/***************************************************************************** * audio_output.h : audio output thread interface ***************************************************************************** * Copyright (C) 1999, 2000 VideoLAN * $Id: audio_output.h,v 1.48 2002/06/01 18:04:48 sam Exp $ * * Authors: Michel Kaempf * Cyril Deguet * * 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., 59 Temple Place - Suite 330, Boston, MA 02111, USA. *****************************************************************************/ /***************************************************************************** * aout_increment_t ***************************************************************************** * This structure is used to keep the progression of an index up-to-date, in * order to avoid rounding problems and heavy computations, as the function * that handles this structure only uses additions. *****************************************************************************/ typedef struct aout_increment_s { /* The remainder is used to keep track of the fractional part of the * index. */ int i_r; /* * The increment structure is initialized with the result of an euclidean * division : * * i_x i_b * ----- = i_a + ----- * i_y i_c * */ int i_a, i_b, i_c; } aout_increment_t; /***************************************************************************** * aout_fifo_t *****************************************************************************/ struct aout_fifo_s { /* See the fifo formats below */ int i_format; int i_channels; int i_rate; int i_frame_size; vlc_bool_t b_die; int i_fifo; /* Just to keep track of the fifo index */ vlc_mutex_t data_lock; vlc_cond_t data_wait; u8 * buffer; mtime_t * date; /* The start frame is the first frame in the buffer that contains decoded * audio data. It it also the first frame in the current timestamped frame * area, ie the first dated frame in the decoded part of the buffer. :-p */ int i_start_frame; vlc_bool_t b_start_frame; /* The next frame is the end frame of the current timestamped frame area, * ie the first dated frame after the start frame. */ int i_next_frame; vlc_bool_t b_next_frame; /* The end frame is the first frame, after the start frame, that doesn't * contain decoded audio data. That's why the end frame is the first frame * where the audio decoder can store its decoded audio frames. */ int i_end_frame; /* Current index in p_aout->buffer */ int i_unit; /* Max index in p_aout->buffer */ int i_unit_limit; /* Structure used to calculate i_unit with a Bresenham algorithm */ aout_increment_t unit_increment; /* The following variable is used to store the number of remaining audio * units in the current timestamped frame area. */ int i_units; }; #define AOUT_FIFO_ISEMPTY( fifo ) \ ( (fifo).i_end_frame == (fifo).i_start_frame ) #define AOUT_FIFO_ISFULL( fifo ) \ ( ((((fifo).i_end_frame + 1) - (fifo).i_start_frame) & AOUT_FIFO_SIZE) == 0 ) #define AOUT_FIFO_INC( i_index ) \ ( ((i_index) + 1) & AOUT_FIFO_SIZE ) /* List of known fifo formats */ #define AOUT_FIFO_NONE 0 #define AOUT_FIFO_PCM 1 #define AOUT_FIFO_SPDIF 2 /***************************************************************************** * aout_thread_t : audio output thread descriptor *****************************************************************************/ struct aout_thread_s { VLC_COMMON_MEMBERS vlc_mutex_t fifos_lock; aout_fifo_t fifo[ AOUT_MAX_FIFOS ]; /* Plugin used and shortcuts to access its capabilities */ module_t * p_module; int ( *pf_open ) ( aout_thread_t * ); int ( *pf_setformat ) ( aout_thread_t * ); int ( *pf_getbufinfo ) ( aout_thread_t * , int ); void ( *pf_play ) ( aout_thread_t * , byte_t *, int ); void ( *pf_close ) ( aout_thread_t * ); void * buffer; /* The s32 buffer is used to mix all the audio fifos together before * converting them and storing them in the audio output buffer */ s32 * s32_buffer; /* The size of the audio output buffer is kept in audio units, as this is * the only unit that is common with every audio decoder and audio fifo */ int i_units; /* date is the moment where the first audio unit of the output buffer * will be played */ mtime_t date; /* The current volume */ int i_volume; int i_savedvolume; /* Format of the audio output samples, number of channels, and * rate and gain (in Hz) of the audio output sound */ int i_format; int i_channels; int i_rate; /* Latency of the audio output plugin, in bytes */ int i_latency; /* there might be some useful private structure, such as audio_buf_info * for the OSS output */ aout_sys_t * p_sys; }; /* Those are from but are needed because of formats * on other platforms */ #define AOUT_FMT_U8 0x00000008 #define AOUT_FMT_S16_LE 0x00000010 /* Little endian signed 16 */ #define AOUT_FMT_S16_BE 0x00000020 /* Big endian signed 16 */ #define AOUT_FMT_S8 0x00000040 #define AOUT_FMT_U16_LE 0x00000080 /* Little endian U16 */ #define AOUT_FMT_U16_BE 0x00000100 /* Big endian U16 */ #define AOUT_FMT_AC3 0x00000400 /* Dolby Digital AC3 */ #ifdef WORDS_BIGENDIAN #define AOUT_FMT_S16_NE AOUT_FMT_S16_BE #else #define AOUT_FMT_S16_NE AOUT_FMT_S16_LE #endif /* Number of samples in an AC3 frame */ #define AC3_FRAME_SIZE 1536 /* Size of a frame for spdif output */ #define SPDIF_FRAME_SIZE 6144 /***************************************************************************** * Prototypes *****************************************************************************/ aout_thread_t * aout_CreateThread ( vlc_object_t *, int, int ); void aout_DestroyThread ( aout_thread_t * ); #define aout_CreateFifo(a,b,c,d,e,f) __aout_CreateFifo(CAST_TO_VLC_OBJECT(a),b,c,d,e,f) VLC_EXPORT( aout_fifo_t *, __aout_CreateFifo, ( vlc_object_t *, int, int, int, int, void * ) ); VLC_EXPORT( void, aout_DestroyFifo, ( aout_fifo_t *p_fifo ) ); void aout_FreeFifo ( aout_fifo_t *p_fifo );