refactor jpegdec implementation into libstrat (thanks again, Behemoth!)

libstratosphere/include/stratosphere.hpp

@@ -41,6 +41,7 @@
 /* At this point, just include the rest alphabetically. */
 /* TODO: Figure out optimal order. */
 #include <stratosphere/boot2.hpp>
+#include <stratosphere/capsrv.hpp>
 #include <stratosphere/cfg.hpp>
 #include <stratosphere/dmnt.hpp>
 #include <stratosphere/erpt.hpp>

libstratosphere/include/stratosphere/capsrv.hpp

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <stratosphere/capsrv/capsrv_screen_shot_decode_option.hpp>
+#include <stratosphere/capsrv/server/capsrv_server_config.hpp>
+#include <stratosphere/capsrv/server/capsrv_server_decoder_api.hpp>

libstratosphere/include/stratosphere/capsrv/capsrv_screen_shot_decode_option.hpp

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2019-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#include <vapours.hpp>
+
+namespace ams::capsrv {
+
+    enum ScreenShotDecoderFlag : u64 {
+        ScreenShotDecoderFlag_None                  = (0 << 0),
+        ScreenShotDecoderFlag_EnableFancyUpsampling = (1 << 0),
+        ScreenShotDecoderFlag_EnableBlockSmoothing  = (1 << 1),
+    };
+
+    using ScreenShotJpegDecoderFlagType = typename std::underlying_type<ScreenShotDecoderFlag>::type;
+
+    struct ScreenShotDecodeOption {
+        ScreenShotJpegDecoderFlagType flags;
+        u8 reserved[0x20 - sizeof(ScreenShotJpegDecoderFlagType)];
+
+        static constexpr ScreenShotDecodeOption GetDefaultOption() {
+            return ScreenShotDecodeOption{};
+        }
+
+        constexpr bool HasJpegDecoderFlag(ScreenShotJpegDecoderFlagType flag) const {
+            return (this->flags & flag) != 0;
+        }
+    };
+    static_assert(sizeof(ScreenShotDecodeOption) == 0x20);
+    static_assert(sizeof(ScreenShotDecodeOption) == sizeof(::CapsScreenShotDecodeOption));
+    static_assert(std::is_pod<ScreenShotDecodeOption>::value);
+
+}

libstratosphere/include/stratosphere/capsrv/server/capsrv_server_config.hpp

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2019-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#include <vapours.hpp>
+
+namespace ams::capsrv::server {
+
+    constexpr inline int ScreenShotWidth  = 1280;
+    constexpr inline int ScreenShotHeight = 720;
+
+    constexpr inline int MovieWidth  = 1280;
+    constexpr inline int MovieHeight = 720;
+
+    constexpr inline size_t SoftwareJpegDecoderWorkMemorySize = 16_KB;
+
+}

libstratosphere/include/stratosphere/capsrv/server/capsrv_server_decoder_api.hpp

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2019-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#include <vapours.hpp>
+
+namespace ams::capsrv::server {
+
+    Result InitializeForDecoderServer();
+    void FinalizeForDecoderServer();
+
+    void DecoderControlServerThreadFunction(void *);
+
+}

libstratosphere/source/capsrv/server/capsrv_server_decoder_api.cpp

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <stratosphere.hpp>
+#include "decodersrv/decodersrv_decoder_server_object.hpp"
+
+namespace ams::capsrv::server {
+
+    namespace {
+
+        bool g_initialized = false;
+
+    }
+
+    Result InitializeForDecoderServer() {
+        /* Ensure we initialize only once. */
+        AMS_ABORT_UNLESS(!g_initialized);
+
+        /* Clear work memory. */
+        std::memset(std::addressof(g_work_memory), 0, sizeof(g_work_memory));
+
+        /* Initialize the decoder server. */
+        R_ABORT_UNLESS(g_decoder_control_server_manager.Initialize());
+
+        /* Start the server. */
+        g_decoder_control_server_manager.StartServer();
+
+        /* We're initialized. */
+        g_initialized = true;
+        return ResultSuccess();
+    }
+
+    void FinalizeForDecoderServer() {
+        /* Ensure we don't finalize when uninitialized. */
+        AMS_ABORT_UNLESS(g_initialized);
+
+        /* Finalize the server. */
+        g_decoder_control_server_manager.Finalize();
+
+        /* Mark uninitialized. */
+        g_initialized = false;
+    }
+
+    void DecoderControlServerThreadFunction(void *) {
+        /* We need to be initialized. */
+        AMS_ABORT_UNLESS(g_initialized);
+
+        /* Run the server. */
+        g_decoder_control_server_manager.RunServer();
+    }
+
+}

libstratosphere/source/capsrv/server/decodersrv/decodersrv_decoder_control_server_manager.cpp

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <stratosphere.hpp>
+#include "decodersrv_decoder_server_object.hpp"
+
+namespace ams::capsrv::server {
+
+    Result DecoderControlServerManager::Initialize() {
+        /* Create the objects. */
+        this->service_holder.emplace();
+        this->server_manager_holder.emplace();
+
+        /* Register the service. */
+        R_ABORT_UNLESS(this->server_manager_holder->RegisterServer<Service>(ServiceName, MaxSessions, sf::ServiceObjectTraits<Service>::SharedPointerHelper::GetEmptyDeleteSharedPointer(std::addressof(*this->service_holder))));
+
+        /* Initialize the idle event, we're idle initially. */
+        os::InitializeEvent(std::addressof(this->idle_event), true, os::EventClearMode_ManualClear);
+
+        return ResultSuccess();
+    }
+
+    void DecoderControlServerManager::Finalize() {
+        /* Check that the server is idle. */
+        AMS_ASSERT(os::TryWaitEvent(std::addressof(this->idle_event)));
+
+        /* Destroy the server. */
+        os::FinalizeEvent(std::addressof(this->idle_event));
+        this->server_manager_holder = std::nullopt;
+        this->service_holder        = std::nullopt;
+    }
+
+    void DecoderControlServerManager::StartServer() {
+        this->server_manager_holder->ResumeProcessing();
+    }
+
+    void DecoderControlServerManager::StopServer() {
+        /* Request the server stop, and wait until it does. */
+        this->server_manager_holder->RequestStopProcessing();
+        os::WaitEvent(std::addressof(this->idle_event));
+    }
+
+    void DecoderControlServerManager::RunServer() {
+        /* Ensure that we are allowed to run. */
+        AMS_ABORT_UNLESS(os::TryWaitEvent(std::addressof(this->idle_event)));
+
+        /* Clear the event. */
+        os::ClearEvent(std::addressof(this->idle_event));
+
+        /* Process forever. */
+        this->server_manager_holder->LoopProcess();
+
+        /* Signal that we're idle again. */
+        os::SignalEvent(std::addressof(this->idle_event));
+    }
+
+}

libstratosphere/source/capsrv/server/decodersrv/decodersrv_decoder_control_server_manager.hpp

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2019-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+#include <stratosphere.hpp>
+#include "decodersrv_decoder_control_service.hpp"
+
+namespace ams::capsrv::server {
+
+    class DecoderControlServerManager {
+        public:
+            /* NOTE: Nintendo only allows one session. */
+            static constexpr inline size_t NumServers           = 1;
+            static constexpr inline size_t MaxSessions          = 2;
+            static constexpr inline sm::ServiceName ServiceName = sm::ServiceName::Encode("caps:dc");
+
+            using Service       = DecoderControlService;
+            using ServerOptions = sf::hipc::DefaultServerManagerOptions;
+            using ServerManager = sf::hipc::ServerManager<NumServers, ServerOptions, MaxSessions>;
+        private:
+            std::optional<Service> service_holder;
+            std::optional<ServerManager> server_manager_holder;
+            os::EventType idle_event;
+        public:
+            constexpr DecoderControlServerManager() : service_holder(), server_manager_holder(), idle_event{} { /* ... */ }
+
+            Result Initialize();
+            void   Finalize();
+
+            void StartServer();
+            void StopServer();
+
+            void RunServer();
+    };
+
+}

libstratosphere/source/capsrv/server/decodersrv/decodersrv_decoder_control_service.cpp

@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2018-2019 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <stratosphere.hpp>
+#include "decodersrv_decoder_server_object.hpp"
+#include "../jpeg/decodersrv_software_jpeg_decoder.hpp"
+
+namespace ams::capsrv::server {
+
+    namespace {
+
+        Result DecodeJpegImpl(void *dst, size_t dst_size, const void *src_jpeg, size_t src_jpeg_size, u32 width, u32 height, const ScreenShotDecodeOption &option, void *work, size_t work_size) {
+            /* Clear the work memory. */
+            std::memset(work, 0, work_size);
+            ON_SCOPE_EXIT { std::memset(work, 0, work_size); };
+
+            /* Clear the output memory. */
+            std::memset(dst, 0, dst_size);
+            auto clear_guard = SCOPE_GUARD { std::memset(dst, 0, dst_size); };
+
+            /* Validate parameters. */
+            R_UNLESS(util::IsAligned(width, 0x10),   capsrv::ResultAlbumOutOfRange());
+            R_UNLESS(util::IsAligned(height, 0x4),   capsrv::ResultAlbumOutOfRange());
+
+            R_UNLESS(dst != nullptr,                 capsrv::ResultAlbumReadBufferShortage());
+            R_UNLESS(dst_size >= 4 * width * height, capsrv::ResultAlbumReadBufferShortage());
+
+            R_UNLESS(src_jpeg != nullptr,            capsrv::ResultAlbumInvalidFileData());
+            R_UNLESS(src_jpeg_size != 0,             capsrv::ResultAlbumInvalidFileData());
+
+            /* Create the input. */
+            const jpeg::SoftwareJpegDecoderInput decode_input = {
+                .jpeg             = src_jpeg,
+                .jpeg_size        = src_jpeg_size,
+                .width            = width,
+                .height           = height,
+                .fancy_upsampling = option.HasJpegDecoderFlag(ScreenShotDecoderFlag_EnableFancyUpsampling),
+                .block_smoothing  = option.HasJpegDecoderFlag(ScreenShotDecoderFlag_EnableBlockSmoothing),
+            };
+
+            /* Create the output. */
+            s32 out_width = 0, out_height = 0;
+            jpeg::SoftwareJpegDecoderOutput decode_output = {
+                .out_width  = std::addressof(out_width),
+                .out_height = std::addressof(out_height),
+                .dst        = dst,
+                .dst_size   = dst_size,
+            };
+
+            /* Decode the jpeg. */
+            R_TRY(jpeg::SoftwareJpegDecoder::DecodeRgba8(decode_output, decode_input, work, work_size));
+
+            /* We succeeded, so we shouldn't clear the output memory. */
+            clear_guard.Cancel();
+            return ResultSuccess();
+        }
+
+    }
+
+    Result DecoderControlService::DecodeJpeg(const sf::OutNonSecureBuffer &out, const sf::InBuffer &in, u32 width, u32 height, const ScreenShotDecodeOption &option) {
+        /* Get the work buffer. */
+        void *work       = g_work_memory.jpeg_decoder_memory;
+        size_t work_size = sizeof(g_work_memory.jpeg_decoder_memory);
+
+        /* Call the decoder implementation. */
+        return DecodeJpegImpl(out.GetPointer(), out.GetSize(), in.GetPointer(), in.GetSize(), width, height, option, work, work_size);
+    }
+
+}

libstratosphere/source/capsrv/server/decodersrv/decodersrv_decoder_control_service.hpp

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2018-2019 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+#include <stratosphere.hpp>
+
+namespace ams::capsrv::server {
+
+    class DecoderControlService final : public sf::IServiceObject {
+        protected:
+            enum class CommandId {
+                DecodeJpeg  = 3001,
+            };
+        public:
+            /* Actual commands. */
+            virtual Result DecodeJpeg(const sf::OutNonSecureBuffer &out, const sf::InBuffer &in, u32 width, u32 height, const ScreenShotDecodeOption &option);
+        public:
+            DEFINE_SERVICE_DISPATCH_TABLE {
+                MAKE_SERVICE_COMMAND_META(DecodeJpeg)
+            };
+    };
+}

libstratosphere/source/capsrv/server/decodersrv/decodersrv_decoder_server_object.cpp

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <stratosphere.hpp>
+#include "decodersrv_decoder_server_object.hpp"
+
+namespace ams::capsrv::server {
+
+    /* Instantiate the decoder server globals in a single TU. */
+    DecoderWorkMemory g_work_memory;
+    DecoderControlServerManager g_decoder_control_server_manager;
+
+}

libstratosphere/source/capsrv/server/decodersrv/decodersrv_decoder_server_object.hpp

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2019-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+#include <stratosphere.hpp>
+#include "decodersrv_decoder_work_memory.hpp"
+#include "decodersrv_decoder_control_server_manager.hpp"
+
+namespace ams::capsrv::server {
+
+    extern DecoderWorkMemory g_work_memory;
+    extern DecoderControlServerManager g_decoder_control_server_manager;
+
+}

libstratosphere/source/capsrv/server/decodersrv/decodersrv_decoder_work_memory.hpp

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2019-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+#include <stratosphere.hpp>
+
+namespace ams::capsrv::server {
+
+    struct DecoderWorkMemory {
+        alignas(os::MemoryPageSize) u8 jpeg_decoder_memory[SoftwareJpegDecoderWorkMemorySize];
+    };
+    static_assert(sizeof(DecoderWorkMemory)  == SoftwareJpegDecoderWorkMemorySize);
+    static_assert(alignof(DecoderWorkMemory) == os::MemoryPageSize);
+    static_assert(std::is_pod<DecoderWorkMemory>::value);
+
+}

libstratosphere/source/capsrv/server/jpeg/capsrv_server_jpeg_error_handler.hpp

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2019-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+#include <stratosphere.hpp>
+#include <csetjmp>
+#include "capsrv_server_jpeg_library_types.hpp"
+
+namespace ams::capsrv::server::jpeg {
+
+    struct JpegErrorHandler : public JpegLibraryType::jpeg_error_mgr {
+        public:
+            std::jmp_buf jmp_buf;
+            Result result;
+        public:
+            static void HandleError(JpegLibraryType::jpeg_common_struct *common) {
+                /* Retrieve the handler. */
+                JpegErrorHandler *handler = reinterpret_cast<JpegErrorHandler *>(common->err);
+
+                /* Set the result. */
+                handler->result = GetResult(handler->msg_code, handler->msg_parm.i[0]);
+
+                /* Return to the caller. */
+                longjmp(handler->jmp_buf, -1);
+            }
+
+            static Result GetResult(int msg_code, int msg_param) {
+                switch (msg_code) {
+                    case JpegLibraryType::J_MESSAGE_CODE::JERR_BUFFER_SIZE:
+                    case JpegLibraryType::J_MESSAGE_CODE::JERR_NO_BACKING_STORE:
+                    case JpegLibraryType::J_MESSAGE_CODE::JERR_OUT_OF_MEMORY:
+                    case JpegLibraryType::J_MESSAGE_CODE::JERR_TFILE_CREATE:
+                    case JpegLibraryType::J_MESSAGE_CODE::JERR_TFILE_READ:
+                    case JpegLibraryType::J_MESSAGE_CODE::JERR_TFILE_SEEK:
+                    case JpegLibraryType::J_MESSAGE_CODE::JERR_TFILE_WRITE:
+                        return capsrv::ResultInternalJpegWorkMemoryShortage();
+                    default:
+                        return capsrv::ResultInternalJpegEncoderError();
+                }
+            }
+    };
+
+}

libstratosphere/source/capsrv/server/jpeg/capsrv_server_jpeg_library_types.hpp

@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2019-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#include <stratosphere.hpp>
+#include <jpeglib.h>
+#include <jerror.h>
+
+namespace ams::capsrv::server::jpeg {
+
+    class JpegLibraryType {
+        public:
+            using jpeg_common_struct     = ::jpeg_common_struct;
+            using jpeg_compress_struct   = ::jpeg_compress_struct;
+            using jpeg_decompress_struct = ::jpeg_decompress_struct;
+            using jpeg_error_mgr         = ::jpeg_error_mgr;
+            using jpeg_destination_mgr   = ::jpeg_destination_mgr;
+
+            using j_common_ptr           = ::j_common_ptr;
+            using j_compress_ptr         = ::j_compress_ptr;
+
+            using boolean                = ::boolean;
+            using JOCTET                 = ::JOCTET;
+            using JDIMENSION             = ::JDIMENSION;
+
+            using JSAMPARRAY             = ::JSAMPARRAY;
+            using JSAMPROW               = ::JSAMPROW;
+
+            using J_COLOR_SPACE          = ::J_COLOR_SPACE;
+            using J_DCT_METHOD           = ::J_DCT_METHOD;
+            using J_MESSAGE_CODE         = ::J_MESSAGE_CODE;
+    };
+
+}

libstratosphere/source/capsrv/server/jpeg/decodersrv_software_jpeg_decoder.cpp

@@ -0,0 +1,185 @@
+/*
+ * Copyright (c) 2018-2019 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <stratosphere.hpp>
+#include "decodersrv_software_jpeg_decoder.hpp"
+#include "capsrv_server_jpeg_library_types.hpp"
+#include "capsrv_server_jpeg_error_handler.hpp"
+
+
+namespace ams::capsrv::server::jpeg {
+
+    #define CAPSRV_ABORT_UNLESS(expr) do {                          \
+        const bool __capsrv_assert_res = (expr);                    \
+        AMS_ASSERT(__capsrv_assert_res);                            \
+        AMS_ABORT_UNLESS(__capsrv_assert_res);                      \
+    } while (0)
+
+    #define CAPSRV_ASSERT(expr) do {                                \
+        const bool __capsrv_assert_res = (expr);                    \
+        AMS_ASSERT(__capsrv_assert_res);                            \
+        R_UNLESS(__capsrv_assert_res, capsrv::ResultAlbumError());  \
+    } while (0)
+
+    namespace {
+
+        constexpr s32 ImageSizeHorizonalUnit  = 0x10;
+        constexpr s32 ImageSizeVerticalUnit   = 0x4;
+
+        constexpr s32 RgbColorComponentCount  = 3;
+        constexpr s32 RgbaColorComponentCount = 4;
+
+        Result GetRgbBufferSize(size_t *out_size, size_t *out_stride, s32 width, size_t work_size) {
+            /* Calculate the space we need and verify we have enough. */
+            const size_t rgb_width  = util::AlignUp(static_cast<size_t>(width), ImageSizeHorizonalUnit);
+            const size_t rgb_stride = rgb_width * RgbColorComponentCount;
+            const size_t rgb_size   = rgb_stride * ImageSizeVerticalUnit;
+            R_UNLESS(work_size >= rgb_size, capsrv::ResultInternalJpegWorkMemoryShortage());
+
+            /* Return the output to the caller. */
+            *out_size   = rgb_size;
+            *out_stride = rgb_stride;
+            return ResultSuccess();
+        }
+
+    }
+
+    Result SoftwareJpegDecoder::DecodeRgba8(SoftwareJpegDecoderOutput &output, const SoftwareJpegDecoderInput &input, void *work, size_t work_size) {
+        CAPSRV_ABORT_UNLESS(util::IsAligned(input.width,  ImageSizeHorizonalUnit));
+        CAPSRV_ABORT_UNLESS(util::IsAligned(input.height, ImageSizeVerticalUnit));
+
+        CAPSRV_ABORT_UNLESS(output.dst != nullptr);
+        CAPSRV_ABORT_UNLESS(output.dst_size >= static_cast<size_t>(RgbaColorComponentCount * input.width * input.height));
+
+        CAPSRV_ABORT_UNLESS(output.out_width != nullptr);
+        CAPSRV_ABORT_UNLESS(output.out_height != nullptr);
+
+        /* Determine work buffer extents. */
+        char *work_start = static_cast<char *>(work);
+        char *work_end   = work_start + work_size;
+
+        /* Determine the buffer extents for our linebuffers. */
+        u8 *rgb_buffer = static_cast<u8 *>(static_cast<void *>(work_start));
+        size_t rgb_buffer_size;
+        size_t rgb_buffer_stride;
+        R_TRY(GetRgbBufferSize(std::addressof(rgb_buffer_size), std::addressof(rgb_buffer_stride), input.width, work_size));
+
+        /* The start of the workbuffer is reserved for linebuffer space. */
+        work_start += rgb_buffer_size;
+
+        /* Create our decompression structure. */
+        JpegLibraryType::jpeg_decompress_struct cinfo = {};
+
+        /* Here nintendo creates a work buffer structure containing work_start + work_size. */
+        /* This seems to be a custom patch for/to libjpeg-turbo. */
+        /* It would be desirable for us to mimic this, because it gives Nintendo strong */
+        /* fixed memory usage guarantees. */
+        /* TODO: Determine if it is feasible for us to recreate this ourselves, */
+        /* Either by adding support to the devkitPro libjpeg-turbo portlib or otherwise. */
+        AMS_UNUSED(work_end);
+
+        /* Create our error manager. */
+        JpegErrorHandler jerr = {
+            .result     = ResultSuccess(),
+        };
+        jerr.error_exit = JpegErrorHandler::HandleError,
+
+
+        /* Link our error manager to our decompression structure. */
+        cinfo.err = jpeg_std_error(std::addressof(jerr));
+
+        /* Use setjmp, so that on error our handler will longjmp to return an error result. */
+        if (setjmp(jerr.jmp_buf) == 0) {
+            /* Create our decompressor. */
+            jpeg_create_decompress(std::addressof(cinfo));
+            ON_SCOPE_EXIT { jpeg_destroy_decompress(std::addressof(cinfo)); };
+
+            /* Setup our memory reader, ensure the header is correct. */
+            jpeg_mem_src(std::addressof(cinfo), const_cast<unsigned char *>(static_cast<const unsigned char *>(input.jpeg)), input.jpeg_size);
+            R_UNLESS(jpeg_read_header(std::addressof(cinfo), true) == JPEG_HEADER_OK,  capsrv::ResultAlbumInvalidFileData());
+
+            /* Ensure width and height are correct. */
+            R_UNLESS(cinfo.image_width  == input.width,    capsrv::ResultAlbumInvalidFileData());
+            R_UNLESS(cinfo.image_height == input.height,   capsrv::ResultAlbumInvalidFileData());
+
+            /* Set output parameters. */
+            cinfo.out_color_space       = JpegLibraryType::J_COLOR_SPACE::JCS_RGB;
+            cinfo.dct_method            = JpegLibraryType::J_DCT_METHOD::JDCT_ISLOW;
+            cinfo.do_fancy_upsampling   = input.fancy_upsampling;
+            cinfo.do_block_smoothing    = input.block_smoothing;
+
+            /* Start decompression. */
+            R_UNLESS(jpeg_start_decompress(&cinfo) == TRUE, capsrv::ResultAlbumInvalidFileData());
+
+            /* Check the parameters. */
+            CAPSRV_ASSERT(cinfo.output_width         == input.width);
+            CAPSRV_ASSERT(cinfo.output_height        == input.height);
+            CAPSRV_ASSERT(cinfo.out_color_components == RgbColorComponentCount);
+            CAPSRV_ASSERT(cinfo.output_components    == RgbColorComponentCount);
+
+            /* Parse the scanlines. */
+            {
+                /* Convert our destination to a writable u8 buffer. */
+                u8 *dst = static_cast<u8 *>(output.dst);
+
+                /* Create our linebuffer structure. */
+                JpegLibraryType::JSAMPROW linebuffers[ImageSizeVerticalUnit] = {};
+                for (int i = 0; i < ImageSizeVerticalUnit; i++) {
+                    linebuffers[i] = rgb_buffer + rgb_buffer_stride * i;
+                }
+
+                /* While we still have scanlines, parse! */
+                while (cinfo.output_scanline < input.height) {
+                    /* Decode scanlines. */
+                    int num_scanlines = jpeg_read_scanlines(std::addressof(cinfo), linebuffers, ImageSizeVerticalUnit);
+                    CAPSRV_ASSERT(num_scanlines <= ImageSizeVerticalUnit);
+
+                    /* Write out line by line. */
+                    for (s32 i = 0; i < num_scanlines; i++) {
+                        const u8 *src = linebuffers[i];
+                        for (s32 j = 0; j < static_cast<s32>(input.width); j++) {
+                            /* Write the output. */
+
+                            /* First R, */
+                            *(dst++) = *(src++);
+
+                            /* Then G, */
+                            *(dst++) = *(src++);
+
+                            /* Then B, */
+                            *(dst++) = *(src++);
+
+                            /* Then A. */
+                            *(dst++) = 0xFF;
+                        }
+                    }
+                }
+            }
+
+            /* Finish the decompression. */
+            R_UNLESS(jpeg_finish_decompress(&cinfo) == TRUE, capsrv::ResultAlbumInvalidFileData());
+        } else {
+            /* Some unknown error was caught by our handler. */
+            return capsrv::ResultAlbumInvalidFileData();
+        }
+
+        /* Write the size we decoded to output. */
+        *output.out_width = static_cast<s32>(cinfo.output_width);
+        *output.out_width = static_cast<s32>(cinfo.output_height);
+
+        return ResultSuccess();
+    }
+
+}

libstratosphere/source/capsrv/server/jpeg/decodersrv_software_jpeg_decoder.hpp

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2019-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+#include <stratosphere.hpp>
+
+namespace ams::capsrv::server::jpeg {
+
+    struct SoftwareJpegDecoderInput {
+        const void *jpeg;
+        size_t jpeg_size;
+        u32 width;
+        u32 height;
+        bool fancy_upsampling;
+        bool block_smoothing;
+    };
+
+    struct SoftwareJpegDecoderOutput {
+        s32 *out_width;
+        s32 *out_height;
+        void *dst;
+        size_t dst_size;
+    };
+
+    class SoftwareJpegDecoder {
+        public:
+            static Result DecodeRgba8(SoftwareJpegDecoderOutput &output, const SoftwareJpegDecoderInput &input, void *work, size_t work_size);
+    };
+
+}

libvapours/include/vapours/results/capsrv_results.hpp

@@ -52,6 +52,7 @@ namespace ams::capsrv {
     R_DEFINE_ERROR_RESULT(NotSupported, 1023);
 
     R_DEFINE_ERROR_RANGE(InternalError, 1024, 2047);
+        R_DEFINE_ERROR_RESULT(InternalJpegEncoderError,         1210);
         R_DEFINE_ERROR_RESULT(InternalJpegWorkMemoryShortage,   1212);
 
         R_DEFINE_ERROR_RANGE(InternalFileDataVerificationError, 1300, 1399);