[asterisk-commits] file: branch file/bridging r81328 - /team/file/bridging/bridges/bridge_softmix.c

SVN commits to the Asterisk project asterisk-commits at lists.digium.com
Tue Aug 28 21:26:39 CDT 2007


Author: file
Date: Tue Aug 28 21:26:38 2007
New Revision: 81328

URL: http://svn.digium.com/view/asterisk?view=rev&rev=81328
Log:
Add working software based mixing bridge technology.

Modified:
    team/file/bridging/bridges/bridge_softmix.c

Modified: team/file/bridging/bridges/bridge_softmix.c
URL: http://svn.digium.com/view/asterisk/team/file/bridging/bridges/bridge_softmix.c?view=diff&rev=81328&r1=81327&r2=81328
==============================================================================
--- team/file/bridging/bridges/bridge_softmix.c (original)
+++ team/file/bridging/bridges/bridge_softmix.c Tue Aug 28 21:26:38 2007
@@ -32,51 +32,56 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/types.h>
-#include <sys/stat.h>
+#include <sys/time.h>
+#include <signal.h>
+#include <errno.h>
+#include <unistd.h>
 
 #include "asterisk/module.h"
 #include "asterisk/channel.h"
 #include "asterisk/bridging.h"
 #include "asterisk/frame.h"
-#include "asterisk/slinfactory.h"
 #include "asterisk/options.h"
 #include "asterisk/logger.h"
-
-#define SOFTMIX_SAMPLES 160
-
-struct softmix_bridge_pvt {
-	struct ast_slinfactory *factory;
+#include "asterisk/slinfactory.h"
+
+#define SOFTMIX_INTERVAL 20 /* Valid options are 10, 20, and 30 */
+#define SOFTMIX_SAMPLES (160*(SOFTMIX_INTERVAL/10))
+
+struct softmix_channel {
+	ast_mutex_t lock;
+	struct ast_slinfactory factory;
+	struct ast_frame frame;
+	int have_audio:1;
+	int have_frame:1;
+	short final_buf[SOFTMIX_SAMPLES];
+	short our_buf[SOFTMIX_SAMPLES];
 };
-
-struct softmix_bridge_channel_pvt {
-	struct ast_slinfactory *factory;
-	struct ast_frame *frame;
-};
-
-/* Called when the bridge is created */
-static int softmix_bridge_create(struct ast_bridge *bridge)
-{
-	return 0;
-}
-
-/* Called when the bridge is destroyed */
-static int softmix_bridge_destroy(struct ast_bridge *bridge)
-{
-	return 0;
-}
 
 /* Called when a channel is joined to the bridge. We need to setup a smoother so that frames from all channels will be consistent */
 static int softmix_bridge_join(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
 {
-	struct softmix_bridge_channel_pvt *sbcp = NULL;
-
-	/* Allocate new memory for the bridged channel private structure */
-	if (!(sbcp = ast_calloc(1, sizeof(*sbcp))))
+	struct softmix_channel *sc = NULL;
+
+	/* Create a new softmix_channel structure and allocate various things on it */
+	if (!(sc = ast_calloc(1, sizeof(*sc))))
 		return -1;
 
-	/* Associate our private structure with the bridged channel, it would be rather useless without it */
-	bridge_channel->bridge_pvt = sbcp;
+	/* Can't forget the lock */
+	ast_mutex_init(&sc->lock);
+
+	/* Setup smoother */
+	ast_slinfactory_init(&sc->factory);
+
+	/* Setup frame parameters */
+	sc->frame.frametype = AST_FRAME_VOICE;
+	sc->frame.subclass = AST_FORMAT_SLINEAR;
+	sc->frame.data = sc->final_buf;
+	sc->frame.datalen = sizeof(sc->final_buf);
+	sc->frame.samples = SOFTMIX_SAMPLES;
+
+	/* Can't forget to record our pvt structure within the bridged channel structure */
+	bridge_channel->bridge_pvt = sc;
 
 	return 0;
 }
@@ -84,25 +89,165 @@
 /* Called when a channel leaves the bridge */
 static int softmix_bridge_leave(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
 {
+	struct softmix_channel *sc = bridge_channel->bridge_pvt;
+
+	/* Drop mutex lock */
+	ast_mutex_destroy(&sc->lock);
+
+	/* Drop the factory */
+	ast_slinfactory_destroy(&sc->factory);
+
+	/* Eep! drop ourselves */
+	ast_free(sc);
+
 	return 0;
 }
 
 /* Called when a frame comes from a channel and should go into the bridge */
 static enum ast_bridge_write_result softmix_bridge_write(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, struct ast_frame *frame)
 {
-	return AST_BRIDGE_WRITE_FAILED;
+	struct softmix_channel *sc = bridge_channel->bridge_pvt;
+
+        /* Only accept audio frames, all others are unsupported */
+        if (frame->frametype != AST_FRAME_VOICE)
+                return AST_BRIDGE_WRITE_UNSUPPORTED;
+
+	ast_mutex_lock(&sc->lock);
+
+	/* If a frame was provided add it to the smoother */
+	if (frame->frametype == AST_FRAME_VOICE && frame->subclass == AST_FORMAT_SLINEAR)
+		ast_slinfactory_feed(&sc->factory, frame);
+	
+	/* If a frame is ready to be written out, do so */
+	if (sc->have_frame) {
+		ast_write(bridge_channel->chan, &sc->frame);
+		sc->have_frame = 0;
+	}
+
+	/* Alllll done */
+	ast_mutex_unlock(&sc->lock);
+
+	return AST_BRIDGE_WRITE_SUCCESS;
+}
+
+/* Called when a bridged channel thread is interrupted */
+static int softmix_bridge_poke(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel)
+{
+	struct softmix_channel *sc = bridge_channel->bridge_pvt;
+
+	ast_mutex_lock(&sc->lock);
+
+	if (sc->have_frame) {
+		ast_write(bridge_channel->chan, &sc->frame);
+		sc->have_frame = 0;
+	}
+
+	ast_mutex_unlock(&sc->lock);
+	
+	return 0;
+}
+
+/* Main bridge thread function */
+static int softmix_bridge_thread(struct ast_bridge *bridge)
+{
+	struct timeval base = ast_tvnow();
+	int skew = 0, previous_skew = 0, last_adjust = 0;
+	ast_cond_t cond;
+
+	ast_cond_init(&cond, NULL);
+
+	while (bridge->thread != AST_PTHREADT_STOP) {
+		struct ast_bridge_channel *bridge_channel = NULL;
+		short buf[SOFTMIX_SAMPLES] = {0, };
+		struct timeval next_wakeup;
+		struct timespec ts = {0, };
+
+		/* Go through pulling audio from each factory that has it available */
+		AST_LIST_TRAVERSE(&bridge->channels, bridge_channel, list) {
+			struct softmix_channel *sc = bridge_channel->bridge_pvt;
+
+			ast_mutex_lock(&sc->lock);
+
+			/* Try to get audio from the factory if available */
+			if (ast_slinfactory_available(&sc->factory) >= SOFTMIX_SAMPLES && ast_slinfactory_read(&sc->factory, sc->our_buf, SOFTMIX_SAMPLES)) {
+				short *data1, *data2;
+				int i;
+
+				/* Put into the local final buffer */
+				for (i = 0, data1 = buf, data2 = sc->our_buf; i < SOFTMIX_SAMPLES; i++, data1++, data2++)
+					ast_slinear_saturated_add(data1, data2);
+				/* Yay we have our own audio */
+				sc->have_audio = 1;
+			} else {
+				/* Awww we don't have audio ;( */
+				sc->have_audio = 0;
+			}
+			ast_mutex_unlock(&sc->lock);
+		}
+
+		/* Next step go through removing the channel's own audio and creating a good frame... */
+		AST_LIST_TRAVERSE(&bridge->channels, bridge_channel, list) {
+			struct softmix_channel *sc = bridge_channel->bridge_pvt;
+			int i = 0;
+			
+			/* Copy from local final buffer to our final buffer while subtracting our audio if present */
+			for (i = 0; i < SOFTMIX_SAMPLES; i++) {
+				sc->final_buf[i] = buf[i];
+				/* Subtract our own audio from the end frame if present */
+				if (sc->have_audio)
+					ast_slinear_saturated_subtract(&sc->final_buf[i], &sc->our_buf[i]);
+			}
+			
+			/* The frame is now ready for use... */
+			sc->have_frame = 1;
+			
+			/* Poke bridged channel thread just in case */
+			pthread_kill(bridge_channel->thread, SIGURG);
+		}
+
+		/* If there is a skew value incorporate it into the base time to adjust for timing */
+		if (previous_skew && skew) {
+			int adjust = abs(skew-previous_skew), new_adjust = 0;
+			if (adjust > 0)
+				new_adjust = abs(adjust-last_adjust);
+			base = ast_tvadd(base, ast_tv(0, ((SOFTMIX_INTERVAL-new_adjust)+SOFTMIX_INTERVAL)*1000));
+			last_adjust = new_adjust;
+		} else {
+			base = ast_tvadd(base, ast_tv(0, (SOFTMIX_INTERVAL*2)*1000));
+		}
+
+                /* Calculate next time until we should wake up */
+                next_wakeup = ast_tvadd(ast_tvnow(), ast_tvsub(base, ast_tvnow()));
+
+                /* Apply this time to the timespec */
+                ts.tv_sec = next_wakeup.tv_sec;
+                ts.tv_nsec = next_wakeup.tv_usec * 1000;
+
+                /* Wait until then */
+                ast_cond_timedwait(&cond, &bridge->lock, &ts);
+
+		/* Before we calculate the skew value... record the previous one */
+		previous_skew = skew;
+		
+		/* Calculate a skew value (what we wanted versus what we got) */
+		skew = ast_tvdiff_ms(ast_tvnow(), next_wakeup);
+	}
+
+	ast_cond_destroy(&cond);
+
+	return 0;
 }
 
 static struct ast_bridge_technology softmix_bridge = {
 	.name = "softmix",
-	.capabilities = AST_BRIDGE_CAPABILITY_MULTIMIX,
+	.capabilities = AST_BRIDGE_CAPABILITY_MULTIMIX | AST_BRIDGE_CAPABILITY_THREAD | AST_BRIDGE_CAPABILITY_MULTITHREADED,
 	.preference = AST_BRIDGE_PREFERENCE_LOW,
 	.formats = AST_FORMAT_SLINEAR,
-	.create = softmix_bridge_create,
-	.destroy = softmix_bridge_destroy,
 	.join = softmix_bridge_join,
 	.leave = softmix_bridge_leave,
 	.write = softmix_bridge_write,
+	.thread = softmix_bridge_thread,
+	.poke = softmix_bridge_poke,
 };
 
 static int unload_module(void)




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