avfilter/interlace_vulkan: add interlace_vulkan filter

This is a Vulkan-accelerated version of the existing interlace filter.

configure

@@ -3920,6 +3920,7 @@ iccdetect_filter_deps="lcms2"
 iccgen_filter_deps="lcms2"
 identity_filter_select="scene_sad"
 interlace_filter_deps="gpl"
+interlace_vulkan_filter_deps="vulkan spirv_compiler"
 kerndeint_filter_deps="gpl"
 ladspa_filter_deps="ladspa libdl"
 lcevc_filter_deps="liblcevc_dec"

doc/filters.texi

@@ -16041,7 +16041,7 @@ If 0, plane will remain unchanged.
 
 This filter supports the all above options as @ref{commands}.
 
-@section interlace
+@section interlace, interlace_vulkan
 
 Simple interlacing filter from progressive contents. This interleaves upper (or
 lower) lines from odd frames with lower (or upper) lines from even frames,

libavfilter/Makefile

@@ -358,6 +358,7 @@ OBJS-$(CONFIG_IDET_FILTER)                   += vf_idet.o
 OBJS-$(CONFIG_IL_FILTER)                     += vf_il.o
 OBJS-$(CONFIG_INFLATE_FILTER)                += vf_neighbor.o
 OBJS-$(CONFIG_INTERLACE_FILTER)              += vf_tinterlace.o
+OBJS-$(CONFIG_INTERLACE_VULKAN_FILTER)       += vf_interlace_vulkan.o vulkan.o vulkan_filter.o
 OBJS-$(CONFIG_INTERLEAVE_FILTER)             += f_interleave.o
 OBJS-$(CONFIG_KERNDEINT_FILTER)              += vf_kerndeint.o
 OBJS-$(CONFIG_KIRSCH_FILTER)                 += vf_convolution.o

libavfilter/allfilters.c

@@ -333,6 +333,7 @@ extern const FFFilter ff_vf_idet;
 extern const FFFilter ff_vf_il;
 extern const FFFilter ff_vf_inflate;
 extern const FFFilter ff_vf_interlace;
+extern const FFFilter ff_vf_interlace_vulkan;
 extern const FFFilter ff_vf_interleave;
 extern const FFFilter ff_vf_kerndeint;
 extern const FFFilter ff_vf_kirsch;

libavfilter/vf_interlace_vulkan.c

@@ -0,0 +1,313 @@
+/*
+ * 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/vulkan_spirv.h"
+#include "libavutil/opt.h"
+#include "vulkan_filter.h"
+
+#include "tinterlace.h"
+#include "filters.h"
+#include "video.h"
+
+typedef struct InterlaceVulkanContext {
+    FFVulkanContext vkctx;
+
+    int initialized;
+    FFVkExecPool e;
+    AVVulkanDeviceQueueFamily *qf;
+    VkSampler sampler;
+    FFVulkanShader shd;
+
+    int mode;
+    int lowpass;
+
+    AVFrame *cur; /* first frame in pair */
+} InterlaceVulkanContext;
+
+static const char lowpass_off[] = {
+    C(0, vec4 get_line(sampler2D tex, const vec2 pos)                         )
+    C(0, {                                                                    )
+    C(1,     return texture(tex, pos);                                        )
+    C(0, }                                                                    )
+};
+
+static const char lowpass_lin[] = {
+    C(0, vec4 get_line(sampler2D tex, const vec2 pos)                         )
+    C(0, {                                                                    )
+    C(1,     return 0.50 * texture(tex, pos) +                                )
+    C(1,            0.25 * texture(tex, pos - ivec2(0, 1)) +                  )
+    C(1,            0.25 * texture(tex, pos + ivec2(0, 1));                   )
+    C(0, }                                                                    )
+};
+
+static const char lowpass_complex[] = {
+    C(0, vec4 get_line(sampler2D tex, const vec2 pos)                         )
+    C(0, {                                                                    )
+    C(1,     return  0.75  * texture(tex, pos) +                              )
+    C(1,             0.25  * texture(tex, pos - ivec2(0, 1)) +                )
+    C(1,             0.25  * texture(tex, pos + ivec2(0, 1)) +                )
+    C(1,            -0.125 * texture(tex, pos - ivec2(0, 2)) +                )
+    C(1,            -0.125 * texture(tex, pos + ivec2(0, 2));                 )
+    C(0, }                                                                    )
+};
+
+static av_cold int init_filter(AVFilterContext *ctx)
+{
+    int err;
+    uint8_t *spv_data;
+    size_t spv_len;
+    void *spv_opaque = NULL;
+    InterlaceVulkanContext *s = ctx->priv;
+    FFVulkanContext *vkctx = &s->vkctx;
+    const int planes = av_pix_fmt_count_planes(s->vkctx.output_format);
+    FFVulkanShader *shd;
+    FFVkSPIRVCompiler *spv;
+    FFVulkanDescriptorSetBinding *desc;
+
+    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_init_sampler(vkctx, &s->sampler, 1,
+                           s->lowpass == VLPF_OFF ? VK_FILTER_NEAREST
+                                                  : VK_FILTER_LINEAR));
+    RET(ff_vk_shader_init(vkctx, &s->shd, "interlace",
+                          VK_SHADER_STAGE_COMPUTE_BIT,
+                          NULL, 0,
+                          32, 32, 1,
+                          0));
+    shd = &s->shd;
+
+    desc = (FFVulkanDescriptorSetBinding []) {
+        {
+            .name       = "top_field",
+            .type       = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
+            .dimensions = 2,
+            .elems      = planes,
+            .stages     = VK_SHADER_STAGE_COMPUTE_BIT,
+            .samplers   = DUP_SAMPLER(s->sampler),
+        },
+        {
+            .name       = "bot_field",
+            .type       = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
+            .dimensions = 2,
+            .elems      = planes,
+            .stages     = VK_SHADER_STAGE_COMPUTE_BIT,
+            .samplers   = DUP_SAMPLER(s->sampler),
+        },
+        {
+            .name       = "output_img",
+            .type       = VK_DESCRIPTOR_TYPE_STORAGE_IMAGE,
+            .mem_layout = ff_vk_shader_rep_fmt(s->vkctx.output_format, FF_VK_REP_FLOAT),
+            .mem_quali  = "writeonly",
+            .dimensions = 2,
+            .elems      = planes,
+            .stages     = VK_SHADER_STAGE_COMPUTE_BIT,
+        },
+    };
+
+    RET(ff_vk_shader_add_descriptor_set(vkctx, shd, desc, 3, 0, 0));
+
+    switch (s->lowpass) {
+    case VLPF_OFF:
+        GLSLD(lowpass_off);
+        break;
+    case VLPF_LIN:
+        GLSLD(lowpass_lin);
+        break;
+    case VLPF_CMP:
+        GLSLD(lowpass_complex);
+        break;
+    }
+
+    GLSLC(0, void main()                                                  );
+    GLSLC(0, {                                                            );
+    GLSLC(1,     vec4 res;                                                );
+    GLSLC(1,     ivec2 size;                                              );
+    GLSLC(1,     const ivec2 pos = ivec2(gl_GlobalInvocationID.xy);       );
+    GLSLC(1,     const vec2 ipos = pos + vec2(0.5);                       );
+    for (int i = 0; i < planes; i++) {
+        GLSLC(0,                                                          );
+        GLSLF(1,  size = imageSize(output_img[%i]);                     ,i);
+        GLSLC(1,  if (!IS_WITHIN(pos, size))                              );
+        GLSLC(2,      return;                                             );
+        GLSLC(1,  if (pos.y %% 2 == 0)                                    );
+        GLSLF(1,      res = get_line(top_field[%i], ipos);              ,i);
+        GLSLC(1,  else                                                    );
+        GLSLF(1,      res = get_line(bot_field[%i], ipos);              ,i);
+        GLSLF(1,  imageStore(output_img[%i], pos, res);                 ,i);
+    }
+    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 int interlace_vulkan_filter_frame(AVFilterLink *link, AVFrame *in)
+{
+    int err;
+    AVFrame *out = NULL, *input_top, *input_bot;
+    AVFilterContext *ctx = link->dst;
+    InterlaceVulkanContext *s = ctx->priv;
+    AVFilterLink *outlink = ctx->outputs[0];
+
+    if (!s->initialized)
+        RET(init_filter(ctx));
+
+    /* Need both frames to filter */
+    if (!s->cur) {
+        s->cur = in;
+        return 0;
+    }
+
+    out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+    if (!out) {
+        err = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    if (s->mode == MODE_TFF) {
+        input_top = s->cur;
+        input_bot = in;
+    } else {
+        input_top = in;
+        input_bot = s->cur;
+    }
+
+    RET(ff_vk_filter_process_Nin(&s->vkctx, &s->e, &s->shd,
+                                 out, (AVFrame *[]){ input_top, input_bot }, 2,
+                                 s->sampler, NULL, 0));
+
+    err = av_frame_copy_props(out, s->cur);
+    if (err < 0)
+        goto fail;
+
+    out->flags |= AV_FRAME_FLAG_INTERLACED;
+    if (s->mode == MODE_TFF)
+        out->flags |= AV_FRAME_FLAG_TOP_FIELD_FIRST;
+
+    av_frame_free(&s->cur);
+    av_frame_free(&in);
+
+    return ff_filter_frame(outlink, out);
+
+fail:
+    av_frame_free(&s->cur);
+    av_frame_free(&in);
+    av_frame_free(&out);
+    return err;
+}
+
+static void interlace_vulkan_uninit(AVFilterContext *avctx)
+{
+    InterlaceVulkanContext *s = avctx->priv;
+    FFVulkanContext *vkctx = &s->vkctx;
+    FFVulkanFunctions *vk = &vkctx->vkfn;
+
+    av_frame_free(&s->cur);
+
+    ff_vk_exec_pool_free(vkctx, &s->e);
+    ff_vk_shader_free(vkctx, &s->shd);
+
+    if (s->sampler)
+        vk->DestroySampler(vkctx->hwctx->act_dev, s->sampler,
+                           vkctx->hwctx->alloc);
+
+    ff_vk_uninit(&s->vkctx);
+
+    s->initialized = 0;
+}
+
+static int config_out_props(AVFilterLink *outlink)
+{
+    FilterLink *ol = ff_filter_link(outlink);
+
+    ol->frame_rate = av_mul_q(ol->frame_rate, av_make_q(1, 2));
+    return ff_vk_filter_config_output(outlink);
+}
+
+#define OFFSET(x) offsetof(InterlaceVulkanContext, x)
+#define FLAGS (AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_VIDEO_PARAM)
+static const AVOption interlace_vulkan_options[] = {
+    { "scan",              "scanning mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64 = MODE_TFF}, 0, 1, FLAGS, .unit = "mode"},
+    { "tff",               "top field first",                              0, AV_OPT_TYPE_CONST, {.i64 = MODE_TFF}, INT_MIN, INT_MAX, FLAGS, .unit = "mode"},
+    { "bff",               "bottom field first",                           0, AV_OPT_TYPE_CONST, {.i64 = MODE_BFF}, INT_MIN, INT_MAX, FLAGS, .unit = "mode"},
+    { "lowpass",           "set vertical low-pass filter", OFFSET(lowpass), AV_OPT_TYPE_INT,   {.i64 = VLPF_LIN}, 0, 2, FLAGS, .unit = "lowpass" },
+    {     "off",           "disable vertical low-pass filter",             0, AV_OPT_TYPE_CONST, {.i64 = VLPF_OFF}, INT_MIN, INT_MAX, FLAGS, .unit = "lowpass" },
+    {     "linear",        "linear vertical low-pass filter",              0, AV_OPT_TYPE_CONST, {.i64 = VLPF_LIN}, INT_MIN, INT_MAX, FLAGS, .unit = "lowpass" },
+    {     "complex",       "complex vertical low-pass filter",             0, AV_OPT_TYPE_CONST, {.i64 = VLPF_CMP}, INT_MIN, INT_MAX, FLAGS, .unit = "lowpass" },
+    { NULL },
+};
+
+AVFILTER_DEFINE_CLASS(interlace_vulkan);
+
+static const AVFilterPad interlace_vulkan_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .filter_frame = &interlace_vulkan_filter_frame,
+        .config_props = &ff_vk_filter_config_input,
+    },
+};
+
+static const AVFilterPad interlace_vulkan_outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+        .config_props = &config_out_props,
+    },
+};
+
+const FFFilter ff_vf_interlace_vulkan = {
+    .p.name         = "interlace_vulkan",
+    .p.description  = NULL_IF_CONFIG_SMALL("Convert progressive video into interlaced."),
+    .p.priv_class   = &interlace_vulkan_class,
+    .p.flags        = AVFILTER_FLAG_HWDEVICE,
+    .priv_size      = sizeof(InterlaceVulkanContext),
+    .init           = &ff_vk_filter_init,
+    .uninit         = &interlace_vulkan_uninit,
+    FILTER_INPUTS(interlace_vulkan_inputs),
+    FILTER_OUTPUTS(interlace_vulkan_outputs),
+    FILTER_SINGLE_PIXFMT(AV_PIX_FMT_VULKAN),
+    .flags_internal = FF_FILTER_FLAG_HWFRAME_AWARE,
+};