Adding volume control and moving control() call parameters to a seperate file

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@7746 b3059339-0415-0410-9bf9-f77b7e298cf2

1 files changed, 222 insertions, 0 deletions

diff --git a/libaf/af_volume.c b/libaf/af_volume.c
new file mode 100644
index 0000000000..7d0d2fd0f0
--- /dev/null
+++ b/libaf/af_volume.c
@@ -0,0 +1,222 @@
+/* This audio filter changes the volume of the sound, and can be used
+   when the mixer doesn't support the PCM channel. It can handel
+   between 1 and 6 channels. The volume can be adjusted between -60dB
+   to +10dB and is set on a per channels basis. The volume can be
+   written ad read by AF_CONTROL_VOLUME_SET and AF_CONTROL_VOLUME_GET
+   respectivly.
+
+   The plugin has support for softclipping, it is enabled by
+   AF_CONTROL_VOLUME_SOFTCLIPP. It has also a probing feature which
+   can be used to measure the power in the audio stream, both an
+   instantanious value and the maximum value can be probed. The
+   probing is enable by AF_CONTROL_VOLUME_PROBE_ON_OFF and is done on a
+   per channel basis. The result from the probing is obtained using
+   AF_CONTROL_VOLUME_PROBE_GET and AF_CONTROL_VOLUME_PROBE_GET_MAX. The
+   probed values are calculated in dB. The control of the volume can
+   be turned off by the AF_CONTROL_VOLUME_ON_OFF switch.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <unistd.h>
+#include <inttypes.h>
+#include <math.h>
+
+#include "../config.h"
+#include "../mp_msg.h"
+
+#include "af.h"
+
+// Some limits
+#define MIN_S16 -32650
+#define MAX_S16  32650
+
+#define MAX_VOL +10.0
+#define MIN_VOL	-60.0
+
+// Number of channels
+#define NCH 6
+
+#include "../libao2/afmt.h"
+
+
+// Data for specific instances of this filter
+typedef struct af_volume_s
+{
+  double volume[NCH];	// Volume for each channel
+  double power[NCH];	// Instantaneous power in each channel
+  double maxpower[NCH];	// Maximum power in each channel
+  double alpha;		// Forgetting factor for power estimate
+  int softclip;		// Soft clippng on/off
+  int probe;		// Probing on/off
+  int onoff;		// Volume control on/off
+}af_volume_t;
+
+/* Convert to gain value from dB. Returns AF_OK if of and AF_ERROR if
+   fail */
+inline int from_dB(double* in, double* out) 
+{
+  int i = 0; 
+  // Sanity check
+  if(!in || !out) 
+    return AF_ERROR;
+
+  for(i=0;i<NCH;i++) 
+    out[i]=pow(10.0,clamp(in[i],MIN_VOL,MAX_VOL)/10.0);
+  return AF_OK;
+}
+
+/* Convert from gain value to dB. Returns AF_OK if of and AF_ERROR if
+   fail */
+inline int to_dB(double* in, double* out) 
+{
+  int i = 0; 
+  // Sanity check
+  if(!in || !out) 
+    return AF_ERROR;
+
+  for(i=0;i<NCH;i++) 
+    out[i]=10.0*log10(clamp(in[i],MIN_VOL,MAX_VOL));
+  return AF_OK;
+}
+
+// Initialization and runtime control
+static int control(struct af_instance_s* af, int cmd, void* arg)
+{
+  af_volume_t* s   = (af_volume_t*)af->setup; 
+
+  switch(cmd){
+  case AF_CONTROL_REINIT:
+    // Sanity check
+    if(!arg) return AF_ERROR;
+    
+    af->data->rate   = ((af_data_t*)arg)->rate;
+    af->data->nch    = ((af_data_t*)arg)->nch;
+    af->data->format = AFMT_S16_LE;
+    af->data->bps    = 2;
+    
+    // Time constant set to 0.1s
+    s->alpha = (1.0/0.2)/(2.0*M_PI*(double)((af_data_t*)arg)->rate); 
+
+    // Only AFMT_S16_LE is supported for now
+    if(af->data->format != ((af_data_t*)arg)->format || 
+       af->data->bps != ((af_data_t*)arg)->bps)
+      return AF_FALSE;
+    return AF_OK;
+  case AF_CONTROL_VOLUME_SET:
+    return from_dB((double*)arg,s->volume);
+  case AF_CONTROL_VOLUME_GET:
+    return to_dB(s->volume,(double*)arg);
+  case AF_CONTROL_VOLUME_PROBE_GET:
+    return to_dB(s->power,(double*)arg);
+  case AF_CONTROL_VOLUME_PROBE_GET_MAX:
+    return to_dB(s->maxpower,(double*)arg);
+  case AF_CONTROL_VOLUME_SOFTCLIP:
+    s->softclip = (int)arg;
+    return AF_OK;
+  case AF_CONTROL_VOLUME_PROBE_ON_OFF:
+    s->probe = (int)arg;
+    return AF_OK;
+  case AF_CONTROL_VOLUME_ON_OFF:
+    s->onoff = (int)arg;
+    return AF_OK;
+  }
+  return AF_UNKNOWN;
+}
+
+// Deallocate memory 
+static void uninit(struct af_instance_s* af)
+{
+  if(af->data)
+    free(af->data);
+  if(af->setup)
+    free(af->setup);
+}
+
+// Filter data through filter
+static af_data_t* play(struct af_instance_s* af, af_data_t* data)
+{
+  af_data_t*     c = data;			// Current working data
+  af_volume_t*   s = (af_volume_t*)af->setup; 	// Setup for this instance
+  int16_t*       a = (int16_t*)c->audio;	// Audio data
+  int          len = c->len/2;			// Number of samples
+  int           ch = 0;				// Channel counter
+  register int nch = c->nch;			// Number of channels	
+  register int   i = 0;
+  
+  // Probe the data stream 
+  if(s->probe){
+    for(ch = 0; ch < nch ; ch++){
+      double alpha  = s->alpha;
+      double beta   = 1 - alpha;
+      double pow    = s->power[ch];
+      double maxpow = s->maxpower[ch];
+      register double t = 0;
+      for(i=ch;i<len;i+=nch){
+	t = ((double)a[i])/32768.0;
+	t *= t;
+	// Check maximum power value
+	if(t>maxpow) 
+	  maxpow=t;
+	// Power estimate made using first order AR model
+	if(t>pow)
+	  pow=t;
+	else
+	  pow = beta*pow+alpha*t;
+      }
+      s->power[ch]    = pow;
+      s->maxpower[ch] = maxpow;
+    }
+  }
+
+  // Change the volume.
+  if(s->onoff){
+    register int sc  = s->softclip;
+    for(ch = 0; ch < nch ; ch++){
+      register int vol = (int)(255.0 * s->volume[ch]); 
+      for(i=ch;i<len;i+=nch){
+	register int x;
+	x=(a[i] * vol) >> 8;
+	if(sc){
+	  int64_t t=x*x;
+	  t=(t*x) >> 30;
+	  x = (3*x - (int)t) >> 1;
+	}
+	a[i]=clamp(x,MIN_S16,MAX_S16);
+      }
+    }
+  }
+
+  return c;
+}
+
+// Allocate memory and set function pointers
+static int open(af_instance_t* af){
+  int i = 0;
+  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_volume_t));
+  if(af->data == NULL || af->setup == NULL)
+    return AF_ERROR;
+  // Enable volume control and set initial volume to 0.1
+  ((af_volume_t*)af->setup)->onoff = 1;
+  for(i=0;i<NCH;i++)
+    ((af_volume_t*)af->setup)->volume[i]=0.1;
+
+  return AF_OK;
+}
+
+// Description of this filter
+af_info_t af_info_volume = {
+    "Volume control audio filter",
+    "volume",
+    "Anders",
+    "",
+    AF_FLAGS_NOT_REENTRANT,
+    open
+};