Introducing DecoderBuffer and general Buffer cleanup.

FFmpeg expects data to be padded and aligned in a certain way. It's
currently possible to do this incorrectly and introduce dangerous issues.

I enforce padding and alignment by introducing a new Buffer called
DecoderBuffer and forcing DemuxerStream::Read to only accept it for
transfer into decoders.

DecoderBuffer allocates all memory through av_malloc (which takes care of
alignment) with the appropriate padding size (except for Android, which
doesn't care about this).

Along the way it was necessary to clean up a large smattering of code to
replace usage of DataBuffer with DecoderBuffer.

I've rolled in several cleanup actions as well:
- Moved DecryptConfig from Buffer to DecoderBuffer.
- Replaced AVPacketBuffer and av_dup_packet with a DecoderBuffer::CopyFrom.
- Fixed a resultant issue with FFmpegBitStreamConverter after removing the
  av_dup_packet functionality.  Removed some unsupported bitstream filters.
- Reduce TestDataUtil::ReadTestDataFile() to a single method returning a
  DecoderBuffer so unit tests will always have safe buffers.
- Replace new DataBuffer(0)/new DecoderBuffer(0) w/
  DecoderBuffer::CreateEOSBuffer.
- Remove extraneous IsEndOfStream check from FFmpegAudioDecoder.

BUG=129843
TEST=media_unittests + valgrind, layout tests.

Review URL: https://chromiumcodereview.appspot.com/10447035

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@139857 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 22 insertions, 20 deletions

diff --git a/media/crypto/aes_decryptor.cc b/media/crypto/aes_decryptor.cc
index 8d56d76..cbb75b3 100644
--- a/media/crypto/aes_decryptor.cc
+++ b/media/crypto/aes_decryptor.cc
@@ -9,8 +9,7 @@
 #include "base/string_piece.h"
 #include "crypto/encryptor.h"
 #include "crypto/symmetric_key.h"
-#include "media/base/buffers.h"
-#include "media/base/data_buffer.h"
+#include "media/base/decoder_buffer.h"
 #include "media/base/decrypt_config.h"
 
 namespace media {
@@ -19,10 +18,10 @@ namespace media {
 static const char kInitialCounter[] = "0000000000000000";
 
 // Decrypt |input| using |key|.
-// Return a scoped_refptr to a Buffer object with the decrypted data on success.
-// Return a scoped_refptr to NULL if the data could not be decrypted.
-static scoped_refptr<Buffer> DecryptData(const Buffer& input,
-                                         crypto::SymmetricKey* key) {
+// Return a DecoderBuffer with the decrypted data if decryption succeeded.
+// Return NULL if decryption failed.
+static scoped_refptr<DecoderBuffer> DecryptData(const DecoderBuffer& input,
+                                                crypto::SymmetricKey* key) {
   CHECK(input.GetDataSize());
   CHECK(key);
 
@@ -43,9 +42,8 @@ static scoped_refptr<Buffer> DecryptData(const Buffer& input,
     return NULL;
   }
 
-  // TODO(xhwang): Implement a string based Buffer implementation to avoid
-  // data copying.
-  return DataBuffer::CopyFrom(
+  // TODO(xhwang): Find a way to avoid this data copy.
+  return DecoderBuffer::CopyFrom(
       reinterpret_cast<const uint8*>(decrypted_text.data()),
       decrypted_text.size());
 }
@@ -81,8 +79,8 @@ void AesDecryptor::AddKey(const uint8* key_id, int key_id_size,
   key_map_[key_id_string] = symmetric_key;
 }
 
-scoped_refptr<Buffer> AesDecryptor::Decrypt(
-    const scoped_refptr<Buffer>& encrypted) {
+scoped_refptr<DecoderBuffer> AesDecryptor::Decrypt(
+    const scoped_refptr<DecoderBuffer>& encrypted) {
   CHECK(encrypted->GetDecryptConfig());
   const uint8* key_id = encrypted->GetDecryptConfig()->key_id();
   const int key_id_size = encrypted->GetDecryptConfig()->key_id_size();
@@ -101,7 +99,7 @@ scoped_refptr<Buffer> AesDecryptor::Decrypt(
     key = found->second;
   }
 
-  scoped_refptr<Buffer> decrypted = DecryptData(*encrypted, key);
+  scoped_refptr<DecoderBuffer> decrypted = DecryptData(*encrypted, key);
 
   if (decrypted) {
     decrypted->SetTimestamp(encrypted->GetTimestamp());
diff --git a/media/crypto/aes_decryptor.h b/media/crypto/aes_decryptor.h
index 212c9ac..d62528f 100644
--- a/media/crypto/aes_decryptor.h
+++ b/media/crypto/aes_decryptor.h
@@ -19,7 +19,7 @@ class SymmetricKey;
 
 namespace media {
 
-class Buffer;
+class DecoderBuffer;
 
 // Decrypts AES encrypted buffer into unencrypted buffer.
 class MEDIA_EXPORT AesDecryptor {
@@ -35,9 +35,10 @@ class MEDIA_EXPORT AesDecryptor {
               const uint8* key, int key_size);
 
   // Decrypt |input| buffer. The |input| should not be NULL.
-  // Return a Buffer that contains decrypted data if decryption succeeded.
+  // Return a DecoderBuffer with the decrypted data if decryption succeeded.
   // Return NULL if decryption failed.
-  scoped_refptr<Buffer> Decrypt(const scoped_refptr<Buffer>& input);
+  scoped_refptr<DecoderBuffer> Decrypt(
+      const scoped_refptr<DecoderBuffer>& input);
 
  private:
   // KeyMap owns the crypto::SymmetricKey* and must delete them when they are
diff --git a/media/crypto/aes_decryptor_unittest.cc b/media/crypto/aes_decryptor_unittest.cc
index 70b6881..0b33f61 100644
--- a/media/crypto/aes_decryptor_unittest.cc
+++ b/media/crypto/aes_decryptor_unittest.cc
@@ -4,7 +4,7 @@
 
 #include <string>
 
-#include "media/base/data_buffer.h"
+#include "media/base/decoder_buffer.h"
 #include "media/base/decrypt_config.h"
 #include "media/crypto/aes_decryptor.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -28,7 +28,8 @@ static const unsigned char kKeyId2[] = "Key ID 2.";
 class AesDecryptorTest : public testing::Test {
  public:
   AesDecryptorTest() {
-    encrypted_data_ = DataBuffer::CopyFrom(kEncryptedData, kEncryptedDataSize);
+    encrypted_data_ = DecoderBuffer::CopyFrom(
+        kEncryptedData, kEncryptedDataSize);
   }
 
  protected:
@@ -38,7 +39,8 @@ class AesDecryptorTest : public testing::Test {
   }
 
   void DecryptAndExpectToSucceed() {
-    scoped_refptr<Buffer> decrypted = decryptor_.Decrypt(encrypted_data_);
+    scoped_refptr<DecoderBuffer> decrypted =
+        decryptor_.Decrypt(encrypted_data_);
     ASSERT_TRUE(decrypted);
     int data_length = sizeof(kOriginalData) - 1;
     ASSERT_EQ(data_length, decrypted->GetDataSize());
@@ -46,11 +48,12 @@ class AesDecryptorTest : public testing::Test {
   }
 
   void DecryptAndExpectToFail() {
-    scoped_refptr<Buffer> decrypted = decryptor_.Decrypt(encrypted_data_);
+    scoped_refptr<DecoderBuffer> decrypted =
+        decryptor_.Decrypt(encrypted_data_);
     EXPECT_FALSE(decrypted);
   }
 
-  scoped_refptr<DataBuffer> encrypted_data_;
+  scoped_refptr<DecoderBuffer> encrypted_data_;
   AesDecryptor decryptor_;
 };