From: Andre Noll <maan@systemlinux.org>
Date: Thu, 5 Sep 2013 00:57:53 +0000 (+0000)
Subject: alsa: Improve documentation of struct private_alsa_write_data.
X-Git-Tag: v0.5.3~22^2~7
X-Git-Url: http://git.tue.mpg.de/?a=commitdiff_plain;h=dc26e5bc49d839fd966b7ad6f596e444ac8908d3;p=paraslash.git

alsa: Improve documentation of struct private_alsa_write_data.

Remove the stale reference to writer node groups and explain how
sample_rate and channel count are determined.
---

diff --git a/alsa_write.c b/alsa_write.c
index 0824640b..53854e08 100644
--- a/alsa_write.c
+++ b/alsa_write.c
@@ -34,16 +34,21 @@ struct private_alsa_write_data {
 	snd_pcm_t *handle;
 	/** Determined and set by alsa_init(). */
 	int bytes_per_frame;
-	/**
-	 * The sample rate given by command line option or the decoder
-	 * of the writer node group.
+	/*
+	 * If the sample rate is not given at the command line and no wav
+	 * header was detected, the btr exec mechanism is employed to query the
+	 * ancestor buffer tree nodes for this information. In a typical setup
+	 * the decoder passes the sample rate back to the alsa writer.
+	 *
+	 *  \sa \ref btr_exec_up().
 	 */
 	unsigned sample_rate;
-	snd_pcm_format_t sample_format;
-	/**
-	 * The number of channels, given by command line option or the
-	 * decoder of the writer node group.
+	/*
+	 * The sample format (8/16 bit, signed/unsigned, little/big endian) is
+	 * determined in the same way as the \a sample_rate.
 	 */
+	snd_pcm_format_t sample_format;
+	/* The number of channels, again determined like \a sample_rate. */
 	unsigned channels;
 	struct timeval drain_barrier;
 	/* File descriptor for select(). */