/* * Copyright 2003-2019 The Music Player Daemon Project * http://www.musicpd.org * * This program 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 2 of the License, or * (at your option) any later version. * * This program 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 this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #ifndef MPD_DECODER_BRIDGE_HXX #define MPD_DECODER_BRIDGE_HXX #include "Client.hxx" #include "ReplayGainInfo.hxx" #include "MusicChunkPtr.hxx" #include #include class PcmConvert; struct MusicChunk; class DecoderControl; class Path; struct Tag; /** * A bridge between the #DecoderClient interface and the MPD core * (#DecoderControl, #MusicPipe etc.). */ class DecoderBridge final : public DecoderClient { public: DecoderControl &dc; private: /** * For converting input data to the configured audio format. * nullptr means no conversion necessary. */ std::unique_ptr convert; /** * The time stamp of the next data chunk, in seconds. */ FloatDuration timestamp = FloatDuration::zero(); /** * The time stamp of the next data chunk, in PCM frames. */ uint64_t absolute_frame = 0; /** * Is the initial seek (to the start position of the sub-song) * pending, or has it been performed already? */ bool initial_seek_pending; /** * Is the initial seek currently running? During this time, * the decoder command is SEEK. This flag is set by * decoder_get_virtual_command(), when the virtual SEEK * command is generated for the first time. */ bool initial_seek_running = false; /** * This flag is set by GetSeekTime(), and checked by * CommandFinished(). It is used to clean up after seeking. */ bool seeking = false; /** * The tag from the song object. This is only used for local * files, because we expect the stream server to send us a new * tag each time we play it. */ std::unique_ptr song_tag; public: /** the last tag received from the stream */ std::unique_ptr stream_tag; /** the last tag received from the decoder plugin */ std::unique_ptr decoder_tag; private: /** the chunk currently being written to */ MusicChunkPtr current_chunk; ReplayGainInfo replay_gain_info; /** * A positive serial number for checking if replay gain info * has changed since the last check. */ unsigned replay_gain_serial = 0; /** * An error has occurred (in DecoderAPI.cxx), and the plugin * will be asked to stop. */ std::exception_ptr error; public: DecoderBridge(DecoderControl &_dc, bool _initial_seek_pending, std::unique_ptr _tag) noexcept; ~DecoderBridge() noexcept; void Reset() noexcept { error = {}; } /** * Should be read operation be cancelled? That is the case when the * player thread has sent a command such as "STOP". * * Caller must lock the #DecoderControl object. */ gcc_pure bool CheckCancelRead() const noexcept; /** * Returns the current chunk the decoder writes to, or allocates a new * chunk if there is none. * * @return the chunk, or NULL if we have received a decoder command */ MusicChunk *GetChunk() noexcept; /** * Flushes the current chunk. * * Caller must not lock the #DecoderControl object. */ void FlushChunk() noexcept; void CheckFlushChunk() { if (current_chunk != nullptr) FlushChunk(); } void CheckRethrowError() { if (error) std::rethrow_exception(error); } /** * Open a local file. */ InputStreamPtr OpenLocal(Path path_fs, const char *uri_utf8); /* virtual methods from DecoderClient */ void Ready(AudioFormat audio_format, bool seekable, SignedSongTime duration) override; DecoderCommand GetCommand() noexcept override; void CommandFinished() noexcept override; SongTime GetSeekTime() noexcept override; uint64_t GetSeekFrame() noexcept override; void SeekError() noexcept override; InputStreamPtr OpenUri(const char *uri) override; size_t Read(InputStream &is, void *buffer, size_t length) override; void SubmitTimestamp(FloatDuration t) noexcept override; DecoderCommand SubmitData(InputStream *is, const void *data, size_t length, uint16_t kbit_rate) noexcept override; DecoderCommand SubmitTag(InputStream *is, Tag &&tag) noexcept override; void SubmitReplayGain(const ReplayGainInfo *replay_gain_info) noexcept override; void SubmitMixRamp(MixRampInfo &&mix_ramp) noexcept override; private: /** * Checks if we need an "initial seek". If so, then the * initial seek is prepared, and the function returns true. */ bool PrepareInitialSeek() noexcept; /** * Returns the current decoder command. May return a * "virtual" synthesized command, e.g. to seek to the * beginning of the CUE track. */ DecoderCommand GetVirtualCommand() noexcept; DecoderCommand LockGetVirtualCommand() noexcept; /** * Sends a #Tag as-is to the #MusicPipe. Flushes the current * chunk (DecoderBridge::chunk) if there is one. */ DecoderCommand DoSendTag(const Tag &tag) noexcept; bool UpdateStreamTag(InputStream *is) noexcept; }; #endif