Switched from sync transcoder to async transcoder

2020-12-12 14:43:33 +01:00
parent 0586e93655
commit eea27b86f0
34 changed files with 959 additions and 504 deletions
@@ -0,0 +1,230 @@
+/*
+ * 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 "Transcoder.hpp"
+
+#include <atomic>
+#include <iomanip>
+
+#include "utils/IChildProcessManager.hpp"
+#include "utils/IConfig.hpp"
+#include "utils/Path.hpp"
+#include "utils/Logger.hpp"
+#include "utils/Service.hpp"
+
+namespace Av {
+
+#define LOG(sev)	LMS_LOG(TRANSCODE, sev) << "[" << _id << "] - "
+
+static std::atomic<size_t>		globalId {};
+static std::filesystem::path	ffmpegPath;
+
+void
+Transcoder::init()
+{
+	ffmpegPath = Service<IConfig>::get()->getPath("ffmpeg-file", "/usr/bin/ffmpeg");
+	if (!std::filesystem::exists(ffmpegPath))
+		throw Exception {"File '" + ffmpegPath.string() + "' does not exist!"};
+}
+
+Transcoder::Transcoder(const std::filesystem::path& filePath, const TranscodeParameters& parameters)
+:  _id {globalId++}
+, _filePath {filePath}
+, _parameters {parameters}
+{
+
+}
+
+Transcoder::~Transcoder() = default;
+
+bool
+Transcoder::start()
+{
+	if (ffmpegPath.empty())
+		init();
+
+	try
+	{
+		if (!std::filesystem::exists(_filePath))
+		{
+			LOG(ERROR) << "File '" << _filePath << "' does not exist!";
+			return false;
+		}
+		else if (!std::filesystem::is_regular_file( _filePath) )
+		{
+			LOG(ERROR) << "File '" << _filePath << "' is not regular!";
+			return false;
+		}
+	}
+	catch (const std::filesystem::filesystem_error& e)
+	{
+		LOG(ERROR) << "File error on '" << _filePath.string() << "': " << e.what();
+		return false;
+	}
+
+	LOG(INFO) << "Transcoding file '" << _filePath.string() << "'";
+
+	std::vector<std::string> args;
+
+	args.emplace_back(ffmpegPath.string());
+
+	// Make sure:
+	// - we do not produce anything in the stderr output
+	// - we do not rely on input
+	// in order not to block the whole forked process
+	args.emplace_back("-loglevel");
+	args.emplace_back("quiet");
+	args.emplace_back("-nostdin");
+
+	// input Offset
+	{
+		args.emplace_back("-ss");
+
+		std::ostringstream oss;
+		oss << std::fixed << std::showpoint << std::setprecision(3) << (_parameters.offset.count() / float {1000});
+		args.emplace_back(oss.str());
+	}
+
+	// Input file
+	args.emplace_back("-i");
+	args.emplace_back(_filePath.string());
+
+	// Stream mapping, if set
+	if (_parameters.stream)
+	{
+		args.emplace_back("-map");
+		args.emplace_back("0:" + std::to_string(*_parameters.stream));
+	}
+
+	if (_parameters.stripMetadata)
+	{
+		// Strip metadata
+		args.emplace_back("-map_metadata");
+		args.emplace_back("-1");
+	}
+
+	// Skip video flows (including covers)
+	args.emplace_back("-vn");
+
+	// Output bitrates
+	args.emplace_back("-b:a");
+	args.emplace_back(std::to_string(_parameters.bitrate));
+
+
+	// Codecs and formats
+	switch (_parameters.format)
+	{
+		case Format::MP3:
+			args.emplace_back("-f");
+			args.emplace_back("mp3");
+			break;
+
+		case Format::OGG_OPUS:
+			args.emplace_back("-acodec");
+			args.emplace_back("libopus");
+			args.emplace_back("-f");
+			args.emplace_back("ogg");
+			break;
+
+		case Format::MATROSKA_OPUS:
+			args.emplace_back("-acodec");
+			args.emplace_back("libopus");
+			args.emplace_back("-f");
+			args.emplace_back("matroska");
+			break;
+
+		case Format::OGG_VORBIS:
+			args.emplace_back("-acodec");
+			args.emplace_back("libvorbis");
+			args.emplace_back("-f");
+			args.emplace_back("ogg");
+			break;
+
+		case Format::WEBM_VORBIS:
+			args.emplace_back("-acodec");
+			args.emplace_back("libvorbis");
+			args.emplace_back("-f");
+			args.emplace_back("webm");
+			break;
+
+		default:
+			return false;
+	}
+
+	_outputMimeType = formatToMimetype(_parameters.format);
+
+	args.emplace_back("pipe:1");
+
+	LOG(DEBUG) << "Dumping args (" << args.size() << ")";
+	for (const std::string& arg : args)
+		LOG(DEBUG) << "Arg = '" << arg << "'";
+
+	// Caution: stdin must have been closed before
+	try
+	{
+		_childProcess = Service<IChildProcessManager>::get()->spawnChildProcess(ffmpegPath, args);
+	}
+	catch (ChildProcessException& exception)
+	{
+		LOG(ERROR) << "Cannot execute '" << ffmpegPath << "': " << exception.what();
+		return false;
+	}
+
+	return true;
+}
+
+void
+Transcoder::asyncWaitForData(WaitCallback cb)
+{
+	assert(_childProcess);
+
+	LOG(DEBUG) << "Want to wait for data";
+
+	_childProcess->asyncWaitForData([cb = std::move(cb)]
+	{
+		cb();
+	});
+}
+
+void
+Transcoder::asyncRead(std::byte* buffer, std::size_t bufferSize, ReadCallback readCallback)
+{
+	assert(_childProcess);
+
+	return _childProcess->asyncRead(buffer, bufferSize, [readCallback {std::move(readCallback)}](IChildProcess::ReadResult /*res*/, std::size_t nbBytesRead)
+	{
+		readCallback(nbBytesRead);
+	});
+}
+
+std::size_t
+Transcoder::readSome(std::byte* buffer, std::size_t bufferSize)
+{
+	assert(_childProcess);
+
+	return _childProcess->readSome(buffer, bufferSize);
+}
+
+bool
+Transcoder::finished() const
+{
+	return _childProcess->finished();
+}
+
+} // namespace Transcode