lavfi/glslang: migrate to the C API and robustify library detection

Finally, this is as close to usable as it gets for glslang.
Much faster to compile as well, and eliminates the need for a C++
compiler, which is great.
Also, changes to the resource limits won't break users, as we
can use designated initializers in C90.

10 files changed, 325 insertions, 326 deletions

diff --git a/configure b/configure
index 804bbe4c53..eb451d2782 100755
--- a/configure
+++ b/configure
@@ -3564,7 +3564,7 @@ ass_filter_deps="libass"
 atempo_filter_deps="avcodec"
 atempo_filter_select="rdft"
 avgblur_opencl_filter_deps="opencl"
-avgblur_vulkan_filter_deps="libglslang"
+avgblur_vulkan_filter_deps="vulkan libglslang"
 azmq_filter_deps="libzmq"
 blackframe_filter_deps="gpl"
 bm3d_filter_deps="avcodec"
@@ -3572,7 +3572,7 @@ bm3d_filter_select="dct"
 boxblur_filter_deps="gpl"
 boxblur_opencl_filter_deps="opencl gpl"
 bs2b_filter_deps="libbs2b"
-chromaber_vulkan_filter_deps="libglslang"
+chromaber_vulkan_filter_deps="vulkan libglslang"
 colorkey_opencl_filter_deps="opencl"
 colormatrix_filter_deps="gpl"
 convolution_opencl_filter_deps="opencl"
@@ -3635,7 +3635,7 @@ openclsrc_filter_deps="opencl"
 overlay_opencl_filter_deps="opencl"
 overlay_qsv_filter_deps="libmfx"
 overlay_qsv_filter_select="qsvvpp"
-overlay_vulkan_filter_deps="libglslang"
+overlay_vulkan_filter_deps="vulkan libglslang"
 owdenoise_filter_deps="gpl"
 pad_opencl_filter_deps="opencl"
 pan_filter_deps="swresample"
@@ -3698,7 +3698,7 @@ zmq_filter_deps="libzmq"
 zoompan_filter_deps="swscale"
 zscale_filter_deps="libzimg const_nan"
 scale_vaapi_filter_deps="vaapi"
-scale_vulkan_filter_deps="libglslang"
+scale_vulkan_filter_deps="vulkan libglslang"
 vpp_qsv_filter_deps="libmfx"
 vpp_qsv_filter_select="qsvvpp"
 xfade_opencl_filter_deps="opencl"
@@ -6440,7 +6440,12 @@ enabled fontconfig        && enable libfontconfig
 enabled libfontconfig     && require_pkg_config libfontconfig fontconfig "fontconfig/fontconfig.h" FcInit
 enabled libfreetype       && require_pkg_config libfreetype freetype2 "ft2build.h FT_FREETYPE_H" FT_Init_FreeType
 enabled libfribidi        && require_pkg_config libfribidi fribidi fribidi.h fribidi_version_info
-enabled libglslang        && require_cpp libglslang glslang/SPIRV/GlslangToSpv.h "glslang::TIntermediate*" -lglslang -lMachineIndependent -lOSDependent -lHLSL -lOGLCompiler -lGenericCodeGen -lSPVRemapper -lSPIRV -lSPIRV-Tools-opt -lSPIRV-Tools -lpthread -lstdc++
+enabled libglslang && { check_lib libglslang glslang/Include/glslang_c_interface.h glslang_initialize_process \
+                            -lglslang -lMachineIndependent -lOSDependent -lHLSL -lOGLCompiler -lGenericCodeGen \
+                            -lSPVRemapper -lSPIRV -lSPIRV-Tools-opt -lSPIRV-Tools -lpthread -lstdc++ -lm ||
+                        require libglslang glslang/Include/glslang_c_interface.h glslang_initialize_process \
+                            -lglslang -lOSDependent -lHLSL -lOGLCompiler \
+                            -lSPVRemapper -lSPIRV -lSPIRV-Tools-opt -lSPIRV-Tools -lpthread -lstdc++ -lm; }
 enabled libgme            && { check_pkg_config libgme libgme gme/gme.h gme_new_emu ||
                                require libgme gme/gme.h gme_new_emu -lgme -lstdc++; }
 enabled libgsm            && { for gsm_hdr in "gsm.h" "gsm/gsm.h"; do
diff --git a/libavfilter/glslang.c b/libavfilter/glslang.c
new file mode 100644
index 0000000000..e5a8d4dc2a
--- /dev/null
+++ b/libavfilter/glslang.c
@@ -0,0 +1,256 @@
+/*
+ * 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 <pthread.h>
+
+#include <glslang/build_info.h>
+#include <glslang/Include/glslang_c_interface.h>
+
+#include "libavutil/mem.h"
+#include "libavutil/avassert.h"
+
+#include "glslang.h"
+
+static pthread_mutex_t glslang_mutex = PTHREAD_MUTEX_INITIALIZER;
+static int glslang_refcount = 0;
+
+static const glslang_resource_t glslc_resource_limits = {
+    .max_lights = 32,
+    .max_clip_planes = 6,
+    .max_texture_units = 32,
+    .max_texture_coords = 32,
+    .max_vertex_attribs = 64,
+    .max_vertex_uniform_components = 4096,
+    .max_varying_floats = 64,
+    .max_vertex_texture_image_units = 32,
+    .max_combined_texture_image_units = 80,
+    .max_texture_image_units = 32,
+    .max_fragment_uniform_components = 4096,
+    .max_draw_buffers = 32,
+    .max_vertex_uniform_vectors = 128,
+    .max_varying_vectors = 8,
+    .max_fragment_uniform_vectors = 16,
+    .max_vertex_output_vectors = 16,
+    .max_fragment_input_vectors = 15,
+    .min_program_texel_offset = -8,
+    .max_program_texel_offset = 7,
+    .max_clip_distances = 8,
+    .max_compute_work_group_count_x = 65535,
+    .max_compute_work_group_count_y = 65535,
+    .max_compute_work_group_count_z = 65535,
+    .max_compute_work_group_size_x = 1024,
+    .max_compute_work_group_size_y = 1024,
+    .max_compute_work_group_size_z = 64,
+    .max_compute_uniform_components = 1024,
+    .max_compute_texture_image_units = 16,
+    .max_compute_image_uniforms = 8,
+    .max_compute_atomic_counters = 8,
+    .max_compute_atomic_counter_buffers = 1,
+    .max_varying_components = 60,
+    .max_vertex_output_components = 64,
+    .max_geometry_input_components = 64,
+    .max_geometry_output_components = 128,
+    .max_fragment_input_components = 128,
+    .max_image_units = 8,
+    .max_combined_image_units_and_fragment_outputs = 8,
+    .max_combined_shader_output_resources = 8,
+    .max_image_samples = 0,
+    .max_vertex_image_uniforms = 0,
+    .max_tess_control_image_uniforms = 0,
+    .max_tess_evaluation_image_uniforms = 0,
+    .max_geometry_image_uniforms = 0,
+    .max_fragment_image_uniforms = 8,
+    .max_combined_image_uniforms = 8,
+    .max_geometry_texture_image_units = 16,
+    .max_geometry_output_vertices = 256,
+    .max_geometry_total_output_components = 1024,
+    .max_geometry_uniform_components = 1024,
+    .max_geometry_varying_components = 64,
+    .max_tess_control_input_components = 128,
+    .max_tess_control_output_components = 128,
+    .max_tess_control_texture_image_units = 16,
+    .max_tess_control_uniform_components = 1024,
+    .max_tess_control_total_output_components = 4096,
+    .max_tess_evaluation_input_components = 128,
+    .max_tess_evaluation_output_components = 128,
+    .max_tess_evaluation_texture_image_units = 16,
+    .max_tess_evaluation_uniform_components = 1024,
+    .max_tess_patch_components = 120,
+    .max_patch_vertices = 32,
+    .max_tess_gen_level = 64,
+    .max_viewports = 16,
+    .max_vertex_atomic_counters = 0,
+    .max_tess_control_atomic_counters = 0,
+    .max_tess_evaluation_atomic_counters = 0,
+    .max_geometry_atomic_counters = 0,
+    .max_fragment_atomic_counters = 8,
+    .max_combined_atomic_counters = 8,
+    .max_atomic_counter_bindings = 1,
+    .max_vertex_atomic_counter_buffers = 0,
+    .max_tess_control_atomic_counter_buffers = 0,
+    .max_tess_evaluation_atomic_counter_buffers = 0,
+    .max_geometry_atomic_counter_buffers = 0,
+    .max_fragment_atomic_counter_buffers = 1,
+    .max_combined_atomic_counter_buffers = 1,
+    .max_atomic_counter_buffer_size = 16384,
+    .max_transform_feedback_buffers = 4,
+    .max_transform_feedback_interleaved_components = 64,
+    .max_cull_distances = 8,
+    .max_combined_clip_and_cull_distances = 8,
+    .max_samples = 4,
+    .max_mesh_output_vertices_nv = 256,
+    .max_mesh_output_primitives_nv = 512,
+    .max_mesh_work_group_size_x_nv = 32,
+    .max_mesh_work_group_size_y_nv = 1,
+    .max_mesh_work_group_size_z_nv = 1,
+    .max_task_work_group_size_x_nv = 32,
+    .max_task_work_group_size_y_nv = 1,
+    .max_task_work_group_size_z_nv = 1,
+    .max_mesh_view_count_nv = 4,
+    .maxDualSourceDrawBuffersEXT = 1,
+
+    .limits = {
+        .non_inductive_for_loops = 1,
+        .while_loops = 1,
+        .do_while_loops = 1,
+        .general_uniform_indexing = 1,
+        .general_attribute_matrix_vector_indexing = 1,
+        .general_varying_indexing = 1,
+        .general_sampler_indexing = 1,
+        .general_variable_indexing = 1,
+        .general_constant_matrix_vector_indexing = 1,
+    }
+};
+
+int ff_vk_glslang_shader_compile(AVFilterContext *avctx, FFSPIRVShader *shd,
+                                 uint8_t **data, size_t *size, void **opaque)
+{
+    const char *messages;
+    glslang_shader_t *glslc_shader;
+    glslang_program_t *glslc_program;
+
+    static const glslang_stage_t glslc_stage[] = {
+        [VK_SHADER_STAGE_VERTEX_BIT]   = GLSLANG_STAGE_VERTEX,
+        [VK_SHADER_STAGE_FRAGMENT_BIT] = GLSLANG_STAGE_FRAGMENT,
+        [VK_SHADER_STAGE_COMPUTE_BIT]  = GLSLANG_STAGE_COMPUTE,
+    };
+
+    const glslang_input_t glslc_input = {
+        .language                          = GLSLANG_SOURCE_GLSL,
+        .stage                             = glslc_stage[shd->shader.stage],
+        .client                            = GLSLANG_CLIENT_VULKAN,
+        /* GLSLANG_TARGET_VULKAN_1_2 before 11.6 resulted in targeting 1.0 */
+#if (((GLSLANG_VERSION_MAJOR) > 11) || ((GLSLANG_VERSION_MAJOR) == 11 && \
+    (((GLSLANG_VERSION_MINOR) >  6) || ((GLSLANG_VERSION_MINOR) ==  6 && \
+     ((GLSLANG_VERSION_PATCH) > 0)))))
+        .client_version                    = GLSLANG_TARGET_VULKAN_1_2,
+        .target_language_version           = GLSLANG_TARGET_SPV_1_5,
+#else
+        .client_version                    = GLSLANG_TARGET_VULKAN_1_1,
+        .target_language_version           = GLSLANG_TARGET_SPV_1_3,
+#endif
+        .target_language                   = GLSLANG_TARGET_SPV,
+        .code                              = shd->src.str,
+        .default_version                   = 460,
+        .default_profile                   = GLSLANG_NO_PROFILE,
+        .force_default_version_and_profile = false,
+        .forward_compatible                = false,
+        .messages                          = GLSLANG_MSG_DEFAULT_BIT,
+        .resource                          = &glslc_resource_limits,
+    };
+
+    av_assert0(glslang_refcount);
+
+    if (!(glslc_shader = glslang_shader_create(&glslc_input)))
+        return AVERROR(ENOMEM);
+
+    if (!glslang_shader_preprocess(glslc_shader, &glslc_input)) {
+        ff_vk_print_shader(avctx, shd, AV_LOG_WARNING);
+        av_log(avctx, AV_LOG_ERROR, "Unable to preprocess shader: %s (%s)!\n",
+               glslang_shader_get_info_log(glslc_shader),
+               glslang_shader_get_info_debug_log(glslc_shader));
+        glslang_shader_delete(glslc_shader);
+        return AVERROR(EINVAL);
+    }
+
+    if (!glslang_shader_parse(glslc_shader, &glslc_input)) {
+        ff_vk_print_shader(avctx, shd, AV_LOG_WARNING);
+        av_log(avctx, AV_LOG_ERROR, "Unable to parse shader: %s (%s)!\n",
+               glslang_shader_get_info_log(glslc_shader),
+               glslang_shader_get_info_debug_log(glslc_shader));
+        glslang_shader_delete(glslc_shader);
+        return AVERROR(EINVAL);
+    }
+
+    if (!(glslc_program = glslang_program_create())) {
+        glslang_shader_delete(glslc_shader);
+        return AVERROR(EINVAL);
+    }
+
+    glslang_program_add_shader(glslc_program, glslc_shader);
+
+    if (!glslang_program_link(glslc_program, GLSLANG_MSG_SPV_RULES_BIT |
+                                             GLSLANG_MSG_VULKAN_RULES_BIT)) {
+        ff_vk_print_shader(avctx, shd, AV_LOG_WARNING);
+        av_log(avctx, AV_LOG_ERROR, "Unable to link shader: %s (%s)!\n",
+               glslang_program_get_info_log(glslc_program),
+               glslang_program_get_info_debug_log(glslc_program));
+        glslang_program_delete(glslc_program);
+        glslang_shader_delete(glslc_shader);
+        return AVERROR(EINVAL);
+    }
+
+    glslang_program_SPIRV_generate(glslc_program, glslc_input.stage);
+
+    messages = glslang_program_SPIRV_get_messages(glslc_program);
+    if (messages)
+        av_log(avctx, AV_LOG_WARNING, "%s\n", messages);
+
+    glslang_shader_delete(glslc_shader);
+
+    *size = glslang_program_SPIRV_get_size(glslc_program) * sizeof(unsigned int);
+    *data = (void *)glslang_program_SPIRV_get_ptr(glslc_program);
+    *opaque = glslc_program;
+
+    return 0;
+}
+
+void ff_vk_glslang_shader_free(void *opaque)
+{
+    glslang_program_delete(opaque);
+}
+
+int ff_vk_glslang_init(void)
+{
+    int ret = 0;
+
+    pthread_mutex_lock(&glslang_mutex);
+    if (glslang_refcount++ == 0)
+        ret = !glslang_initialize_process();
+    pthread_mutex_unlock(&glslang_mutex);
+
+    return ret;
+}
+
+void ff_vk_glslang_uninit(void)
+{
+    pthread_mutex_lock(&glslang_mutex);
+    if (glslang_refcount && (--glslang_refcount == 0))
+        glslang_finalize_process();
+    pthread_mutex_unlock(&glslang_mutex);
+}
diff --git a/libavfilter/glslang.cpp b/libavfilter/glslang.cpp
deleted file mode 100644
index 986bddd789..0000000000
--- a/libavfilter/glslang.cpp
+++ /dev/null
@@ -1,241 +0,0 @@
-/*
- * 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 <pthread.h>
-
-extern "C" {
-#include "libavutil/mem.h"
-#include "libavutil/avassert.h"
-}
-
-#include <glslang/Include/ResourceLimits.h>
-#include <glslang/Public/ShaderLang.h>
-#include <glslang/SPIRV/GlslangToSpv.h>
-
-#include "glslang.h"
-
-using namespace glslang;
-
-static pthread_mutex_t glslang_mutex = PTHREAD_MUTEX_INITIALIZER;
-static int glslang_refcount = 0;
-
-/* We require Vulkan 1.1 */
-#define GLSL_VERSION EShTargetVulkan_1_1
-
-/* Vulkan 1.1 implementations require SPIR-V 1.3 to be implemented */
-#define SPIRV_VERSION EShTargetSpv_1_3
-
-// Taken from glslang's examples, which apparently generally bases the choices
-// on OpenGL specification limits
-static const TBuiltInResource DefaultTBuiltInResource = {
-    /* .MaxLights = */ 32,
-    /* .MaxClipPlanes = */ 6,
-    /* .MaxTextureUnits = */ 32,
-    /* .MaxTextureCoords = */ 32,
-    /* .MaxVertexAttribs = */ 64,
-    /* .MaxVertexUniformComponents = */ 4096,
-    /* .MaxVaryingFloats = */ 64,
-    /* .MaxVertexTextureImageUnits = */ 32,
-    /* .MaxCombinedTextureImageUnits = */ 80,
-    /* .MaxTextureImageUnits = */ 32,
-    /* .MaxFragmentUniformComponents = */ 4096,
-    /* .MaxDrawBuffers = */ 32,
-    /* .MaxVertexUniformVectors = */ 128,
-    /* .MaxVaryingVectors = */ 8,
-    /* .MaxFragmentUniformVectors = */ 16,
-    /* .MaxVertexOutputVectors = */ 16,
-    /* .MaxFragmentInputVectors = */ 15,
-    /* .MinProgramTexelOffset = */ -8,
-    /* .MaxProgramTexelOffset = */ 7,
-    /* .MaxClipDistances = */ 8,
-    /* .MaxComputeWorkGroupCountX = */ 65535,
-    /* .MaxComputeWorkGroupCountY = */ 65535,
-    /* .MaxComputeWorkGroupCountZ = */ 65535,
-    /* .MaxComputeWorkGroupSizeX = */ 1024,
-    /* .MaxComputeWorkGroupSizeY = */ 1024,
-    /* .MaxComputeWorkGroupSizeZ = */ 64,
-    /* .MaxComputeUniformComponents = */ 1024,
-    /* .MaxComputeTextureImageUnits = */ 16,
-    /* .MaxComputeImageUniforms = */ 8,
-    /* .MaxComputeAtomicCounters = */ 8,
-    /* .MaxComputeAtomicCounterBuffers = */ 1,
-    /* .MaxVaryingComponents = */ 60,
-    /* .MaxVertexOutputComponents = */ 64,
-    /* .MaxGeometryInputComponents = */ 64,
-    /* .MaxGeometryOutputComponents = */ 128,
-    /* .MaxFragmentInputComponents = */ 128,
-    /* .MaxImageUnits = */ 8,
-    /* .MaxCombinedImageUnitsAndFragmentOutputs = */ 8,
-    /* .MaxCombinedShaderOutputResources = */ 8,
-    /* .MaxImageSamples = */ 0,
-    /* .MaxVertexImageUniforms = */ 0,
-    /* .MaxTessControlImageUniforms = */ 0,
-    /* .MaxTessEvaluationImageUniforms = */ 0,
-    /* .MaxGeometryImageUniforms = */ 0,
-    /* .MaxFragmentImageUniforms = */ 8,
-    /* .MaxCombinedImageUniforms = */ 8,
-    /* .MaxGeometryTextureImageUnits = */ 16,
-    /* .MaxGeometryOutputVertices = */ 256,
-    /* .MaxGeometryTotalOutputComponents = */ 1024,
-    /* .MaxGeometryUniformComponents = */ 1024,
-    /* .MaxGeometryVaryingComponents = */ 64,
-    /* .MaxTessControlInputComponents = */ 128,
-    /* .MaxTessControlOutputComponents = */ 128,
-    /* .MaxTessControlTextureImageUnits = */ 16,
-    /* .MaxTessControlUniformComponents = */ 1024,
-    /* .MaxTessControlTotalOutputComponents = */ 4096,
-    /* .MaxTessEvaluationInputComponents = */ 128,
-    /* .MaxTessEvaluationOutputComponents = */ 128,
-    /* .MaxTessEvaluationTextureImageUnits = */ 16,
-    /* .MaxTessEvaluationUniformComponents = */ 1024,
-    /* .MaxTessPatchComponents = */ 120,
-    /* .MaxPatchVertices = */ 32,
-    /* .MaxTessGenLevel = */ 64,
-    /* .MaxViewports = */ 16,
-    /* .MaxVertexAtomicCounters = */ 0,
-    /* .MaxTessControlAtomicCounters = */ 0,
-    /* .MaxTessEvaluationAtomicCounters = */ 0,
-    /* .MaxGeometryAtomicCounters = */ 0,
-    /* .MaxFragmentAtomicCounters = */ 8,
-    /* .MaxCombinedAtomicCounters = */ 8,
-    /* .MaxAtomicCounterBindings = */ 1,
-    /* .MaxVertexAtomicCounterBuffers = */ 0,
-    /* .MaxTessControlAtomicCounterBuffers = */ 0,
-    /* .MaxTessEvaluationAtomicCounterBuffers = */ 0,
-    /* .MaxGeometryAtomicCounterBuffers = */ 0,
-    /* .MaxFragmentAtomicCounterBuffers = */ 1,
-    /* .MaxCombinedAtomicCounterBuffers = */ 1,
-    /* .MaxAtomicCounterBufferSize = */ 16384,
-    /* .MaxTransformFeedbackBuffers = */ 4,
-    /* .MaxTransformFeedbackInterleavedComponents = */ 64,
-    /* .MaxCullDistances = */ 8,
-    /* .MaxCombinedClipAndCullDistances = */ 8,
-    /* .MaxSamples = */ 4,
-    /* .maxMeshOutputVerticesNV = */ 256,
-    /* .maxMeshOutputPrimitivesNV = */ 512,
-    /* .maxMeshWorkGroupSizeX_NV = */ 32,
-    /* .maxMeshWorkGroupSizeY_NV = */ 1,
-    /* .maxMeshWorkGroupSizeZ_NV = */ 1,
-    /* .maxTaskWorkGroupSizeX_NV = */ 32,
-    /* .maxTaskWorkGroupSizeY_NV = */ 1,
-    /* .maxTaskWorkGroupSizeZ_NV = */ 1,
-    /* .maxMeshViewCountNV = */ 4,
-
-    .limits = {
-        /* .nonInductiveForLoops = */ 1,
-        /* .whileLoops = */ 1,
-        /* .doWhileLoops = */ 1,
-        /* .generalUniformIndexing = */ 1,
-        /* .generalAttributeMatrixVectorIndexing = */ 1,
-        /* .generalVaryingIndexing = */ 1,
-        /* .generalSamplerIndexing = */ 1,
-        /* .generalVariableIndexing = */ 1,
-        /* .generalConstantMatrixVectorIndexing = */ 1,
-    }
-};
-
-GLSlangResult *glslang_compile(const char *glsl, enum GLSlangStage stage)
-{
-    GLSlangResult *res = (GLSlangResult *)av_mallocz(sizeof(*res));
-    if (!res)
-        return NULL;
-
-    static const EShLanguage lang[] = {
-        [GLSLANG_VERTEX]   = EShLangVertex,
-        [GLSLANG_FRAGMENT] = EShLangFragment,
-        [GLSLANG_COMPUTE]  = EShLangCompute,
-    };
-
-    assert(glslang_refcount);
-    TShader *shader = new TShader(lang[stage]);
-    if (!shader) {
-        res->rval = AVERROR(ENOMEM);
-        return res;
-    }
-
-    shader->setEnvClient(EShClientVulkan, GLSL_VERSION);
-    shader->setEnvTarget(EShTargetSpv, SPIRV_VERSION);
-    shader->setStrings(&glsl, 1);
-    if (!shader->parse(&DefaultTBuiltInResource, GLSL_VERSION, true, EShMsgDefault)) {
-        res->error_msg = av_strdup(shader->getInfoLog());
-        res->rval = AVERROR_EXTERNAL;
-        delete shader;
-        return res;
-    }
-
-    TProgram *prog = new TProgram();
-    if (!prog) {
-        res->rval = AVERROR(ENOMEM);
-        delete shader;
-        return res;
-    }
-
-    prog->addShader(shader);
-    if (!prog->link(EShMsgDefault)) {
-        res->error_msg = av_strdup(prog->getInfoLog());
-        res->rval = AVERROR_EXTERNAL;
-        delete shader;
-        delete prog;
-        return res;
-    }
-
-    std::vector<unsigned int> spirv; /* Result */
-
-    SpvOptions options; /* Options - by default all optimizations are off */
-    options.generateDebugInfo = false; /* Makes sense for files but not here */
-    options.disassemble = false; /* Will print disassembly on compilation */
-    options.validate = false; /* Validates the generated SPIRV, unneeded */
-    options.disableOptimizer = false; /* For debugging */
-    options.optimizeSize = true; /* Its faster */
-
-    GlslangToSpv(*prog->getIntermediate(lang[stage]), spirv, NULL, &options);
-
-    res->size = spirv.size()*sizeof(unsigned int);
-    res->data = av_memdup(spirv.data(), res->size);
-    if (!res->data) {
-        res->rval = AVERROR(ENOMEM);
-        delete shader;
-        delete prog;
-        return res;
-    }
-
-    delete shader;
-    delete prog;
-
-    return res;
-}
-
-int glslang_init(void)
-{
-    int ret = 0;
-
-    pthread_mutex_lock(&glslang_mutex);
-    if (glslang_refcount++ == 0)
-        ret = !InitializeProcess();
-    pthread_mutex_unlock(&glslang_mutex);
-
-    return ret;
-}
-
-void glslang_uninit(void)
-{
-    pthread_mutex_lock(&glslang_mutex);
-    if (glslang_refcount && (--glslang_refcount == 0))
-        FinalizeProcess();
-    pthread_mutex_unlock(&glslang_mutex);
-}
diff --git a/libavfilter/glslang.h b/libavfilter/glslang.h
index d33808b945..93a077dbfc 100644
--- a/libavfilter/glslang.h
+++ b/libavfilter/glslang.h
@@ -19,34 +19,23 @@
 #ifndef AVFILTER_GLSLANG_H
 #define AVFILTER_GLSLANG_H
 
-#include <stdlib.h>
+#include "vulkan.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-int glslang_init(void);
-void glslang_uninit(void);
-
-typedef struct GLSlangResult {
-    int rval;
-    char *error_msg;
-
-    void *data; /* Shader data or NULL */
-    size_t size;
-} GLSlangResult;
-
-enum GLSlangStage {
-    GLSLANG_VERTEX,
-    GLSLANG_FRAGMENT,
-    GLSLANG_COMPUTE,
-};
+/**
+ * Un/initialize glslang's global state. Thread-safe and reference counted.
+ */
+int ff_vk_glslang_init(void);
+void ff_vk_glslang_uninit(void);
 
-/* Compile GLSL into a SPIRV stream, if possible */
-GLSlangResult *glslang_compile(const char *glsl, enum GLSlangStage stage);
+/**
+ * Compile GLSL into SPIR-V using glslang.
+ */
+int ff_vk_glslang_shader_compile(AVFilterContext *avctx, FFSPIRVShader *shd,
+                                 uint8_t **data, size_t *size, void **opaque);
 
-#ifdef __cplusplus
-}
-#endif
+/**
+ * Frees the shader-specific context.
+ */
+void ff_vk_glslang_shader_free(void *opaque);
 
 #endif /* AVFILTER_GLSLANG_H */
diff --git a/libavfilter/vf_avgblur_vulkan.c b/libavfilter/vf_avgblur_vulkan.c
index 158ccf02df..bf02dab1db 100644
--- a/libavfilter/vf_avgblur_vulkan.c
+++ b/libavfilter/vf_avgblur_vulkan.c
@@ -70,7 +70,7 @@ static const char blur_kernel[] = {
 static av_cold int init_filter(AVFilterContext *ctx, AVFrame *in)
 {
     int err;
-    SPIRVShader *shd;
+    FFSPIRVShader *shd;
     AvgBlurVulkanContext *s = ctx->priv;
     const int planes = av_pix_fmt_count_planes(s->vkctx.output_format);
     VkSampler *sampler = ff_vk_init_sampler(ctx, 1, VK_FILTER_LINEAR);
diff --git a/libavfilter/vf_chromaber_vulkan.c b/libavfilter/vf_chromaber_vulkan.c
index 2503972c2a..25ef20fe73 100644
--- a/libavfilter/vf_chromaber_vulkan.c
+++ b/libavfilter/vf_chromaber_vulkan.c
@@ -109,8 +109,8 @@ static av_cold int init_filter(AVFilterContext *ctx, AVFrame *in)
             },
         };
 
-        SPIRVShader *shd = ff_vk_init_shader(ctx, s->pl, "chromaber_compute",
-                                             VK_SHADER_STAGE_COMPUTE_BIT);
+        FFSPIRVShader *shd = ff_vk_init_shader(ctx, s->pl, "chromaber_compute",
+                                               VK_SHADER_STAGE_COMPUTE_BIT);
         if (!shd)
             return AVERROR(ENOMEM);
 
diff --git a/libavfilter/vf_overlay_vulkan.c b/libavfilter/vf_overlay_vulkan.c
index 77b3668819..f08800af2c 100644
--- a/libavfilter/vf_overlay_vulkan.c
+++ b/libavfilter/vf_overlay_vulkan.c
@@ -136,8 +136,8 @@ static av_cold int init_filter(AVFilterContext *ctx)
             .buf_content = "ivec2 o_offset[3], o_size[3];",
         };
 
-        SPIRVShader *shd = ff_vk_init_shader(ctx, s->pl, "overlay_compute",
-                                             VK_SHADER_STAGE_COMPUTE_BIT);
+        FFSPIRVShader *shd = ff_vk_init_shader(ctx, s->pl, "overlay_compute",
+                                               VK_SHADER_STAGE_COMPUTE_BIT);
         if (!shd)
             return AVERROR(ENOMEM);
 
diff --git a/libavfilter/vf_scale_vulkan.c b/libavfilter/vf_scale_vulkan.c
index 83e101954b..680e9c2f4f 100644
--- a/libavfilter/vf_scale_vulkan.c
+++ b/libavfilter/vf_scale_vulkan.c
@@ -170,8 +170,8 @@ static av_cold int init_filter(AVFilterContext *ctx, AVFrame *in)
             .buf_content = "mat4 yuv_matrix;",
         };
 
-        SPIRVShader *shd = ff_vk_init_shader(ctx, s->pl, "scale_compute",
-                                             VK_SHADER_STAGE_COMPUTE_BIT);
+        FFSPIRVShader *shd = ff_vk_init_shader(ctx, s->pl, "scale_compute",
+                                               VK_SHADER_STAGE_COMPUTE_BIT);
         if (!shd)
             return AVERROR(ENOMEM);
 
diff --git a/libavfilter/vulkan.c b/libavfilter/vulkan.c
index 4ac8e5e90a..c9a2ae4593 100644
--- a/libavfilter/vulkan.c
+++ b/libavfilter/vulkan.c
@@ -794,7 +794,7 @@ int ff_vk_filter_init(AVFilterContext *avctx)
 
     s->output_format = AV_PIX_FMT_NONE;
 
-    if (glslang_init())
+    if (ff_vk_glslang_init())
         return AVERROR_EXTERNAL;
 
     return 0;
@@ -924,11 +924,11 @@ int ff_vk_create_imageview(AVFilterContext *avctx, FFVkExecContext *e,
     return 0;
 }
 
-FN_CREATING(VulkanPipeline, SPIRVShader, shader, shaders, shaders_num)
-SPIRVShader *ff_vk_init_shader(AVFilterContext *avctx, VulkanPipeline *pl,
-                               const char *name, VkShaderStageFlags stage)
+FN_CREATING(VulkanPipeline, FFSPIRVShader, shader, shaders, shaders_num)
+FFSPIRVShader *ff_vk_init_shader(AVFilterContext *avctx, VulkanPipeline *pl,
+                                 const char *name, VkShaderStageFlags stage)
 {
-    SPIRVShader *shd = create_shader(pl);
+    FFSPIRVShader *shd = create_shader(pl);
     if (!shd)
         return NULL;
 
@@ -946,7 +946,7 @@ SPIRVShader *ff_vk_init_shader(AVFilterContext *avctx, VulkanPipeline *pl,
     return shd;
 }
 
-void ff_vk_set_compute_shader_sizes(AVFilterContext *avctx, SPIRVShader *shd,
+void ff_vk_set_compute_shader_sizes(AVFilterContext *avctx, FFSPIRVShader *shd,
                                         int local_size[3])
 {
     shd->local_size[0] = local_size[0];
@@ -958,7 +958,7 @@ void ff_vk_set_compute_shader_sizes(AVFilterContext *avctx, SPIRVShader *shd,
                shd->local_size[0], shd->local_size[1], shd->local_size[2]);
 }
 
-static void print_shader(AVFilterContext *avctx, SPIRVShader *shd, int prio)
+void ff_vk_print_shader(AVFilterContext *avctx, FFSPIRVShader *shd, int prio)
 {
     int line = 0;
     const char *p = shd->src.str;
@@ -979,51 +979,39 @@ static void print_shader(AVFilterContext *avctx, SPIRVShader *shd, int prio)
     av_bprint_finalize(&buf, NULL);
 }
 
-int ff_vk_compile_shader(AVFilterContext *avctx, SPIRVShader *shd,
+int ff_vk_compile_shader(AVFilterContext *avctx, FFSPIRVShader *shd,
                          const char *entrypoint)
 {
+    int err;
     VkResult ret;
     VulkanFilterContext *s = avctx->priv;
     FFVulkanFunctions *vk = &s->vkfn;
     VkShaderModuleCreateInfo shader_create;
-    GLSlangResult *res;
-
-    static const enum GLSlangStage emap[] = {
-        [VK_SHADER_STAGE_VERTEX_BIT]   = GLSLANG_VERTEX,
-        [VK_SHADER_STAGE_FRAGMENT_BIT] = GLSLANG_FRAGMENT,
-        [VK_SHADER_STAGE_COMPUTE_BIT]  = GLSLANG_COMPUTE,
-    };
+    uint8_t *spirv;
+    size_t spirv_size;
+    void *priv;
 
     shd->shader.pName = entrypoint;
 
-    res = glslang_compile(shd->src.str, emap[shd->shader.stage]);
-    if (!res)
-        return AVERROR(ENOMEM);
+    err = ff_vk_glslang_shader_compile(avctx, shd, &spirv, &spirv_size, &priv);
+    if (err < 0)
+        return err;
 
-    if (res->rval) {
-        av_log(avctx, AV_LOG_ERROR, "Error compiling shader %s: %s!\n",
-               shd->name, av_err2str(res->rval));
-        print_shader(avctx, shd, AV_LOG_ERROR);
-        if (res->error_msg)
-            av_log(avctx, AV_LOG_ERROR, "%s", res->error_msg);
-        av_free(res->error_msg);
-        return res->rval;
-    }
+    ff_vk_print_shader(avctx, shd, AV_LOG_VERBOSE);
 
-    print_shader(avctx, shd, AV_LOG_VERBOSE);
+    av_log(avctx, AV_LOG_VERBOSE, "Shader %s compiled! Size: %zu bytes\n",
+           shd->name, spirv_size);
 
     shader_create.sType    = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
     shader_create.pNext    = NULL;
-    shader_create.codeSize = res->size;
+    shader_create.codeSize = spirv_size;
     shader_create.flags    = 0;
-    shader_create.pCode    = res->data;
+    shader_create.pCode    = (void *)spirv;
 
     ret = vk->CreateShaderModule(s->hwctx->act_dev, &shader_create, NULL,
                                  &shd->shader.module);
 
-    /* Free the GLSlangResult struct */
-    av_free(res->data);
-    av_free(res);
+    ff_vk_glslang_shader_free(priv);
 
     if (ret != VK_SUCCESS) {
         av_log(avctx, AV_LOG_ERROR, "Unable to create shader module: %s\n",
@@ -1031,9 +1019,6 @@ int ff_vk_compile_shader(AVFilterContext *avctx, SPIRVShader *shd,
         return AVERROR_EXTERNAL;
     }
 
-    av_log(avctx, AV_LOG_VERBOSE, "Shader %s linked! Size: %zu bytes\n",
-           shd->name, shader_create.codeSize);
-
     return 0;
 }
 
@@ -1059,7 +1044,7 @@ static const struct descriptor_props {
 };
 
 int ff_vk_add_descriptor_set(AVFilterContext *avctx, VulkanPipeline *pl,
-                             SPIRVShader *shd, VulkanDescriptorSetBinding *desc,
+                             FFSPIRVShader *shd, VulkanDescriptorSetBinding *desc,
                              int num, int only_print_to_shader)
 {
     VkResult ret;
@@ -1423,7 +1408,7 @@ static void free_pipeline(VulkanFilterContext *s, VulkanPipeline *pl)
     FFVulkanFunctions *vk = &s->vkfn;
 
     for (int i = 0; i < pl->shaders_num; i++) {
-        SPIRVShader *shd = pl->shaders[i];
+        FFSPIRVShader *shd = pl->shaders[i];
         av_bprint_finalize(&shd->src, NULL);
         vk->DestroyShaderModule(s->hwctx->act_dev, shd->shader.module,
                                 s->hwctx->alloc);
@@ -1471,7 +1456,7 @@ void ff_vk_filter_uninit(AVFilterContext *avctx)
     VulkanFilterContext *s = avctx->priv;
     FFVulkanFunctions *vk = &s->vkfn;
 
-    glslang_uninit();
+    ff_vk_glslang_uninit();
 
     for (int i = 0; i < s->exec_ctx_num; i++)
         free_exec_ctx(s, s->exec_ctx[i]);
diff --git a/libavfilter/vulkan.h b/libavfilter/vulkan.h
index da5936dd43..89b76ba355 100644
--- a/libavfilter/vulkan.h
+++ b/libavfilter/vulkan.h
@@ -55,12 +55,12 @@
 /* Useful for attaching immutable samplers to arrays */
 #define DUP_SAMPLER_ARRAY4(x) (VkSampler []){ x, x, x, x, }
 
-typedef struct SPIRVShader {
+typedef struct FFSPIRVShader {
     const char *name;                       /* Name for id/debugging purposes */
     AVBPrint src;
     int local_size[3];                      /* Compute shader workgroup sizes */
     VkPipelineShaderStageCreateInfo shader;
-} SPIRVShader;
+} FFSPIRVShader;
 
 typedef struct VulkanDescriptorSetBinding {
     const char         *name;
@@ -89,7 +89,7 @@ typedef struct VulkanPipeline {
     VkPipeline       pipeline;
 
     /* Shaders */
-    SPIRVShader **shaders;
+    FFSPIRVShader **shaders;
     int shaders_num;
 
     /* Push consts */
@@ -249,29 +249,34 @@ VulkanPipeline *ff_vk_create_pipeline(AVFilterContext *avctx);
 /**
  * Inits a shader for a specific pipeline. Will be auto-freed on uninit.
  */
-SPIRVShader *ff_vk_init_shader(AVFilterContext *avctx, VulkanPipeline *pl,
-                               const char *name, VkShaderStageFlags stage);
+FFSPIRVShader *ff_vk_init_shader(AVFilterContext *avctx, VulkanPipeline *pl,
+                                 const char *name, VkShaderStageFlags stage);
 
 /**
  * Writes the workgroup size for a shader.
  */
-void ff_vk_set_compute_shader_sizes(AVFilterContext *avctx, SPIRVShader *shd,
+void ff_vk_set_compute_shader_sizes(AVFilterContext *avctx, FFSPIRVShader *shd,
                                     int local_size[3]);
 
 /**
  * Adds a descriptor set to the shader and registers them in the pipeline.
  */
 int ff_vk_add_descriptor_set(AVFilterContext *avctx, VulkanPipeline *pl,
-                             SPIRVShader *shd, VulkanDescriptorSetBinding *desc,
+                             FFSPIRVShader *shd, VulkanDescriptorSetBinding *desc,
                              int num, int only_print_to_shader);
 
 /**
  * Compiles the shader, entrypoint must be set to "main".
  */
-int ff_vk_compile_shader(AVFilterContext *avctx, SPIRVShader *shd,
+int ff_vk_compile_shader(AVFilterContext *avctx, FFSPIRVShader *shd,
                          const char *entrypoint);
 
 /**
+ * Pretty print shader, mainly used by shader compilers.
+ */
+void ff_vk_print_shader(AVFilterContext *avctx, FFSPIRVShader *shd, int prio);
+
+/**
  * Initializes the pipeline layout after all shaders and descriptor sets have
  * been finished.
  */