mpv/libaf/af_export.c

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/* This audio filter exports the incomming signal to other processes
using memory mapping. Memory mapped area contains a header:
int nch,
int size,
unsigned long long counter (updated every time the contents of
the area changes),
the rest is payload (non-interleaved).
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>
#include <unistd.h>
#include "config.h"
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "af.h"
#include "get_path.h"
#define DEF_SZ 512 // default buffer size (in samples)
#define SHARED_FILE "mplayer-af_export" /* default file name
(relative to ~/.mplayer/ */
#define SIZE_HEADER (2 * sizeof(int) + sizeof(unsigned long long))
// Data for specific instances of this filter
typedef struct af_export_s
{
unsigned long long count; // Used for sync
void* buf[AF_NCH]; // Buffers for storing the data before it is exported
int sz; // Size of buffer in samples
int wi; // Write index
int fd; // File descriptor to shared memory area
char* filename; // File to export data
void* mmap_area; // MMap shared area
} af_export_t;
/* Initialization and runtime control
af audio filter instance
cmd control command
arg argument
*/
static int control(struct af_instance_s* af, int cmd, void* arg)
{
af_export_t* s = af->setup;
switch (cmd){
case AF_CONTROL_REINIT:{
int i=0;
int mapsize;
// Free previous buffers
if (s->buf && s->buf[0])
free(s->buf[0]);
// unmap previous area
if(s->mmap_area)
munmap(s->mmap_area, SIZE_HEADER + (af->data->bps*s->sz*af->data->nch));
// close previous file descriptor
if(s->fd)
close(s->fd);
// Accept only int16_t as input format (which sucks)
af->data->rate = ((af_data_t*)arg)->rate;
af->data->nch = ((af_data_t*)arg)->nch;
af->data->format = AF_FORMAT_S16_NE;
af->data->bps = 2;
// If buffer length isn't set, set it to the default value
if(s->sz == 0)
s->sz = DEF_SZ;
// Allocate new buffers (as one continuous block)
s->buf[0] = calloc(s->sz*af->data->nch, af->data->bps);
if(NULL == s->buf[0])
af_msg(AF_MSG_FATAL, "[export] Out of memory\n");
for(i = 1; i < af->data->nch; i++)
s->buf[i] = s->buf[0] + i*s->sz*af->data->bps;
// Init memory mapping
s->fd = open(s->filename, O_RDWR | O_CREAT | O_TRUNC, 0640);
af_msg(AF_MSG_INFO, "[export] Exporting to file: %s\n", s->filename);
if(s->fd < 0)
af_msg(AF_MSG_FATAL, "[export] Could not open/create file: %s\n",
s->filename);
// header + buffer
mapsize = (SIZE_HEADER + (af->data->bps * s->sz * af->data->nch));
// grow file to needed size
for(i = 0; i < mapsize; i++){
char null = 0;
write(s->fd, (void*) &null, 1);
}
// mmap size
s->mmap_area = mmap(0, mapsize, PROT_READ|PROT_WRITE,MAP_SHARED, s->fd, 0);
if(s->mmap_area == NULL)
af_msg(AF_MSG_FATAL, "[export] Could not mmap file %s\n", s->filename);
af_msg(AF_MSG_INFO, "[export] Memory mapped to file: %s (%p)\n",
s->filename, s->mmap_area);
// Initialize header
*((int*)s->mmap_area) = af->data->nch;
*((int*)s->mmap_area + 1) = s->sz * af->data->bps * af->data->nch;
msync(s->mmap_area, mapsize, MS_ASYNC);
// Use test_output to return FALSE if necessary
return af_test_output(af, (af_data_t*)arg);
}
case AF_CONTROL_COMMAND_LINE:{
int i=0;
char *str = arg;
if (!str){
if(s->filename)
free(s->filename);
s->filename = get_path(SHARED_FILE);
return AF_OK;
}
while((str[i]) && (str[i] != ':'))
i++;
if(s->filename)
free(s->filename);
s->filename = calloc(i + 1, 1);
memcpy(s->filename, str, i);
s->filename[i] = 0;
sscanf(str + i + 1, "%d", &(s->sz));
return af->control(af, AF_CONTROL_EXPORT_SZ | AF_CONTROL_SET, &s->sz);
}
case AF_CONTROL_EXPORT_SZ | AF_CONTROL_SET:
s->sz = * (int *) arg;
if((s->sz <= 0) || (s->sz > 2048))
af_msg( AF_MSG_ERROR, "[export] Buffer size must be between"
" 1 and 2048\n" );
return AF_OK;
case AF_CONTROL_EXPORT_SZ | AF_CONTROL_GET:
*(int*) arg = s->sz;
return AF_OK;
}
return AF_UNKNOWN;
}
/* Free allocated memory and clean up other stuff too.
af audio filter instance
*/
static void uninit( struct af_instance_s* af )
{
if (af->data){
free(af->data);
af->data = NULL;
}
if(af->setup){
af_export_t* s = af->setup;
if (s->buf && s->buf[0])
free(s->buf[0]);
// Free mmaped area
if(s->mmap_area)
munmap(s->mmap_area, sizeof(af_export_t));
if(s->fd > -1)
close(s->fd);
if(s->filename)
free(s->filename);
free(af->setup);
af->setup = NULL;
}
}
/* Filter data through filter
af audio filter instance
data audio data
*/
static af_data_t* play( struct af_instance_s* af, af_data_t* data )
{
af_data_t* c = data; // Current working data
af_export_t* s = af->setup; // Setup for this instance
int16_t* a = c->audio; // Incomming sound
int nch = c->nch; // Number of channels
int len = c->len/c->bps; // Number of sample in data chunk
int sz = s->sz; // buffer size (in samples)
int flag = 0; // Set to 1 if buffer is filled
int ch, i;
// Fill all buffers
for(ch = 0; ch < nch; ch++){
int wi = s->wi; // Reset write index
int16_t* b = s->buf[ch]; // Current buffer
// Copy data to export buffers
for(i = ch; i < len; i += nch){
b[wi++] = a[i];
if(wi >= sz){ // Don't write outside the end of the buffer
flag = 1;
break;
}
}
s->wi = wi % s->sz;
}
// Export buffer to mmaped area
if(flag){
// update buffer in mapped area
memcpy(s->mmap_area + SIZE_HEADER, s->buf[0], sz * c->bps * nch);
s->count++; // increment counter (to sync)
memcpy(s->mmap_area + SIZE_HEADER - sizeof(s->count),
&(s->count), sizeof(s->count));
}
// We don't modify data, just export it
return data;
}
/* Allocate memory and set function pointers
af audio filter instance
returns AF_OK or AF_ERROR
*/
static int af_open( af_instance_t* af )
{
af->control = control;
af->uninit = uninit;
af->play = play;
af->mul.n = 1;
af->mul.d = 1;
af->data = calloc(1, sizeof(af_data_t));
af->setup = calloc(1, sizeof(af_export_t));
if((af->data == NULL) || (af->setup == NULL))
return AF_ERROR;
((af_export_t *)af->setup)->filename = get_path(SHARED_FILE);
return AF_OK;
}
// Description of this filter
af_info_t af_info_export = {
"Sound export filter",
"export",
"Anders; Gustavo Sverzut Barbieri <gustavo.barbieri@ic.unicamp.br>",
"",
AF_FLAGS_REENTRANT,
af_open
};