mpd/src/decoder_api.h

174 lines
5.1 KiB
C

/*
* Copyright (C) 2003-2011 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.
*/
/*! \file
* \brief The MPD Decoder API
*
* This is the public API which is used by decoder plugins to
* communicate with the mpd core.
*/
#ifndef MPD_DECODER_API_H
#define MPD_DECODER_API_H
#include "check.h"
#include "decoder_command.h"
#include "decoder_plugin.h"
#include "input_stream.h"
#include "replay_gain_info.h"
#include "tag.h"
#include "audio_format.h"
#include "conf.h"
#include <stdbool.h>
/**
* Notify the player thread that it has finished initialization and
* that it has read the song's meta data.
*
* @param decoder the decoder object
* @param audio_format the audio format which is going to be sent to
* decoder_data()
* @param seekable true if the song is seekable
* @param total_time the total number of seconds in this song; -1 if unknown
*/
void
decoder_initialized(struct decoder *decoder,
const struct audio_format *audio_format,
bool seekable, float total_time);
/**
* Determines the pending decoder command.
*
* @param decoder the decoder object
* @return the current command, or DECODE_COMMAND_NONE if there is no
* command pending
*/
enum decoder_command
decoder_get_command(struct decoder *decoder);
/**
* Called by the decoder when it has performed the requested command
* (dc->command). This function resets dc->command and wakes up the
* player thread.
*
* @param decoder the decoder object
*/
void
decoder_command_finished(struct decoder *decoder);
/**
* Call this when you have received the DECODE_COMMAND_SEEK command.
*
* @param decoder the decoder object
* @return the destination position for the week
*/
double
decoder_seek_where(struct decoder *decoder);
/**
* Call this instead of decoder_command_finished() when seeking has
* failed.
*
* @param decoder the decoder object
*/
void
decoder_seek_error(struct decoder *decoder);
/**
* Blocking read from the input stream.
*
* @param decoder the decoder object
* @param is the input stream to read from
* @param buffer the destination buffer
* @param length the maximum number of bytes to read
* @return the number of bytes read, or 0 if one of the following
* occurs: end of file; error; command (like SEEK or STOP).
*/
size_t
decoder_read(struct decoder *decoder, struct input_stream *is,
void *buffer, size_t length);
/**
* Sets the time stamp for the next data chunk [seconds]. The MPD
* core automatically counts it up, and a decoder plugin only needs to
* use this function if it thinks that adding to the time stamp based
* on the buffer size won't work.
*/
void
decoder_timestamp(struct decoder *decoder, double t);
/**
* This function is called by the decoder plugin when it has
* successfully decoded block of input data.
*
* @param decoder the decoder object
* @param is an input stream which is buffering while we are waiting
* for the player
* @param data the source buffer
* @param length the number of bytes in the buffer
* @return the current command, or DECODE_COMMAND_NONE if there is no
* command pending
*/
enum decoder_command
decoder_data(struct decoder *decoder, struct input_stream *is,
const void *data, size_t length,
uint16_t kbit_rate);
/**
* This function is called by the decoder plugin when it has
* successfully decoded a tag.
*
* @param decoder the decoder object
* @param is an input stream which is buffering while we are waiting
* for the player
* @param tag the tag to send
* @return the current command, or DECODE_COMMAND_NONE if there is no
* command pending
*/
enum decoder_command
decoder_tag(struct decoder *decoder, struct input_stream *is,
const struct tag *tag);
/**
* Set replay gain values for the following chunks.
*
* @param decoder the decoder object
* @param rgi the replay_gain_info object; may be NULL to invalidate
* the previous replay gain values
* @return the replay gain adjustment used
*/
float
decoder_replay_gain(struct decoder *decoder,
const struct replay_gain_info *replay_gain_info);
/**
* Store MixRamp tags.
*
* @param decoder the decoder object
* @param replay_gain_db the ReplayGain adjustment used for this song
* @param mixramp_start the mixramp_start tag; may be NULL to invalidate
* @param mixramp_end the mixramp_end tag; may be NULL to invalidate
*/
void
decoder_mixramp(struct decoder *decoder, float replay_gain_db,
char *mixramp_start, char *mixramp_end);
#endif