[PATCH] fix resamplers.

[James Courtier-Dutton <James@superbug.demon.co.uk>]

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The current pcm_rate.c tends to insert zero samples in the stream.

E.g. Downsampling from 48000 -> 16000
Starts with a block of 2048, and has to create 682 samples.
The current code sometimes only produces 681 samples, leaving the last 
one zero.

The attached patch fixes this problem.

James

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? alsa-lib/ltconfig
? alsa-lib/src/pcm/pcm_rate.c.org
Index: alsa-lib/src/pcm/pcm_rate.c
===================================================================
RCS file: /cvsroot/alsa/alsa-lib/src/pcm/pcm_rate.c,v
retrieving revision 1.84
diff -u -r1.84 pcm_rate.c
--- alsa-lib/src/pcm/pcm_rate.c	26 Apr 2004 07:40:13 -0000	1.84
+++ alsa-lib/src/pcm/pcm_rate.c	21 Jul 2004 15:02:59 -0000
@@ -585,47 +585,47 @@
 		do {
 			snd_pcm_uframes_t cframes;
 			
-			cframes = snd_pcm_rate_client_frames(pcm, slave->period_size - 1);
-			if (cframes == pcm->period_size - 1)
+			cframes = snd_pcm_rate_client_frames(pcm, slave->period_size);
+			if (cframes == pcm->period_size)
 				break;
-			if (cframes > pcm->period_size - 1) {
+			if (cframes > pcm->period_size) {
 				rate->pitch++;
-				if ((snd_pcm_uframes_t)snd_pcm_rate_client_frames(pcm, slave->period_size - 1) < pcm->period_size - 1) {
-					SNDERR("Unable to satisfy pitch condition (%i/%i - %li/%li)\n", slave->rate, pcm->rate, slave->period_size - 1, pcm->period_size - 1);
+				if ((snd_pcm_uframes_t)snd_pcm_rate_client_frames(pcm, slave->period_size) < pcm->period_size) {
+					SNDERR("Unable to satisfy pitch condition (%i/%i - %li/%li)\n", slave->rate, pcm->rate, slave->period_size, pcm->period_size);
 					return -EIO;
 				}
 			} else {
 				rate->pitch--;
-				if ((snd_pcm_uframes_t)snd_pcm_rate_client_frames(pcm, slave->period_size - 1) > pcm->period_size - 1) {
+				if ((snd_pcm_uframes_t)snd_pcm_rate_client_frames(pcm, slave->period_size) > pcm->period_size) {
 					SNDERR("Unable to satisfy pitch condition (%i/%i - %li/%li)\n", slave->rate, pcm->rate, slave->period_size - 1, pcm->period_size - 1);
 					return -EIO;
 				}
 			}
 		} while (1);
-		assert((snd_pcm_uframes_t)snd_pcm_rate_client_frames(pcm, slave->period_size - 1) == pcm->period_size - 1);
+		assert((snd_pcm_uframes_t)snd_pcm_rate_client_frames(pcm, slave->period_size) == pcm->period_size);
 	} else {
 		rate->pitch = (((u_int64_t)pcm->period_size * LINEAR_DIV) + slave->period_size - 1) / slave->period_size;
 		do {
 			snd_pcm_uframes_t cframes;
 			
-			cframes = snd_pcm_rate_slave_frames(pcm, pcm->period_size - 1);
-			if (cframes == slave->period_size - 1)
+			cframes = snd_pcm_rate_slave_frames(pcm, pcm->period_size);
+			if (cframes == slave->period_size)
 				break;
-			if (cframes > slave->period_size - 1) {
+			if (cframes > slave->period_size) {
 				rate->pitch++;
-				if ((snd_pcm_uframes_t)snd_pcm_rate_slave_frames(pcm, pcm->period_size - 1) < slave->period_size - 1) {
-					SNDERR("Unable to satisfy pitch condition (%i/%i - %li/%li)\n", slave->rate, pcm->rate, slave->period_size - 1, pcm->period_size - 1);
+				if ((snd_pcm_uframes_t)snd_pcm_rate_slave_frames(pcm, pcm->period_size) < slave->period_size) {
+					SNDERR("Unable to satisfy pitch condition (%i/%i - %li/%li)\n", slave->rate, pcm->rate, slave->period_size, pcm->period_size);
 					return -EIO;
 				}
 			} else {
 				rate->pitch--;
-				if ((snd_pcm_uframes_t)snd_pcm_rate_slave_frames(pcm, pcm->period_size - 1) > slave->period_size - 1) {
-					SNDERR("Unable to satisfy pitch condition (%i/%i - %li/%li)\n", slave->rate, pcm->rate, slave->period_size - 1, pcm->period_size - 1);
+				if ((snd_pcm_uframes_t)snd_pcm_rate_slave_frames(pcm, pcm->period_size) > slave->period_size) {
+					SNDERR("Unable to satisfy pitch condition (%i/%i - %li/%li)\n", slave->rate, pcm->rate, slave->period_size, pcm->period_size);
 					return -EIO;
 				}
 			}
 		} while (1);
-		assert((snd_pcm_uframes_t)snd_pcm_rate_slave_frames(pcm, pcm->period_size - 1) == slave->period_size - 1);
+		assert((snd_pcm_uframes_t)snd_pcm_rate_slave_frames(pcm, pcm->period_size) == slave->period_size);
 	}
 	recalc(pcm, &sparams->avail_min);
 	rate->orig_avail_min = sparams->avail_min;