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, 160 insertions, 0 deletions

diff --git a/libaf/af.h b/libaf/af.h
new file mode 100644
index 0000000000..b0ea7b710a
--- /dev/null
+++ b/libaf/af.h
@@ -0,0 +1,160 @@
+#ifndef __aop_h__
+#define __aop_h__
+
+struct af_instance_s;
+
+// Audio data chunk
+typedef struct af_data_s
+{
+  void* audio;  // data buffer
+  int len;      // buffer length
+  int rate;	// sample rate
+  int nch;	// number of channels
+  int format;	// format
+  int bps; 	// bytes per sample
+} af_data_t;
+
+// Fraction, used to calculate buffer lengths
+typedef struct frac_s
+{
+  int n; // Numerator
+  int d; // Denominator
+} frac_t;
+
+/* Audio filter information not specific for current instance, but for
+   a specific filter */ 
+typedef struct af_info_s 
+{
+  const char *info;
+  const char *name;
+  const char *author;
+  const char *comment;
+  int (*open)(struct af_instance_s* vf);
+} af_info_t;
+
+// Linked list of audio filters
+typedef struct af_instance_s
+{
+  af_info_t* info;
+  int (*control)(struct af_instance_s* af, int cmd, void* arg);
+  void (*uninit)(struct af_instance_s* af);
+  af_data_t* (*play)(struct af_instance_s* af, af_data_t* data);
+  void* setup;	  // setup data for this specific instance and filter
+  af_data_t* data; // configuration for outgoing data stream
+  struct af_instance_s* next;
+  struct af_instance_s* prev;  
+  frac_t mul; /* length multiplier: how much does this instance change
+		 the length of the buffer. */
+}af_instance_t;
+
+/*********************************************
+// Control parameters 
+*/
+
+/* The control system is divided into 3 levels 
+   mandatory calls 	 - all filters must answer to all of these
+   optional calls  	 - are optional
+   filter specific calls - applies only to some filters
+*/
+
+#define AF_CONTROL_MANDATORY_BASE	0
+#define AF_CONTROL_OPTIONAL_BASE	100
+#define AF_CONTROL_FILTER_SPECIFIC_BASE	200
+
+// MANDATORY CALLS
+
+/* Reinitialize filter. The optional argument contains the new
+   configuration in form of a af_data_t struct. If the filter does not
+   support the new format the struct should be changed and AF_FALSE
+   should be returned. If the incoming and outgoing data streams are
+   identical the filter can return AF_DETACH. This will remove the
+   filter. */
+#define AF_CONTROL_REINIT  		1 + AF_CONTROL_MANDATORY_BASE
+
+// OPTIONAL CALLS
+
+
+// FILTER SPECIFIC CALLS
+
+// Set output rate in resample
+#define AF_CONTROL_RESAMPLE		1 + AF_CONTROL_FILTER_SPECIFIC_BASE
+// Set output format in format
+#define AF_CONTROL_FORMAT		2 + AF_CONTROL_FILTER_SPECIFIC_BASE
+// Set number of output channels in channels
+#define AF_CONTROL_CHANNELS		3 + AF_CONTROL_FILTER_SPECIFIC_BASE
+// Set delay length in delay
+#define AF_CONTROL_SET_DELAY_LEN	4 + AF_CONTROL_FILTER_SPECIFIC_BASE
+/*********************************************
+// Return values
+*/
+
+#define AF_DETACH   2
+#define AF_OK       1
+#define AF_TRUE     1
+#define AF_FALSE    0
+#define AF_UNKNOWN -1
+#define AF_ERROR   -2
+#define AF_NA      -3
+
+
+/*********************************************
+// Command line configuration switches
+*/
+typedef struct af_cfg_s{
+  int rate;
+  int format;
+  int bps;
+  int force;
+  char** list;
+}af_cfg_t;
+
+
+// Export functions
+
+/* Init read configuration and create filter list accordingly. In and
+   out contains the format of the current movie and the formate of the
+   prefered output respectively */
+int af_init(af_data_t* in, af_data_t* out);
+// Uninit and remove all filters
+void af_uninit();
+// Filter data chunk through the filters in the list
+af_data_t* af_play(af_data_t* data);
+/* Calculate how long the output from the filters will be given the
+   input length "len" */
+int af_outputlen(int len);
+/* Calculate how long the input to the filters should be to produce a
+   certain output length, i.e. the return value of this function is
+   the input length required to produce the output length "len". */
+int af_inputlen(int len);
+
+
+
+// Helper functions and macros used inside the audio filters
+
+/* Helper function called by the macro with the same name only to be
+   called from inside filters */
+int af_resize_local_buffer(af_instance_t* af, af_data_t* data);
+
+/* Helper function used to calculate the exact buffer length needed
+   when buffers are resized */
+int af_lencalc(frac_t mul, int len);
+
+/* Memory reallocation macro: if a local buffer is used (i.e. if the
+   filter doesn't operate on the incoming buffer this macro must be
+   called to ensure the buffer is big enough. */
+#define RESIZE_LOCAL_BUFFER(a,d)\
+((af->data->len < af_lencalc(af->mul,data->len))?af_resize_local_buffer(af,data):AF_OK)
+
+#ifndef min
+#define min(a,b)(((a)>(b))?(b):(a))
+#endif
+
+#ifndef max
+#define max(a,b)(((a)>(b))?(a):(b))
+#endif
+
+#ifndef AUDIO_FILTER
+extern af_cfg_t af_cfg;
+#endif /* AUDIO_FILTER */
+
+#endif