1 files changed, 149 insertions, 0 deletions
diff --git a/wsutil/codecs.h b/wsutil/codecs.h
new file mode 100644
index 0000000..be340bc
--- /dev/null
+++ b/wsutil/codecs.h
@@ -0,0 +1,149 @@
+/** @file
+ * codecs interface   2007 Tomas Kukosa
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef _CODECS_H_
+#define _CODECS_H_
+
+#include "ws_symbol_export.h"
+#include "ws_attributes.h"
+
+#include <stdbool.h>
+
+#include "wsutil/wmem/wmem_map.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+typedef struct {
+    void (*register_codec_module)(void);  /* routine to call to register a codec */
+} codecs_plugin;
+
+WS_DLL_PUBLIC void codecs_register_plugin(const codecs_plugin *plug);
+
+/**
+ * For all built-in codecs and codec plugins, call their register routines.
+ */
+WS_DLL_PUBLIC void codecs_init(void);
+
+WS_DLL_PUBLIC void codecs_cleanup(void);
+
+/**
+ * Get compile-time information for libraries used by libwscodecs.
+ */
+WS_DLL_PUBLIC void codec_get_compiled_version_info(GString *str);
+
+struct codec_handle;
+typedef struct codec_handle *codec_handle_t;
+
+typedef struct _codec_context_t {
+    unsigned sample_rate;
+    unsigned channels;
+    wmem_map_t *fmtp_map;
+    void *priv; /* Private state set by the decoder */
+} codec_context_t;
+
+/*****************************************************************************/
+/* Interface which must be implemented by a codec */
+/* Codec decodes bytes to samples. Sample is 2 bytes! Codec writer must
+ * be careful when API refers bytes and when samples and its counts.
+ */
+/*****************************************************************************/
+
+/** Initialize context of codec.
+ * Context can contain any information required by codec to pass between calls
+ * Note: There is just one codec context in runtime therefore no RTP stream
+ * related information should be stored in the context!
+ *
+ * @return Pointer to codec context
+ */
+typedef void *(*codec_init_fn)(codec_context_t *context);
+
+/** Destroy context of codec
+ *
+ * @param context Pointer to codec context
+ */
+typedef void (*codec_release_fn)(codec_context_t *context);
+
+/** Get count of channels provided by the codec
+ *
+ * @param context Pointer to codec context
+ *
+ * @return Count of channels (e.g. 1)
+ */
+typedef unsigned (*codec_get_channels_fn)(codec_context_t *context);
+
+/** Get frequency/rate provided by the codec
+ *
+ * @param context Pointer to codec context
+ *
+ * @return Frequency (e.g. 8000)
+ */
+typedef unsigned (*codec_get_frequency_fn)(codec_context_t *context);
+
+/** Decode one frame of payload
+ *  Function is called twice, with different values of parameters:
+ *  (1) To query size of required buffer in bytes for decoded samples
+ *      pointed by inputBytes:
+ *      outputSamples or outputSamplesSize must be set NULL
+ *  (2) To decode samples:
+ *      outputSamples points to allocated memory, outputSamplesSize is set to
+ *      value returned in step (1)
+ *
+ * @param context Pointer to codec context
+ * @param inputBytes Pointer to input frame
+ * @param inputBytesSize Length of input frame in bytes
+ *        (count of bytes to decode)
+ * @param outputSamples Pointer to output buffer with samples
+ * @param outputSamplesSize Length of output buffer in bytes (not samples!)
+ *        Function can override this value. All codecs set it to same value as it returns in (2) when (2) is called.
+ *
+ * @return Count of reqired bytes (!not samples) to allocate in (1) or
+ *         Count of decoded bytes (!not samples) in (2)
+ */
+typedef size_t (*codec_decode_fn)(codec_context_t *context,
+        const void *inputBytes, size_t inputBytesSize,
+        void *outputSamples, size_t *outputSamplesSize);
+
+/*****************************************************************************/
+/* Codec registering interface */
+/*****************************************************************************/
+
+WS_DLL_PUBLIC bool register_codec(const char *name, codec_init_fn init_fn,
+        codec_release_fn release_fn, codec_get_channels_fn channels_fn,
+        codec_get_frequency_fn frequency_fn, codec_decode_fn decode_fn);
+WS_DLL_PUBLIC bool deregister_codec(const char *name);
+WS_DLL_PUBLIC codec_handle_t find_codec(const char *name);
+WS_DLL_PUBLIC void *codec_init(codec_handle_t codec, codec_context_t *context);
+WS_DLL_PUBLIC void codec_release(codec_handle_t codec, codec_context_t *context);
+WS_DLL_PUBLIC unsigned codec_get_channels(codec_handle_t codec, codec_context_t *context);
+WS_DLL_PUBLIC unsigned codec_get_frequency(codec_handle_t codec, codec_context_t *context);
+WS_DLL_PUBLIC size_t codec_decode(codec_handle_t codec, codec_context_t *context,
+        const void *inputBytes, size_t inputBytesSize,
+        void *outputSamples, size_t *outputSamplesSize);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* _CODECS_H_ */
+
+/*
+ * Editor modelines  -  https://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:
+ */