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| author | sergeyu@chromium.org <sergeyu@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> | 2010-10-20 23:53:49 +0000 |
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| committer | sergeyu@chromium.org <sergeyu@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> | 2010-10-20 23:53:49 +0000 |
| commit | aacbaac07bef57ef5ae79c2bb73cc493697523a3 (patch) | |
| tree | 9b3b167c132d69268133c9a7cf845b2808e3b693 /remoting/protocol/rtp_utils.cc | |
| parent | 2d39c51b903086f01adf5470ee6725ced14df8ee (diff) | |
| download | chromium_src-aacbaac07bef57ef5ae79c2bb73cc493697523a3.zip chromium_src-aacbaac07bef57ef5ae79c2bb73cc493697523a3.tar.gz chromium_src-aacbaac07bef57ef5ae79c2bb73cc493697523a3.tar.bz2 | |
Simple RTP reader/writer.
This is an implementation of simple RTP reader and writer. It still lacks proper support of VP8 payload header. Will implement it in another CL.
BUG=None
TEST=None
Review URL: http://codereview.chromium.org/3829007
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@63294 0039d316-1c4b-4281-b951-d872f2087c98
Diffstat (limited to 'remoting/protocol/rtp_utils.cc')
| -rw-r--r-- | remoting/protocol/rtp_utils.cc | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/remoting/protocol/rtp_utils.cc b/remoting/protocol/rtp_utils.cc new file mode 100644 index 0000000..df10af2 --- /dev/null +++ b/remoting/protocol/rtp_utils.cc @@ -0,0 +1,90 @@ +// Copyright (c) 2010 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 "remoting/protocol/rtp_utils.h" + +#include "base/logging.h" +#include "third_party/libjingle/source/talk/base/byteorder.h" + +using talk_base::GetBE16; +using talk_base::GetBE32; +using talk_base::SetBE16; +using talk_base::SetBE32; + +namespace remoting { + +namespace { +const int kRtpBaseHeaderSize = 12; +const uint8 kRtpVersionNumber = 2; +const int kRtpMaxSources = 16; +} // namespace + +int GetRtpHeaderSize(int sources) { + DCHECK_GE(sources, 0); + DCHECK_LT(sources, kRtpMaxSources); + return kRtpBaseHeaderSize + sources * 4; +} + +void PackRtpHeader(uint8* buffer, int buffer_size, + const RtpHeader& header) { + DCHECK_LT(header.sources, kRtpMaxSources); + DCHECK_LT(header.payload_type, 1 << 7); + CHECK_GT(buffer_size, GetRtpHeaderSize(header.sources)); + + buffer[0] = (kRtpVersionNumber << 6) + + ((uint8)header.padding << 5) + + ((uint8)header.extension << 4) + + header.sources; + buffer[1] = ((uint8)header.marker << 7) + + header.payload_type; + SetBE16(buffer + 2, header.sequence_number); + SetBE32(buffer + 4, header.timestamp); + SetBE32(buffer + 8, header.sync_source_id); + + for (int i = 0; i < header.sources; i++) { + SetBE32(buffer + i * 4 + 12, header.source_id[i]); + } +} + +static inline uint8 ExtractBits(uint8 byte, int bits_count, int shift) { + return (byte >> shift) && ((1 << bits_count) - 1); +} + +int UnpackRtpHeader(const uint8* buffer, int buffer_size, RtpHeader* header) { + DCHECK_LT(header->sources, 1 << 4); + DCHECK_LT(header->payload_type, 1 << 7); + + if (buffer_size < kRtpBaseHeaderSize) { + return -1; + } + + int version = ExtractBits(buffer[0], 2, 6); + if (version != kRtpVersionNumber) { + return -1; + } + + header->padding = ExtractBits(buffer[0], 1, 5) != 0; + header->extension = ExtractBits(buffer[0], 1, 4) != 0; + header->sources = ExtractBits(buffer[0], 4, 0); + + header->marker = ExtractBits(buffer[1], 1, 7) != 0; + header->sources = ExtractBits(buffer[1], 7, 0); + + header->sequence_number = GetBE16(buffer + 2); + header->timestamp = GetBE32(buffer + 4); + header->sync_source_id = GetBE32(buffer + 8); + + DCHECK_LE(header->sources, 16); + + if (buffer_size < GetRtpHeaderSize(header->sources)) { + return -1; + } + for (int i = 0; i < header->sources; i++) { + header->source_id[i] = GetBE32(buffer + i * 4 + 12); + } + + return GetRtpHeaderSize(header->sources); +} + +} // namespace remoting |