blob: c49c7189db765d8e45bbc63fd517429916c18829 [file] [log] [blame]
// 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/cast/net/rtp/rtp_packet_builder.h"
#include "base/big_endian.h"
#include "base/check_op.h"
namespace media {
namespace cast {
RtpPacketBuilder::RtpPacketBuilder()
: is_key_(false),
frame_id_(0),
packet_id_(0),
max_packet_id_(0),
reference_frame_id_(0),
timestamp_(0),
sequence_number_(0),
marker_(false),
payload_type_(0),
ssrc_(0) {}
void RtpPacketBuilder::SetKeyFrame(bool is_key) { is_key_ = is_key; }
void RtpPacketBuilder::SetFrameIds(uint32_t frame_id,
uint32_t reference_frame_id) {
frame_id_ = frame_id;
reference_frame_id_ = reference_frame_id;
}
void RtpPacketBuilder::SetPacketId(uint16_t packet_id) {
packet_id_ = packet_id;
}
void RtpPacketBuilder::SetMaxPacketId(uint16_t max_packet_id) {
max_packet_id_ = max_packet_id;
}
void RtpPacketBuilder::SetTimestamp(uint32_t timestamp) {
timestamp_ = timestamp;
}
void RtpPacketBuilder::SetSequenceNumber(uint16_t sequence_number) {
sequence_number_ = sequence_number;
}
void RtpPacketBuilder::SetMarkerBit(bool marker) { marker_ = marker; }
void RtpPacketBuilder::SetPayloadType(int payload_type) {
payload_type_ = payload_type;
}
void RtpPacketBuilder::SetSsrc(uint32_t ssrc) {
ssrc_ = ssrc;
}
void RtpPacketBuilder::BuildHeader(uint8_t* data, uint32_t data_length) {
BuildCommonHeader(data, data_length);
BuildCastHeader(data + kRtpHeaderLength, data_length - kRtpHeaderLength);
}
void RtpPacketBuilder::BuildCastHeader(uint8_t* data, uint32_t data_length) {
// Build header.
DCHECK_LE(kCastHeaderLength, data_length);
// Set the first 7 bytes to 0.
memset(data, 0, kCastHeaderLength);
base::BigEndianWriter big_endian_writer(reinterpret_cast<char*>(data), 56);
const bool includes_specific_frame_reference =
(is_key_ && (reference_frame_id_ != frame_id_)) ||
(!is_key_ && (reference_frame_id_ != (frame_id_ - 1)));
big_endian_writer.WriteU8((is_key_ ? 0x80 : 0) |
(includes_specific_frame_reference ? 0x40 : 0));
big_endian_writer.WriteU8(frame_id_);
big_endian_writer.WriteU16(packet_id_);
big_endian_writer.WriteU16(max_packet_id_);
if (includes_specific_frame_reference) {
big_endian_writer.WriteU8(reference_frame_id_);
}
}
void RtpPacketBuilder::BuildCommonHeader(uint8_t* data, uint32_t data_length) {
DCHECK_LE(kRtpHeaderLength, data_length);
base::BigEndianWriter big_endian_writer(reinterpret_cast<char*>(data), 96);
big_endian_writer.WriteU8(0x80);
big_endian_writer.WriteU8(payload_type_ | (marker_ ? kRtpMarkerBitMask : 0));
big_endian_writer.WriteU16(sequence_number_);
big_endian_writer.WriteU32(timestamp_);
big_endian_writer.WriteU32(ssrc_);
}
} // namespace cast
} // namespace media