X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=amp_filter.c;h=c0835f806ad322480cb38e7ca851b1ef78b3e366;hp=e180db437c6a26fe8c978fefccdd51841cd97fd0;hb=83b222427d80c325b6f30e6693fbc5c05d8fa11f;hpb=ef81b9f4f0fa6a26043c68d429c0deeb7c949351

diff --git a/amp_filter.c b/amp_filter.c
index e180db43..c0835f80 100644
--- a/amp_filter.c
+++ b/amp_filter.c
@@ -7,12 +7,14 @@
 /** \file amp_filter.c Paraslash's amplify filter. */
 
 #include <regex.h>
+#include <stdbool.h>
 
 #include "para.h"
 #include "amp_filter.cmdline.h"
 #include "list.h"
 #include "sched.h"
 #include "ggo.h"
+#include "buffer_tree.h"
 #include "filter.h"
 #include "string.h"
 #include "error.h"
@@ -88,6 +90,7 @@ static void amp_open(struct filter_node *fn)
 
 	pad->conf = fn->conf;
 	fn->private_data = pad;
+	fn->min_iqs = 2;
 	if (!pad->conf->amp_given && stat_item_values[SI_AMPLIFICATION])
 		sscanf(stat_item_values[SI_AMPLIFICATION], "%u", &pad->amp);
 	else
@@ -96,6 +99,60 @@ static void amp_open(struct filter_node *fn)
 	fn->buf = para_malloc(fn->bufsize);
 }
 
+static void amp_post_select(__a_unused struct sched *s, struct task *t)
+{
+	struct filter_node *fn = container_of(t, struct filter_node, task);
+	struct private_amp_data *pad = fn->private_data;
+	struct btr_node *btrn = fn->btrn;
+	int ret, factor = 64 + pad->amp;
+	size_t i, in_bytes, len;
+	int16_t *in, *out;
+	bool inplace = btr_inplace_ok(btrn);
+
+	if (pad->amp == 0) { /* no amplification */
+		t->error = -E_AMP_ZERO_AMP;
+		btr_splice_out_node(btrn);
+		amp_close(fn);
+		return;
+	}
+next_buffer:
+	ret = prepare_filter_node(fn);
+	in_bytes = btr_next_buffer(btrn, (char **)&in);
+	if (ret < 0)
+		goto err;
+	len = in_bytes / 2;
+	/* len == 0 happens if eof and in_bytes == 1. */
+	if (ret == 0 || len == 0)
+		return;
+
+	if (inplace)
+		out = in;
+	else
+		out = para_malloc(len * 2);
+
+	for (i = 0; i < len; i++) {
+		int x = (in[i] * factor) >> 6;
+
+		out[i] = x;
+		if (out[i] != x) /* overflow, clip */
+			out[i] = (x >= 0)? 32767 : -32768;
+	}
+
+	if (inplace)
+		btr_pushdown_one(btrn);
+	else {
+		btr_consume(btrn, len * 2);
+		btr_add_output((char *)out, len * 2, btrn);
+	}
+	t->error = 0;
+	goto next_buffer;
+err:
+	assert(ret < 0);
+	t->error = ret;
+	btr_del_node(btrn);
+	amp_close(fn);
+}
+
 /**
  * The init function of the amplify filter.
  *
@@ -109,6 +166,8 @@ void amp_filter_init(struct filter *f)
 	f->open = amp_open;
 	f->close = amp_close;
 	f->convert = amp_convert;
+	f->pre_select = generic_filter_pre_select;
+	f->post_select = amp_post_select;
 	f->parse_config = amp_parse_config;
 	f->help = (struct ggo_help) {
 		.short_help = amp_filter_args_info_help,