get(s->in_fmt);
+    s->out_desc = av_pix_fmt_desc_get(s->out_fmt);
+    s->in_planes  = av_pix_fmt_count_planes(s->in_fmt);
+    s->out_planes = av_pix_fmt_count_planes(s->out_fmt);
+
+    // find maximum step of each component of each plane
+    // For our subset of formats, this should accurately tell us how many channels CUDA needs
+    // i.e. 1 for Y plane, 2 for UV plane of NV12, 4 for single plane of RGB0 formats
+
+    for (i = 0; i < s->in_desc->nb_components; i++) {
+        d = (s->in_desc->comp[i].depth + 7) / 8;
+        p = s->in_desc->comp[i].plane;
+        s->in_plane_channels[p] = FFMAX(s->in_plane_channels[p], s->in_desc->comp[i].step / d);
+
+        s->in_plane_depths[p] = s->in_desc->comp[i].depth;
+    }
+}
+
+static av_cold int init_processing_chain(AVFilterContext *ctx, int width, int height)
+{
+    ChromakeyCUDAContext *s = ctx->priv;
+    AVHWFramesContext *in_frames_ctx;
+    int ret;
+
+    /* check that we have a hw context */
+    if (!ctx->inputs[0]->hw_frames_ctx) {
+        av_log(ctx, AV_LOG_ERROR, "No hw context provided on input\n");
+        return AVERROR(EINVAL);
+    }
+    in_frames_ctx = (AVHWFramesContext*)ctx->inputs[0]->hw_frames_ctx->data;
+
+    if (!format_is_supported(in_frames_ctx->sw_format)) {
+        av_log(ctx, AV_LOG_ERROR, "Unsupported format: %s\n", av_get_pix_fmt_name(in_frames_ctx->sw_format));
+        return AVERROR(ENOSYS);
+    }
+
+    set_format_info(ctx, in_frames_ctx->sw_format,AV_PIX_FMT_YUVA420P );
+
+    ret = init_hwframe_ctx(s, in_frames_ctx->device_ref, width, height);
+    if (ret < 0)
+        return ret;
+
+    ctx->outputs[0]->hw_frames_ctx = av_buffer_ref(s->frames_ctx);
+    if (!ctx->outputs[0]->hw_frames_ctx)
+        return AVERROR(ENOMEM);
+
+    return 0;
+}
+
+static av_cold int cudachromakey_load_functions(AVFilterContext *ctx)
+{
+    ChromakeyCUDAContext *s = ctx->priv;
+    CUcontext context, cuda_ctx = s->hwctx->cuda_ctx;
+    CudaFunctions *cu = s->hwctx->internal->cuda_dl;
+    int ret;
+
+    extern const unsigned char ff_vf_chromakey_cuda_ptx_data[];
+    extern const unsigned int ff_vf_chromakey_cuda_ptx_len;
+
+    ret = CHECK_CU(cu->cuCtxPushCurrent(cuda_ctx));
+    if (ret < 0)
+        return ret;
+
+    ret = ff_cuda_load_module(ctx, s->hwctx, &s->cu_module,
+                              ff_vf_chromakey_cuda_ptx_data, ff_vf_chromakey_cuda_ptx_len);
+    if (ret < 0)
+        goto fail;
+
+    ret = CHECK_CU(cu->cuModuleGetFunction(&s->cu_func, s->cu_module, "Process_uchar"));
+    if (ret < 0) {
+        av_log(ctx, AV_LOG_FATAL, "Failed loading Process_uchar\n");
+        goto fail;
+    }
+
+    ret = CHECK_CU(cu->cuModuleGetFunction(&s->cu_func_uv, s->cu_module, "Process_uchar2"));
+    if (ret < 0) {
+        av_log(ctx, AV_LOG_FATAL, "Failed loading Process_uchar2\n");
+        goto fail;
+    }
+
+fail:
+    CHECK_CU(cu->cuCtxPopCurrent(&context));
+
+    return ret;
+}
+
+static av_cold int cudachromakey_config_props(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    AVFilterLink *inlink = outlink->src->inputs[0];
+    ChromakeyCUDAContext *s  = ctx->priv;
+    AVHWFramesContext     *frames_ctx = (AVHWFramesContext*)inlink->hw_frames_ctx->data;
+    AVCUDADeviceContext *device_hwctx = frames_ctx->device_ctx->hwctx;
+    int ret;
+
+    s->hwctx = device_hwctx;
+    s->cu_stream = s->hwctx->stream;
+
+    ret = init_processing_chain(ctx, inlink->w, inlink->h);
+    if (ret < 0)
+        return ret;
+
+    outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
+
+    ret = cudachromakey_load_functions(ctx);
+    if (ret < 0)
+        return ret;
+
+    return 0;
+}
+
+static int call_cuda_kernel(AVFilterContext *ctx, CUfunction func,
+                            CUtexObject src_tex[3], AVFrame *out_frame,
+                            int width, int height, int pitch,
+                            int width_uv, int height_uv, int pitch_uv,
+                            float u_key,float v_key, float similarity,
+                            float blend )
+{
+    ChromakeyCUDAContext *s = ctx->priv;
+    CudaFunctions *cu = s->hwctx->internal->cuda_dl;
+    int ret;
+
+    CUdeviceptr dst_devptr[4] = {
+        (CUdeviceptr)out_frame->data[0], (CUdeviceptr)out_frame->data[1],
+         (CUdeviceptr)out_frame->data[2], (CUdeviceptr)out_frame->data[3]
+
+    };
+
+    void *args_uchar[] = {
+        &src_tex[0], &src_tex[1], &src_tex[2],
+        &dst_devptr[0], &dst_devptr[1], &dst_devptr[2],&dst_devptr[3],
+        &width, &height, &pitch,
+        &width_uv, &height_uv, &pitch_uv,&u_key,&v_key,&similarity,&blend
+    };
+
+    ret = CHECK_CU(cu->cuLaunchKernel(func,
+                                      DIV_UP(width, BLOCKX), DIV_UP(height, BLOCKY), 1,
+                                      BLOCKX, BLOCKY, 1, 0, s->cu_stream, args_uchar, NULL));
+    if (ret < 0)
+        return ret;
+
+    // This ruins performance, but catches errors that happened in the Kernel immediately
+    // Remove for performance/production test
+    ret = CHECK_CU(cu->cuStreamSynchronize(s->cu_stream));
+
+    return ret;
+}
+
+static int cudachromakey_process_internal(AVFilterContext *ctx,
+                                      AVFrame *out, AVFrame *in)
+{
+    ChromakeyCUDAContext *s = ctx->priv;
+    CudaFunctions *cu = s->hwctx->internal->cuda_dl;
+    CUcontext context, cuda_ctx = s->hwctx->cuda_ctx;
+    float u_key,v_key;
+    int i, ret;
+
+    CUtexObject tex[3] = { 0, 0, 0 };
+    if(s->is_yuv){
+        u_key=s->chromakey_rgba[1];
+        v_key=s->chromakey_rgba[2];
+
+    }else{
+        u_key = RGB_TO_U(s->chromakey_rgba);
+        v_key = RGB_TO_V(s->chromakey_rgba);
+    }
+    ret = CHECK_CU(cu->cuCtxPushCurrent(cuda_ctx));
+    if (ret < 0)
+        return ret;
+
+    for (i = 0; i < s->in_planes; i++) {
+        CUDA_TEXTURE_DESC tex_desc = {
+            .filterMode = CU_TR_FILTER_MODE_LINEAR,
+            .flags = 0, // CU_TRSF_READ_AS_INTEGER to get raw ints instead of normalized floats from tex2D
+        };
+
+        CUDA_RESOURCE_DESC res_desc = {
+            .resType = CU_RESOURCE_TYPE_PITCH2D,
+            .res.pitch2D.format = CU_AD_FORMAT_UNSIGNED_INT8,
+            .res.pitch2D.numChannels = s->in_plane_channels[i],
+            .res.pitch2D.pitchInBytes = in->linesize[i],
+            .res.pitch2D.devPtr = (CUdeviceptr)in->data[i],
+        };
+
+        if (i == 1 || i == 2) {
+            res_desc.res.pitch2D.width = AV_CEIL_RSHIFT(in->width, s->in_desc->log2_chroma_w);
+            res_desc.res.pitch2D.height = AV_CEIL_RSHIFT(in->height, s->in_desc->log2_chroma_h);
+        } else {
+            res_desc.res.pitch2D.width = in->width;
+            res_desc.res.pitch2D.height = in->height;
+        }
+
+        ret = CHECK_CU(cu->cuTexObjectCreate(&tex[i], &res_desc, &tex_desc, NULL));
+        if (ret < 0)
+            goto exit;
+    }
+
+    ret = call_cuda_kernel(ctx, (s->in_plane_channels[1] > 1) ? s->cu_func_uv : s->cu_func,
+                           tex, out,
+                           out->width, out->height, out->linesize[0],
+                           AV_CEIL_RSHIFT(out->width, s->out_desc->log2_chroma_w),
+                           AV_CEIL_RSHIFT(out->height, s->out_desc->log2_chroma_h),
+                           out->linesize[1],
+                           u_key,v_key,s->similarity,s->blend );
+    if (ret < 0)
+        goto exit;
+
+exit:
+    for (i = 0; i < s->in_planes; i++)
+        if (tex[i])
+            CHECK_CU(cu->cuTexObjectDestroy(tex[i]));
+
+    CHECK_CU(cu->cuCtxPopCurrent(&context));
+
+    return ret;
+}
+
+static int cudachromakey_process(AVFilterContext *ctx, AVFrame *out, AVFrame *in)
+{
+    ChromakeyCUDAContext *s = ctx->priv;
+    AVFrame *src = in;
+    int ret;
+
+    ret = cudachromakey_process_internal(ctx, s->frame, src);
+    if (ret < 0)
+        return ret;
+
+    src = s->frame;
+    ret = av_hwframe_get_buffer(src->hw_frames_ctx, s->tmp_frame, 0);
+    if (ret < 0)
+        return ret;
+
+    av_frame_move_ref(out, s->frame);
+    av_frame_move_ref(s->frame, s->tmp_frame);
+
+    ret = av_frame_copy_props(out, in);
+    if (ret < 0)
+        return ret;
+
+    return 0;
+}
+
+static int cudachromakey_filter_frame(AVFilterLink *link, AVFrame *in)
+{
+    AVFilterContext       *ctx = link->dst;
+    ChromakeyCUDAContext        *s = ctx->priv;
+    AVFilterLink      *outlink = ctx->outputs[0];
+    CudaFunctions          *cu = s->hwctx->internal->cuda_dl;
+
+    AVFrame *out = NULL;
+    CUcontext context;
+    int ret = 0;
+
+    out = av_frame_alloc();
+    if (!out) {
+        ret = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    ret = CHECK_CU(cu->cuCtxPushCurrent(s->hwctx->cuda_ctx));
+    if (ret < 0)
+        goto fail;
+
+    ret = cudachromakey_process(ctx, out, in);
+
+    CHECK_CU(cu->cuCtxPopCurrent(&context));
+    if (ret < 0)
+        goto fail;
+
+    av_frame_free(&in);
+    return ff_filter_frame(outlink, out);
+fail:
+    av_frame_free(&in);
+    av_frame_free(&out);
+    return ret;
+}
+
+static AVFrame *cudachromakey_get_video_buffer(AVFilterLink *inlink, int w, int h)
+{
+    return ff_default_get_video_buffer(inlink, w, h);
+}
+
+#define OFFSET(x) offsetof(ChromakeyCUDAContext, x)
+#define FLAGS (AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM)
+static const AVOption options[] = {
+    { "color", "set the chromakey key color", OFFSET(chromakey_rgba), AV_OPT_TYPE_COLOR, { .str = "black" }, 0, 0, FLAGS },
+    { "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 },
+    { "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 },
+    { NULL },
+};
+
+static const AVClass cudachromakey_class = {
+    .class_name = "cudachromakey",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+static const AVFilterPad cudachromakey_inputs[] = {
+    {
+        .name        = "default",
+        .type        = AVMEDIA_TYPE_VIDEO,
+        .filter_frame = cudachromakey_filter_frame,
+        .get_buffer.video = cudachromakey_get_video_buffer,
+    },
+};
+
+static const AVFilterPad cudachromakey_outputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = cudachromakey_config_props,
+    },
+};
+
+const AVFilter ff_vf_chromakey_cuda = {
+    .name        = "chromakey_cuda",
+    .description = NULL_IF_CONFIG_SMALL("GPU accelerated chromakey filter"),
+
+    .init          = cudachromakey_init,
+    .uninit        = cudachromakey_uninit,
+
+    .priv_size = sizeof(ChromakeyCUDAContext),
+    .priv_class = &cudachromakey_class,
+
+    FILTER_INPUTS(cudachromakey_inputs),
+    FILTER_OUTPUTS(cudachromakey_outputs),
+
+    FILTER_SINGLE_PIXFMT(AV_PIX_FMT_CUDA),
+
+    .flags_internal = FF_FILTER_FLAG_HWFRAME_AWARE,
+};
diff --git a/libavfilter/vf_chromakey_cuda.cu b/libavfilter/vf_chromakey_cuda.cu
new file mode 100644
index 0000000000..fef118a0f8
--- /dev/null
+++ b/libavfilter/vf_chromakey_cuda.cu
@@ -0,0 +1,248 @@
+/*
+ * Copyright (c) 2022, Chromakey
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include "cuda/vector_helpers.cuh"
+
+extern "C"
+{
+
+
+/**
+ * @brief function contains the main logic of chroma keying, and changes the alpahc channel with the suitable value
+ *
+ * @param src_tex           texture U or texture UV , decided based on the passed is_uchar2 flag
+ * @param src_tex_V         texture V , used only if is_uchar2 flag is false
+ * @param dst_A             alpha channel destination
+ * @param width_uv          width of uv channels
+ * @param height_uv         height of uv channels
+ * @param width             width of alpha channel
+ * @param height            height of alpha channel
+ * @param pitch             pitch of alpha channel
+ * @param x                 current x coordinate of pixel
+ * @param y                 current y coordinate of pixel
+ * @param chromakey_uv      uv values for chroma keying
+ * @param similarity        similarity of keying
+ * @param blend             blend of keying
+ * @param is_uchar2         true means that sent texture is uchar2 for the UV channels, false means U and V are sent seperatley
+ * @param resize_ratio      the ratio of alpha channel to UV channels
+ * @return void
+ */
+__device__ static inline void change_alpha_channel(
+    cudaTextureObject_t src_tex, cudaTextureObject_t src_tex_V,
+    uchar *dst_A, int width_uv,
+    int height_uv, int width,
+    int height, int pitch,
+    int x, int y,
+    float2 chromakey_uv, float similarity,
+    float blend, bool is_uchar2,
+    uchar resize_ratio)
+{
+
+    uchar window_size = 3;
+    int start_r = x - window_size / 2;
+    int start_c = y - window_size / 2;
+
+    uchar counter = 0;
+    float diff = 0.0f;
+    float du, dv;
+
+    // loop over the eight neighbourhood of the current pixel(x,y)
+    for (uchar i = 0; i < window_size; i++)
+    {
+        for (uchar j = 0; j < window_size; j++)
+        {
+            int r = start_r + i;
+            int c = start_c + j;
+            bool check_flag = (r >= 0 && r < width_uv && c >= 0 && c < height_uv);
+
+            if (!check_flag)
+                continue;
+
+            float u_value, v_value;
+            if (is_uchar2){
+                float2 temp_uv = tex2D<float2>(src_tex, r, c);
+                u_value = temp_uv.x;
+                v_value = temp_uv.y;
+            }else{
+                u_value = tex2D<float>(src_tex, r, c);
+                v_value = tex2D<float>(src_tex_V, r, c);
+            }
+
+            du = (u_value * 255.0f) - chromakey_uv.x;
+            dv = (v_value * 255.0f) - chromakey_uv.y;
+            diff += sqrtf((du * du + dv * dv) / (255.0f * 255.0f * 2.f));
+            counter++;
+        }
+    }
+
+    if (counter > 0){
+        diff = diff / counter;
+    }else{
+        diff /= 9.0f;
+    }
+
+    uchar  alpha_value;
+    if(blend>0.0001f){
+        alpha_value=__saturatef((diff - similarity) / blend)*255;
+    }else{
+        alpha_value=(diff < similarity ? 0 : 1)*255;
+    }
+
+    //write the value in the aloha channel with regarding the ratio of (alpha_size : uv_size)
+    for (uchar k = 0; k < resize_ratio; k++)
+    {
+        for (uchar l = 0; l < resize_ratio; l++)
+        {
+            int x_resize = x * resize_ratio + k;
+            int y_resize = y * resize_ratio + l;
+            int a_channel_resize = y_resize * pitch + x_resize;
+            if (y_resize >= height || x_resize >= width)
+                continue;
+            dst_A[a_channel_resize] = alpha_value;
+        }
+    }
+
+
+}
+
+
+/**
+ * @brief Function to process yuv420p video , and pass it to change_alpha_channel function, the output video is yuva420p
+ *
+ * @param src_tex_Y     Y channel of input video frame
+ * @param src_tex_U     U channel of input video frame
+ * @param src_tex_V     V channel of input video frame
+ * @param dst_Y         Y channel of output video frame
+ * @param dst_U         U channel of output video frame
+ * @param dst_V         V channel of output video frame
+ * @param dst_A         A channel of output video frame
+ * @param width         width of Y channel for input,video frame
+ * @param height        height of Y channel for input,video frame
+ * @param pitch         pitch(line size) of Y channel for input,video frame
+ * @param width_uv      width of UV for input,output video frame
+ * @param height_uv     height of UV for input,output video frame
+ * @param pitch_uv      pitch(line size) of UV for input,output video frame
+ * @param u_key         u part of chromakey (user input)
+ * @param v_key         v part of chromakey (user input)
+ * @param similarity    similairty user want (user input)
+ * @param blend         blend user want (user input)
+ * @return void
+ */
+__global__ void Process_uchar(
+    cudaTextureObject_t src_tex_Y, cudaTextureObject_t src_tex_U,
+    cudaTextureObject_t src_tex_V,uchar *dst_Y,
+    uchar *dst_U, uchar *dst_V,
+    uchar *dst_A,int width,
+    int height, int pitch,
+    int width_uv, int height_uv,
+    int pitch_uv,float u_key,
+    float v_key, float similarity,
+    float blend)
+{
+
+    uchar resize_ratio = 2;
+    int x = blockIdx.x * blockDim.x + threadIdx.x;
+    int y = blockIdx.y * blockDim.y + threadIdx.y;
+
+    if (y >= height || x >= width)
+        return;
+    dst_Y[y * pitch + x] = tex2D<float>(src_tex_Y, x, y)*255;
+    if (y >= height_uv || x >= width_uv)
+        return;
+
+    int uv_index = y * pitch_uv + x;
+    dst_U[uv_index]=tex2D<float>(src_tex_U,x,y)*255;
+    dst_V[uv_index]=tex2D<float>(src_tex_V,x,y)*255;
+
+
+
+    change_alpha_channel(src_tex_U,src_tex_V,
+                        dst_A,width_uv,height_uv,
+                        width,height,
+                        pitch,x,
+                        y,make_float2(u_key,v_key),
+                        similarity,blend,
+                        false,resize_ratio);
+
+}
+
+
+
+/**
+ * @brief Function to process nv12 video , and pass it to change_alpha_channel function, the output video is yuva420p
+ *
+ * @param src_tex_Y     Y channel of input video frame
+ * @param src_tex_UV    UV channels of input video frame
+ * @param unused1       unused parameter
+ * @param dst_Y         Y channel of output video frame
+ * @param dst_U         U channel of output video frame
+ * @param dst_V         V channel of output video frame
+ * @param dst_A         A channel of output video frame
+ * @param width         width of Y channel for input,video frame
+ * @param height        height of Y channel for input,video frame
+ * @param pitch         pitch(line size) of Y channel for input,video frame
+ * @param width_uv      width of UV for input,output video frame
+ * @param height_uv     height of UV for input,output video frame
+ * @param pitch_uv      pitch(line size) of UV for input, output video frame
+ * @param u_key         u part of chromakey (user input)
+ * @param v_key         v part of chromakey (user input)
+ * @param similarity    similairty user want (user input)
+ * @param blend         blend user want (user input)
+ * @return void
+ */
+__global__ void Process_uchar2(
+    cudaTextureObject_t src_tex_Y, cudaTextureObject_t src_tex_UV,
+    cudaTextureObject_t unused1,uchar *dst_Y,
+    uchar *dst_U, uchar *dst_V,
+    uchar *dst_A,int width,
+    int height, int pitch,
+    int width_uv, int height_uv,
+    int pitch_uv,float u_key,
+    float v_key, float similarity,
+    float blend)
+{
+
+    uchar resize_ratio = 2;                         // alphachannel_size : uv_channel_size ratio
+    int x = blockIdx.x * blockDim.x + threadIdx.x;  // x coordinate of current pixel
+    int y = blockIdx.y * blockDim.y + threadIdx.y;  // y coordinate of current pixel
+
+    if (y >= height || x >= width)
+        return;
+    dst_Y[y * pitch + x] = tex2D<float>(src_tex_Y, x, y)*255;
+
+    if (y >= height_uv || x >= width_uv)
+        return;
+    int uv_index= y * pitch_uv + x;
+    float2 uv_temp=tex2D<float2>(src_tex_UV,x,y);
+    dst_U[uv_index]=uv_temp.x*255;
+    dst_V[uv_index]=uv_temp.y*255;
+
+    change_alpha_channel(src_tex_UV, unused1,
+                        dst_A, width_uv,
+                        height_uv, width,
+                        height, pitch,
+                        x, y,
+                        make_float2(u_key,v_key), similarity,
+                        blend, true,
+                        resize_ratio);
+}
+}
-- 
2.36.1



More information about the ffmpeg-devel mailing list