Line data    Source code

       1             : /*
       2             :  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
       3             :  *
       4             :  *  Use of this source code is governed by a BSD-style license
       5             :  *  that can be found in the LICENSE file in the root of the source
       6             :  *  tree. An additional intellectual property rights grant can be found
       7             :  *  in the file PATENTS.  All contributing project authors may
       8             :  *  be found in the AUTHORS file in the root of the source tree.
       9             :  */
      10             : 
      11             : // This file contains codec dependent definitions that are needed in
      12             : // order to compile the WebRTC codebase, even if this codec is not used.
      13             : 
      14             : #ifndef WEBRTC_MODULES_VIDEO_CODING_CODECS_H264_INCLUDE_H264_GLOBALS_H_
      15             : #define WEBRTC_MODULES_VIDEO_CODING_CODECS_H264_INCLUDE_H264_GLOBALS_H_
      16             : 
      17             : namespace webrtc {
      18             : 
      19             : // The packetization types that we support: single, aggregated, and fragmented.
      20             : enum H264PacketizationTypes {
      21             :   kH264SingleNalu,  // This packet contains a single NAL unit.
      22             :   kH264StapA,       // This packet contains STAP-A (single time
      23             :                     // aggregation) packets. If this packet has an
      24             :                     // associated NAL unit type, it'll be for the
      25             :                     // first such aggregated packet.
      26             :   kH264FuA,         // This packet contains a FU-A (fragmentation
      27             :                     // unit) packet, meaning it is a part of a frame
      28             :                     // that was too large to fit into a single packet.
      29             : };
      30             : 
      31             : // Packetization modes are defined in RFC 6184 section 6
      32             : // Due to the structure containing this being initialized with zeroes
      33             : // in some places, and mode 1 being default, mode 1 needs to have the value
      34             : // zero. https://crbug.com/webrtc/6803
      35             : enum class H264PacketizationMode {
      36             :   NonInterleaved = 0,  // Mode 1 - STAP-A, FU-A is allowed
      37             :   SingleNalUnit        // Mode 0 - only single NALU allowed
      38             : };
      39             : 
      40             : // This function is declared inline because it is not clear which
      41             : // .cc file it should belong to.
      42             : // TODO(hta): Refactor. https://bugs.webrtc.org/6842
      43           0 : inline std::ostream& operator<<(std::ostream& stream,
      44             :                                 H264PacketizationMode mode) {
      45           0 :   switch (mode) {
      46             :     case H264PacketizationMode::NonInterleaved:
      47           0 :       stream << "NonInterleaved";
      48           0 :       break;
      49             :     case H264PacketizationMode::SingleNalUnit:
      50           0 :       stream << "SingleNalUnit";
      51           0 :       break;
      52             :   }
      53           0 :   return stream;
      54             : }
      55             : 
      56             : struct NaluInfo {
      57             :   uint8_t type;
      58             :   int sps_id;
      59             :   int pps_id;
      60             : 
      61             :   // Offset and size are only valid for non-FuA packets.
      62             :   size_t offset;
      63             :   size_t size;
      64             : };
      65             : 
      66             : const size_t kMaxNalusPerPacket = 10;
      67             : 
      68             : struct RTPVideoHeaderH264 {
      69             :   // The NAL unit type. If this is a header for a
      70             :   // fragmented packet, it's the NAL unit type of
      71             :   // the original data. If this is the header for an
      72             :   // aggregated packet, it's the NAL unit type of
      73             :   // the first NAL unit in the packet.
      74             :   uint8_t nalu_type;
      75             :   // The packetization type of this buffer - single, aggregated or fragmented.
      76             :   H264PacketizationTypes packetization_type;
      77             :   NaluInfo nalus[kMaxNalusPerPacket];
      78             :   size_t nalus_length;
      79             :   // The packetization mode of this transport. Packetization mode
      80             :   // determines which packetization types are allowed when packetizing.
      81             :   H264PacketizationMode packetization_mode;
      82             : };
      83             : 
      84             : }  // namespace webrtc
      85             : 
      86             : #endif  // WEBRTC_MODULES_VIDEO_CODING_CODECS_H264_INCLUDE_H264_GLOBALS_H_