Introducing DecoderBuffer and general Buffer cleanup.

media/base/decoder_buffer.cc

+// Copyright (c) 2012 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/decoder_buffer.h"
+
+#include "base/logging.h"
+#include "media/base/decrypt_config.h"
+#if !defined(OS_ANDROID)
+#include "media/ffmpeg/ffmpeg_common.h"
+#endif
+
+namespace media {
+
+DecoderBuffer::DecoderBuffer(int buffer_size)
+    : Buffer(base::TimeDelta(), base::TimeDelta()),
+      buffer_size_(buffer_size) {
+  Initialize();
+}
+
+DecoderBuffer::DecoderBuffer(const uint8* data, int buffer_size)
+    : Buffer(base::TimeDelta(), base::TimeDelta()),
+      buffer_size_(data == NULL ? -1 : buffer_size) {
+  Initialize();
+  memcpy(data_, data, buffer_size_);
+}
+
+DecoderBuffer::~DecoderBuffer() {
+#if !defined(OS_ANDROID)
+  av_free(data_);
+#else
+  delete[] data_;
+#endif
+}
+
+void DecoderBuffer::Initialize() {
+  // Prevent invalid allocations.  Also used to create End Of Stream buffers.
+  if (buffer_size_ < 0) {
+    buffer_size_ = 0;
+    data_ = NULL;
+    return;
+  }
+
+#if !defined(OS_ANDROID)
+  // Why FF_INPUT_BUFFER_PADDING_SIZE?  FFmpeg assumes all input buffers are
+  // padded.  Using av_malloc with padding ensures FFmpeg only recieves data
+  // padded and aligned to its specifications.
+  data_ = reinterpret_cast<uint8*>(
+      av_malloc(buffer_size_ + FF_INPUT_BUFFER_PADDING_SIZE));
+  memset(data_ + buffer_size_, 0, FF_INPUT_BUFFER_PADDING_SIZE);
+#else
+  data_ = new uint8[buffer_size_];
+#endif
+}
+
+scoped_refptr<DecoderBuffer> DecoderBuffer::CopyFrom(const uint8* data,
+                                                     int data_size) {
+  return make_scoped_refptr(new DecoderBuffer(data, data_size));
+}
+
+scoped_refptr<DecoderBuffer> DecoderBuffer::CreateEOSBuffer() {
+  return make_scoped_refptr(new DecoderBuffer(-1));

[scherkus (not reviewing), 2012/05/30 00:45:19]

hrm.. doesn't this mean clients can call DataBuffer(-1) instead of this method?

I think I mentioned this somewhere else where it'd be preferable to crash on bad
input (i.e., DataBuffer(-1), CopyFrom(NULL, 0) -- how can I copy a NULL
pointer?), even it means we have to duplicate a few lines of code

[DaleCurtis, 2012/05/30 02:28:25]

Done. Public interfaces DCHECK() this behavior. Internally, the call is still
the same though.

+}
+
+const uint8* DecoderBuffer::GetData() const {
+  return data_;
+}
+
+int DecoderBuffer::GetDataSize() const {
+  return buffer_size_;
+}
+
+uint8* DecoderBuffer::GetWritableData() {
+  return data_;
+}
+
+const DecryptConfig* DecoderBuffer::GetDecryptConfig() const {
+  return decrypt_config_.get();
+}
+
+void DecoderBuffer::SetDecryptConfig(scoped_ptr<DecryptConfig> decrypt_config) {
+  decrypt_config_ = decrypt_config.Pass();
+}
+
+}  // namespace media