1 files changed, 114 insertions, 0 deletions
diff --git a/media/mp4/avc.cc b/media/mp4/avc.cc
new file mode 100644
index 0000000..faf9939
--- /dev/null
+++ b/media/mp4/avc.cc
@@ -0,0 +1,114 @@
+// 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/mp4/avc.h"
+
+#include <algorithm>
+#include <vector>
+
+#include "media/mp4/box_definitions.h"
+#include "media/mp4/box_reader.h"
+
+namespace media {
+namespace mp4 {
+
+static const uint8 kAnnexBStartCode[] = {0, 0, 0, 1};
+static const int kAnnexBStartCodeSize = 4;
+
+static bool ConvertAVCToAnnexBInPlaceForLengthSize4(std::vector<uint8>* buf) {
+  const int kLengthSize = 4;
+  size_t pos = 0;
+  while (pos + kLengthSize < buf->size()) {
+    int nal_size = (*buf)[pos];
+    nal_size = (nal_size << 8) + (*buf)[pos+1];
+    nal_size = (nal_size << 8) + (*buf)[pos+2];
+    nal_size = (nal_size << 8) + (*buf)[pos+3];
+    std::copy(kAnnexBStartCode, kAnnexBStartCode + kAnnexBStartCodeSize,
+              buf->begin() + pos);
+    pos += kLengthSize + nal_size;
+  }
+  return pos == buf->size();
+}
+
+// static
+bool AVC::ConvertToAnnexB(int length_size, std::vector<uint8>* buffer) {
+  RCHECK(length_size == 1 || length_size == 2 || length_size == 4);
+
+  if (length_size == 4)
+    return ConvertAVCToAnnexBInPlaceForLengthSize4(buffer);
+
+  std::vector<uint8> temp;
+  temp.swap(*buffer);
+  buffer->reserve(temp.size() + 32);
+
+  size_t pos = 0;
+  while (pos + length_size < temp.size()) {
+    int nal_size = temp[pos];
+    if (length_size == 2) nal_size = (nal_size << 8) + temp[pos+1];
+    pos += length_size;
+
+    RCHECK(pos + nal_size <= temp.size());
+    buffer->insert(buffer->end(), kAnnexBStartCode,
+                   kAnnexBStartCode + kAnnexBStartCodeSize);
+    buffer->insert(buffer->end(), temp.begin() + pos,
+                   temp.begin() + pos + nal_size);
+    pos += nal_size;
+  }
+  return pos == temp.size();
+}
+
+// static
+bool AVC::InsertParameterSets(const AVCDecoderConfigurationRecord& avc_config,
+                         std::vector<uint8>* buffer) {
+  int total_size = 0;
+  for (size_t i = 0; i < avc_config.sps_list.size(); i++)
+    total_size += avc_config.sps_list[i].size() + kAnnexBStartCodeSize;
+  for (size_t i = 0; i < avc_config.pps_list.size(); i++)
+    total_size += avc_config.pps_list[i].size() + kAnnexBStartCodeSize;
+
+  std::vector<uint8> temp;
+  temp.reserve(total_size);
+
+  for (size_t i = 0; i < avc_config.sps_list.size(); i++) {
+    temp.insert(temp.end(), kAnnexBStartCode,
+                kAnnexBStartCode + kAnnexBStartCodeSize);
+    temp.insert(temp.end(), avc_config.sps_list[i].begin(),
+                avc_config.sps_list[i].end());
+  }
+
+  for (size_t i = 0; i < avc_config.pps_list.size(); i++) {
+    temp.insert(temp.end(), kAnnexBStartCode,
+                kAnnexBStartCode + kAnnexBStartCodeSize);
+    temp.insert(temp.end(), avc_config.pps_list[i].begin(),
+                avc_config.pps_list[i].end());
+  }
+
+  buffer->insert(buffer->begin(), temp.begin(), temp.end());
+  return true;
+}
+
+// static
+ChannelLayout AVC::ConvertAACChannelCountToChannelLayout(int count) {
+  switch (count) {
+    case 1:
+      return CHANNEL_LAYOUT_MONO;
+    case 2:
+      return CHANNEL_LAYOUT_STEREO;
+    case 3:
+      return CHANNEL_LAYOUT_SURROUND;
+    case 4:
+      return CHANNEL_LAYOUT_4_0;
+    case 5:
+      return CHANNEL_LAYOUT_5_0;
+    case 6:
+      return CHANNEL_LAYOUT_5_1;
+    case 8:
+      return CHANNEL_LAYOUT_7_1;
+    default:
+      return CHANNEL_LAYOUT_UNSUPPORTED;
+  }
+}
+
+}  // namespace mp4
+}  // namespace media