feat(*): rewritten the project with C/C++ (#1172)

src/libplacebo.cpp

@@ -0,0 +1,161 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <filesystem>
+
+extern "C" {
+#include <libavcodec/avcodec.h>
+#include <libavfilter/avfilter.h>
+#include <libavfilter/buffersink.h>
+#include <libavfilter/buffersrc.h>
+#include <libavformat/avformat.h>
+#include <libavutil/buffer.h>
+#include <libavutil/hwcontext.h>
+#include <libavutil/opt.h>
+#include <libavutil/pixdesc.h>
+#include <libavutil/rational.h>
+#include <libswscale/swscale.h>
+}
+
+#include "fsutils.h"
+
+int init_libplacebo(
+    AVFilterGraph **filter_graph,
+    AVFilterContext **buffersrc_ctx,
+    AVFilterContext **buffersink_ctx,
+    AVBufferRef **device_ctx,
+    AVCodecContext *dec_ctx,
+    int output_width,
+    int output_height,
+    const std::filesystem::path &shader_path
+) {
+    char args[512];
+    int ret;
+
+    // Initialize the Vulkan hardware device
+    AVBufferRef *hw_device_ctx = av_hwdevice_ctx_alloc(AV_HWDEVICE_TYPE_VULKAN);
+    ret = av_hwdevice_ctx_create(&hw_device_ctx, AV_HWDEVICE_TYPE_VULKAN, NULL, NULL, 0);
+    if (ret < 0) {
+        fprintf(stderr, "Unable to initialize Vulkan device\n");
+        return ret;
+    }
+
+    AVFilterGraph *graph = avfilter_graph_alloc();
+    if (!graph) {
+        fprintf(stderr, "Unable to create filter graph.\n");
+        return AVERROR(ENOMEM);
+    }
+
+    // Create buffer source
+    const AVFilter *buffersrc = avfilter_get_by_name("buffer");
+    snprintf(
+        args,
+        sizeof(args),
+        "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:frame_rate=%d/%d:"
+        "pixel_aspect=%d/%d:colorspace=%d",
+        dec_ctx->width,
+        dec_ctx->height,
+        dec_ctx->pix_fmt,
+        dec_ctx->time_base.num,
+        dec_ctx->time_base.den,
+        dec_ctx->framerate.num,
+        dec_ctx->framerate.den,
+        dec_ctx->sample_aspect_ratio.num,
+        dec_ctx->sample_aspect_ratio.den,
+        dec_ctx->colorspace
+    );
+
+    ret = avfilter_graph_create_filter(buffersrc_ctx, buffersrc, "in", args, NULL, graph);
+    if (ret < 0) {
+        fprintf(stderr, "Cannot create buffer source\n");
+        av_buffer_unref(&hw_device_ctx);
+        avfilter_graph_free(&graph);
+        return ret;
+    }
+
+    AVFilterContext *last_filter = *buffersrc_ctx;
+
+    // Create the libplacebo filter
+    const AVFilter *libplacebo_filter = avfilter_get_by_name("libplacebo");
+    if (!libplacebo_filter) {
+        fprintf(stderr, "Filter 'libplacebo' not found\n");
+        av_buffer_unref(&hw_device_ctx);
+        avfilter_graph_free(&graph);
+        return AVERROR_FILTER_NOT_FOUND;
+    }
+
+    // Convert the shader path to a string since filter args is const char *
+    std::string shader_path_string = path_to_string(shader_path);
+
+#ifdef _WIN32
+    // libplacebo does not recognize the Windows '\\' path separator
+    std::replace(shader_path_string.begin(), shader_path_string.end(), '\\', '/');
+#endif
+
+    // Prepare the filter arguments
+    char filter_args[512];
+    snprintf(
+        filter_args,
+        sizeof(filter_args),
+        "w=%d:h=%d:upscaler=ewa_lanczos:custom_shader_path=%s",
+        output_width,
+        output_height,
+        shader_path_string.c_str()
+    );
+
+    AVFilterContext *libplacebo_ctx;
+    ret = avfilter_graph_create_filter(
+        &libplacebo_ctx, libplacebo_filter, "libplacebo", filter_args, NULL, graph
+    );
+    if (ret < 0) {
+        fprintf(stderr, "Cannot create libplacebo filter\n");
+        av_buffer_unref(&hw_device_ctx);
+        avfilter_graph_free(&graph);
+        return ret;
+    }
+
+    // Set the hardware device context to Vulkan
+    libplacebo_ctx->hw_device_ctx = av_buffer_ref(hw_device_ctx);
+
+    // Link buffersrc to libplacebo
+    ret = avfilter_link(last_filter, 0, libplacebo_ctx, 0);
+    if (ret < 0) {
+        fprintf(stderr, "Error connecting buffersrc to libplacebo filter\n");
+        av_buffer_unref(&hw_device_ctx);
+        avfilter_graph_free(&graph);
+        return ret;
+    }
+
+    last_filter = libplacebo_ctx;
+
+    // Create buffer sink
+    const AVFilter *buffersink = avfilter_get_by_name("buffersink");
+    ret = avfilter_graph_create_filter(buffersink_ctx, buffersink, "out", NULL, NULL, graph);
+    if (ret < 0) {
+        fprintf(stderr, "Cannot create buffer sink\n");
+        av_buffer_unref(&hw_device_ctx);
+        avfilter_graph_free(&graph);
+        return ret;
+    }
+
+    // Link libplacebo to buffersink
+    ret = avfilter_link(last_filter, 0, *buffersink_ctx, 0);
+    if (ret < 0) {
+        fprintf(stderr, "Error connecting libplacebo filter to buffersink\n");
+        av_buffer_unref(&hw_device_ctx);
+        avfilter_graph_free(&graph);
+        return ret;
+    }
+
+    // Configure the filter graph
+    ret = avfilter_graph_config(graph, NULL);
+    if (ret < 0) {
+        fprintf(stderr, "Error configuring the filter graph\n");
+        av_buffer_unref(&hw_device_ctx);
+        avfilter_graph_free(&graph);
+        return ret;
+    }
+
+    *filter_graph = graph;
+    *device_ctx = hw_device_ctx;
+    return 0;
+}