test/rtp_file_reader.cc - src/webrtc - Git at Google

 /*
  *  Copyright (c) 2014 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/test/rtp_file_reader.h"

 #include <stdio.h>

 #include <map>
 #include <string>
 #include <vector>

 #include "webrtc/modules/rtp_rtcp/source/rtp_utility.h"
 #include "webrtc/rtc_base/checks.h"
 #include "webrtc/rtc_base/constructormagic.h"
 #include "webrtc/rtc_base/format_macros.h"
 #include "webrtc/rtc_base/logging.h"

 namespace webrtc {
 namespace test {

 static const size_t kFirstLineLength = 40;
 static uint16_t kPacketHeaderSize = 8;

 #define TRY(expr)                                      \
   do {                                                 \
     if (!(expr)) {                                     \
       LOG(LS_INFO) << "Failed to read";                \
       return false;                                    \
     }                                                  \
   } while (0)

 bool ReadUint32(uint32_t* out, FILE* file) {
   *out = 0;
   for (size_t i = 0; i < 4; ++i) {
     *out <<= 8;
     uint8_t tmp;
     if (fread(&tmp, 1, sizeof(uint8_t), file) != sizeof(uint8_t))
       return false;
     *out |= tmp;
   }
   return true;
 }

 bool ReadUint16(uint16_t* out, FILE* file) {
   *out = 0;
   for (size_t i = 0; i < 2; ++i) {
     *out <<= 8;
     uint8_t tmp;
     if (fread(&tmp, 1, sizeof(uint8_t), file) != sizeof(uint8_t))
       return false;
     *out |= tmp;
   }
   return true;
 }

 class RtpFileReaderImpl : public RtpFileReader {
  public:
   virtual bool Init(const std::string& filename,
                     const std::set<uint32_t>& ssrc_filter) = 0;
 };

 class InterleavedRtpFileReader : public RtpFileReaderImpl {
  public:
   virtual ~InterleavedRtpFileReader() {
     if (file_ != NULL) {
       fclose(file_);
       file_ = NULL;
     }
   }

   virtual bool Init(const std::string& filename,
                     const std::set<uint32_t>& ssrc_filter) {
     file_ = fopen(filename.c_str(), "rb");
     if (file_ == NULL) {
       printf("ERROR: Can't open file: %s\n", filename.c_str());
       return false;
     }
     return true;
   }
   virtual bool NextPacket(RtpPacket* packet) {
     assert(file_ != NULL);
     packet->length = RtpPacket::kMaxPacketBufferSize;
     uint32_t len = 0;
     TRY(ReadUint32(&len, file_));
     if (packet->length < len) {
       FATAL() << "Packet is too large to fit: " << len << " bytes vs "
               << packet->length
               << " bytes allocated. Consider increasing the buffer "
                  "size";
     }
     if (fread(packet->data, 1, len, file_) != len)
       return false;

     packet->length = len;
     packet->original_length = len;
     packet->time_ms = time_ms_;
     time_ms_ += 5;
     return true;
   }

  private:
   FILE* file_ = NULL;
   int64_t time_ms_ = 0;
 };

 // Read RTP packets from file in rtpdump format, as documented at:
 // http://www.cs.columbia.edu/irt/software/rtptools/
 class RtpDumpReader : public RtpFileReaderImpl {
  public:
   RtpDumpReader() : file_(NULL) {}
   virtual ~RtpDumpReader() {
     if (file_ != NULL) {
       fclose(file_);
       file_ = NULL;
     }
   }

   bool Init(const std::string& filename,
             const std::set<uint32_t>& ssrc_filter) override {
     file_ = fopen(filename.c_str(), "rb");
     if (file_ == NULL) {
       printf("ERROR: Can't open file: %s\n", filename.c_str());
       return false;
     }

     char firstline[kFirstLineLength + 1] = {0};
     if (fgets(firstline, kFirstLineLength, file_) == NULL) {
       LOG(LS_INFO) << "Can't read from file";
       return false;
     }
     if (strncmp(firstline, "#!rtpplay", 9) == 0) {
       if (strncmp(firstline, "#!rtpplay1.0", 12) != 0) {
         LOG(LS_INFO) <<  "Wrong rtpplay version, must be 1.0";
         return false;
       }
     } else if (strncmp(firstline, "#!RTPencode", 11) == 0) {
       if (strncmp(firstline, "#!RTPencode1.0", 14) != 0) {
         LOG(LS_INFO) << "Wrong RTPencode version, must be 1.0";
         return false;
       }
     } else {
       LOG(LS_INFO) << "Wrong file format of input file";
       return false;
     }

     uint32_t start_sec;
     uint32_t start_usec;
     uint32_t source;
     uint16_t port;
     uint16_t padding;
     TRY(ReadUint32(&start_sec, file_));
     TRY(ReadUint32(&start_usec, file_));
     TRY(ReadUint32(&source, file_));
     TRY(ReadUint16(&port, file_));
     TRY(ReadUint16(&padding, file_));

     return true;
   }

   bool NextPacket(RtpPacket* packet) override {
     uint8_t* rtp_data = packet->data;
     packet->length = RtpPacket::kMaxPacketBufferSize;

     uint16_t len;
     uint16_t plen;
     uint32_t offset;
     TRY(ReadUint16(&len, file_));
     TRY(ReadUint16(&plen, file_));
     TRY(ReadUint32(&offset, file_));

     // Use 'len' here because a 'plen' of 0 specifies rtcp.
     len -= kPacketHeaderSize;
     if (packet->length < len) {
       FATAL() << "Packet is too large to fit: " << len << " bytes vs "
               << packet->length
               << " bytes allocated. Consider increasing the buffer "
                  "size";
     }
     if (fread(rtp_data, 1, len, file_) != len) {
       return false;
     }

     packet->length = len;
     packet->original_length = plen;
     packet->time_ms = offset;
     return true;
   }

  private:
   FILE* file_;

   RTC_DISALLOW_COPY_AND_ASSIGN(RtpDumpReader);
 };

 enum {
   kResultFail = -1,
   kResultSuccess = 0,
   kResultSkip = 1,

   kPcapVersionMajor = 2,
   kPcapVersionMinor = 4,
   kLinktypeNull = 0,
   kLinktypeEthernet = 1,
   kBsdNullLoopback1 = 0x00000002,
   kBsdNullLoopback2 = 0x02000000,
   kEthernetIIHeaderMacSkip = 12,
   kEthertypeIp = 0x0800,
   kIpVersion4 = 4,
   kMinIpHeaderLength = 20,
   kFragmentOffsetClear = 0x0000,
   kFragmentOffsetDoNotFragment = 0x4000,
   kProtocolTcp = 0x06,
   kProtocolUdp = 0x11,
   kUdpHeaderLength = 8,
   kMaxReadBufferSize = 4096
 };

 const uint32_t kPcapBOMSwapOrder = 0xd4c3b2a1UL;
 const uint32_t kPcapBOMNoSwapOrder = 0xa1b2c3d4UL;

 #define TRY_PCAP(expr)                                 \
   do {                                                 \
     int r = (expr);                                    \
     if (r == kResultFail) {                            \
       LOG(LS_INFO) << "FAIL at " << __FILE__  << ":" << __LINE__; \
       return kResultFail;                              \
     } else if (r == kResultSkip) {                     \
       return kResultSkip;                              \
     }                                                  \
   } while (0)

 // Read RTP packets from file in tcpdump/libpcap format, as documented at:
 // http://wiki.wireshark.org/Development/LibpcapFileFormat
 class PcapReader : public RtpFileReaderImpl {
  public:
   PcapReader()
     : file_(NULL),
       swap_pcap_byte_order_(false),
 #ifdef WEBRTC_ARCH_BIG_ENDIAN
       swap_network_byte_order_(false),
 #else
       swap_network_byte_order_(true),
 #endif
       read_buffer_(),
       packets_by_ssrc_(),
       packets_(),
       next_packet_it_() {
   }

   virtual ~PcapReader() {
     if (file_ != NULL) {
       fclose(file_);
       file_ = NULL;
     }
   }

   bool Init(const std::string& filename,
             const std::set<uint32_t>& ssrc_filter) override {
     return Initialize(filename, ssrc_filter) == kResultSuccess;
   }

   int Initialize(const std::string& filename,
                  const std::set<uint32_t>& ssrc_filter) {
     file_ = fopen(filename.c_str(), "rb");
     if (file_ == NULL) {
       printf("ERROR: Can't open file: %s\n", filename.c_str());
       return kResultFail;
     }

     if (ReadGlobalHeader() < 0) {
       return kResultFail;
     }

     int total_packet_count = 0;
     uint32_t stream_start_ms = 0;
     int32_t next_packet_pos = ftell(file_);
     for (;;) {
       TRY_PCAP(fseek(file_, next_packet_pos, SEEK_SET));
       int result = ReadPacket(&next_packet_pos, stream_start_ms,
                               ++total_packet_count, ssrc_filter);
       if (result == kResultFail) {
         break;
       } else if (result == kResultSuccess && packets_.size() == 1) {
         assert(stream_start_ms == 0);
         PacketIterator it = packets_.begin();
         stream_start_ms = it->time_offset_ms;
         it->time_offset_ms = 0;
       }
     }

     if (feof(file_) == 0) {
       printf("Failed reading file!\n");
       return kResultFail;
     }

     printf("Total packets in file: %d\n", total_packet_count);
     printf("Total RTP/RTCP packets: %" PRIuS "\n", packets_.size());

     for (SsrcMapIterator mit = packets_by_ssrc_.begin();
         mit != packets_by_ssrc_.end(); ++mit) {
       uint32_t ssrc = mit->first;
       const std::vector<uint32_t>& packet_indices = mit->second;
       uint8_t pt = packets_[packet_indices[0]].rtp_header.payloadType;
       printf("SSRC: %08x, %" PRIuS " packets, pt=%d\n", ssrc,
              packet_indices.size(), pt);
     }

     // TODO(solenberg): Better validation of identified SSRC streams.
     //
     // Since we're dealing with raw network data here, we will wrongly identify
     // some packets as RTP. When these packets are consumed by RtpPlayer, they
     // are unlikely to cause issues as they will ultimately be filtered out by
     // the RtpRtcp module. However, we should really do better filtering here,
     // which we can accomplish in a number of ways, e.g.:
     //
     // - Verify that the time stamps and sequence numbers for RTP packets are
     //   both increasing/decreasing. If they move in different directions, the
     //   SSRC is likely bogus and can be dropped. (Normally they should be inc-
     //   reasing but we must allow packet reordering).
     // - If RTP sequence number is not changing, drop the stream.
     // - Can also use srcip:port->dstip:port pairs, assuming few SSRC collisions
     //   for up/down streams.

     next_packet_it_ = packets_.begin();
     return kResultSuccess;
   }

   bool NextPacket(RtpPacket* packet) override {
     uint32_t length = RtpPacket::kMaxPacketBufferSize;
     if (NextPcap(packet->data, &length, &packet->time_ms) != kResultSuccess)
       return false;
     packet->length = static_cast<size_t>(length);
     packet->original_length = packet->length;
     return true;
   }

   virtual int NextPcap(uint8_t* data, uint32_t* length, uint32_t* time_ms) {
     assert(data);
     assert(length);
     assert(time_ms);

     if (next_packet_it_ == packets_.end()) {
       return -1;
     }
     if (*length < next_packet_it_->payload_length) {
       return -1;
     }
     TRY_PCAP(fseek(file_, next_packet_it_->pos_in_file, SEEK_SET));
     TRY_PCAP(Read(data, next_packet_it_->payload_length));
     *length = next_packet_it_->payload_length;
     *time_ms = next_packet_it_->time_offset_ms;
     next_packet_it_++;

     return 0;
   }

  private:
   // A marker of an RTP packet within the file.
   struct RtpPacketMarker {
     uint32_t packet_number;   // One-based index (like in WireShark)
     uint32_t time_offset_ms;
     uint32_t source_ip;
     uint32_t dest_ip;
     uint16_t source_port;
     uint16_t dest_port;
     RTPHeader rtp_header;
     int32_t pos_in_file;      // Byte offset of payload from start of file.
     uint32_t payload_length;
   };

   typedef std::vector<RtpPacketMarker>::iterator PacketIterator;
   typedef std::map<uint32_t, std::vector<uint32_t> > SsrcMap;
   typedef std::map<uint32_t, std::vector<uint32_t> >::iterator SsrcMapIterator;

   int ReadGlobalHeader() {
     uint32_t magic;
     TRY_PCAP(Read(&magic, false));
     if (magic == kPcapBOMSwapOrder) {
       swap_pcap_byte_order_ = true;
     } else if (magic == kPcapBOMNoSwapOrder) {
       swap_pcap_byte_order_ = false;
     } else {
       return kResultFail;
     }

     uint16_t version_major;
     uint16_t version_minor;
     TRY_PCAP(Read(&version_major, false));
     TRY_PCAP(Read(&version_minor, false));
     if (version_major != kPcapVersionMajor ||
         version_minor != kPcapVersionMinor) {
       return kResultFail;
     }

     int32_t this_zone;  // GMT to local correction.
     uint32_t sigfigs;   // Accuracy of timestamps.
     uint32_t snaplen;   // Max length of captured packets, in octets.
     uint32_t network;   // Data link type.
     TRY_PCAP(Read(&this_zone, false));
     TRY_PCAP(Read(&sigfigs, false));
     TRY_PCAP(Read(&snaplen, false));
     TRY_PCAP(Read(&network, false));

     // Accept only LINKTYPE_NULL and LINKTYPE_ETHERNET.
     // See: http://www.tcpdump.org/linktypes.html
     if (network != kLinktypeNull && network != kLinktypeEthernet) {
       return kResultFail;
     }

     return kResultSuccess;
   }

   int ReadPacket(int32_t* next_packet_pos,
                  uint32_t stream_start_ms,
                  uint32_t number,
                  const std::set<uint32_t>& ssrc_filter) {
     assert(next_packet_pos);

     uint32_t ts_sec;    // Timestamp seconds.
     uint32_t ts_usec;   // Timestamp microseconds.
     uint32_t incl_len;  // Number of octets of packet saved in file.
     uint32_t orig_len;  // Actual length of packet.
     TRY_PCAP(Read(&ts_sec, false));
     TRY_PCAP(Read(&ts_usec, false));
     TRY_PCAP(Read(&incl_len, false));
     TRY_PCAP(Read(&orig_len, false));

     *next_packet_pos = ftell(file_) + incl_len;

     RtpPacketMarker marker = {0};
     marker.packet_number = number;
     marker.time_offset_ms = CalcTimeDelta(ts_sec, ts_usec, stream_start_ms);
     TRY_PCAP(ReadPacketHeader(&marker));
     marker.pos_in_file = ftell(file_);

     if (marker.payload_length > sizeof(read_buffer_)) {
       printf("Packet too large!\n");
       return kResultFail;
     }
     TRY_PCAP(Read(read_buffer_, marker.payload_length));

     RtpUtility::RtpHeaderParser rtp_parser(read_buffer_, marker.payload_length);
     if (rtp_parser.RTCP()) {
       rtp_parser.ParseRtcp(&marker.rtp_header);
       packets_.push_back(marker);
     } else {
       if (!rtp_parser.Parse(&marker.rtp_header, nullptr)) {
         LOG(LS_INFO) << "Not recognized as RTP/RTCP";
         return kResultSkip;
       }

       uint32_t ssrc = marker.rtp_header.ssrc;
       if (ssrc_filter.empty() || ssrc_filter.find(ssrc) != ssrc_filter.end()) {
         packets_by_ssrc_[ssrc].push_back(
             static_cast<uint32_t>(packets_.size()));
         packets_.push_back(marker);
       } else {
         return kResultSkip;
       }
     }

     return kResultSuccess;
   }

   int ReadPacketHeader(RtpPacketMarker* marker) {
     int32_t file_pos = ftell(file_);

     // Check for BSD null/loopback frame header. The header is just 4 bytes in
     // native byte order, so we check for both versions as we don't care about
     // the header as such and will likely fail reading the IP header if this is
     // something else than null/loopback.
     uint32_t protocol;
     TRY_PCAP(Read(&protocol, true));
     if (protocol == kBsdNullLoopback1 || protocol == kBsdNullLoopback2) {
       int result = ReadXxpIpHeader(marker);
       LOG(LS_INFO) << "Recognized loopback frame";
       if (result != kResultSkip) {
         return result;
       }
     }

     TRY_PCAP(fseek(file_, file_pos, SEEK_SET));

     // Check for Ethernet II, IP frame header.
     uint16_t type;
     TRY_PCAP(Skip(kEthernetIIHeaderMacSkip));  // Source+destination MAC.
     TRY_PCAP(Read(&type, true));
     if (type == kEthertypeIp) {
       int result = ReadXxpIpHeader(marker);
       LOG(LS_INFO) << "Recognized ethernet 2 frame";
       if (result != kResultSkip) {
         return result;
       }
     }

     return kResultSkip;
   }

   uint32_t CalcTimeDelta(uint32_t ts_sec, uint32_t ts_usec, uint32_t start_ms) {
     // Round to nearest ms.
     uint64_t t2_ms = ((static_cast<uint64_t>(ts_sec) * 1000000) + ts_usec +
         500) / 1000;
     uint64_t t1_ms = static_cast<uint64_t>(start_ms);
     if (t2_ms < t1_ms) {
       return 0;
     } else {
       return t2_ms - t1_ms;
     }
   }

   int ReadXxpIpHeader(RtpPacketMarker* marker) {
     assert(marker);

     uint16_t version;
     uint16_t length;
     uint16_t id;
     uint16_t fragment;
     uint16_t protocol;
     uint16_t checksum;
     TRY_PCAP(Read(&version, true));
     TRY_PCAP(Read(&length, true));
     TRY_PCAP(Read(&id, true));
     TRY_PCAP(Read(&fragment, true));
     TRY_PCAP(Read(&protocol, true));
     TRY_PCAP(Read(&checksum, true));
     TRY_PCAP(Read(&marker->source_ip, true));
     TRY_PCAP(Read(&marker->dest_ip, true));

     if (((version >> 12) & 0x000f) != kIpVersion4) {
       LOG(LS_INFO) << "IP header is not IPv4";
       return kResultSkip;
     }

     if (fragment != kFragmentOffsetClear &&
         fragment != kFragmentOffsetDoNotFragment) {
       LOG(LS_INFO) << "IP fragments cannot be handled";
       return kResultSkip;
     }

     // Skip remaining fields of IP header.
     uint16_t header_length = (version & 0x0f00) >> (8 - 2);
     assert(header_length >= kMinIpHeaderLength);
     TRY_PCAP(Skip(header_length - kMinIpHeaderLength));

     protocol = protocol & 0x00ff;
     if (protocol == kProtocolTcp) {
       LOG(LS_INFO) << "TCP packets are not handled";
       return kResultSkip;
     } else if (protocol == kProtocolUdp) {
       uint16_t length;
       uint16_t checksum;
       TRY_PCAP(Read(&marker->source_port, true));
       TRY_PCAP(Read(&marker->dest_port, true));
       TRY_PCAP(Read(&length, true));
       TRY_PCAP(Read(&checksum, true));
       marker->payload_length = length - kUdpHeaderLength;
     } else {
       LOG(LS_INFO) << "Unknown transport (expected UDP or TCP)";
       return kResultSkip;
     }

     return kResultSuccess;
   }

   int Read(uint32_t* out, bool expect_network_order) {
     uint32_t tmp = 0;
     if (fread(&tmp, 1, sizeof(uint32_t), file_) != sizeof(uint32_t)) {
       return kResultFail;
     }
     if ((!expect_network_order && swap_pcap_byte_order_) ||
         (expect_network_order && swap_network_byte_order_)) {
       tmp = ((tmp >> 24) & 0x000000ff) | (tmp << 24) |
           ((tmp >> 8) & 0x0000ff00) | ((tmp << 8) & 0x00ff0000);
     }
     *out = tmp;
     return kResultSuccess;
   }

   int Read(uint16_t* out, bool expect_network_order) {
     uint16_t tmp = 0;
     if (fread(&tmp, 1, sizeof(uint16_t), file_) != sizeof(uint16_t)) {
       return kResultFail;
     }
     if ((!expect_network_order && swap_pcap_byte_order_) ||
         (expect_network_order && swap_network_byte_order_)) {
       tmp = ((tmp >> 8) & 0x00ff) | (tmp << 8);
     }
     *out = tmp;
     return kResultSuccess;
   }

   int Read(uint8_t* out, uint32_t count) {
     if (fread(out, 1, count, file_) != count) {
       return kResultFail;
     }
     return kResultSuccess;
   }

   int Read(int32_t* out, bool expect_network_order) {
     int32_t tmp = 0;
     if (fread(&tmp, 1, sizeof(uint32_t), file_) != sizeof(uint32_t)) {
       return kResultFail;
     }
     if ((!expect_network_order && swap_pcap_byte_order_) ||
         (expect_network_order && swap_network_byte_order_)) {
       tmp = ((tmp >> 24) & 0x000000ff) | (tmp << 24) |
           ((tmp >> 8) & 0x0000ff00) | ((tmp << 8) & 0x00ff0000);
     }
     *out = tmp;
     return kResultSuccess;
   }

   int Skip(uint32_t length) {
     if (fseek(file_, length, SEEK_CUR) != 0) {
       return kResultFail;
     }
     return kResultSuccess;
   }

   FILE* file_;
   bool swap_pcap_byte_order_;
   const bool swap_network_byte_order_;
   uint8_t read_buffer_[kMaxReadBufferSize];

   SsrcMap packets_by_ssrc_;
   std::vector<RtpPacketMarker> packets_;
   PacketIterator next_packet_it_;

   RTC_DISALLOW_COPY_AND_ASSIGN(PcapReader);
 };

 RtpFileReader* RtpFileReader::Create(FileFormat format,
                                      const std::string& filename,
                                      const std::set<uint32_t>& ssrc_filter) {
   RtpFileReaderImpl* reader = NULL;
   switch (format) {
     case kPcap:
       reader = new PcapReader();
       break;
     case kRtpDump:
       reader = new RtpDumpReader();
       break;
     case kLengthPacketInterleaved:
       reader = new InterleavedRtpFileReader();
       break;
   }
   if (!reader->Init(filename, ssrc_filter)) {
     delete reader;
     return NULL;
   }
   return reader;
 }

 RtpFileReader* RtpFileReader::Create(FileFormat format,
                                      const std::string& filename) {
   return RtpFileReader::Create(format, filename, std::set<uint32_t>());
 }

 }  // namespace test
 }  // namespace webrtc
	/*
	* Copyright (c) 2014 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/test/rtp_file_reader.h"

	#include <stdio.h>

	#include <map>
	#include <string>
	#include <vector>

	#include "webrtc/modules/rtp_rtcp/source/rtp_utility.h"
	#include "webrtc/rtc_base/checks.h"
	#include "webrtc/rtc_base/constructormagic.h"
	#include "webrtc/rtc_base/format_macros.h"
	#include "webrtc/rtc_base/logging.h"

	namespace webrtc {
	namespace test {

	static const size_t kFirstLineLength = 40;
	static uint16_t kPacketHeaderSize = 8;

	#define TRY(expr) \
	do { \
	if (!(expr)) { \
	LOG(LS_INFO) << "Failed to read"; \
	return false; \
	} \
	} while (0)

	bool ReadUint32(uint32_t* out, FILE* file) {
	*out = 0;
	for (size_t i = 0; i < 4; ++i) {
	*out <<= 8;
	uint8_t tmp;
	if (fread(&tmp, 1, sizeof(uint8_t), file) != sizeof(uint8_t))
	return false;
	*out \|= tmp;
	}
	return true;
	}

	bool ReadUint16(uint16_t* out, FILE* file) {
	*out = 0;
	for (size_t i = 0; i < 2; ++i) {
	*out <<= 8;
	uint8_t tmp;
	if (fread(&tmp, 1, sizeof(uint8_t), file) != sizeof(uint8_t))
	return false;
	*out \|= tmp;
	}
	return true;
	}

	class RtpFileReaderImpl : public RtpFileReader {
	public:
	virtual bool Init(const std::string& filename,
	const std::set<uint32_t>& ssrc_filter) = 0;
	};

	class InterleavedRtpFileReader : public RtpFileReaderImpl {
	public:
	virtual ~InterleavedRtpFileReader() {
	if (file_ != NULL) {
	fclose(file_);
	file_ = NULL;
	}
	}

	virtual bool Init(const std::string& filename,
	const std::set<uint32_t>& ssrc_filter) {
	file_ = fopen(filename.c_str(), "rb");
	if (file_ == NULL) {
	printf("ERROR: Can't open file: %s\n", filename.c_str());
	return false;
	}
	return true;
	}
	virtual bool NextPacket(RtpPacket* packet) {
	assert(file_ != NULL);
	packet->length = RtpPacket::kMaxPacketBufferSize;
	uint32_t len = 0;
	TRY(ReadUint32(&len, file_));
	if (packet->length < len) {
	FATAL() << "Packet is too large to fit: " << len << " bytes vs "
	<< packet->length
	<< " bytes allocated. Consider increasing the buffer "
	"size";
	}
	if (fread(packet->data, 1, len, file_) != len)
	return false;

	packet->length = len;
	packet->original_length = len;
	packet->time_ms = time_ms_;
	time_ms_ += 5;
	return true;
	}

	private:
	FILE* file_ = NULL;
	int64_t time_ms_ = 0;
	};

	// Read RTP packets from file in rtpdump format, as documented at:
	// http://www.cs.columbia.edu/irt/software/rtptools/
	class RtpDumpReader : public RtpFileReaderImpl {
	public:
	RtpDumpReader() : file_(NULL) {}
	virtual ~RtpDumpReader() {
	if (file_ != NULL) {
	fclose(file_);
	file_ = NULL;
	}
	}

	bool Init(const std::string& filename,
	const std::set<uint32_t>& ssrc_filter) override {
	file_ = fopen(filename.c_str(), "rb");
	if (file_ == NULL) {
	printf("ERROR: Can't open file: %s\n", filename.c_str());
	return false;
	}

	char firstline[kFirstLineLength + 1] = {0};
	if (fgets(firstline, kFirstLineLength, file_) == NULL) {
	LOG(LS_INFO) << "Can't read from file";
	return false;
	}
	if (strncmp(firstline, "#!rtpplay", 9) == 0) {
	if (strncmp(firstline, "#!rtpplay1.0", 12) != 0) {
	LOG(LS_INFO) << "Wrong rtpplay version, must be 1.0";
	return false;
	}
	} else if (strncmp(firstline, "#!RTPencode", 11) == 0) {
	if (strncmp(firstline, "#!RTPencode1.0", 14) != 0) {
	LOG(LS_INFO) << "Wrong RTPencode version, must be 1.0";
	return false;
	}
	} else {
	LOG(LS_INFO) << "Wrong file format of input file";
	return false;
	}

	uint32_t start_sec;
	uint32_t start_usec;
	uint32_t source;
	uint16_t port;
	uint16_t padding;
	TRY(ReadUint32(&start_sec, file_));
	TRY(ReadUint32(&start_usec, file_));
	TRY(ReadUint32(&source, file_));
	TRY(ReadUint16(&port, file_));
	TRY(ReadUint16(&padding, file_));

	return true;
	}

	bool NextPacket(RtpPacket* packet) override {
	uint8_t* rtp_data = packet->data;
	packet->length = RtpPacket::kMaxPacketBufferSize;

	uint16_t len;
	uint16_t plen;
	uint32_t offset;
	TRY(ReadUint16(&len, file_));
	TRY(ReadUint16(&plen, file_));
	TRY(ReadUint32(&offset, file_));

	// Use 'len' here because a 'plen' of 0 specifies rtcp.
	len -= kPacketHeaderSize;
	if (packet->length < len) {
	FATAL() << "Packet is too large to fit: " << len << " bytes vs "
	<< packet->length
	<< " bytes allocated. Consider increasing the buffer "
	"size";
	}
	if (fread(rtp_data, 1, len, file_) != len) {
	return false;
	}

	packet->length = len;
	packet->original_length = plen;
	packet->time_ms = offset;
	return true;
	}

	private:
	FILE* file_;

	RTC_DISALLOW_COPY_AND_ASSIGN(RtpDumpReader);
	};

	enum {
	kResultFail = -1,
	kResultSuccess = 0,
	kResultSkip = 1,

	kPcapVersionMajor = 2,
	kPcapVersionMinor = 4,
	kLinktypeNull = 0,
	kLinktypeEthernet = 1,
	kBsdNullLoopback1 = 0x00000002,
	kBsdNullLoopback2 = 0x02000000,
	kEthernetIIHeaderMacSkip = 12,
	kEthertypeIp = 0x0800,
	kIpVersion4 = 4,
	kMinIpHeaderLength = 20,
	kFragmentOffsetClear = 0x0000,
	kFragmentOffsetDoNotFragment = 0x4000,
	kProtocolTcp = 0x06,
	kProtocolUdp = 0x11,
	kUdpHeaderLength = 8,
	kMaxReadBufferSize = 4096
	};

	const uint32_t kPcapBOMSwapOrder = 0xd4c3b2a1UL;
	const uint32_t kPcapBOMNoSwapOrder = 0xa1b2c3d4UL;

	#define TRY_PCAP(expr) \
	do { \
	int r = (expr); \
	if (r == kResultFail) { \
	LOG(LS_INFO) << "FAIL at " << __FILE__ << ":" << __LINE__; \
	return kResultFail; \
	} else if (r == kResultSkip) { \
	return kResultSkip; \
	} \
	} while (0)

	// Read RTP packets from file in tcpdump/libpcap format, as documented at:
	// http://wiki.wireshark.org/Development/LibpcapFileFormat
	class PcapReader : public RtpFileReaderImpl {
	public:
	PcapReader()
	: file_(NULL),
	swap_pcap_byte_order_(false),
	#ifdef WEBRTC_ARCH_BIG_ENDIAN
	swap_network_byte_order_(false),
	#else
	swap_network_byte_order_(true),
	#endif
	read_buffer_(),
	packets_by_ssrc_(),
	packets_(),
	next_packet_it_() {
	}

	virtual ~PcapReader() {
	if (file_ != NULL) {
	fclose(file_);
	file_ = NULL;
	}
	}

	bool Init(const std::string& filename,
	const std::set<uint32_t>& ssrc_filter) override {
	return Initialize(filename, ssrc_filter) == kResultSuccess;
	}

	int Initialize(const std::string& filename,
	const std::set<uint32_t>& ssrc_filter) {
	file_ = fopen(filename.c_str(), "rb");
	if (file_ == NULL) {
	printf("ERROR: Can't open file: %s\n", filename.c_str());
	return kResultFail;
	}

	if (ReadGlobalHeader() < 0) {
	return kResultFail;
	}

	int total_packet_count = 0;
	uint32_t stream_start_ms = 0;
	int32_t next_packet_pos = ftell(file_);
	for (;;) {
	TRY_PCAP(fseek(file_, next_packet_pos, SEEK_SET));
	int result = ReadPacket(&next_packet_pos, stream_start_ms,
	++total_packet_count, ssrc_filter);
	if (result == kResultFail) {
	break;
	} else if (result == kResultSuccess && packets_.size() == 1) {
	assert(stream_start_ms == 0);
	PacketIterator it = packets_.begin();
	stream_start_ms = it->time_offset_ms;
	it->time_offset_ms = 0;
	}
	}

	if (feof(file_) == 0) {
	printf("Failed reading file!\n");
	return kResultFail;
	}

	printf("Total packets in file: %d\n", total_packet_count);
	printf("Total RTP/RTCP packets: %" PRIuS "\n", packets_.size());

	for (SsrcMapIterator mit = packets_by_ssrc_.begin();
	mit != packets_by_ssrc_.end(); ++mit) {
	uint32_t ssrc = mit->first;
	const std::vector<uint32_t>& packet_indices = mit->second;
	uint8_t pt = packets_[packet_indices[0]].rtp_header.payloadType;
	printf("SSRC: %08x, %" PRIuS " packets, pt=%d\n", ssrc,
	packet_indices.size(), pt);
	}

	// TODO(solenberg): Better validation of identified SSRC streams.
	//
	// Since we're dealing with raw network data here, we will wrongly identify
	// some packets as RTP. When these packets are consumed by RtpPlayer, they
	// are unlikely to cause issues as they will ultimately be filtered out by
	// the RtpRtcp module. However, we should really do better filtering here,
	// which we can accomplish in a number of ways, e.g.:
	//
	// - Verify that the time stamps and sequence numbers for RTP packets are
	// both increasing/decreasing. If they move in different directions, the
	// SSRC is likely bogus and can be dropped. (Normally they should be inc-
	// reasing but we must allow packet reordering).
	// - If RTP sequence number is not changing, drop the stream.
	// - Can also use srcip:port->dstip:port pairs, assuming few SSRC collisions
	// for up/down streams.

	next_packet_it_ = packets_.begin();
	return kResultSuccess;
	}

	bool NextPacket(RtpPacket* packet) override {
	uint32_t length = RtpPacket::kMaxPacketBufferSize;
	if (NextPcap(packet->data, &length, &packet->time_ms) != kResultSuccess)
	return false;
	packet->length = static_cast<size_t>(length);
	packet->original_length = packet->length;
	return true;
	}

	virtual int NextPcap(uint8_t* data, uint32_t* length, uint32_t* time_ms) {
	assert(data);
	assert(length);
	assert(time_ms);

	if (next_packet_it_ == packets_.end()) {
	return -1;
	}
	if (*length < next_packet_it_->payload_length) {
	return -1;
	}
	TRY_PCAP(fseek(file_, next_packet_it_->pos_in_file, SEEK_SET));
	TRY_PCAP(Read(data, next_packet_it_->payload_length));
	*length = next_packet_it_->payload_length;
	*time_ms = next_packet_it_->time_offset_ms;
	next_packet_it_++;

	return 0;
	}

	private:
	// A marker of an RTP packet within the file.
	struct RtpPacketMarker {
	uint32_t packet_number; // One-based index (like in WireShark)
	uint32_t time_offset_ms;
	uint32_t source_ip;
	uint32_t dest_ip;
	uint16_t source_port;
	uint16_t dest_port;
	RTPHeader rtp_header;
	int32_t pos_in_file; // Byte offset of payload from start of file.
	uint32_t payload_length;
	};

	typedef std::vector<RtpPacketMarker>::iterator PacketIterator;
	typedef std::map<uint32_t, std::vector<uint32_t> > SsrcMap;
	typedef std::map<uint32_t, std::vector<uint32_t> >::iterator SsrcMapIterator;

	int ReadGlobalHeader() {
	uint32_t magic;
	TRY_PCAP(Read(&magic, false));
	if (magic == kPcapBOMSwapOrder) {
	swap_pcap_byte_order_ = true;
	} else if (magic == kPcapBOMNoSwapOrder) {
	swap_pcap_byte_order_ = false;
	} else {
	return kResultFail;
	}

	uint16_t version_major;
	uint16_t version_minor;
	TRY_PCAP(Read(&version_major, false));
	TRY_PCAP(Read(&version_minor, false));
	if (version_major != kPcapVersionMajor \|\|
	version_minor != kPcapVersionMinor) {
	return kResultFail;
	}

	int32_t this_zone; // GMT to local correction.
	uint32_t sigfigs; // Accuracy of timestamps.
	uint32_t snaplen; // Max length of captured packets, in octets.
	uint32_t network; // Data link type.
	TRY_PCAP(Read(&this_zone, false));
	TRY_PCAP(Read(&sigfigs, false));
	TRY_PCAP(Read(&snaplen, false));
	TRY_PCAP(Read(&network, false));

	// Accept only LINKTYPE_NULL and LINKTYPE_ETHERNET.
	// See: http://www.tcpdump.org/linktypes.html
	if (network != kLinktypeNull && network != kLinktypeEthernet) {
	return kResultFail;
	}

	return kResultSuccess;
	}

	int ReadPacket(int32_t* next_packet_pos,
	uint32_t stream_start_ms,
	uint32_t number,
	const std::set<uint32_t>& ssrc_filter) {
	assert(next_packet_pos);

	uint32_t ts_sec; // Timestamp seconds.
	uint32_t ts_usec; // Timestamp microseconds.
	uint32_t incl_len; // Number of octets of packet saved in file.
	uint32_t orig_len; // Actual length of packet.
	TRY_PCAP(Read(&ts_sec, false));
	TRY_PCAP(Read(&ts_usec, false));
	TRY_PCAP(Read(&incl_len, false));
	TRY_PCAP(Read(&orig_len, false));

	*next_packet_pos = ftell(file_) + incl_len;

	RtpPacketMarker marker = {0};
	marker.packet_number = number;
	marker.time_offset_ms = CalcTimeDelta(ts_sec, ts_usec, stream_start_ms);
	TRY_PCAP(ReadPacketHeader(&marker));
	marker.pos_in_file = ftell(file_);

	if (marker.payload_length > sizeof(read_buffer_)) {
	printf("Packet too large!\n");
	return kResultFail;
	}
	TRY_PCAP(Read(read_buffer_, marker.payload_length));

	RtpUtility::RtpHeaderParser rtp_parser(read_buffer_, marker.payload_length);
	if (rtp_parser.RTCP()) {
	rtp_parser.ParseRtcp(&marker.rtp_header);
	packets_.push_back(marker);
	} else {
	if (!rtp_parser.Parse(&marker.rtp_header, nullptr)) {
	LOG(LS_INFO) << "Not recognized as RTP/RTCP";
	return kResultSkip;
	}

	uint32_t ssrc = marker.rtp_header.ssrc;
	if (ssrc_filter.empty() \|\| ssrc_filter.find(ssrc) != ssrc_filter.end()) {
	packets_by_ssrc_[ssrc].push_back(
	static_cast<uint32_t>(packets_.size()));
	packets_.push_back(marker);
	} else {
	return kResultSkip;
	}
	}

	return kResultSuccess;
	}

	int ReadPacketHeader(RtpPacketMarker* marker) {
	int32_t file_pos = ftell(file_);

	// Check for BSD null/loopback frame header. The header is just 4 bytes in
	// native byte order, so we check for both versions as we don't care about
	// the header as such and will likely fail reading the IP header if this is
	// something else than null/loopback.
	uint32_t protocol;
	TRY_PCAP(Read(&protocol, true));
	if (protocol == kBsdNullLoopback1 \|\| protocol == kBsdNullLoopback2) {
	int result = ReadXxpIpHeader(marker);
	LOG(LS_INFO) << "Recognized loopback frame";
	if (result != kResultSkip) {
	return result;
	}
	}

	TRY_PCAP(fseek(file_, file_pos, SEEK_SET));

	// Check for Ethernet II, IP frame header.
	uint16_t type;
	TRY_PCAP(Skip(kEthernetIIHeaderMacSkip)); // Source+destination MAC.
	TRY_PCAP(Read(&type, true));
	if (type == kEthertypeIp) {
	int result = ReadXxpIpHeader(marker);
	LOG(LS_INFO) << "Recognized ethernet 2 frame";
	if (result != kResultSkip) {
	return result;
	}
	}

	return kResultSkip;
	}

	uint32_t CalcTimeDelta(uint32_t ts_sec, uint32_t ts_usec, uint32_t start_ms) {
	// Round to nearest ms.
	uint64_t t2_ms = ((static_cast<uint64_t>(ts_sec) * 1000000) + ts_usec +
	500) / 1000;
	uint64_t t1_ms = static_cast<uint64_t>(start_ms);
	if (t2_ms < t1_ms) {
	return 0;
	} else {
	return t2_ms - t1_ms;
	}
	}

	int ReadXxpIpHeader(RtpPacketMarker* marker) {
	assert(marker);

	uint16_t version;
	uint16_t length;
	uint16_t id;
	uint16_t fragment;
	uint16_t protocol;
	uint16_t checksum;
	TRY_PCAP(Read(&version, true));
	TRY_PCAP(Read(&length, true));
	TRY_PCAP(Read(&id, true));
	TRY_PCAP(Read(&fragment, true));
	TRY_PCAP(Read(&protocol, true));
	TRY_PCAP(Read(&checksum, true));
	TRY_PCAP(Read(&marker->source_ip, true));
	TRY_PCAP(Read(&marker->dest_ip, true));

	if (((version >> 12) & 0x000f) != kIpVersion4) {
	LOG(LS_INFO) << "IP header is not IPv4";
	return kResultSkip;
	}

	if (fragment != kFragmentOffsetClear &&
	fragment != kFragmentOffsetDoNotFragment) {
	LOG(LS_INFO) << "IP fragments cannot be handled";
	return kResultSkip;
	}

	// Skip remaining fields of IP header.
	uint16_t header_length = (version & 0x0f00) >> (8 - 2);
	assert(header_length >= kMinIpHeaderLength);
	TRY_PCAP(Skip(header_length - kMinIpHeaderLength));

	protocol = protocol & 0x00ff;
	if (protocol == kProtocolTcp) {
	LOG(LS_INFO) << "TCP packets are not handled";
	return kResultSkip;
	} else if (protocol == kProtocolUdp) {
	uint16_t length;
	uint16_t checksum;
	TRY_PCAP(Read(&marker->source_port, true));
	TRY_PCAP(Read(&marker->dest_port, true));
	TRY_PCAP(Read(&length, true));
	TRY_PCAP(Read(&checksum, true));
	marker->payload_length = length - kUdpHeaderLength;
	} else {
	LOG(LS_INFO) << "Unknown transport (expected UDP or TCP)";
	return kResultSkip;
	}

	return kResultSuccess;
	}

	int Read(uint32_t* out, bool expect_network_order) {
	uint32_t tmp = 0;
	if (fread(&tmp, 1, sizeof(uint32_t), file_) != sizeof(uint32_t)) {
	return kResultFail;
	}
	if ((!expect_network_order && swap_pcap_byte_order_) \|\|
	(expect_network_order && swap_network_byte_order_)) {
	tmp = ((tmp >> 24) & 0x000000ff) \| (tmp << 24) \|
	((tmp >> 8) & 0x0000ff00) \| ((tmp << 8) & 0x00ff0000);
	}
	*out = tmp;
	return kResultSuccess;
	}

	int Read(uint16_t* out, bool expect_network_order) {
	uint16_t tmp = 0;
	if (fread(&tmp, 1, sizeof(uint16_t), file_) != sizeof(uint16_t)) {
	return kResultFail;
	}
	if ((!expect_network_order && swap_pcap_byte_order_) \|\|
	(expect_network_order && swap_network_byte_order_)) {
	tmp = ((tmp >> 8) & 0x00ff) \| (tmp << 8);
	}
	*out = tmp;
	return kResultSuccess;
	}

	int Read(uint8_t* out, uint32_t count) {
	if (fread(out, 1, count, file_) != count) {
	return kResultFail;
	}
	return kResultSuccess;
	}

	int Read(int32_t* out, bool expect_network_order) {
	int32_t tmp = 0;
	if (fread(&tmp, 1, sizeof(uint32_t), file_) != sizeof(uint32_t)) {
	return kResultFail;
	}
	if ((!expect_network_order && swap_pcap_byte_order_) \|\|
	(expect_network_order && swap_network_byte_order_)) {
	tmp = ((tmp >> 24) & 0x000000ff) \| (tmp << 24) \|
	((tmp >> 8) & 0x0000ff00) \| ((tmp << 8) & 0x00ff0000);
	}
	*out = tmp;
	return kResultSuccess;
	}

	int Skip(uint32_t length) {
	if (fseek(file_, length, SEEK_CUR) != 0) {
	return kResultFail;
	}
	return kResultSuccess;
	}

	FILE* file_;
	bool swap_pcap_byte_order_;
	const bool swap_network_byte_order_;
	uint8_t read_buffer_[kMaxReadBufferSize];

	SsrcMap packets_by_ssrc_;
	std::vector<RtpPacketMarker> packets_;
	PacketIterator next_packet_it_;

	RTC_DISALLOW_COPY_AND_ASSIGN(PcapReader);
	};

	RtpFileReader* RtpFileReader::Create(FileFormat format,
	const std::string& filename,
	const std::set<uint32_t>& ssrc_filter) {
	RtpFileReaderImpl* reader = NULL;
	switch (format) {
	case kPcap:
	reader = new PcapReader();
	break;
	case kRtpDump:
	reader = new RtpDumpReader();
	break;
	case kLengthPacketInterleaved:
	reader = new InterleavedRtpFileReader();
	break;
	}
	if (!reader->Init(filename, ssrc_filter)) {
	delete reader;
	return NULL;
	}
	return reader;
	}

	RtpFileReader* RtpFileReader::Create(FileFormat format,
	const std::string& filename) {
	return RtpFileReader::Create(format, filename, std::set<uint32_t>());
	}

	} // namespace test
	} // namespace webrtc