Adding new audio output filter layer libaf

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@7569 b3059339-0415-0410-9bf9-f77b7e298cf2

1 files changed, 146 insertions, 0 deletions

diff --git a/libaf/af_delay.c b/libaf/af_delay.c
new file mode 100644
index 0000000000..d25e6ed7f2
--- /dev/null
+++ b/libaf/af_delay.c
@@ -0,0 +1,146 @@
+/* This audio filter doesn't really do anything useful but serves an
+   example of how audio filters work. It delays the output signal by
+   the number of seconds set by delay=n where n is the number of
+   seconds.
+*/
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "../config.h"
+#include "../mp_msg.h"
+
+#include "af.h"
+
+// Data for specific instances of this filter
+typedef struct af_delay_s
+{
+  void* buf; 	    // data block used for delaying audio signal
+  int   len;        // local buffer length
+  float tlen;       // Delay in seconds
+}af_delay_t;
+
+// Initialization and runtime control
+static int control(struct af_instance_s* af, int cmd, void* arg)
+{
+  switch(cmd){
+  case AF_CONTROL_REINIT:{
+    af->data->rate   = ((af_data_t*)arg)->rate;
+    af->data->nch    = ((af_data_t*)arg)->nch;
+    af->data->format = ((af_data_t*)arg)->format;
+    af->data->bps    = ((af_data_t*)arg)->bps;
+    
+    return af->control(af,AF_CONTROL_SET_DELAY_LEN,&((af_delay_t*)af->setup)->tlen);
+  }
+  case AF_CONTROL_SET_DELAY_LEN:{
+    af_delay_t* s  = (af_delay_t*)af->setup;
+    void*       bt = s->buf; // Old buffer
+    int         lt = s->len; // Old len
+
+    if(*((float*)arg) > 30 || *((float*)arg) < 0){
+      mp_msg(MSGT_AFILTER,MSGL_ERR,"Error setting delay length in af_delay. Delay must be between 0s and 30s\n");
+      s->len=0;
+      s->tlen=0.0;
+      return AF_ERROR;
+    }
+
+    // Set new len and allocate new buffer
+    s->tlen = *((float*)arg);
+    s->len  = af->data->rate*af->data->bps*af->data->nch*(int)s->tlen;
+    s->buf  = malloc(s->len);
+    mp_msg(MSGT_AFILTER,MSGL_DBG2,"[delay] Delaying audio output by %0.2fs\n",s->tlen);
+    mp_msg(MSGT_AFILTER,MSGL_DBG3,"[delay] Delaying audio output by %i bytes\n",s->len);
+
+    // Out of memory error
+    if(!s->buf){
+      s->len = 0;
+      free(bt);
+      return AF_ERROR;
+    }
+      
+    // Clear the new buffer
+    memset(s->buf, 0, s->len);
+    
+    /* Copy old buffer to avoid click in output 
+       sound (at least most of it) and release it */
+    if(bt){
+      memcpy(s->buf,bt,min(lt,s->len));
+      free(bt);
+    }
+    return AF_OK;
+  }
+  }
+  return AF_UNKNOWN;
+}
+
+// Deallocate memory 
+static void uninit(struct af_instance_s* af)
+{
+  if(af->data->audio)
+    free(af->data->audio);
+  if(af->data)
+    free(af->data);
+  if(((af_delay_t*)(af->setup))->buf)
+    free(((af_delay_t*)(af->setup))->buf);
+  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_data_t*   l = af->data;	 		// Local data
+  af_delay_t*  s = (af_delay_t*)af->setup; 	// Setup for this instance
+ 
+  
+  if(AF_OK != RESIZE_LOCAL_BUFFER(af , data))
+    return NULL;
+  
+  if(s->len > c->len){ // Delay bigger than buffer
+    // Copy beginning of buffer to beginning of output buffer
+    memcpy(l->audio,s->buf,c->len);
+    // Move buffer left
+    memcpy(s->buf,s->buf+c->len,s->len-c->len);
+    // Save away current audio to end of buffer
+    memcpy(s->buf+s->len-c->len,c->audio,c->len);
+  }
+  else{
+    // Copy end of previous block to beginning of output buffer
+    memcpy(l->audio,s->buf,s->len);
+    // Copy current block except end
+    memcpy(l->audio+s->len,c->audio,c->len-s->len);
+    // Save away end of current block for next call
+    memcpy(s->buf,c->audio+c->len-s->len,s->len);
+  }
+  
+  // Set output data
+  c->audio=l->audio;
+
+  return c;
+}
+
+// Allocate memory and set function pointers
+static int 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_delay_t));
+  if(af->data == NULL || af->setup == NULL)
+    return AF_ERROR;
+  return AF_OK;
+}
+
+// Description of this filter
+af_info_t af_info_delay = {
+    "Delay audio filter",
+    "delay",
+    "Anders",
+    "",
+    open
+};
+
+