1 files changed, 99 insertions, 0 deletions
diff --git a/chromium/media/formats/mpeg/adts_stream_parser.cc b/chromium/media/formats/mpeg/adts_stream_parser.cc
new file mode 100644
index 00000000000..beb94350c9c
--- /dev/null
+++ b/chromium/media/formats/mpeg/adts_stream_parser.cc
@@ -0,0 +1,99 @@
+// Copyright 2014 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/formats/mpeg/adts_stream_parser.h"
+
+#include "media/formats/mpeg/adts_constants.h"
+
+namespace media {
+
+static const uint32 kADTSStartCodeMask = 0xfff00000;
+
+ADTSStreamParser::ADTSStreamParser()
+    : MPEGAudioStreamParserBase(kADTSStartCodeMask, kCodecAAC, 0) {}
+
+ADTSStreamParser::~ADTSStreamParser() {}
+
+int ADTSStreamParser::ParseFrameHeader(const uint8* data,
+                                       int size,
+                                       int* frame_size,
+                                       int* sample_rate,
+                                       ChannelLayout* channel_layout,
+                                       int* sample_count,
+                                       bool* metadata_frame) const {
+  DCHECK(data);
+  DCHECK_GE(size, 0);
+  DCHECK(frame_size);
+
+  if (size < 8)
+    return 0;
+
+  BitReader reader(data, size);
+  int sync;
+  int version;
+  int layer;
+  int protection_absent;
+  int profile;
+  size_t sample_rate_index;
+  size_t channel_layout_index;
+  int frame_length;
+  size_t num_data_blocks;
+  int unused;
+
+  if (!reader.ReadBits(12, &sync) ||
+      !reader.ReadBits(1, &version) ||
+      !reader.ReadBits(2, &layer) ||
+      !reader.ReadBits(1, &protection_absent) ||
+      !reader.ReadBits(2, &profile) ||
+      !reader.ReadBits(4, &sample_rate_index) ||
+      !reader.ReadBits(1, &unused) ||
+      !reader.ReadBits(3, &channel_layout_index) ||
+      !reader.ReadBits(4, &unused) ||
+      !reader.ReadBits(13, &frame_length) ||
+      !reader.ReadBits(11, &unused) ||
+      !reader.ReadBits(2, &num_data_blocks) ||
+      (!protection_absent && !reader.ReadBits(16, &unused))) {
+    return -1;
+  }
+
+  DVLOG(2) << "Header data :" << std::hex
+           << " sync 0x" << sync
+           << " version 0x" << version
+           << " layer 0x" << layer
+           << " profile 0x" << profile
+           << " sample_rate_index 0x" << sample_rate_index
+           << " channel_layout_index 0x" << channel_layout_index;
+
+  const int bytes_read = reader.bits_read() / 8;
+  if (sync != 0xfff || layer != 0 || frame_length < bytes_read ||
+      sample_rate_index >= kADTSFrequencyTableSize ||
+      channel_layout_index >= kADTSChannelLayoutTableSize) {
+    MEDIA_LOG(log_cb()) << "Invalid header data :" << std::hex
+                        << " sync 0x" << sync
+                        << " version 0x" << version
+                        << " layer 0x" << layer
+                        << " sample_rate_index 0x" << sample_rate_index
+                        << " channel_layout_index 0x" << channel_layout_index;
+    return -1;
+  }
+
+  if (sample_rate)
+    *sample_rate = kADTSFrequencyTable[sample_rate_index];
+
+  if (frame_size)
+    *frame_size = frame_length;
+
+  if (sample_count)
+    *sample_count = (num_data_blocks + 1) * kSamplesPerAACFrame;
+
+  if (channel_layout)
+    *channel_layout = kADTSChannelLayoutTable[channel_layout_index];
+
+  if (metadata_frame)
+    *metadata_frame = false;
+
+  return bytes_read;
+}
+
+}  // namespace media