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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* 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.
*
* $URL$
* $Id$
*
*/
#ifndef SCI_SFX_SFX_PCM_H
#define SCI_SFX_SFX_PCM_H
#include "sci/sfx/sfx_core.h"
#include "sci/sfx/sfx_time.h"
namespace Sci {
#define SFX_PCM_MONO 0
#define SFX_PCM_STEREO_LR 1 /* left sample, then right sample */
#define SFX_PCM_STEREO_RL 2 /* right sample, then left sample */
/* The following are used internally by the mixer */
#define SFX_PCM_FORMAT_LMASK 0x7
#define SFX_PCM_FORMAT_BE 0
#define SFX_PCM_FORMAT_LE 1
#define SFX_PCM_FORMAT_ENDIANNESS 1
#define SFX_PCM_FORMAT_8 0
#define SFX_PCM_FORMAT_16 2
/* Pick one of these formats (including the _NATIVE) ones for your PCM feed */
#define SFX_PCM_FORMAT_U8 (0x0080 | SFX_PCM_FORMAT_8) /* Unsigned (bias 128) 8 bit format */
#define SFX_PCM_FORMAT_S8 (0x0000 | SFX_PCM_FORMAT_8) /* Signed 8 bit format */
#define SFX_PCM_FORMAT_U16_LE (0x8000 | SFX_PCM_FORMAT_16 | SFX_PCM_FORMAT_LE) /* Unsigned (bias 32768) 16 bit LE format */
#define SFX_PCM_FORMAT_S16_LE (0x0000 | SFX_PCM_FORMAT_16 | SFX_PCM_FORMAT_LE) /* Signed 16 bit format, little endian */
#define SFX_PCM_FORMAT_U16_BE (0x8000 | SFX_PCM_FORMAT_16 | SFX_PCM_FORMAT_BE) /* Unsigned (bias 32768) 16 bit BE format */
#define SFX_PCM_FORMAT_S16_BE (0x0000 | SFX_PCM_FORMAT_16 | SFX_PCM_FORMAT_BE) /* Signed 16 bit format, big endian */
#ifdef SCUMM_BIG_ENDIAN
# define SFX_PCM_FORMAT_U16_NATIVE SFX_PCM_FORMAT_U16_BE
# define SFX_PCM_FORMAT_S16_NATIVE SFX_PCM_FORMAT_S16_BE
#else
# define SFX_PCM_FORMAT_U16_NATIVE SFX_PCM_FORMAT_U16_LE
# define SFX_PCM_FORMAT_S16_NATIVE SFX_PCM_FORMAT_S16_LE
#endif
#define SFX_PCM_FRAME_SIZE(conf) ((conf).stereo? 2 : 1) * (((conf).format & SFX_PCM_FORMAT_16)? 2 : 1)
struct sfx_pcm_config_t {
int rate; /* Sampling rate */
int stereo; /* The stereo mode used (SFX_PCM_MONO or SFX_PCM_STEREO_*) */
unsigned int format; /* Sample format (SFX_PCM_FORMAT_*) */
};
struct sfx_pcm_device_t {
/* SFX devices are PCM players, i.e. output drivers for digitalised audio (sequences of audio samples).
** Implementors are (in general) allowed to export specifics of these devices and let the mixer handle
** endianness/signedness/bit size/mono-vs-stereo conversions.
*/
int (*init)(sfx_pcm_device_t *self);
/* Initializes the device
** Parameters: (sfx_pcm_device_t *) self: Self reference
** Returns : (int) SFX_OK on success, SFX_ERROR if the device could not be
** opened
** This should attempt to open the highest quality output allowed by any options
** specified beforehand.
*/
int (*output)(sfx_pcm_device_t *self, byte *buf,
int count, sfx_timestamp_t *timestamp);
/* Writes output to the device
** Parameters: (sfx_pcm_device_t *) self: Self reference
** (byte *) buf: The buffer to write
** (int) count: Number of /frames/ that should be written
** (sfx_timestamp_t *) timestamp: Optional point in time
** for which the PCM data is scheduled
** Returns : (int) SFX_OK on success, SFX_ERROR on error
** The size of the buffer allocated as 'buf' equals buf_size.
** 'buf' is guaranteed not to be modified in between calls to 'output()'.
** 'timestamp' is guaranteed to be used only in sequential order, but not
** guaranteed to be used in all cases. It is guaranteed to be compaible with
** the sample rate used by the device itself (i.e., the sfx_time.h functionality
** is applicable)
*/
sfx_timestamp_t
(*get_output_timestamp)(sfx_pcm_device_t *self);
/* Determines the timestamp for 'output'
** Parameters: (sfx_pcm_device_t *) self: Self reference
** Returns : (sfx_timestamp_t) A timestamp (with the device's conf.rate)
** describing the point in time at which
** the next frame passed to 'output'
** will be played
** This function is OPTIONAL and may be NULL, but it is recommended
** that pcm device implementers attempt to really implement it.
*/
/* The following must be set after initialisation */
sfx_pcm_config_t conf;
int buf_size; /* Output buffer size, i.e. the number of frames (!)
** that can be queued by this driver before calling
** output() will block or fail, drained according
** to conf.rate */
};
#define PCM_FEED_TIMESTAMP 0 /* New timestamp available */
#define PCM_FEED_IDLE 1 /* No sound ATM, but new timestamp may be available later */
#define PCM_FEED_EMPTY 2 /* Feed is finished, can be destroyed */
struct sfx_pcm_feed_t {
/* PCM feeds are sources of input for the PCM mixer. Their member functions
** are invoked as callbacks on demand, to provide the mixer with input it
** (in turn) passes on to PCM output devices.
** PCM feeds must explicitly register themselves with the mixer in order
** to be considered.
*/
int (*poll)(sfx_pcm_feed_t *self, byte *dest, int size);
/* Asks the PCM feed to write out the next stuff it would like to have written
** Parameters: (sfx_pcm_feed_t *) self: Self reference
** (byte *) dest: The destination buffer to write to
** (int) size: The maximum number of _frames_ (not neccessarily bytes)
** to write
** Returns : (int) The number of frames written
** If the number of frames written is smaller than 'size', the PCM feed will
** be queried for a new timestamp afterwards, or destroyed if no new timestamp
** is available.
*/
void (*destroy)(sfx_pcm_feed_t *self);
/* Asks the PCM feed to free all resources it occupies
** Parameters: (sfx_pcm_feed_t *) self: Self reference
** free(self) should be part of this function, if applicable.
*/
int
(*get_timestamp)(sfx_pcm_feed_t *self, sfx_timestamp_t *timestamp);
/* Determines the timestamp of the next frame-to-read
** Returns : (sfx_timestamp_t) timestamp: The timestamp of the next frame
** (int) PCM_FEED_*
** This function is OPTIONAL and may be NULL
*/
void *internal; /* The private bits of a PCM feed. */
sfx_pcm_config_t conf; /* The channel's setup */
const char *debug_name; /* The channel name, for debugging */
int debug_nr; /* A channel number relative to the channel name, for debugging
** (print in hex) */
int frame_size; /* Frame size, computed by the mixer for the feed */
};
int sfx_pcm_available();
/* Determines whether a PCM device is available and has been initialised
** Returns : (int) zero iff no PCM device is available
*/
} // End of namespace Sci
#endif // SCI_SFX_SFX_PCM_H
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