From 3ad05589aab3ab066930760786167dea846fefcd Mon Sep 17 00:00:00 2001
From: Ahmet Inan <ainan@mathematik.uni-freiburg.de>
Date: Fri, 9 Sep 2011 11:32:36 +0200
Subject: [PATCH] now alsa playback is also limited by seconds

---
 alsa.c | 14 ++++++++++++--
 alsa.h |  2 +-
 pcm.c  |  2 +-
 3 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/alsa.c b/alsa.c
index 22dc874..091e301 100644
--- a/alsa.c
+++ b/alsa.c
@@ -18,6 +18,8 @@ typedef struct {
 	int (*channels)(pcm_t *);
 	int (*rw)(struct pcm *, short *, int);
 	snd_pcm_t *pcm;
+	int index;
+	int frames;
 	int r;
 	int c;
 } alsa_t;
@@ -32,7 +34,10 @@ void close_alsa(pcm_t *pcm)
 void info_alsa(pcm_t *pcm)
 {
 	alsa_t *alsa = (alsa_t *)pcm;
-	fprintf(stderr, "%d channel(s), %d rate\n", alsa->c, alsa->r);
+	if (alsa->frames)
+		fprintf(stderr, "%d channel(s), %d rate, %.2f seconds\n", alsa->c, alsa->r, (float)alsa->frames / (float)alsa->r);
+	else
+		fprintf(stderr, "%d channel(s), %d rate\n", alsa->c, alsa->r);
 }
 int rate_alsa(pcm_t *pcm)
 {
@@ -60,6 +65,9 @@ int read_alsa(pcm_t *pcm, short *buff, int frames)
 int write_alsa(pcm_t *pcm, short *buff, int frames)
 {
 	alsa_t *alsa = (alsa_t *)pcm;
+	if (alsa->frames && (alsa->index + frames) > alsa->frames)
+		return 0;
+	alsa->index += frames;
 	int got = 0;
 	while (0 < frames) {
 		while ((got = snd_pcm_writei(alsa->pcm, buff, frames)) < 0)
@@ -144,7 +152,7 @@ int open_alsa_read(pcm_t **p, char *name)
 	return 1;
 }
 
-int open_alsa_write(pcm_t **p, char *name, int rate, int channels)
+int open_alsa_write(pcm_t **p, char *name, int rate, int channels, float seconds)
 {
 	alsa_t *alsa = (alsa_t *)malloc(sizeof(alsa_t));
 	alsa->close = close_alsa;
@@ -210,6 +218,8 @@ int open_alsa_write(pcm_t **p, char *name, int rate, int channels)
 	alsa->pcm = pcm;
 	alsa->r = rate;
 	alsa->c = channels;
+	alsa->frames = seconds * rate;
+	alsa->index = 0;
 	*p = (pcm_t *)alsa;
 	return 1;
 }
diff --git a/alsa.h b/alsa.h
index d10f78b..57991a8 100644
--- a/alsa.h
+++ b/alsa.h
@@ -10,6 +10,6 @@ You should have received a copy of the CC0 Public Domain Dedication along with t
 #define ALSA_H
 #include "pcm.h"
 int open_alsa_read(pcm_t **, char *);
-int open_alsa_write(pcm_t **, char *, int, int);
+int open_alsa_write(pcm_t **, char *, int, int, float);
 #endif
 
diff --git a/pcm.c b/pcm.c
index 32dab4e..5515761 100644
--- a/pcm.c
+++ b/pcm.c
@@ -56,7 +56,7 @@ int open_pcm_read(pcm_t **p, char *name)
 int open_pcm_write(pcm_t **p, char *name, int rate, int channels, float seconds)
 {
 	if (strstr(name, "plughw:") == name || strstr(name, "hw:") == name || strstr(name, "default") == name)
-		return open_alsa_write(p, name, rate, channels);
+		return open_alsa_write(p, name, rate, channels, seconds);
 	if (strstr(name, ".wav") == (name + (strlen(name) - strlen(".wav"))))
 		return open_wav_write(p, name, rate, channels, seconds);
 	return 0;