lavu/vulkan: add support for using libshaderc as a GLSL compiler

It's got a much better API that's actually maintained, it eliminates
race conditions, it comes with a pkg-config file by default, and
unfortunately isn't currently packaged by Debian or other large
distributions.

configure

@@ -262,6 +262,7 @@ External library support:
   --enable-librsvg         enable SVG rasterization via librsvg [no]
   --enable-librubberband   enable rubberband needed for rubberband filter [no]
   --enable-librtmp         enable RTMP[E] support via librtmp [no]
+  --enable-libshaderc      enable GLSL->SPIRV compilation via libshaderc [no]
   --enable-libshine        enable fixed-point MP3 encoding via libshine [no]
   --enable-libsmbclient    enable Samba protocol via libsmbclient [no]
   --enable-libsnappy       enable Snappy compression, needed for hap encoding [no]
@@ -1834,6 +1835,7 @@ EXTERNAL_LIBRARY_LIST="
     librist
     librsvg
     librtmp
+    libshaderc
     libshine
     libsmbclient
     libsnappy
@@ -3565,7 +3567,7 @@ ass_filter_deps="libass"
 atempo_filter_deps="avcodec"
 atempo_filter_select="rdft"
 avgblur_opencl_filter_deps="opencl"
-avgblur_vulkan_filter_deps="vulkan libglslang"
+avgblur_vulkan_filter_deps="vulkan spirv_compiler"
 azmq_filter_deps="libzmq"
 blackframe_filter_deps="gpl"
 bm3d_filter_deps="avcodec"
@@ -3573,7 +3575,7 @@ bm3d_filter_select="dct"
 boxblur_filter_deps="gpl"
 boxblur_opencl_filter_deps="opencl gpl"
 bs2b_filter_deps="libbs2b"
-chromaber_vulkan_filter_deps="vulkan libglslang"
+chromaber_vulkan_filter_deps="vulkan spirv_compiler"
 colorkey_opencl_filter_deps="opencl"
 colormatrix_filter_deps="gpl"
 convolution_opencl_filter_deps="opencl"
@@ -3613,7 +3615,7 @@ frei0r_deps_any="libdl LoadLibrary"
 frei0r_filter_deps="frei0r"
 frei0r_src_filter_deps="frei0r"
 fspp_filter_deps="gpl"
-gblur_vulkan_filter_deps="vulkan libglslang"
+gblur_vulkan_filter_deps="vulkan spirv_compiler"
 histeq_filter_deps="gpl"
 hqdn3d_filter_deps="gpl"
 interlace_filter_deps="gpl"
@@ -3638,7 +3640,7 @@ openclsrc_filter_deps="opencl"
 overlay_opencl_filter_deps="opencl"
 overlay_qsv_filter_deps="libmfx"
 overlay_qsv_filter_select="qsvvpp"
-overlay_vulkan_filter_deps="vulkan libglslang"
+overlay_vulkan_filter_deps="vulkan spirv_compiler"
 owdenoise_filter_deps="gpl"
 pad_opencl_filter_deps="opencl"
 pan_filter_deps="swresample"
@@ -3701,7 +3703,7 @@ zmq_filter_deps="libzmq"
 zoompan_filter_deps="swscale"
 zscale_filter_deps="libzimg const_nan"
 scale_vaapi_filter_deps="vaapi"
-scale_vulkan_filter_deps="vulkan libglslang"
+scale_vulkan_filter_deps="vulkan spirv_compiler"
 vpp_qsv_filter_deps="libmfx"
 vpp_qsv_filter_select="qsvvpp"
 xfade_opencl_filter_deps="opencl"
@@ -6327,6 +6329,10 @@ if ! disabled ffnvcodec; then
       check_pkg_config ffnvcodec "ffnvcodec >= 8.1.24.11 ffnvcodec < 8.2" "$ffnv_hdr_list" ""
 fi
 
+if enabled_all libglslang libshaderc; then
+    die "ERROR: libshaderc and libglslang are mutually exclusive, if in doubt, disable libglslang"
+fi
+
 check_cpp_condition winrt windows.h "!WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)"
 
 if ! disabled w32threads && ! enabled pthreads; then
@@ -6443,10 +6449,10 @@ 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 && { check_lib libglslang glslang/Include/glslang_c_interface.h glslang_initialize_process \
+enabled libglslang && { check_lib spirv_compiler 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 \
+                        require spirv_compiler 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 ||
@@ -6504,6 +6510,7 @@ enabled librist           && require_pkg_config librist "librist >= 0.2" librist
 enabled librsvg           && require_pkg_config librsvg librsvg-2.0 librsvg-2.0/librsvg/rsvg.h rsvg_handle_render_cairo
 enabled librtmp           && require_pkg_config librtmp librtmp librtmp/rtmp.h RTMP_Socket
 enabled librubberband     && require_pkg_config librubberband "rubberband >= 1.8.1" rubberband/rubberband-c.h rubberband_new -lstdc++ && append librubberband_extralibs "-lstdc++"
+enabled libshaderc        && require_pkg_config spirv_compiler "shaderc >= 2019.1" shaderc/shaderc.h shaderc_compiler_initialize
 enabled libshine          && require_pkg_config libshine shine shine/layer3.h shine_encode_buffer
 enabled libsmbclient      && { check_pkg_config libsmbclient smbclient libsmbclient.h smbc_init ||
                                require libsmbclient libsmbclient.h smbc_init -lsmbclient; }

libavutil/vulkan.c

@@ -23,6 +23,8 @@
 
 #if CONFIG_LIBGLSLANG
 #include "vulkan_glslang.c"
+#elif CONFIG_LIBSHADERC
+#include "vulkan_shaderc.c"
 #endif
 
 /* Generic macro for creating contexts which need to keep their addresses
@@ -859,6 +861,8 @@ int ff_vk_compile_shader(FFVulkanContext *s, FFVkSPIRVShader *shd,
     if (!s->spirv_compiler) {
 #if CONFIG_LIBGLSLANG
         s->spirv_compiler = ff_vk_glslang_init();
+#elif CONFIG_LIBSHADERC
+        s->spirv_compiler = ff_vk_shaderc_init();
 #else
         return AVERROR(ENOSYS);
 #endif

libavutil/vulkan_shaderc.c

@@ -0,0 +1,122 @@
+/*
+ * 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 <shaderc/shaderc.h>
+
+#include "mem.h"
+
+static int shdc_shader_compile(FFVkSPIRVCompiler *ctx, void *avctx,
+                               FFVkSPIRVShader *shd, uint8_t **data,
+                               size_t *size, const char *entrypoint,
+                               void **opaque)
+{
+    int loglevel, err, warn, ret;
+    const char *status, *message;
+    shaderc_compilation_result_t res;
+    static const char *shdc_result[] = {
+        [shaderc_compilation_status_success]            = "success",
+        [shaderc_compilation_status_invalid_stage]      = "invalid stage",
+        [shaderc_compilation_status_compilation_error]  = "error",
+        [shaderc_compilation_status_internal_error]     = "internal error",
+        [shaderc_compilation_status_null_result_object] = "no result",
+        [shaderc_compilation_status_invalid_assembly]   = "invalid assembly",
+    };
+    static const shaderc_shader_kind shdc_kind[] = {
+        [VK_SHADER_STAGE_VERTEX_BIT]   = shaderc_glsl_vertex_shader,
+        [VK_SHADER_STAGE_FRAGMENT_BIT] = shaderc_glsl_fragment_shader,
+        [VK_SHADER_STAGE_COMPUTE_BIT]  = shaderc_glsl_compute_shader,
+    };
+
+    shaderc_compile_options_t opts = shaderc_compile_options_initialize();
+    if (!opts)
+        return AVERROR(ENOMEM);
+
+    shaderc_compile_options_set_target_env(opts, shaderc_target_env_vulkan,
+                                           shaderc_env_version_vulkan_1_2);
+    shaderc_compile_options_set_target_spirv(opts, shaderc_spirv_version_1_5);
+    shaderc_compile_options_set_optimization_level(opts,
+                                                   shaderc_optimization_level_performance);
+
+    res = shaderc_compile_into_spv((shaderc_compiler_t)ctx->priv,
+                                   shd->src.str, strlen(shd->src.str),
+                                   shdc_kind[shd->shader.stage],
+                                   shd->name, entrypoint, opts);
+    shaderc_compile_options_release(opts);
+
+    ret = shaderc_result_get_compilation_status(res);
+    err = shaderc_result_get_num_errors(res);
+    warn = shaderc_result_get_num_warnings(res);
+    message = shaderc_result_get_error_message(res);
+
+    loglevel = err ? AV_LOG_ERROR : warn ? AV_LOG_WARNING : AV_LOG_VERBOSE;
+
+    ff_vk_print_shader(avctx, shd, loglevel);
+    if (message && (err || warn))
+        av_log(avctx, loglevel, "%s\n", message);
+    status = ret < FF_ARRAY_ELEMS(shdc_result) ? shdc_result[ret] : "unknown";
+    av_log(avctx, loglevel, "shaderc compile status '%s' (%d errors, %d warnings)\n",
+           status, err, warn);
+
+    if (err > 0)
+        return AVERROR(EINVAL);
+
+    *data = (uint8_t *)shaderc_result_get_bytes(res);
+    *size = shaderc_result_get_length(res);
+    *opaque = res;
+
+    return 0;
+}
+
+static void shdc_shader_free(FFVkSPIRVCompiler *ctx, void **opaque)
+{
+    if (!opaque || !*opaque)
+        return;
+
+    shaderc_result_release((shaderc_compilation_result_t)*opaque);
+    *opaque = NULL;
+}
+
+static void shdc_uninit(FFVkSPIRVCompiler **ctx)
+{
+    FFVkSPIRVCompiler *s;
+
+    if (!ctx || !*ctx)
+        return;
+
+    s = *ctx;
+
+    shaderc_compiler_release((shaderc_compiler_t)s->priv);
+    av_freep(ctx);
+}
+
+static FFVkSPIRVCompiler *ff_vk_shaderc_init(void)
+{
+    FFVkSPIRVCompiler *ret = av_mallocz(sizeof(*ret));
+    if (!ret)
+        return NULL;
+
+    ret->compile_shader = shdc_shader_compile;
+    ret->free_shader    = shdc_shader_free;
+    ret->uninit         = shdc_uninit;
+
+    ret->priv           = (void *)shaderc_compiler_initialize();
+    if (!ret->priv)
+        av_freep(&ret);
+
+    return ret;
+}