Refactor MediaCodecBridge to add support for NDK APIs

media/base/android/ndk_media_codec_wrapper.cc

+// Copyright 2015 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.
+
+// The file defines the symbols from NDKMediaCodec that android is using. It
+// then loads the library dynamically on first use.
+
+#include <media/NdkMediaCodec.h>
+#include <media/NdkMediaFormat.h>
+
+#include "base/files/file_path.h"
+#include "base/logging.h"
+#include "base/native_library.h"
+
+#define LOOKUP_FUNC(func_name, return_type, args, arg_names)                   \
+  return_type func_name args {                                                 \
+    typedef return_type(*signature) args;                                      \
+    static signature g_##func_name =                                           \
+        reinterpret_cast<signature>(base::GetFunctionPointerFromNativeLibrary( \
+            LibraryHandle(), #func_name));                                     \
+    return g_##func_name arg_names;                                            \
+  }
+
+// The constants used in chromium. Those symbols are defined as extern symbols
+// in the NdkMediaFormat headers. They will be initialized to their correct
+// values when the library is loaded.
+const char* AMEDIAFORMAT_KEY_HEIGHT;
+const char* AMEDIAFORMAT_KEY_SAMPLE_RATE;
+const char* AMEDIAFORMAT_KEY_WIDTH;
+
+namespace {
+
+// The name of the library to load.
+const char kMediaNDKLibraryName[] = "libmediandk.so";
+
+// Loads the OpenSLES library, and initializes all the proxies.
+base::NativeLibrary IntializeLibraryHandle() {
+  base::NativeLibrary handle =
+      base::LoadNativeLibrary(base::FilePath(kMediaNDKLibraryName), NULL);
+  DCHECK(handle) << "Unable to load " << kMediaNDKLibraryName;
+
+  // Setup the proxy for each symbol.
+  // Attach the symbol name to the proxy address.
+  struct SymbolDefinition {
+    const char* name;
+    const char** value;
+  };
+
+  // The list of defined symbols.
+  const SymbolDefinition kSymbols[] = {
+      {"AMEDIAFORMAT_KEY_HEIGHT", &AMEDIAFORMAT_KEY_HEIGHT},
+      {"AMEDIAFORMAT_KEY_SAMPLE_RATE", &AMEDIAFORMAT_KEY_SAMPLE_RATE},
+      {"AMEDIAFORMAT_KEY_SAMPLE_RATE", &AMEDIAFORMAT_KEY_SAMPLE_RATE},
+  };
+
+  for (size_t i = 0; i < sizeof(kSymbols) / sizeof(kSymbols[0]); ++i) {
+    memcpy(kSymbols[i].value,
+           base::GetFunctionPointerFromNativeLibrary(handle, kSymbols[i].name),
+           sizeof(char*));
+    DCHECK(*kSymbols[i].value) << "Unable to find symbol for "
+                               << kSymbols[i].name;
+  }
+  return handle;
+}
+
+// Returns the handler to the shared library. The library itself will be lazily
+// loaded during the first call to this function.
+base::NativeLibrary LibraryHandle() {
+  // The handle is lazily initialized on the first call.
+  static base::NativeLibrary g_mediandk_LibraryHandle =
+      IntializeLibraryHandle();
+  return g_mediandk_LibraryHandle;
+}
+}
+
+LOOKUP_FUNC(AMediaCodec_createDecoderByType,
+            AMediaCodec*,
+            (const char* mime_type),
+            (mime_type));
+LOOKUP_FUNC(AMediaCodec_createEncoderByType,
+            AMediaCodec*,
+            (const char* mime_type),
+            (mime_type));
+LOOKUP_FUNC(AMediaCodec_delete, media_status_t, (AMediaCodec * codec), (codec));
+LOOKUP_FUNC(AMediaCodec_configure,
+            media_status_t,
+            (AMediaCodec * codec,
+             const AMediaFormat* format,
+             ANativeWindow* surface,
+             AMediaCrypto* crypto,
+             uint32_t flags),
+            (codec, format, surface, crypto, flags));
+LOOKUP_FUNC(AMediaCodec_start, media_status_t, (AMediaCodec * codec), (codec));
+LOOKUP_FUNC(AMediaCodec_stop, media_status_t, (AMediaCodec * codec), (codec));
+LOOKUP_FUNC(AMediaCodec_flush, media_status_t, (AMediaCodec * codec), (codec));
+LOOKUP_FUNC(AMediaCodec_getInputBuffer,
+            uint8_t*,
+            (AMediaCodec * codec, size_t idx, size_t* out_size),
+            (codec, idx, out_size));
+LOOKUP_FUNC(AMediaCodec_getOutputBuffer,
+            uint8_t*,
+            (AMediaCodec * codec, size_t idx, size_t* out_size),
+            (codec, idx, out_size));
+LOOKUP_FUNC(AMediaCodec_dequeueInputBuffer,
+            ssize_t,
+            (AMediaCodec * codec, int64_t timeoutUs),
+            (codec, timeoutUs));
+LOOKUP_FUNC(AMediaCodec_queueInputBuffer,
+            media_status_t,
+            (AMediaCodec * codec,
+             size_t idx,
+             off_t offset,
+             size_t size,
+             uint64_t time,
+             uint32_t flags),
+            (codec, idx, offset, size, time, flags));
+LOOKUP_FUNC(AMediaCodec_queueSecureInputBuffer,
+            media_status_t,
+            (AMediaCodec * codec,
+             size_t idx,
+             off_t offset,
+             AMediaCodecCryptoInfo* cryto,
+             uint64_t time,
+             uint32_t flags),
+            (codec, idx, offset, cryto, time, flags));
+LOOKUP_FUNC(AMediaCodec_dequeueInputBuffer,
+            ssize_t,
+            (AMediaCodec * codec,
+             AMediaCodecBufferInfo* info,
+             int64_t timeoutUs),
+            (codec, info, timeoutUs));
+LOOKUP_FUNC(AMediaCodec_dequeueOutputBuffer,
+            ssize_t,
+            (AMediaCodec * codec,
+             AMediaCodecBufferInfo* info,
+             int64_t timeoutUs),
+            (codec, info, timeoutUs));
+LOOKUP_FUNC(AMediaCodec_getOutputFormat,
+            AMediaFormat*,
+            (AMediaCodec * codec),
+            (codec));
+LOOKUP_FUNC(AMediaCodec_releaseOutputBuffer,
+            media_status_t,
+            (AMediaCodec * codec, size_t idx, bool render),
+            (codec, idx, render));
+LOOKUP_FUNC(AMediaCodecCryptoInfo_new,
+            AMediaCodecCryptoInfo*,
+            (int num_subsamples,
+             uint8_t key[16],
+             uint8_t iv[16],
+             cryptoinfo_mode_t mode,
+             size_t* clear_bytes,
+             size_t* encrypted_bytes),
+            (num_subsamples, key, iv, mode, clear_bytes, encrypted_bytes));
+LOOKUP_FUNC(AMediaCodecCryptoInfo_delete,
+            media_status_t,
+            (AMediaCodecCryptoInfo * info),
+            (info));
+LOOKUP_FUNC(AMediaFormat_getInt32,
+            bool,
+            (AMediaFormat * format, const char* name, int32_t* out),
+            (format, name, out));