/*
*
* ao_au.c
*
* Copyright (C) Wil Mahan - May 2001
*
* This file is part of libao, a cross-platform audio output library. See
* README for a history of this source code.
*
* libao 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, or (at your option)
* any later version.
*
* libao 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 GNU Make; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*
********************************************************************
last mod: $Id: ao_au.c 18200 2012-02-14 00:44:01Z ph3-der-loewe $
********************************************************************/
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#ifndef _MSC_VER
# include <unistd.h>
#endif
#include <ao/ao.h>
#include <ao/plugin.h>
#define AUDIO_FILE_MAGIC ((uint_32)0x2e736e64) /* ".snd" */
#define AUDIO_UNKNOWN_SIZE (~0) /* (unsigned) -1 */
/* Format codes (not comprehensive) */
#define AUDIO_FILE_ENCODING_LINEAR_8 (2) /* 8-bit linear PCM */
#define AUDIO_FILE_ENCODING_LINEAR_16 (3) /* 16-bit linear PCM */
#define AU_HEADER_LEN (28)
#define DEFAULT_SWAP_BUFFER_SIZE 2048
/* Write a uint_32 in big-endian order. */
#define WRITE_U32(buf, x) \
*(buf) = (unsigned char)(((x)>>24)&0xff);\
*((buf)+1) = (unsigned char)(((x)>>16)&0xff);\
*((buf)+2) = (unsigned char)(((x)>>8)&0xff);\
*((buf)+3) = (unsigned char)((x)&0xff);
typedef struct Audio_filehdr {
uint_32 magic; /* magic number */
uint_32 hdr_size; /* offset of the data */
uint_32 data_size; /* length of data (optional) */
uint_32 encoding; /* data format code */
uint_32 sample_rate; /* samples per second */
uint_32 channels; /* number of interleaved channels */
char info[4]; /* optional text information */
} Audio_filehdr;
static char *ao_au_options[] = {"matrix","verbose","quiet","debug"};
static ao_info ao_au_info =
{
AO_TYPE_FILE,
"AU file output",
"au",
"Wil Mahan <wtm2@duke.edu>",
"Sends output to a .au file",
AO_FMT_BIG,
0,
ao_au_options,
sizeof(ao_au_options)/sizeof(*ao_au_options)
};
typedef struct ao_au_internal
{
Audio_filehdr au;
} ao_au_internal;
static int ao_au_test(void)
{
return 1; /* File driver always works */
}
static ao_info *ao_au_driver_info(void)
{
return &ao_au_info;
}
static int ao_au_device_init(ao_device *device)
{
ao_au_internal *internal;
internal = (ao_au_internal *) malloc(sizeof(ao_au_internal));
if (internal == NULL)
return 0; /* Could not initialize device memory */
memset(&(internal->au), 0, sizeof(internal->au));
device->internal = internal;
device->output_matrix_order = AO_OUTPUT_MATRIX_FIXED;
return 1; /* Memory alloc successful */
}
static int ao_au_set_option(ao_device *device, const char *key,
const char *value)
{
return 1; /* No options! */
}
static int ao_au_open(ao_device *device, ao_sample_format *format)
{
ao_au_internal *internal = (ao_au_internal *) device->internal;
unsigned char buf[AU_HEADER_LEN];
/* The AU format is big-endian */
device->driver_byte_format = AO_FMT_BIG;
/* Fill out the header */
internal->au.magic = AUDIO_FILE_MAGIC;
internal->au.channels = device->output_channels;
if (format->bits == 8)
internal->au.encoding = AUDIO_FILE_ENCODING_LINEAR_8;
else if (format->bits == 16)
internal->au.encoding = AUDIO_FILE_ENCODING_LINEAR_16;
else {
/* Only 8 and 16 bits are supported at present. */
return 0;
}
internal->au.sample_rate = format->rate;
internal->au.hdr_size = AU_HEADER_LEN;
/* From the AU specification: "When audio files are passed
* through pipes, the 'data_size' field may not be known in
* advance. In such cases, the 'data_size' should be set
* to AUDIO_UNKNOWN_SIZE."
*/
internal->au.data_size = AUDIO_UNKNOWN_SIZE;
/* strncpy(state->au.info, "OGG ", 4); */
/* Write the header in big-endian order */
WRITE_U32(buf, internal->au.magic);
WRITE_U32(buf + 4, internal->au.hdr_size);
WRITE_U32(buf + 8, internal->au.data_size);
WRITE_U32(buf + 12, internal->au.encoding);
WRITE_U32(buf + 16, internal->au.sample_rate);
WRITE_U32(buf + 20, internal->au.channels);
strncpy (buf + 24, internal->au.info, 4);
if (fwrite(buf, sizeof(char), AU_HEADER_LEN, device->file)
!= AU_HEADER_LEN) {
return 0; /* Error writing header */
}
if(!device->inter_matrix){
/* set up matrix such that users are warned about > stereo playback */
if(device->output_channels<=2)
device->inter_matrix=strdup("L,R");
//else no matrix, which results in a warning
}
return 1;
}
/*
* play the sample to the already opened file descriptor
*/
static int ao_au_play(ao_device *device, const char *output_samples,
uint_32 num_bytes)
{
if (fwrite(output_samples, sizeof(char), num_bytes,
device->file) < num_bytes)
return 0;
else
return 1;
}
static int ao_au_close(ao_device *device)
{
ao_au_internal *internal = (ao_au_internal *) device->internal;
off_t size;
unsigned char buf[4];
/* Try to find the total file length, including header */
size = ftell(device->file);
/* It's not a problem if the lseek() fails; the AU
* format does not require a file length. This is
* useful for writing to non-seekable files (e.g.
* pipes).
*/
if (size > 0) {
internal->au.data_size = size - AU_HEADER_LEN;
/* Rewind the file */
if (fseek(device->file, 8 /* offset of data_size */,
SEEK_SET) < 0)
{
return 1; /* Seek failed; that's okay */
}
/* Fill in the file length */
WRITE_U32 (buf, internal->au.data_size);
if (fwrite(buf, sizeof(char), 4, device->file) < 4) {
return 1; /* Header write failed; that's okay */
}
}
return 1;
}
static void ao_au_device_clear(ao_device *device)
{
ao_au_internal *internal = (ao_au_internal *) device->internal;
free(internal);
device->internal=NULL;
}
const char *ao_au_file_extension(void)
{
return "au";
}
ao_functions ao_au = {
ao_au_test,
ao_au_driver_info,
ao_au_device_init,
ao_au_set_option,
ao_au_open,
ao_au_play,
ao_au_close,
ao_au_device_clear,
ao_au_file_extension
};