RTP: Enable GSM codec.

Change-Id: Iae1913fb0643f1c66b5d16f24d51924d363e5ef5

voip/java/android/net/rtp/AudioCodec.java

@@ -81,7 +81,7 @@ public class AudioCodec {
     public static final AudioCodec AMR = new AudioCodec(97, "AMR/8000", null);
 
     // TODO: add rest of the codecs when the native part is done.
-    private static final AudioCodec[] sCodecs = {PCMU, PCMA};
+    private static final AudioCodec[] sCodecs = {GSM, PCMU, PCMA};
 
     private AudioCodec(int type, String rtpmap, String fmtp) {
         this.type = type;

voip/jni/rtp/Android.mk

@@ -22,21 +22,25 @@ LOCAL_MODULE := librtp_jni
 LOCAL_SRC_FILES := \
 	AudioCodec.cpp \
 	AudioGroup.cpp \
-	G711Codec.cpp \
 	RtpStream.cpp \
 	util.cpp \
 	rtp_jni.cpp
 
+LOCAL_SRC_FILES += \
+	G711Codec.cpp \
+	GsmCodec.cpp
+
 LOCAL_SHARED_LIBRARIES := \
 	libnativehelper \
 	libcutils \
 	libutils \
 	libmedia
 
-LOCAL_STATIC_LIBRARIES :=
+LOCAL_STATIC_LIBRARIES := libgsm
 
 LOCAL_C_INCLUDES += \
-	$(JNI_H_INCLUDE)
+	$(JNI_H_INCLUDE) \
+	external/libgsm/inc
 
 LOCAL_CFLAGS += -fvisibility=hidden
 

voip/jni/rtp/AudioCodec.cpp

@@ -20,6 +20,7 @@
 
 extern AudioCodec *newAlawCodec();
 extern AudioCodec *newUlawCodec();
+extern AudioCodec *newGsmCodec();
 
 struct AudioCodecType {
     const char *name;
@@ -27,6 +28,7 @@ struct AudioCodecType {
 } gAudioCodecTypes[] = {
     {"PCMA", newAlawCodec},
     {"PCMU", newUlawCodec},
+    {"GSM", newGsmCodec},
     {NULL, NULL},
 };
 

voip/jni/rtp/GsmCodec.cpp

@@ -0,0 +1,74 @@
+/*
+ * Copyrightm (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "AudioCodec.h"
+
+extern "C" {
+#include "gsm.h"
+}
+
+namespace {
+
+class GsmCodec : public AudioCodec
+{
+public:
+    GsmCodec() {
+        mEncode = gsm_create();
+        mDecode = gsm_create();
+    }
+
+    ~GsmCodec() {
+        if (mEncode) {
+            gsm_destroy(mEncode);
+        }
+        if (mDecode) {
+            gsm_destroy(mDecode);
+        }
+    }
+
+    int set(int sampleRate, const char *fmtp) {
+        return (sampleRate == 8000 && mEncode && mDecode) ? 160 : -1;
+    }
+
+    int encode(void *payload, int16_t *samples);
+    int decode(int16_t *samples, void *payload, int length);
+
+private:
+    gsm mEncode;
+    gsm mDecode;
+};
+
+int GsmCodec::encode(void *payload, int16_t *samples)
+{
+    gsm_encode(mEncode, samples, (unsigned char *)payload);
+    return 33;
+}
+
+int GsmCodec::decode(int16_t *samples, void *payload, int length)
+{
+    if (length == 33 &&
+        gsm_decode(mDecode, (unsigned char *)payload, samples) == 0) {
+        return 160;
+    }
+    return -1;
+}
+
+} // namespace
+
+AudioCodec *newGsmCodec()
+{
+    return new GsmCodec;
+}