| | Open Sound System |
| Do you have problems with sound/audio application development? Don't panic! Click here for help! |
This file is part of Open Sound System.
Copyright (C) 4Front Technologies 1996-2008.
This this source file is released under GPL v2 license (no other versions). See the COPYING file included in the main directory of this source distribution for the license terms and conditions.
#define SUPPORTED_FORMATS (AFMT_S16_NE | AFMT_S16_OE | AFMT_S32_NE | AFMT_S32_OE)
Maximum number of clients per "real" device is defined by MAX_CLIENTS. Limit of 4 would be good for 95% of systems. For each client there will be a mixer volume control and peak meter in the mixer interface. Raising the client limit will make the mixer interface larger and larger. Something like 8 is probably the practical limit for number of clients.
Mixing more than 16 streams together doesn't make much sense since the result is likely to be just noise. Mixing a stream will cause some overhead so it's not a good idea to let large number of iddle applications running muted or playing silence.
#define MAX_CLIENTS 9 #define MAX_LOOPDEVS 2 /* Maximum number of vmix loopback devices */
8 play channels and 2 rec channels might be OK for most devices. However envy24 requires 10 play and 12 rec channels for the "raw devices". Some professional (ADAT) cards like Digi96 requires 8+8 channels.
#define MAX_PLAY_CHANNELS 12
/* MAX_REC_CHANNELS must be less or equal than MAX_PLAY_CHANNELS */
#define MAX_REC_CHANNELS 12
#define CHBUF_SAMPLES 2048 /* Max samples (frames) per fragment */
typedef struct _vmix_mixer_t vmix_mixer_t;
typedef struct _vmix_portc_t vmix_portc_t;
typedef struct _vmix_engine_t vmix_engine_t;
struct _vmix_portc_t /* Audio device specific data */
{
int num;
vmix_mixer_t *mixer;
vmix_portc_t *next; /* Linked list for all portc structures */
int dev_type;
#define DT_IN 1
#define DT_OUT 2
#define DT_LOOP 3
int disabled_modes;
int fmt, bits;
int channels;
int rate;
int audio_dev;
int open_mode;
int trigger_bits;
int open_pending; /* Set to 1 by vmix_create_client() and cleared by vmix_open() */
int play_dma_pointer;
int play_choffs; /* Index of the first channel on multich play engines */
int rec_choffs; /* Index of the first channel on multich rec engines */
#ifdef CONFIG_OSS_VMIX_FLOAT
double play_dma_pointer_src;
#endif
int rec_dma_pointer;
int volume[2]; /* Left and right ch volumes */
int vu[2];
void (*play_mixing_func) (vmix_portc_t * portc, int nsamples);
void (*rec_mixing_func) (vmix_portc_t * portc, int nsamples);
int do_src;
};
#ifdef CONFIG_OSS_VMIX_FLOAT
typedef float vmix_sample_t;
#else
typedef int vmix_sample_t;
#endif
typedef void (*converter_t) (vmix_engine_t * engine, void *outbuf,
vmix_sample_t * chbufs[], int channels,
int samples);
struct _vmix_engine_t
{
int rate, channels, fmt, bits;
int max_playahead;
int fragsize;
int samples_per_frag;
converter_t converter;
vmix_sample_t *chbufs[MAX_PLAY_CHANNELS];
unsigned int limiter_statevar;
Mixer volumes, etc.
int outvol;
int vu[2];
int num_active_outputs;
};
struct _vmix_mixer_t /* Instance specific data */
{
vmix_mixer_t *next; /* Pointer to the next vmix instance */
int instance_num;
int disabled;
oss_device_t *osdev;
oss_device_t *master_osdev;
oss_mutex_t mutex;
unsigned int attach_flags;
int installed_ok;
int open_devices, open_inputs;
struct fileinfo master_finfo, input_finfo;
int masterdev_opened;
int vmix_flags; /* Copy of adev[master]->vmix_flags */
Config options for this instance
int masterdev; int inputdev; int rate; int src_quality; /* Control panel setting */ int multich_enable; /* Enable multi channel mode */ int max_channels; vmix_engine_t play_engine, record_engine; vmix_portc_t *client_portc[MAX_CLIENTS]; vmix_portc_t *loop_portc[MAX_LOOPDEVS]; int num_clientdevs, num_loopdevs;
Mixer interface
Mixer device numbers for the master audio devices
int output_mixer_dev; int input_mixer_dev; int first_input_mixext; int first_output_mixext; int client_mixer_group; /* Create the client controls under this mixer group */ }; extern void vmix_setup_play_engine (vmix_mixer_t * mixer, adev_t * adev, dmap_t * dmap); extern void vmix_setup_record_engine (vmix_mixer_t * mixer, adev_t * adev, dmap_t * dmap); extern void finalize_record_engine (vmix_mixer_t * mixer, int fmt, adev_t * adev, dmap_p dmap); extern void vmix_outmix_16ne (vmix_portc_t * portc, int nsamples); extern void vmix_outmix_16oe (vmix_portc_t * portc, int nsamples); extern void vmix_outmix_32ne (vmix_portc_t * portc, int nsamples); extern void vmix_outmix_32oe (vmix_portc_t * portc, int nsamples); #ifdef CONFIG_OSS_VMIX_FLOAT extern void vmix_outmix_float (vmix_portc_t * portc, int nsamples); #endif #ifdef CONFIG_OSS_VMIX_FLOAT
For the time being these routines will only work in floating point.
extern void vmix_outmix_16ne_src (vmix_portc_t * portc, int nsamples); extern void vmix_outmix_16oe_src (vmix_portc_t * portc, int nsamples); extern void vmix_outmix_32ne_src (vmix_portc_t * portc, int nsamples); extern void vmix_outmix_32oe_src (vmix_portc_t * portc, int nsamples); extern void vmix_outmix_float_src (vmix_portc_t * portc, int nsamples); #endif extern void vmix_rec_export_16ne (vmix_portc_t * portc, int nsamples); extern void vmix_rec_export_16oe (vmix_portc_t * portc, int nsamples); extern void vmix_rec_export_32ne (vmix_portc_t * portc, int nsamples); extern void vmix_rec_export_32oe (vmix_portc_t * portc, int nsamples); #ifdef CONFIG_OSS_VMIX_FLOAT extern void vmix_rec_export_float (vmix_portc_t * portc, int nsamples); #endif #define DB_SIZE 50 #define VMIX_VOL_SCALE 127 #ifdef CONFIG_OSS_VMIX_FLOAT extern const float vmix_db_table[DB_SIZE + 1]; #else extern const int vmix_db_table[DB_SIZE + 1]; #endif #ifdef VMIX_MAIN #include "db_scale.h" #endif #ifdef SWAP_SUPPORT
Endianess swapping functions
static __inline__ short
bswap16 (short x)
{
short y = 0;
unsigned char *a = ((unsigned char *) &x) + 1;
unsigned char *b = (unsigned char *) &y;
*b++ = *a--;
*b++ = *a--;
return y;
}
static __inline__ int
bswap32 (int x)
{
int y = 0;
unsigned char *a = ((unsigned char *) &x) + 3;
unsigned char *b = (unsigned char *) &y;
*b++ = *a--;
*b++ = *a--;
*b++ = *a--;
*b++ = *a--;
return y;
}
#endif