Comment out the correct #endif directive.
[mplayer/greg.git] / libaf / af_center.c
blobdd9f624ebe6eebd7722d9996ae968883ba8daa70
1 /*
2 (C) Alex Beregszaszi
3 License: GPL
5 This filter adds a center channel to the audio stream by
6 averaging the left and right channel.
7 There are two runtime controls one for setting which channel to
8 insert the center-audio into called AF_CONTROL_SUB_CH.
10 FIXME: implement a high-pass filter for better results.
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <string.h>
17 #include "af.h"
19 // Data for specific instances of this filter
20 typedef struct af_center_s
22 int ch; // Channel number which to insert the filtered data
23 }af_center_t;
25 // Initialization and runtime control
26 static int control(struct af_instance_s* af, int cmd, void* arg)
28 af_center_t* s = af->setup;
30 switch(cmd){
31 case AF_CONTROL_REINIT:{
32 // Sanity check
33 if(!arg) return AF_ERROR;
35 af->data->rate = ((af_data_t*)arg)->rate;
36 af->data->nch = max(s->ch+1,((af_data_t*)arg)->nch);
37 af->data->format = AF_FORMAT_FLOAT_NE;
38 af->data->bps = 4;
40 return af_test_output(af,(af_data_t*)arg);
42 case AF_CONTROL_COMMAND_LINE:{
43 int ch=1;
44 sscanf(arg,"%i", &ch);
45 return control(af,AF_CONTROL_CENTER_CH | AF_CONTROL_SET, &ch);
47 case AF_CONTROL_CENTER_CH | AF_CONTROL_SET: // Requires reinit
48 // Sanity check
49 if((*(int*)arg >= AF_NCH) || (*(int*)arg < 0)){
50 af_msg(AF_MSG_ERROR,"[sub] Center channel number must be between "
51 " 0 and %i current value is %i\n", AF_NCH-1, *(int*)arg);
52 return AF_ERROR;
54 s->ch = *(int*)arg;
55 return AF_OK;
56 case AF_CONTROL_CENTER_CH | AF_CONTROL_GET:
57 *(int*)arg = s->ch;
58 return AF_OK;
60 return AF_UNKNOWN;
63 // Deallocate memory
64 static void uninit(struct af_instance_s* af)
66 if(af->data)
67 free(af->data);
68 if(af->setup)
69 free(af->setup);
72 // Filter data through filter
73 static af_data_t* play(struct af_instance_s* af, af_data_t* data)
75 af_data_t* c = data; // Current working data
76 af_center_t* s = af->setup; // Setup for this instance
77 float* a = c->audio; // Audio data
78 int len = c->len/4; // Number of samples in current audio block
79 int nch = c->nch; // Number of channels
80 int ch = s->ch; // Channel in which to insert the center audio
81 register int i;
83 // Run filter
84 for(i=0;i<len;i+=nch){
85 // Average left and right
86 a[i+ch] = (a[i]/2) + (a[i+1]/2);
89 return c;
92 // Allocate memory and set function pointers
93 static int af_open(af_instance_t* af){
94 af_center_t* s;
95 af->control=control;
96 af->uninit=uninit;
97 af->play=play;
98 af->mul=1;
99 af->data=calloc(1,sizeof(af_data_t));
100 af->setup=s=calloc(1,sizeof(af_center_t));
101 if(af->data == NULL || af->setup == NULL)
102 return AF_ERROR;
103 // Set default values
104 s->ch = 1; // Channel nr 2
105 return AF_OK;
108 // Description of this filter
109 af_info_t af_info_center = {
110 "Audio filter for adding a center channel",
111 "center",
112 "Alex Beregszaszi",
114 AF_FLAGS_NOT_REENTRANT,
115 af_open