1 files changed, 135 insertions, 0 deletions
diff --git a/plugins/codecs/G726/G726decode.c b/plugins/codecs/G726/G726decode.c
new file mode 100644
index 00000000..92965251
--- /dev/null
+++ b/plugins/codecs/G726/G726decode.c
@@ -0,0 +1,135 @@
+/* G726decode.c
+ * G.726 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 "spandsp.h"
+#include "wsutil/codecs.h"
+#include "ws_attributes.h"
+
+typedef struct _g726_codec_ctx {
+    g726_state_t *state;
+    int bit_rate;
+} g726_codec_ctx;
+
+void codec_register_g726(void);
+
+static void *
+codec_g726_init(int bit_rate, int packing)
+{
+    g726_state_t *decoder = g726_init(NULL, bit_rate, G726_ENCODING_LINEAR, packing);
+
+    if (!decoder) {
+        return NULL;  /* out-of-memory; */
+    }
+
+    g726_codec_ctx *state = g_new(g726_codec_ctx, 1);
+    state->state = decoder;
+    state->bit_rate = bit_rate;
+
+    return state;
+}
+
+static void *codec_g726_16_init(codec_context_t *ctx _U_) { return codec_g726_init(16000, G726_PACKING_RIGHT); }
+static void *codec_g726_24_init(codec_context_t *ctx _U_) { return codec_g726_init(24000, G726_PACKING_RIGHT); }
+static void *codec_g726_32_init(codec_context_t *ctx _U_) { return codec_g726_init(32000, G726_PACKING_RIGHT); }
+static void *codec_g726_40_init(codec_context_t *ctx _U_) { return codec_g726_init(40000, G726_PACKING_RIGHT); }
+static void *codec_aal2_g726_16_init(codec_context_t *ctx _U_) { return codec_g726_init(16000, G726_PACKING_LEFT); }
+static void *codec_aal2_g726_24_init(codec_context_t *ctx _U_) { return codec_g726_init(24000, G726_PACKING_LEFT); }
+static void *codec_aal2_g726_32_init(codec_context_t *ctx _U_) { return codec_g726_init(32000, G726_PACKING_LEFT); }
+static void *codec_aal2_g726_40_init(codec_context_t *ctx _U_) { return codec_g726_init(40000, G726_PACKING_LEFT); }
+
+static void
+codec_g726_release(codec_context_t *ctx)
+{
+    g726_codec_ctx *state = (g726_codec_ctx *)(ctx->priv);
+
+    if (!state) {
+        return;  /* out-of-memory; */
+    }
+
+    /* Note: replaces g726_release since SpanDSP 20090211 */
+    g726_free(state->state);
+    g_free(state);
+}
+
+static unsigned
+codec_g726_get_channels(codec_context_t *ctx _U_)
+{
+    return 1;
+}
+
+static unsigned
+codec_g726_get_frequency(codec_context_t *ctx _U_)
+{
+    return 8000;
+}
+
+static size_t
+codec_g726_decode(codec_context_t *ctx, const void *inputBytes,
+        size_t inputBytesSize, void *outputSamples, size_t *outputSamplesSize)
+{
+    g726_codec_ctx *state = (g726_codec_ctx *)ctx->priv;
+
+    if (!state) {
+        return 0;  /* out-of-memory; */
+    }
+
+    if (!outputSamples || !outputSamplesSize) {
+        /*
+         * sample rate 8kHz, for bitrate 16kHz we have 16/8 = 2 bits/sample, so
+         * 1 input byte (8 bits) will expand to four 16-bit samples. Likewise,
+         * for bitrate 40kHz we have 40/8 = 5 bits/sample.  Alternatively:
+         * bitsPerSample = bitRate / sampleRate (8kHz).
+         * outputBytes = (inputBits / bitsPerSample) * sizeof(sample)
+         */
+        return inputBytesSize * 8 / (state->bit_rate / 8000) * 2;
+    }
+
+    /* g726_decode returns the number of 16-bit samples. */
+    *outputSamplesSize = 2 * g726_decode(state->state, (int16_t *)outputSamples, (const uint8_t *) inputBytes, (int)inputBytesSize);
+    return *outputSamplesSize;
+}
+
+void
+codec_register_g726(void)
+{
+    register_codec("G726-16", codec_g726_16_init, codec_g726_release,
+            codec_g726_get_channels, codec_g726_get_frequency, codec_g726_decode);
+    register_codec("G726-24", codec_g726_24_init, codec_g726_release,
+            codec_g726_get_channels, codec_g726_get_frequency, codec_g726_decode);
+    register_codec("G726-32", codec_g726_32_init, codec_g726_release,
+            codec_g726_get_channels, codec_g726_get_frequency, codec_g726_decode);
+    register_codec("G726-40", codec_g726_40_init, codec_g726_release,
+            codec_g726_get_channels, codec_g726_get_frequency, codec_g726_decode);
+    register_codec("AAL2-G726-16", codec_aal2_g726_16_init, codec_g726_release,
+            codec_g726_get_channels, codec_g726_get_frequency, codec_g726_decode);
+    register_codec("AAL2-G726-24", codec_aal2_g726_24_init, codec_g726_release,
+            codec_g726_get_channels, codec_g726_get_frequency, codec_g726_decode);
+    register_codec("AAL2-G726-32", codec_aal2_g726_32_init, codec_g726_release,
+            codec_g726_get_channels, codec_g726_get_frequency, codec_g726_decode);
+    register_codec("AAL2-G726-40", codec_aal2_g726_40_init, codec_g726_release,
+            codec_g726_get_channels, codec_g726_get_frequency, codec_g726_decode);
+}
+
+/*
+ * 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:
+ */