AndroidVDA by using Android's MediaCodec API.

media/base/android/media_codec_bridge.cc

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "media/base/android/media_codec_bridge.h"
+
+#include <jni.h>
+
+#include "base/android/jni_android.h"
+#include "base/android/jni_array.h"
+#include "base/android/jni_string.h"
+#include "base/basictypes.h"
+#include "base/logging.h"
+#include "base/stringprintf.h"
+
+#include "jni/MediaFormat_jni.h"
+#include "jni/MediaCodec_jni.h"
+
+
+using base::android::AttachCurrentThread;
+using base::android::ConvertUTF8ToJavaString;
+using base::android::ScopedJavaLocalRef;
+
+namespace {
+
+static jclass g_MediaCodecBufferInfo_clazz = NULL;
+
+static const char kMediaCodecBufferInfoClassPath[] =
+    "android/media/MediaCodec$BufferInfo";
+
+static bool MediaCodecBufferInfo_RegisterNativesImpl(JNIEnv* env) {
+  g_MediaCodecBufferInfo_clazz = reinterpret_cast<jclass>(env->NewGlobalRef(
+      base::android::GetUnscopedClass(env, kMediaCodecBufferInfoClassPath)));
+  base::android::CheckException(env);
+  return true;
+}
+
+static void GetBufferInfo(JNIEnv* env, jobject buffer_info, int* offset,
+                          int* size, int64* presentation_time, int* flags) {
+  static jfieldID offset_id =
+      env->GetFieldID(g_MediaCodecBufferInfo_clazz, "offset", "I");
+  static jfieldID size_id =
+      env->GetFieldID(g_MediaCodecBufferInfo_clazz, "size", "I");
+  static jfieldID presentation_time_id =
+      env->GetFieldID(g_MediaCodecBufferInfo_clazz, "presentationTimeUs", "J");
+  static jfieldID flags_id =
+      env->GetFieldID(g_MediaCodecBufferInfo_clazz, "flags", "I");
+
+  *offset = env->GetIntField(buffer_info, offset_id);
+  *size = env->GetIntField(buffer_info, size_id);
+  *presentation_time = env->GetLongField(buffer_info, presentation_time_id);
+  *flags = env->GetIntField(buffer_info, flags_id);
+}
+
+static base::subtle::AtomicWord g_MediaCodecBufferInfo_Constructor = 0;
+static ScopedJavaLocalRef<jobject> Java_MediaCodecBufferInfo_Constructor(
+    JNIEnv* env) {
+  /* Must call RegisterNativesImpl()  */
+  DCHECK(g_MediaCodecBufferInfo_clazz);
+  jmethodID method_id =
+      base::android::MethodID::LazyGet<base::android::MethodID::TYPE_INSTANCE>(
+      env, g_MediaCodecBufferInfo_clazz,
+      "<init>", "()V",
+      &g_MediaCodecBufferInfo_Constructor);
+
+  jobject ret = env->NewObject(g_MediaCodecBufferInfo_clazz, method_id);
+  base::android::CheckException(env);
+  return ScopedJavaLocalRef<jobject>(env, ret);
+}
+
+void RegisterNativesIfNeeded(JNIEnv* env) {
+  static bool jni_initialized =

[Ami GONE FROM CHROMIUM, 2013/02/05 20:24:33]

Thanks for asking about thread-safety of this approach.  Turns out it's not safe
for chromium!
See
https://groups.google.com/a/chromium.org/forum/#!msg/chromium-dev/p6h3HC8Wro4...
for relevant info.

So, apparently the thing to do is to replace this with a LazyInstance. 
:(

[dwkang1, 2013/02/07 14:01:36]

Changed by using LazyInstance.

+      JNI_MediaCodec::RegisterNativesImpl(env)
+      && MediaCodecBufferInfo_RegisterNativesImpl(env)

[Ami GONE FROM CHROMIUM, 2013/02/05 20:24:33]

Operator (&&) belongs on previous line, here and elsewhere.

[dwkang1, 2013/02/07 14:01:36]

Done.

+      && JNI_MediaFormat::RegisterNativesImpl(env);
+  DCHECK(jni_initialized);
+}
+}  // namespace
+
+namespace media {
+
+static const char* CodecToMimeType(const MediaCodecBridge::Codec codec) {
+  switch (codec) {
+    case MediaCodecBridge::AUDIO_MPEG: return "audio/mpeg";
+    case MediaCodecBridge::VIDEO_H264: return "video/avc";
+    case MediaCodecBridge::VIDEO_VP8: return "video/x-vnd.on2.vp8";
+    default: return NULL;
+  }
+}
+
+// static
+const base::TimeDelta MediaCodecBridge::kTimeOutInfinity =
+    base::TimeDelta::FromMicroseconds(-1);
+
+MediaCodecBridge::MediaCodecBridge(const Codec codec) {
+  JNIEnv* env = AttachCurrentThread();
+  CHECK(env);
+  RegisterNativesIfNeeded(env);
+  DCHECK(CodecToMimeType(codec));
+
+  ScopedJavaLocalRef<jstring> j_type =
+      ConvertUTF8ToJavaString(env, CodecToMimeType(codec));
+
+  ScopedJavaLocalRef<jobject> tmp(
+      JNI_MediaCodec::Java_MediaCodec_createDecoderByType(env, j_type.obj()));
+  DCHECK(!tmp.is_null());
+  j_media_codec_.Reset(tmp);
+}
+
+MediaCodecBridge::~MediaCodecBridge() {
+  JNIEnv* env = AttachCurrentThread();
+  CHECK(env);
+
+  JNI_MediaCodec::Java_MediaCodec_release(env, j_media_codec_.obj());
+}
+
+void MediaCodecBridge::StartAudio(
+    const Codec codec, int sample_rate, int channel_count) {
+  JNIEnv* env = AttachCurrentThread();
+  CHECK(env);
+  DCHECK(CodecToMimeType(codec));
+
+  ScopedJavaLocalRef<jstring> j_mime =
+      ConvertUTF8ToJavaString(env, CodecToMimeType(codec));
+  ScopedJavaLocalRef<jobject> j_format(
+      JNI_MediaFormat::Java_MediaFormat_createAudioFormat(
+          env, j_mime.obj(), sample_rate, channel_count));
+  DCHECK(!j_format.is_null());
+
+  JNI_MediaCodec::Java_MediaCodec_configure(
+      env, j_media_codec_.obj(), j_format.obj(), NULL, NULL, 0);
+
+  Start();
+}
+
+void MediaCodecBridge::StartVideo(
+    const Codec codec, const gfx::Size& size, jobject surface) {
+  JNIEnv* env = AttachCurrentThread();
+  CHECK(env);
+  DCHECK(CodecToMimeType(codec));
+
+  ScopedJavaLocalRef<jstring> j_mime =
+      ConvertUTF8ToJavaString(env, CodecToMimeType(codec));
+  ScopedJavaLocalRef<jobject> j_format(
+      JNI_MediaFormat::Java_MediaFormat_createVideoFormat(
+          env, j_mime.obj(), size.width(), size.height()));
+  DCHECK(!j_format.is_null());
+
+  JNI_MediaCodec::Java_MediaCodec_configure(
+      env, j_media_codec_.obj(), j_format.obj(), surface, NULL, 0);
+
+  Start();
+}
+
+void MediaCodecBridge::Start() {
+  JNIEnv* env = AttachCurrentThread();
+  CHECK(env);
+
+  JNI_MediaCodec::Java_MediaCodec_start(env, j_media_codec_.obj());
+}
+
+void MediaCodecBridge::Flush() {
+  JNIEnv* env = AttachCurrentThread();
+  CHECK(env);
+
+  JNI_MediaCodec::Java_MediaCodec_flush(env, j_media_codec_.obj());
+}
+
+void MediaCodecBridge::Stop() {
+  JNIEnv* env = AttachCurrentThread();
+  CHECK(env);
+
+  JNI_MediaCodec::Java_MediaCodec_stop(env, j_media_codec_.obj());
+}
+
+void MediaCodecBridge::GetOutputFormat(int* format, int* width, int* height) {
+  JNIEnv* env = AttachCurrentThread();
+  CHECK(env);
+
+  ScopedJavaLocalRef<jobject> j_format(
+     JNI_MediaCodec::Java_MediaCodec_getOutputFormat(
+         env, j_media_codec_.obj()));
+  if (!j_format.is_null()) {
+    ScopedJavaLocalRef<jstring> j_key_format =
+        ConvertUTF8ToJavaString(env, "color-format");
+    *format = JNI_MediaFormat::Java_MediaFormat_getInteger(
+        env, j_format.obj(), j_key_format.obj());
+
+    ScopedJavaLocalRef<jstring> j_key_width =
+        ConvertUTF8ToJavaString(env, "width");
+    *width = JNI_MediaFormat::Java_MediaFormat_getInteger(
+        env, j_format.obj(), j_key_width.obj());
+
+    ScopedJavaLocalRef<jstring> j_key_height =
+        ConvertUTF8ToJavaString(env, "height");
+    *height = JNI_MediaFormat::Java_MediaFormat_getInteger(
+        env, j_format.obj(), j_key_height.obj());
+  }
+}
+
+void MediaCodecBridge::QueueInputBuffer(
+    int index, int offset, int size, base::TimeDelta presentation_time,
+    int flags) {
+  JNIEnv* env = AttachCurrentThread();
+  CHECK(env);
+
+  JNI_MediaCodec::Java_MediaCodec_queueInputBuffer(
+      env, j_media_codec_.obj(),
+      index, offset, size, presentation_time.InMicroseconds(), flags);
+}
+
+int MediaCodecBridge::DequeueInputBuffer(base::TimeDelta timeout) {
+  JNIEnv* env = AttachCurrentThread();
+  CHECK(env);
+
+  return JNI_MediaCodec::Java_MediaCodec_dequeueInputBuffer(
+      env, j_media_codec_.obj(), timeout.InMicroseconds());
+}
+
+int MediaCodecBridge::DequeueOutputBuffer(
+    base::TimeDelta timeout, int* offset, int* size,
+    base::TimeDelta& presentation_time, int* flags) {
+  JNIEnv* env = AttachCurrentThread();
+  CHECK(env);
+
+  ScopedJavaLocalRef<jobject> j_info(
+      Java_MediaCodecBufferInfo_Constructor(env));
+  jint j_buffer = JNI_MediaCodec::Java_MediaCodec_dequeueOutputBuffer(
+      env, j_media_codec_.obj(), j_info.obj(), timeout.InMicroseconds());
+
+  if (j_buffer >= 0) {
+    int64 presentation_time_us;
+    GetBufferInfo(
+        env, j_info.obj(), offset, size, &presentation_time_us, flags);
+    presentation_time = base::TimeDelta::FromMicroseconds(presentation_time_us);
+  }
+  return j_buffer;
+}
+
+void MediaCodecBridge::ReleaseOutputBuffer(int index, bool render) {
+  JNIEnv* env = AttachCurrentThread();
+  CHECK(env);
+
+  JNI_MediaCodec::Java_MediaCodec_releaseOutputBuffer(
+      env, j_media_codec_.obj(), index, static_cast<jboolean>(render));

[qinmin, 2013/02/05 07:43:13]

do we need static_cast for this? I think boolean and jboolean are of the same
type underneath.

[dwkang1, 2013/02/05 11:49:36]

Done.

+}
+
+int MediaCodecBridge::GetInputBuffers() {

[Ami GONE FROM CHROMIUM, 2013/02/05 20:24:33]

I think given the two unattractive facts:
1) An asymmetric API (GOB exists but GIB doesn't)
2) A method is exposed that is called exactly one exactly after another method
and so could have been inlined into it
I'd rather my API have #1 than #2.

[dwkang1, 2013/02/07 14:01:36]

Okay. I'll include this to Start().

+  JNIEnv* env = AttachCurrentThread();
+  CHECK(env);
+
+  j_input_buffers_.Reset(
+      JNI_MediaCodec::Java_MediaCodec_getInputBuffers(
+          env, j_media_codec_.obj()));
+
+  return env->GetArrayLength(j_input_buffers_.obj());
+}
+
+int MediaCodecBridge::GetOutputBuffers() {
+  JNIEnv* env = AttachCurrentThread();
+  CHECK(env);
+
+  j_output_buffers_.Reset(
+      JNI_MediaCodec::Java_MediaCodec_getOutputBuffers(
+          env, j_media_codec_.obj()));
+
+  return env->GetArrayLength(j_output_buffers_.obj());
+}
+
+size_t MediaCodecBridge::PutToInputBuffer(
+    int index, const uint8* data, int size) {
+  JNIEnv* env = AttachCurrentThread();
+  CHECK(env);
+
+  ScopedJavaLocalRef<jobject> j_buffer(
+      env, env->GetObjectArrayElement(j_input_buffers_.obj(), index));
+
+  uint8* direct_buffer =
+      static_cast<uint8*>(env->GetDirectBufferAddress(j_buffer.obj()));
+  int64 buffer_capacity = env->GetDirectBufferCapacity(j_buffer.obj());
+
+  size_t size_to_copy = (buffer_capacity < size) ? buffer_capacity : size;
+  memcpy(direct_buffer, data, size_to_copy);
+  return size_to_copy;
+}
+
+}  // namespace media
+