Try to establish a more generic low level soundcard/ISDN/winmodem hardware

abstraction layer at the most fundamental level.

amodemd.c

@@ -197,7 +197,7 @@ void main(int ac, char **av)
 	mh = modem_initialize();
 
 	linedriver = ifax_create_module(IFAX_LINEDRIVER);
-	ifax_command(linedriver,CMD_LINEDRIVER_ISDN,hh);
+	ifax_command(linedriver,CMD_LINEDRIVER_HARDWARE,hh);
 
 	/* ifax_command(linedriver,CMD_LINEDRIVER_AUDIO); */
 	/* ifax_command(linedriver,CMD_LINEDRIVER_RECORD,"modem.dat"); */

include/ifax/misc/hardware-driver.h

@@ -98,11 +98,11 @@ struct HardwareHandle {
 
 	/* Read a number of samples from the hardware driver.
 	 */
-	void (*read)(struct HardwareHandle *hh, ifax_uint8 *samples);
+	void (*read)(struct HardwareHandle *hh, ifax_uint8 *smpls, int cnt);
 
 	/* Write a number of (16-bit signed) samples to the hardware driver.
 	 */
-	void (*write)(struct HardwareHandle *hh, ifax_sint16 *samples);
+	void (*write)(struct HardwareHandle *hh, ifax_sint16 *smpls, int cnt);
 
 	/* Supply the hardware driver with configuration parameters.
 	 */

misc/isdnline.c

@@ -34,6 +34,8 @@
  * and work with the hardware abstraction layer in 'hardware-driver.c'
  */
 
+#define _GNU_SOURCE
+
 #define FSM_DEBUG_STATES
 
 #include <stdio.h>
@@ -178,27 +180,33 @@ static void isdn_service_select(struct HardwareHandle *hh, fd_set *rfd,
 }
 
 
-/* Write a set of voice samples to the ISDN device.  The samples are in the
+/*
+ * Write a set of voice samples to the ISDN device.  The samples are in the
  * form of an array, containing 16-bit signed, linear values.
  * The array is *modified* by this function to the linear values actually
  * transmitted.  This is to help an echo cancel function to work on the true
  * values as sent over the ISDN line to the remote end.
- *
- * The number of samples that needs to be sent is dictated by the value
- * in the hardware driver handle: hh->write_size.  This function will assume
- * there are exactly this many samples in the 'src' array.
  */
 
-static void isdn_write_samples(struct HardwareHandle *hh, ifax_sint16 *src)
+#define ISDN_MAX_WRITE	4096
+
+static void isdn_write_samples(struct HardwareHandle *hh,
+			       ifax_sint16 *src, int cnt)
 {
 	struct IsdnHandle *ih = hh->private;
 	ifax_uint8 *dst, wala;
 	ifax_uint16 linear;
-	int t;
+	ifax_uint8 tmp[2 * ISDN_MAX_WRITE];
 
-	dst = &ih->tmp_write[0];
+	if ( cnt > ISDN_MAX_WRITE ) {
+	  ifax_dprintf(DEBUG_ERROR,"Dropping %d samples in isdn_write_samples",
+		       cnt - ISDN_MAX_WRITE);
+	  cnt = ISDN_MAX_WRITE;
+	}
 
-	for ( t=0; t < hh->write_size; t++ ) {
+	dst = &tmp[0];
+
+	while ( cnt-- > 0 ) {
 
 		linear = (ifax_uint16) *src;
 		wala = sint2wala[linear>>4];
@@ -209,8 +217,7 @@ static void isdn_write_samples(struct HardwareHandle *hh, ifax_sint16 *src)
 		*dst++ = wala;
 	}
 
-	iobuffer_fill(ih->outgoing_buffer,&ih->tmp_write[0],
-		      dst - &ih->tmp_write[0]);
+	iobuffer_fill(ih->outgoing_buffer, &tmp[0], dst - &tmp[0]);
 }
 
 

misc/statemachine.c

@@ -47,7 +47,7 @@
  *
  */
 
-#include <strings.h>
+#include <string.h>
 
 #include <ifax/types.h>
 #include <ifax/debug.h>

modules/linedriver.c

@@ -26,19 +26,8 @@
 ******************************************************************************
 */
 
-/* NOTE: This code deals with timing-critical device-driver
- *       buffering with synchronized read/write on same
- *       device and between devices (ISDN/Audio).
- *       The relationships between buffer-sizes, read/write
- *       strategy and possible timing glitches should be
- *       investigated more closely. UPDATE: Should work well
- *       as long as (low-level) transmit-buffer is
- *       pre-charged to avoid draining.
- *
- * BUGS: Error situations are not handeled well (no warnings etc.)
- */
-
-/* Maintain buffers and send/receive samples to the underlying
+/*
+ * Maintain buffers and send/receive samples to the underlying
  * physical transmission medium, like ISDN or a soundcard, named
  * pipes for faxing self (debugging) etc.
  *
@@ -83,7 +72,8 @@
 #include <ifax/misc/isdnline.h>
 #include <ifax/modules/linedriver.h>
 
-/* These defines should probably be run-time configurable.
+/*
+ * These defines should probably be run-time configurable.
  * BUFFERSIZE is the size of the main output buffer which is
  * filled by the handle function (incomming signal-chain).
  * We need a buffer here since the signaling-chain may not generate
@@ -97,7 +87,8 @@
 #define MAXIOSIZE       256
 
 
-/* An instance of this linedriver module holds the following
+/*
+ * An instance of this linedriver module holds the following
  * state-information and buffer storage.
  */
 
@@ -122,7 +113,8 @@ typedef struct {
 } linedriver_private;
 
 
-/* Method of operation:
+/*
+ * Method of operation:
  *
  * The 'handle' function is called, possibly as a result of a 'demand'
  * request, with data to fill the output queue (TX).  However, no data
@@ -158,6 +150,7 @@ static int work(ifax_modp self)
 	ifax_sint32 sp;
 	ifax_uint32 up;
 	linedriver_private *priv = self->private;
+	struct HardwareHandle *hh;
 
 	/* When driving the ISDN-line, this is how it works:
 	 * Read as much as we can from the line, and then
@@ -171,17 +164,20 @@ static int work(ifax_modp self)
 
 	do {
 
-    chunk = MAXIOSIZE;      /* Default buffer-size of IO-operations */
+		chunk = MAXIOSIZE;	/* Default size of IO-operations */
 
-    if ( priv->ih != 0 ) {
-      /* ISDN is online, read first, then transmit */
-      chunk = IsdnReadSamples(priv->ih,&priv->rx_buffer[0],MAXIOSIZE);
+		if ( priv->hh != 0 && priv->hh->state == ONLINE ) {
+			/* Hardware is online, read first, then transmit */
+			hh = priv->hh;
+			chunk = hh->read(hh,&priv->rx_buffer[0],MAXIOSIZE);
 			if ( chunk < 0 )
 				return -1;
 			more = chunk == MAXIOSIZE;
-    } else
+		} else {
 			for ( t=0; t < chunk; t++)
 				priv->rx_buffer[t] = 0;
+		}
+		
 
 		/* Fill output queue by demanding data (if needed) */
 		while ( priv->output.size < chunk ) {