Introduced new transcoding service

2025-05-30 23:27:01 +02:00
parent 8cf2e2b660
commit dc52ea4ea5
32 changed files with 487 additions and 301 deletions
@@ -0,0 +1,17 @@
+add_library(lmstranscoding STATIC
+	impl/TranscodingResourceHandler.cpp
+	impl/TranscodingService.cpp
+	)
+
+target_include_directories(lmstranscoding INTERFACE
+	include
+	)
+
+target_include_directories(lmstranscoding PRIVATE
+	include
+	impl
+	)
+
+target_link_libraries(lmstranscoding PRIVATE
+	lmsav
+	)
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2020 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * LMS 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "TranscodingResourceHandler.hpp"
+
+#include "av/Exception.hpp"
+#include "av/ITranscoder.hpp"
+#include "core/ILogger.hpp"
+
+namespace lms::transcoding
+{
+    namespace
+    {
+        std::size_t doEstimateContentLength(const InputParameters& inputParameters, const OutputParameters& outputParameters)
+        {
+            const std::size_t estimatedContentLength{ outputParameters.bitrate / 8 * static_cast<std::size_t>(std::chrono::duration_cast<std::chrono::milliseconds>(inputParameters.duration).count()) / 1000 };
+            return estimatedContentLength;
+        }
+
+        av::InputParameters toAv(const InputParameters& in)
+        {
+            return { .file = in.file, .offset = in.offset, .streamIndex = in.streamIndex };
+        }
+
+        av::OutputParameters toAv(const OutputParameters& out)
+        {
+            return { .format = static_cast<lms::av::OutputFormat>(out.format), .bitrate = out.bitrate, .stripMetadata = out.stripMetadata };
+        }
+
+    } // namespace
+
+    std::unique_ptr<core::IResourceHandler> createResourceHandler(const InputParameters& inputParameters, const OutputParameters& outputParameters, bool estimateContentLength)
+    {
+        return std::make_unique<TranscodingResourceHandler>(inputParameters, outputParameters, estimateContentLength);
+    }
+
+    // TODO set some nice HTTP return code
+
+    TranscodingResourceHandler::TranscodingResourceHandler(const InputParameters& inputParameters, const OutputParameters& outputParameters, bool estimateContentLength)
+        : _estimatedContentLength{ estimateContentLength ? std::make_optional(doEstimateContentLength(inputParameters, outputParameters)) : std::nullopt }
+    {
+        try
+        {
+            _transcoder = av::createTranscoder(toAv(inputParameters), toAv(outputParameters));
+
+            if (_estimatedContentLength)
+                LMS_LOG(TRANSCODING, DEBUG, "Estimated content length = " << *_estimatedContentLength);
+            else
+                LMS_LOG(TRANSCODING, DEBUG, "Not using estimated content length");
+        }
+        catch (av::Exception& e)
+        {
+            LMS_LOG(TRANSCODING, ERROR, "Failed to create transcoder: " << e.what());
+        }
+    }
+
+    TranscodingResourceHandler::~TranscodingResourceHandler() = default;
+
+    Wt::Http::ResponseContinuation* TranscodingResourceHandler::processRequest(const Wt::Http::Request& /*request*/, Wt::Http::Response& response)
+    {
+        if (!_transcoder)
+        {
+            response.setStatus(404);
+            return {};
+        }
+
+        if (_estimatedContentLength)
+            response.setContentLength(*_estimatedContentLength);
+        response.setMimeType(std::string{ _transcoder->getOutputMimeType() });
+        LMS_LOG(TRANSCODING, DEBUG, "Transcoder finished = " << _transcoder->finished() << ", total served bytes = " << _totalServedByteCount << ", mime type = " << _transcoder->getOutputMimeType());
+
+        if (_bytesReadyCount > 0)
+        {
+            LMS_LOG(TRANSCODING, DEBUG, "Writing " << _bytesReadyCount << " bytes back to client");
+
+            response.out().write(reinterpret_cast<const char*>(_buffer.data()), _bytesReadyCount);
+            _totalServedByteCount += _bytesReadyCount;
+            _bytesReadyCount = 0;
+        }
+
+        if (!_transcoder->finished())
+        {
+            Wt::Http::ResponseContinuation* continuation{ response.createContinuation() };
+            continuation->waitForMoreData();
+            _transcoder->asyncRead(_buffer.data(), _buffer.size(), [this, continuation](std::size_t nbBytesRead) {
+                LMS_LOG(TRANSCODING, DEBUG, "Have " << nbBytesRead << " more bytes to send back");
+
+                assert(_bytesReadyCount == 0);
+                _bytesReadyCount = nbBytesRead;
+                continuation->haveMoreData();
+            });
+
+            return continuation;
+        }
+
+        // pad with 0 if necessary as duration may not be accurate
+        if (_estimatedContentLength && *_estimatedContentLength > _totalServedByteCount)
+        {
+            const std::size_t padSize{ *_estimatedContentLength - _totalServedByteCount };
+
+            LMS_LOG(TRANSCODING, DEBUG, "Adding " << padSize << " padding bytes");
+
+            for (std::size_t i{}; i < padSize; ++i)
+                response.out().put(0);
+
+            _totalServedByteCount += padSize;
+        }
+
+        LMS_LOG(TRANSCODING, DEBUG, "Transcoding finished. Total served byte count = " << _totalServedByteCount);
+
+        return {};
+    }
+} // namespace lms::transcoding
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2020 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * LMS 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <array>
+#include <memory>
+#include <optional>
+
+#include "core/IResourceHandler.hpp"
+#include "services/transcoding/ITranscodingService.hpp"
+
+namespace lms::av
+{
+    class ITranscoder;
+}
+
+namespace lms::transcoding
+{
+    class TranscodingResourceHandler final : public core::IResourceHandler
+    {
+    public:
+        TranscodingResourceHandler(const InputParameters& inputParameters, const OutputParameters& outputParameters, bool estimateContentLength);
+        ~TranscodingResourceHandler() override;
+
+        TranscodingResourceHandler(const TranscodingResourceHandler&) = delete;
+        TranscodingResourceHandler& operator=(const TranscodingResourceHandler&) = delete;
+
+    private:
+        Wt::Http::ResponseContinuation* processRequest(const Wt::Http::Request& request, Wt::Http::Response& response) override;
+        void abort() override{};
+
+        static constexpr std::size_t _chunkSize{ 262'144 };
+        std::optional<std::size_t> _estimatedContentLength;
+        std::array<std::byte, _chunkSize> _buffer;
+        std::size_t _bytesReadyCount{};
+        std::size_t _totalServedByteCount{};
+        std::unique_ptr<av::ITranscoder> _transcoder;
+    };
+} // namespace lms::transcoding
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2025 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * LMS 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "TranscodingService.hpp"
+
+#include "core/ILogger.hpp"
+
+#include "TranscodingResourceHandler.hpp"
+
+namespace lms::transcoding
+{
+    std::unique_ptr<ITranscodingService> createTranscodingService(core::IChildProcessManager& childProcessManager)
+    {
+        return std::make_unique<TranscodingService>(childProcessManager);
+    }
+
+    TranscodingService::TranscodingService(core::IChildProcessManager& childProcessManager)
+        : _childProcessManager(childProcessManager)
+    {
+        LMS_LOG(TRANSCODING, INFO, "Service started!");
+    }
+
+    TranscodingService::~TranscodingService()
+    {
+        LMS_LOG(TRANSCODING, INFO, "Service stopped!");
+    }
+
+    std::unique_ptr<core::IResourceHandler> TranscodingService::createResourceHandler(const InputParameters& inputParameters, const OutputParameters& outputParameters, bool estimateContentLength)
+    {
+        return std::make_unique<TranscodingResourceHandler>(inputParameters, outputParameters, estimateContentLength);
+    }
+} // namespace lms::transcoding
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2025 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * LMS 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "services/transcoding/ITranscodingService.hpp"
+
+namespace lms::transcoding
+{
+    class TranscodingService : public ITranscodingService
+    {
+    public:
+        explicit TranscodingService(core::IChildProcessManager& childProcessManager);
+        ~TranscodingService() override;
+
+        TranscodingService(const TranscodingService&) = delete;
+        TranscodingService& operator=(const TranscodingService&) = delete;
+
+    private:
+        std::unique_ptr<core::IResourceHandler> createResourceHandler(const InputParameters& inputParameters, const OutputParameters& outputParameters, bool estimateContentLength) override;
+
+        core::IChildProcessManager& _childProcessManager;
+    };
+} // namespace lms::transcoding
@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) 2025 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * LMS 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <filesystem>
+#include <memory>
+#include <optional>
+
+namespace lms::core
+{
+    class IChildProcessManager;
+    class IResourceHandler;
+} // namespace lms::core
+
+namespace lms::transcoding
+{
+    struct InputParameters
+    {
+        std::filesystem::path file;             // Path to the input file
+        std::chrono::milliseconds duration;     // Offset in the input file to start transcoding from
+        std::chrono::milliseconds offset{};     // Offset in the input file to start transcoding from
+        std::optional<std::size_t> streamIndex; // Index of the stream to be transcoded (select "best" audio stream if not set)
+    };
+
+    enum class OutputFormat
+    {
+        MP3,
+        OGG_OPUS,
+        MATROSKA_OPUS,
+        OGG_VORBIS,
+        WEBM_VORBIS,
+    };
+
+    struct OutputParameters
+    {
+        OutputFormat format;
+        std::size_t bitrate{ 128'000 };
+        bool stripMetadata{ true };
+    };
+
+    class ITranscodingService
+    {
+    public:
+        virtual ~ITranscodingService() = default;
+
+        virtual std::unique_ptr<core::IResourceHandler> createResourceHandler(const InputParameters& inputParameters, const OutputParameters& outputParameters, bool estimateContentLength) = 0;
+    };
+
+    std::unique_ptr<ITranscodingService> createTranscodingService(core::IChildProcessManager& childProcessManager);
+} // namespace lms::transcoding