Index: webrtc/modules/rtp_rtcp/source/rtcp_packet/tmmbn.cc |
diff --git a/webrtc/modules/rtp_rtcp/source/rtcp_packet/tmmbn.cc b/webrtc/modules/rtp_rtcp/source/rtcp_packet/tmmbn.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..fd0219cf82076a7227cb3188d558e252856365f1 |
--- /dev/null |
+++ b/webrtc/modules/rtp_rtcp/source/rtcp_packet/tmmbn.cc |
@@ -0,0 +1,119 @@ |
+/* |
+ * Copyright (c) 2016 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. |
+ */ |
+ |
+#include "webrtc/modules/rtp_rtcp/source/rtcp_packet/tmmbn.h" |
+ |
+#include "webrtc/base/logging.h" |
+#include "webrtc/modules/rtp_rtcp/source/byte_io.h" |
+ |
+using webrtc::RTCPUtility::PT_RTPFB; |
+using webrtc::RTCPUtility::RTCPPacketRTPFBTMMBN; |
+using webrtc::RTCPUtility::RTCPPacketRTPFBTMMBRItem; |
+ |
+namespace webrtc { |
+namespace rtcp { |
+namespace { |
+const uint32_t kUnusedMediaSourceSsrc0 = 0; |
+void AssignUWord8(uint8_t* buffer, size_t* offset, uint8_t value) { |
+ buffer[(*offset)++] = value; |
+} |
+void AssignUWord32(uint8_t* buffer, size_t* offset, uint32_t value) { |
tommi
2016/01/11 15:45:40
empty line above this one
|
+ ByteWriter<uint32_t>::WriteBigEndian(buffer + *offset, value); |
+ *offset += 4; |
+} |
+ |
+void ComputeMantissaAnd6bitBase2Exponent(uint32_t input_base10, |
+ uint8_t bits_mantissa, |
+ uint32_t* mantissa, |
+ uint8_t* exp) { |
+ // input_base10 = mantissa * 2^exp |
+ assert(bits_mantissa <= 32); |
+ uint32_t mantissa_max = (1 << bits_mantissa) - 1; |
+ uint8_t exponent = 0; |
+ for (uint32_t i = 0; i < 64; ++i) { |
+ if (input_base10 <= (mantissa_max << i)) { |
+ exponent = i; |
+ break; |
+ } |
+ } |
+ *exp = exponent; |
+ *mantissa = (input_base10 >> exponent); |
+} |
+ |
+void CreateTmmbrItem(const RTCPPacketRTPFBTMMBRItem& tmmbr_item, |
+ uint8_t* buffer, |
+ size_t* pos) { |
+ uint32_t bitrate_bps = tmmbr_item.MaxTotalMediaBitRate * 1000; |
+ uint32_t mantissa = 0; |
+ uint8_t exp = 0; |
+ ComputeMantissaAnd6bitBase2Exponent(bitrate_bps, 17, &mantissa, &exp); |
+ |
+ AssignUWord32(buffer, pos, tmmbr_item.SSRC); |
+ AssignUWord8(buffer, pos, (exp << 2) + ((mantissa >> 15) & 0x03)); |
+ AssignUWord8(buffer, pos, mantissa >> 7); |
+ AssignUWord8(buffer, pos, (mantissa << 1) + |
+ ((tmmbr_item.MeasuredOverhead >> 8) & 0x01)); |
+ AssignUWord8(buffer, pos, tmmbr_item.MeasuredOverhead); |
+} |
+ |
+// Temporary Maximum Media Stream Bit Rate Notification (TMMBN) (RFC 5104). |
+// |
+// FCI: |
+// |
+// 0 1 2 3 |
+// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
+// | SSRC | |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
+// | MxTBR Exp | MxTBR Mantissa |Measured Overhead| |
+// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
+ |
+void CreateTmmbn(const RTCPPacketRTPFBTMMBN& tmmbn, |
+ const std::vector<RTCPPacketRTPFBTMMBRItem>& tmmbn_items, |
+ uint8_t* buffer, |
+ size_t* pos) { |
+ AssignUWord32(buffer, pos, tmmbn.SenderSSRC); |
+ AssignUWord32(buffer, pos, kUnusedMediaSourceSsrc0); |
+ for (uint8_t i = 0; i < tmmbn_items.size(); ++i) { |
+ CreateTmmbrItem(tmmbn_items[i], buffer, pos); |
+ } |
+} |
+} // namespace |
+ |
+bool Tmmbn::WithTmmbr(uint32_t ssrc, uint32_t bitrate_kbps, uint16_t overhead) { |
+ assert(overhead <= 0x1ff); |
tommi
2016/01/11 15:45:40
use RTC_DCHECK
|
+ if (tmmbn_items_.size() >= kMaxNumberOfTmmbrs) { |
tommi
2016/01/11 15:45:40
assuming single threaded? If so, please use Threa
|
+ LOG(LS_WARNING) << "Max TMMBN size reached."; |
+ return false; |
+ } |
+ RTCPPacketRTPFBTMMBRItem tmmbn_item; |
+ tmmbn_item.SSRC = ssrc; |
+ tmmbn_item.MaxTotalMediaBitRate = bitrate_kbps; |
+ tmmbn_item.MeasuredOverhead = overhead; |
+ tmmbn_items_.push_back(tmmbn_item); |
+ return true; |
+} |
+ |
+bool Tmmbn::Create(uint8_t* packet, |
+ size_t* index, |
+ size_t max_length, |
+ RtcpPacket::PacketReadyCallback* callback) const { |
+ while (*index + BlockLength() > max_length) { |
tommi
2016/01/11 15:45:40
would also be good to state the threading model he
|
+ if (!OnBufferFull(packet, index, callback)) |
+ return false; |
+ } |
+ const uint8_t kFmt = 4; |
+ CreateHeader(kFmt, PT_RTPFB, HeaderLength(), packet, index); |
+ CreateTmmbn(tmmbn_, tmmbn_items_, packet, index); |
+ return true; |
+} |
+ |
+} // namespace rtcp |
+} // namespace webrtc |