Move all codec specific definitions from modules_include

This CL moves all codec specific definitions into their own
header files in the respective codec directory, and replaces
it with an include in the top level directory.

This is to facilitate getting the code out of the header files.

No behavioral changes are expected.

BUG=webrtc:6842

Review-Url: https://codereview.webrtc.org/2555993003
Cr-Commit-Position: refs/heads/master@{#15623}

webrtc/modules/video_coding/codecs/h264/include/h264_globals.h

@@ -0,0 +1,86 @@
+/*
+ *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+// This file contains codec dependent definitions that are needed in
+// order to compile the WebRTC codebase, even if this codec is not used.
+
+#ifndef WEBRTC_MODULES_VIDEO_CODING_CODECS_H264_INCLUDE_H264_GLOBALS_H_
+#define WEBRTC_MODULES_VIDEO_CODING_CODECS_H264_INCLUDE_H264_GLOBALS_H_
+
+namespace webrtc {
+
+// The packetization types that we support: single, aggregated, and fragmented.
+enum H264PacketizationTypes {
+  kH264SingleNalu,  // This packet contains a single NAL unit.
+  kH264StapA,       // This packet contains STAP-A (single time
+                    // aggregation) packets. If this packet has an
+                    // associated NAL unit type, it'll be for the
+                    // first such aggregated packet.
+  kH264FuA,         // This packet contains a FU-A (fragmentation
+                    // unit) packet, meaning it is a part of a frame
+                    // that was too large to fit into a single packet.
+};
+
+// Packetization modes are defined in RFC 6184 section 6
+// Due to the structure containing this being initialized with zeroes
+// in some places, and mode 1 being default, mode 1 needs to have the value
+// zero. https://crbug.com/webrtc/6803
+enum class H264PacketizationMode {
+  NonInterleaved = 0,  // Mode 1 - STAP-A, FU-A is allowed
+  SingleNalUnit        // Mode 0 - only single NALU allowed
+};
+
+// This function is declared inline because it is not clear which
+// .cc file it should belong to.
+// TODO(hta): Refactor. https://bugs.webrtc.org/6842
+inline std::ostream& operator<<(std::ostream& stream,
+                                H264PacketizationMode mode) {
+  switch (mode) {
+    case H264PacketizationMode::NonInterleaved:
+      stream << "NonInterleaved";
+      break;
+    case H264PacketizationMode::SingleNalUnit:
+      stream << "SingleNalUnit";
+      break;
+  }
+  return stream;
+}
+
+struct NaluInfo {
+  uint8_t type;
+  int sps_id;
+  int pps_id;
+
+  // Offset and size are only valid for non-FuA packets.
+  size_t offset;
+  size_t size;
+};
+
+const size_t kMaxNalusPerPacket = 10;
+
+struct RTPVideoHeaderH264 {
+  // The NAL unit type. If this is a header for a
+  // fragmented packet, it's the NAL unit type of
+  // the original data. If this is the header for an
+  // aggregated packet, it's the NAL unit type of
+  // the first NAL unit in the packet.
+  uint8_t nalu_type;
+  // The packetization type of this buffer - single, aggregated or fragmented.
+  H264PacketizationTypes packetization_type;
+  NaluInfo nalus[kMaxNalusPerPacket];
+  size_t nalus_length;
+  // The packetization mode of this transport. Packetization mode
+  // determines which packetization types are allowed when packetizing.
+  H264PacketizationMode packetization_mode;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_VIDEO_CODING_CODECS_H264_INCLUDE_H264_GLOBALS_H_