L16_mono: Add L16 monaural codec plugin as functional example

This codec plugin serves a dual purpose.
First it is to add L16 codec suppport to Wireshark.
Second it is an illustration of a basic codec plugin module.

Change-Id: I64394dab3257ae49dece0257b16cd969503918e2
Reviewed-on: https://code.wireshark.org/review/26131
Reviewed-by: Jaap Keuter <jaap.keuter@xs4all.nl>
Petri-Dish: Jaap Keuter <jaap.keuter@xs4all.nl>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 83 insertions, 0 deletions

diff --git a/plugins/codecs/l16_mono/l16decode.c b/plugins/codecs/l16_mono/l16decode.c
new file mode 100644
index 0000000000..6c4453f457
--- /dev/null
+++ b/plugins/codecs/l16_mono/l16decode.c
@@ -0,0 +1,83 @@
+/* l16decode.c
+ * 16-bit audio, mono codec
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "config.h"
+
+#include <glib.h>
+#include <string.h>
+
+#include "codecs/codecs.h"
+#include "ws_attributes.h"
+
+void *
+codec_l16_init(void)
+{
+    return NULL;
+}
+
+void
+codec_l16_release(void *ctx _U_)
+{
+
+}
+
+unsigned
+codec_l16_get_channels(void *ctx _U_)
+{
+    return 1;
+}
+
+unsigned
+codec_l16_get_frequency(void *ctx _U_)
+{
+    return 44100;
+}
+
+size_t
+codec_l16_decode(void *ctx _U_, const void *input, size_t inputSizeBytes,
+                 void *output, size_t *outputSizeBytes)
+{
+    const guint16 *dataIn  = (const guint16 *)input;
+    guint16       *dataOut = (guint16 *)output;
+    size_t         i;
+
+    if (!output || !outputSizeBytes)
+    {
+        return inputSizeBytes;
+    }
+
+    for (i=0; i<inputSizeBytes/2; i++)
+    {
+        dataOut[i] = g_ntohs(dataIn[i]);
+    }
+
+    *outputSizeBytes = inputSizeBytes;
+    return *outputSizeBytes;
+}
+
+void
+codec_register_l16(void)
+{
+    register_codec("16-bit audio, monaural", codec_l16_init, codec_l16_release,
+        codec_l16_get_channels, codec_l16_get_frequency, codec_l16_decode);
+}
+
+/*
+ * Editor modelines  -  http://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 4
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * vi: set shiftwidth=4 tabstop=8 expandtab:
+ * :indentSize=4:tabSize=8:noTabs=true:
+ */