[FFmpeg-devel] [PATCH 7/7] avutil/vf_scdet_vulkan: add new filter

Niklas Haas ffmpeg at haasn.xyz
Sun May 18 15:11:52 EEST 2025


From: Niklas Haas <git at haasn.dev>

Carbon copy of vf_scdet.

Signed-off-by: Niklas Haas <git at haasn.dev>
Sponsored-by: nxtedition
---
 configure                     |   1 +
 libavfilter/Makefile          |   1 +
 libavfilter/allfilters.c      |   1 +
 libavfilter/vf_scdet_vulkan.c | 412 ++++++++++++++++++++++++++++++++++
 4 files changed, 415 insertions(+)
 create mode 100644 libavfilter/vf_scdet_vulkan.c

diff --git a/configure b/configure
index 9556d7c86f..e42ebbad06 100755
--- a/configure
+++ b/configure
@@ -3986,6 +3986,7 @@ vpp_amf_filter_deps="amf"
 scale_qsv_filter_deps="libmfx"
 scale_qsv_filter_select="qsvvpp"
 scdet_filter_select="scene_sad"
+scdet_vulkan_filter_deps="vulkan spirv_compiler"
 select_filter_select="scene_sad"
 sharpness_vaapi_filter_deps="vaapi"
 showcqt_filter_deps="avformat swscale"
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 76a4f53932..79113b3948 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -473,6 +473,7 @@ OBJS-$(CONFIG_SCALE_VULKAN_FILTER)           += vf_scale_vulkan.o vulkan.o vulka
 OBJS-$(CONFIG_SCALE2REF_FILTER)              += vf_scale.o scale_eval.o framesync.o
 OBJS-$(CONFIG_SCALE2REF_NPP_FILTER)          += vf_scale_npp.o scale_eval.o
 OBJS-$(CONFIG_SCDET_FILTER)                  += vf_scdet.o
+OBJS-$(CONFIG_SCDET_VULKAN_FILTER)           += vf_scdet_vulkan.o
 OBJS-$(CONFIG_SCHARR_FILTER)                 += vf_convolution.o
 OBJS-$(CONFIG_SCROLL_FILTER)                 += vf_scroll.o
 OBJS-$(CONFIG_SEGMENT_FILTER)                += f_segment.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 88204e070c..ffa8397c62 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -445,6 +445,7 @@ extern const FFFilter ff_vf_scale_vulkan;
 extern const FFFilter ff_vf_scale2ref;
 extern const FFFilter ff_vf_scale2ref_npp;
 extern const FFFilter ff_vf_scdet;
+extern const FFFilter ff_vf_scdet_vulkan;
 extern const FFFilter ff_vf_scharr;
 extern const FFFilter ff_vf_scroll;
 extern const FFFilter ff_vf_segment;
diff --git a/libavfilter/vf_scdet_vulkan.c b/libavfilter/vf_scdet_vulkan.c
new file mode 100644
index 0000000000..fadc0842ae
--- /dev/null
+++ b/libavfilter/vf_scdet_vulkan.c
@@ -0,0 +1,412 @@
+/*
+ * Copyright 2025 (c) Niklas Haas
+ *
+ * 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/avassert.h"
+#include "libavutil/vulkan_spirv.h"
+#include "libavutil/opt.h"
+#include "libavutil/timestamp.h"
+#include "vulkan_filter.h"
+
+#include "filters.h"
+
+typedef struct SceneDetectVulkanContext {
+    FFVulkanContext vkctx;
+
+    int initialized;
+    FFVkExecPool e;
+    AVVulkanDeviceQueueFamily *qf;
+    FFVulkanShader shd;
+    AVBufferPool *det_buf_pool;
+
+    double threshold;
+    int sc_pass;
+
+    int nb_planes;
+    double prev_mafd;
+    AVFrame *prev;
+    AVFrame *cur;
+} SceneDetectVulkanContext;
+
+typedef struct SceneDetectBuf {
+#define SLICES 16
+    uint32_t frame_sad[SLICES];
+} SceneDetectBuf;
+
+static av_cold int init_filter(AVFilterContext *ctx)
+{
+    int err;
+    uint8_t *spv_data;
+    size_t spv_len;
+    void *spv_opaque = NULL;
+    SceneDetectVulkanContext *s = ctx->priv;
+    FFVulkanContext *vkctx = &s->vkctx;
+    FFVulkanShader *shd;
+    FFVkSPIRVCompiler *spv;
+    FFVulkanDescriptorSetBinding *desc;
+
+    const AVPixFmtDescriptor *pixdesc = av_pix_fmt_desc_get(s->vkctx.input_format);
+    const int lumaonly = !(pixdesc->flags & AV_PIX_FMT_FLAG_RGB) &&
+                         (pixdesc->flags & AV_PIX_FMT_FLAG_PLANAR);
+    s->nb_planes = lumaonly ? 1 : av_pix_fmt_count_planes(s->vkctx.input_format);
+
+    spv = ff_vk_spirv_init();
+    if (!spv) {
+        av_log(ctx, AV_LOG_ERROR, "Unable to initialize SPIR-V compiler!\n");
+        return AVERROR_EXTERNAL;
+    }
+
+    s->qf = ff_vk_qf_find(vkctx, VK_QUEUE_COMPUTE_BIT, 0);
+    if (!s->qf) {
+        av_log(ctx, AV_LOG_ERROR, "Device has no compute queues\n");
+        err = AVERROR(ENOTSUP);
+        goto fail;
+    }
+
+    RET(ff_vk_exec_pool_init(vkctx, s->qf, &s->e, s->qf->num*4, 0, 0, 0, NULL));
+    RET(ff_vk_shader_init(vkctx, &s->shd, "scdet",
+                          VK_SHADER_STAGE_COMPUTE_BIT,
+                          (const char *[]) { "GL_KHR_shader_subgroup_arithmetic" }, 1,
+                          32, 32, 1,
+                          0));
+    shd = &s->shd;
+
+    desc = (FFVulkanDescriptorSetBinding []) {
+        {
+            .name       = "prev_img",
+            .type       = VK_DESCRIPTOR_TYPE_STORAGE_IMAGE,
+            .mem_layout = ff_vk_shader_rep_fmt(s->vkctx.input_format, FF_VK_REP_UINT),
+            .mem_quali  = "readonly",
+            .dimensions = 2,
+            .elems      = av_pix_fmt_count_planes(s->vkctx.input_format),
+            .stages     = VK_SHADER_STAGE_COMPUTE_BIT,
+        }, {
+            .name       = "cur_img",
+            .type       = VK_DESCRIPTOR_TYPE_STORAGE_IMAGE,
+            .mem_layout = ff_vk_shader_rep_fmt(s->vkctx.input_format, FF_VK_REP_UINT),
+            .mem_quali  = "readonly",
+            .dimensions = 2,
+            .elems      = av_pix_fmt_count_planes(s->vkctx.input_format),
+            .stages     = VK_SHADER_STAGE_COMPUTE_BIT,
+        }, {
+            .name        = "sad_buffer",
+            .type        = VK_DESCRIPTOR_TYPE_STORAGE_BUFFER,
+            .stages      = VK_SHADER_STAGE_COMPUTE_BIT,
+            .buf_content = "uint frame_sad[];",
+        }
+    };
+
+    RET(ff_vk_shader_add_descriptor_set(vkctx, &s->shd, desc, 3, 0, 0));
+
+    GLSLC(0, shared uint wg_sum;                                              );
+    GLSLC(0, void main()                                                      );
+    GLSLC(0, {                                                                );
+    GLSLF(1,     const uint slice = gl_WorkGroupID.x %% %u;            ,SLICES);
+    GLSLC(1,     const ivec2 pos = ivec2(gl_GlobalInvocationID.xy);           );
+    GLSLC(1,     wg_sum = 0;                                                  );
+    GLSLC(1,     barrier();                                                   );
+    for (int i = 0; i < s->nb_planes; i++) {
+        GLSLF(1, if (IS_WITHIN(pos, imageSize(cur_img[%d]))) {              ,i);
+        GLSLF(2,     uvec4 prev = imageLoad(prev_img[%d], pos);             ,i);
+        GLSLF(2,     uvec4 cur  = imageLoad(cur_img[%d],  pos);             ,i);
+        GLSLC(2,     uvec4 sad = abs(ivec4(cur) - ivec4(prev));               );
+        GLSLC(2,     uint sum = subgroupAdd(sad.x + sad.y + sad.z);           );
+        GLSLC(2,     if (subgroupElect())                                     );
+        GLSLC(3,         atomicAdd(wg_sum, sum);                              );
+        GLSLC(1, }                                                            );
+    }
+    GLSLC(1,     barrier();                                                   );
+    GLSLC(1,     if (gl_LocalInvocationIndex == 0)                            );
+    GLSLC(2,         atomicAdd(frame_sad[slice], wg_sum);                     );
+    GLSLC(0, }                                                                );
+
+    RET(spv->compile_shader(vkctx, spv, &s->shd, &spv_data, &spv_len, "main",
+                            &spv_opaque));
+    RET(ff_vk_shader_link(vkctx, &s->shd, spv_data, spv_len, "main"));
+
+    RET(ff_vk_shader_register_exec(vkctx, &s->e, &s->shd));
+
+    s->initialized = 1;
+
+fail:
+    if (spv_opaque)
+        spv->free_shader(spv, &spv_opaque);
+    if (spv)
+        spv->uninit(&spv);
+
+    return err;
+}
+
+static double evaluate(AVFilterContext *ctx, const SceneDetectBuf *buf)
+{
+    SceneDetectVulkanContext *s = ctx->priv;
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(s->vkctx.input_format);
+    const AVFilterLink *inlink = ctx->inputs[0];
+    uint64_t count;
+    double mafd, diff;
+
+    uint64_t sad = 0;
+    for (int i = 0; i < SLICES; i++)
+        sad += buf->frame_sad[i];
+
+    av_assert2(s->nb_planes == 1 || !(desc->log2_chroma_w || desc->log2_chroma_h));
+    count = s->nb_planes * inlink->w * inlink->h;
+    mafd = (double) sad * 100.0 / count / (1ULL << desc->comp[0].depth);
+    diff = fabs(mafd - s->prev_mafd);
+    s->prev_mafd = mafd;
+
+    return av_clipf(FFMIN(mafd, diff), 0.0, 100.0);
+}
+
+static int scdet_vulkan_filter_frame(AVFilterLink *link, AVFrame *in)
+{
+    int err;
+    AVFilterContext *ctx = link->dst;
+    SceneDetectVulkanContext *s = ctx->priv;
+    AVFilterLink *outlink = ctx->outputs[0];
+
+    VkImageView prev_views[AV_NUM_DATA_POINTERS];
+    VkImageView cur_views[AV_NUM_DATA_POINTERS];
+    VkImageMemoryBarrier2 img_bar[8];
+    int nb_img_bar = 0;
+
+    FFVulkanContext *vkctx = &s->vkctx;
+    FFVulkanFunctions *vk = &vkctx->vkfn;
+    FFVkExecContext *exec = NULL;
+    AVBufferRef *buf = NULL;
+    FFVkBuffer *buf_vk;
+
+    SceneDetectBuf *sad;
+    double score = 0.0;
+    char str[64];
+
+    if (!s->initialized)
+        RET(init_filter(ctx));
+
+    av_frame_free(&s->prev);
+    s->prev = s->cur;
+    s->cur = av_frame_clone(in);
+    if (!s->prev)
+        goto done;
+
+    RET(ff_vk_get_pooled_buffer(vkctx, &s->det_buf_pool, &buf,
+                                VK_BUFFER_USAGE_TRANSFER_DST_BIT |
+                                VK_BUFFER_USAGE_STORAGE_BUFFER_BIT,
+                                NULL,
+                                sizeof(SceneDetectBuf),
+                                VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT |
+                                VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT |
+                                VK_MEMORY_PROPERTY_HOST_COHERENT_BIT));
+    buf_vk = (FFVkBuffer *)buf->data;
+    sad = (SceneDetectBuf *) buf_vk->mapped_mem;
+
+    exec = ff_vk_exec_get(vkctx, &s->e);
+    ff_vk_exec_start(vkctx, exec);
+
+    RET(ff_vk_exec_add_dep_frame(vkctx, exec, s->prev,
+                                 VK_PIPELINE_STAGE_2_NONE,
+                                 VK_PIPELINE_STAGE_2_COMPUTE_SHADER_BIT));
+    RET(ff_vk_create_imageviews(vkctx, exec, prev_views, s->prev, FF_VK_REP_UINT));
+
+    ff_vk_shader_update_img_array(vkctx, exec, &s->shd, s->prev, prev_views, 0, 0,
+                                  VK_IMAGE_LAYOUT_GENERAL, VK_NULL_HANDLE);
+
+    ff_vk_frame_barrier(vkctx, exec, s->prev, img_bar, &nb_img_bar,
+                        VK_PIPELINE_STAGE_2_ALL_COMMANDS_BIT,
+                        VK_PIPELINE_STAGE_2_COMPUTE_SHADER_BIT,
+                        VK_ACCESS_SHADER_READ_BIT,
+                        VK_IMAGE_LAYOUT_GENERAL,
+                        VK_QUEUE_FAMILY_IGNORED);
+
+    RET(ff_vk_exec_add_dep_frame(vkctx, exec, s->cur,
+                                 VK_PIPELINE_STAGE_2_NONE,
+                                 VK_PIPELINE_STAGE_2_COMPUTE_SHADER_BIT));
+    RET(ff_vk_create_imageviews(vkctx, exec, cur_views, s->cur, FF_VK_REP_UINT));
+
+    ff_vk_shader_update_img_array(vkctx, exec, &s->shd, s->cur, cur_views, 0, 1,
+                                  VK_IMAGE_LAYOUT_GENERAL, VK_NULL_HANDLE);
+
+    ff_vk_frame_barrier(vkctx, exec, s->cur, img_bar, &nb_img_bar,
+                        VK_PIPELINE_STAGE_2_ALL_COMMANDS_BIT,
+                        VK_PIPELINE_STAGE_2_COMPUTE_SHADER_BIT,
+                        VK_ACCESS_SHADER_READ_BIT,
+                        VK_IMAGE_LAYOUT_GENERAL,
+                        VK_QUEUE_FAMILY_IGNORED);
+
+    /* zero buffer */
+    vk->CmdPipelineBarrier2(exec->buf, &(VkDependencyInfo) {
+            .sType = VK_STRUCTURE_TYPE_DEPENDENCY_INFO,
+            .pBufferMemoryBarriers = &(VkBufferMemoryBarrier2) {
+                .sType = VK_STRUCTURE_TYPE_BUFFER_MEMORY_BARRIER_2,
+                .srcStageMask = VK_PIPELINE_STAGE_2_NONE,
+                .dstStageMask = VK_PIPELINE_STAGE_2_TRANSFER_BIT,
+                .dstAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT,
+                .srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
+                .dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
+                .buffer = buf_vk->buf,
+                .size = buf_vk->size,
+                .offset = 0,
+            },
+            .bufferMemoryBarrierCount = 1,
+        });
+
+    vk->CmdFillBuffer(exec->buf, buf_vk->buf, 0, buf_vk->size, 0x0);
+
+    vk->CmdPipelineBarrier2(exec->buf, &(VkDependencyInfo) {
+            .sType = VK_STRUCTURE_TYPE_DEPENDENCY_INFO,
+            .pImageMemoryBarriers = img_bar,
+            .imageMemoryBarrierCount = nb_img_bar,
+            .pBufferMemoryBarriers = &(VkBufferMemoryBarrier2) {
+                .sType = VK_STRUCTURE_TYPE_BUFFER_MEMORY_BARRIER_2,
+                .srcStageMask = VK_PIPELINE_STAGE_2_TRANSFER_BIT,
+                .dstStageMask = VK_PIPELINE_STAGE_2_COMPUTE_SHADER_BIT,
+                .srcAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT,
+                .dstAccessMask = VK_ACCESS_2_SHADER_STORAGE_READ_BIT |
+                                 VK_ACCESS_2_SHADER_STORAGE_WRITE_BIT,
+                .srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
+                .dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
+                .buffer = buf_vk->buf,
+                .size = buf_vk->size,
+                .offset = 0,
+            },
+            .bufferMemoryBarrierCount = 1,
+        });
+
+    RET(ff_vk_shader_update_desc_buffer(&s->vkctx, exec, &s->shd, 0, 2, 0,
+                                        buf_vk, 0, buf_vk->size,
+                                        VK_FORMAT_UNDEFINED));
+
+    ff_vk_exec_bind_shader(vkctx, exec, &s->shd);
+
+    vk->CmdDispatch(exec->buf,
+                    FFALIGN(in->width,  s->shd.lg_size[0]) / s->shd.lg_size[0],
+                    FFALIGN(in->height, s->shd.lg_size[1]) / s->shd.lg_size[1],
+                    s->shd.lg_size[2]);
+
+    vk->CmdPipelineBarrier2(exec->buf, &(VkDependencyInfo) {
+            .sType = VK_STRUCTURE_TYPE_DEPENDENCY_INFO,
+            .pBufferMemoryBarriers = &(VkBufferMemoryBarrier2) {
+                .sType = VK_STRUCTURE_TYPE_BUFFER_MEMORY_BARRIER_2,
+                .srcStageMask = VK_PIPELINE_STAGE_2_COMPUTE_SHADER_BIT,
+                .dstStageMask = VK_PIPELINE_STAGE_2_HOST_BIT,
+                .srcAccessMask = VK_ACCESS_2_SHADER_STORAGE_READ_BIT |
+                                 VK_ACCESS_2_SHADER_STORAGE_WRITE_BIT,
+                .dstAccessMask = VK_ACCESS_HOST_READ_BIT,
+                .srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
+                .dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED,
+                .buffer = buf_vk->buf,
+                .size = buf_vk->size,
+                .offset = 0,
+            },
+            .bufferMemoryBarrierCount = 1,
+        });
+
+    RET(ff_vk_exec_submit(vkctx, exec));
+    ff_vk_exec_wait(vkctx, exec);
+    score = evaluate(ctx, sad);
+
+done:
+    snprintf(str, sizeof(str), "%0.3f", s->prev_mafd);
+    av_dict_set(&in->metadata, "lavfi.scd.mafd", str, 0);
+    snprintf(str, sizeof(str), "%0.3f", score);
+    av_dict_set(&in->metadata, "lavfi.scd.score", str, 0);
+
+    if (score >= s->threshold) {
+        const char *pts = av_ts2timestr(in->pts, &link->time_base);
+        av_dict_set(&in->metadata, "lavfi.scd.time", pts, 0);
+        av_log(s, AV_LOG_INFO, "lavfi.scd.score: %.3f, lavfi.scd.time: %s\n",
+               score, pts);
+    }
+
+    av_buffer_unref(&buf);
+    if (!s->sc_pass || score >= s->threshold)
+        return ff_filter_frame(outlink, in);
+    else {
+        av_frame_free(&in);
+        return 0;
+    }
+
+fail:
+    if (exec)
+        ff_vk_exec_discard_deps(&s->vkctx, exec);
+    av_frame_free(&in);
+    av_buffer_unref(&buf);
+    return err;
+}
+
+static void scdet_vulkan_uninit(AVFilterContext *avctx)
+{
+    SceneDetectVulkanContext *s = avctx->priv;
+    FFVulkanContext *vkctx = &s->vkctx;
+
+    av_frame_free(&s->prev);
+    av_frame_free(&s->cur);
+
+    ff_vk_exec_pool_free(vkctx, &s->e);
+    ff_vk_shader_free(vkctx, &s->shd);
+
+    av_buffer_pool_uninit(&s->det_buf_pool);
+
+    ff_vk_uninit(&s->vkctx);
+
+    s->initialized = 0;
+}
+
+#define OFFSET(x) offsetof(SceneDetectVulkanContext, x)
+#define FLAGS (AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_VIDEO_PARAM)
+static const AVOption scdet_vulkan_options[] = {
+    { "threshold",   "set scene change detect threshold",        OFFSET(threshold),  AV_OPT_TYPE_DOUBLE,   {.dbl = 10.},     0,  100., FLAGS },
+    { "t",           "set scene change detect threshold",        OFFSET(threshold),  AV_OPT_TYPE_DOUBLE,   {.dbl = 10.},     0,  100., FLAGS },
+    { "sc_pass",     "Set the flag to pass scene change frames", OFFSET(sc_pass),    AV_OPT_TYPE_BOOL,     {.i64 = 0  },     0,    1,  FLAGS },
+    { "s",           "Set the flag to pass scene change frames", OFFSET(sc_pass),    AV_OPT_TYPE_BOOL,     {.i64 = 0  },     0,    1,  FLAGS },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(scdet_vulkan);
+
+static const AVFilterPad scdet_vulkan_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .filter_frame = &scdet_vulkan_filter_frame,
+        .config_props = &ff_vk_filter_config_input,
+    },
+};
+
+static const AVFilterPad scdet_vulkan_outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+        .config_props = &ff_vk_filter_config_output,
+    },
+};
+
+const FFFilter ff_vf_scdet_vulkan = {
+    .p.name         = "scdet_vulkan",
+    .p.description  = NULL_IF_CONFIG_SMALL("Detect video scene change"),
+    .p.priv_class   = &scdet_vulkan_class,
+    .p.flags        = AVFILTER_FLAG_HWDEVICE,
+    .priv_size      = sizeof(SceneDetectVulkanContext),
+    .init           = &ff_vk_filter_init,
+    .uninit         = &scdet_vulkan_uninit,
+    FILTER_INPUTS(scdet_vulkan_inputs),
+    FILTER_OUTPUTS(scdet_vulkan_outputs),
+    FILTER_SINGLE_PIXFMT(AV_PIX_FMT_VULKAN),
+    .flags_internal = FF_FILTER_FLAG_HWFRAME_AWARE,
+};
-- 
2.49.0



More information about the ffmpeg-devel mailing list