AudioFormat: move MAX_CHANNELS to pcm/ChannelDefs.hxx

Reduce header dependencies.

src/AudioFormat.hxx

@@ -21,6 +21,7 @@
 #define MPD_AUDIO_FORMAT_HXX
 
 #include "pcm/SampleFormat.hxx"
+#include "pcm/ChannelDefs.hxx"
 #include "util/Compiler.h"
 
 #include <chrono>
@@ -30,8 +31,6 @@
 
 template<size_t CAPACITY> class StringBuffer;
 
-static constexpr unsigned MAX_CHANNELS = 8;
-
 /**
  * This structure describes the format of a raw PCM stream.
  */
@@ -184,15 +183,6 @@ audio_valid_sample_rate(unsigned sample_rate) noexcept
 	return sample_rate > 0 && sample_rate < (1 << 30);
 }
 
-/**
- * Checks whether the number of channels is valid.
- */
-constexpr bool
-audio_valid_channel_count(unsigned channels) noexcept
-{
-	return channels >= 1 && channels <= MAX_CHANNELS;
-}
-
 /**
  * Returns false if the format is not valid for playback with MPD.
  * This function performs some basic validity checks.

src/pcm/ChannelDefs.hxx

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2003-2019 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_PCM_CHANNEL_DEFS_HXX
+#define MPD_PCM_CHANNEL_DEFS_HXX
+
+static constexpr unsigned MAX_CHANNELS = 8;
+
+/**
+ * Checks whether the number of channels is valid.
+ */
+constexpr bool
+audio_valid_channel_count(unsigned channels) noexcept
+{
+	return channels >= 1 && channels <= MAX_CHANNELS;
+}
+
+#endif

src/pcm/Dop.cxx

@@ -19,7 +19,7 @@
 
 #include "Dop.hxx"
 #include "Buffer.hxx"
-#include "AudioFormat.hxx"
+#include "ChannelDefs.hxx"
 #include "util/ConstBuffer.hxx"
 
 #include <assert.h>

src/pcm/PcmChannels.cxx

@@ -18,10 +18,10 @@
  */
 
 #include "PcmChannels.hxx"
+#include "ChannelDefs.hxx"
 #include "Buffer.hxx"
 #include "Silence.hxx"
 #include "Traits.hxx"
-#include "AudioFormat.hxx"
 #include "util/ConstBuffer.hxx"
 #include "util/WritableBuffer.hxx"
 

src/pcm/PcmDsd.hxx

@@ -21,7 +21,7 @@
 #define MPD_PCM_DSD_HXX
 
 #include "Buffer.hxx"
-#include "AudioFormat.hxx"
+#include "ChannelDefs.hxx"
 
 #include <array>