X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=filter_common.c;h=ffb2199b60e75836c345f09ef8cac1b1202d1956;hp=1317192006e44f2a0ce93aeb1b6c616db39fcb68;hb=869f0e06ec4e15abc9230c1b2d7615da5250802e;hpb=67ba58404e6187699c806bfe19a3e6a70faf9738

diff --git a/filter_common.c b/filter_common.c
index 13171920..ffb2199b 100644
--- a/filter_common.c
+++ b/filter_common.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005-2012 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -8,8 +8,6 @@
 
 #include <regex.h>
 #include <sys/types.h>
-#include <dirent.h>
-#include <stdbool.h>
 
 #include "para.h"
 #include "list.h"
@@ -109,6 +107,11 @@ int check_filter_arg(char *fa, void **conf)
 	return -E_UNSUPPORTED_FILTER;
 }
 
+/**
+ * Print help text of each filter to stdout.
+ *
+ * \param detailed If non-zero, print detailed help.
+ */
 void print_filter_helps(int detailed)
 {
 	int i;
@@ -128,6 +131,17 @@ void print_filter_helps(int detailed)
 	}
 }
 
+/**
+ * Set select timeout of the the scheduler.
+ *
+ * \param s The scheduler.
+ * \param t The task struct of this filter.
+ *
+ * This looks at the status of the btr node of the filter. If data is available
+ * in the input queue of the filter, or if an error occured, a minimal timeout
+ * for the next select call is requested from the scheduler. Otherwise the
+ * scheduler timeout is left unchanged.
+ */
 void generic_filter_pre_select(struct sched *s, struct task *t)
 {
 	struct filter_node *fn = container_of(t, struct filter_node, task);
@@ -136,3 +150,45 @@ void generic_filter_pre_select(struct sched *s, struct task *t)
 	if (btr_node_status(fn->btrn, fn->min_iqs, BTR_NT_INTERNAL) != 0)
 		sched_min_delay(s);
 }
+
+#ifdef WORDS_BIGENDIAN
+#define DECODER_SAMPLE_FORMAT SF_S16_BE
+#else
+#define DECODER_SAMPLE_FORMAT SF_S16_LE
+#endif
+
+/**
+ * Execute a btr command for a decoder.
+ *
+ * The buffer tree nodes of the writers ask the parent nodes about sample_rate,
+ * channels count and sample format. This function is called by all decoders to
+ * answer these queries.
+ *
+ * \param cmd The command to be executed by the child node.
+ * \param sample_rate Known to the decoder.
+ * \param channels Known to the decoder.
+ * \param result Ascii representation on the answer is stored here.
+ *
+ * \return Standard.
+ */
+int decoder_execute(const char *cmd, unsigned sample_rate, unsigned channels,
+		char **result)
+{
+	if (!strcmp(cmd, "sample_rate")) {
+		if (sample_rate == 0)
+			return -E_BTR_NAVAIL;
+		*result = make_message("%u", sample_rate);
+		return 1;
+	}
+	if (!strcmp(cmd, "channels")) {
+		if (channels == 0)
+			return -E_BTR_NAVAIL;
+		*result = make_message("%u", channels);
+		return 1;
+	}
+	if (!strcmp(cmd, "sample_format")) {
+		*result = make_message("%u", DECODER_SAMPLE_FORMAT);
+		return 1;
+	}
+	return -ERRNO_TO_PARA_ERROR(ENOTSUP);
+}