RTP Testing (RFC3518)(1)

padding:P

• encryption
• carry several RTP packets on transport layer.

marker:M

  for voice packet the marker indicates the begining of the talkspurts, which is the good opportunities to adjust the payload delay on receive end to compensate for  diffierence between the sender and receiver clock rates as well as the jetter of network. Well, packets during the talkspurt should be played continiously thus the listener will not be sensitive to the slight viarations in the durations of a pause.

  marker bit is a hint,begining od talk spurt can also be caculated by comparing the diffierence in time stamp and squence number berween two packets,we assumiing that the clock rate is known.

packet may be in disorder, if only the playout delay>reordering receiver can do adaption.if not,it simplely to wait for next talk spurt.

sequence nuber:

  detect losses.

timestamp:

  audio:

20ms, or each 160 sampling.

  vedio:

increase 3000 for 30/sec sampling

increase 3600 for 25/sec sampling

if the sampling is aperiordically, will use sys closk such as method gettimeofday().

payload type:

      PT         encoding      audio/video    clock rate    channels
                 name          (A/V)          (Hz)          (audio)
      _______________________________________________________________
      0          PCMU          A              8000          1     [RFC3551]
      1          Reserved  
      2          Reserved
      3          GSM           A              8000          1     [RFC3551]
      4          G723          A              8000          1     [Kumar]
      5          DVI4          A              8000          1     [RFC3551]
      6          DVI4          A              16000         1     [RFC3551]
      7          LPC           A              8000          1     [RFC3551]
      8          PCMA          A              8000          1     [RFC3551]
      9          G722          A              8000          1     [RFC3551]
      10         L16           A              44100         2     [RFC3551]
      11         L16           A              44100         1     [RFC3551]
      12         QCELP         A              8000          1
      13         CN            A              8000          1     [RFC3389]
      14         MPA           A              90000               [RFC3551][RFC2250]
      15         G728          A              8000          1     [RFC3551]
      16         DVI4          A              11025         1     [DiPol]
      17         DVI4          A              22050         1     [DiPol]
      18         G729          A              8000          1
      19         reserved      A
      20         unassigned    A
      21         unassigned    A
      22         unassigned    A
      23         unassigned    A
      24         unassigned    V
      25         CelB          V              90000               [RFC2029]
      26         JPEG          V              90000               [RFC2435]
      27         unassigned    V
      28         nv            V              90000               [RFC3551]
      29         unassigned    V
      30         unassigned    V
      31         H261          V              90000               [RFC2032]
      32         MPV           V              90000               [RFC2250]
      33         MP2T          AV             90000               [RFC2250]
      34         H263          V              90000               [Zhu]
      35--71     unassigned    ?
      72--76     reserved for RTCP conflict avoidance             [RFC3550]
      77--95     unassigned    ?
      96--127    dynamic       ?                                  [RFC3551] 
                        clock rate    channels
      media type     subtype       (Hz)          (audio)
      _______________________________________________________________
      application    parityfec                              [RFC3009]
      application    rtx                                    [RFC4588]
      audio          AMR           8000                     [RFC4867][RFC3267]
      audio          AMR-WB        16000                    [RFC4867][RFC3267]
      audio          DAT12                                  [RFC3190]
      audio          dsr-es201108                           [RFC3557]
      audio          EVRC          8000          1          [RFC4788]
      audio          EVRC0         8000          1          [RFC4788]
      audio          EVRC1         8000          1          [RFC4788]
      audio          EVRCB         8000          1          [RFC4788]
      audio          EVRCB0        8000          1          [RFC4788]
      audio          EVRCB1        8000          1          [RFC4788]
      audio          G7221         16000         1          [RFC3047]
      audio          G726-16       8000          1          [RFC3551][RFC4856]
      audio          G726-24       8000          1          [RFC3551][RFC4856]
      audio          G726-32       8000          1          [RFC3551][RFC4856]
      audio          G726-40       8000          1          [RFC3551][RFC4856]
      audio          G729D         8000          1          [RFC3551][RFC4856]
      audio          G729E         8000          1          [RFC3551][RFC4856]
      audio          GSM-EFR       8000          1          [RFC3551][RFC4856]
      audio          L8                                     [RFC3551][RFC4856]
      audio          RED                                    [RFC2198][RFC3555]
      audio          rtx                                    [RFC4588]
      audio          VDVI                        1          [RFC3551][RFC4856]
      audio          L20                                    [RFC3190]
      audio          L24                                    [RFC3190]
      audio          MP4A-LATM                              [RFC3016]
      audio          mpa-robust    90000                    [RFC3119]
      audio          parityfec                              [RFC3009]
      audio          SMV           8000          1          [RFC3558]
      audio          SMV0          8000          1          [RFC3558]
      audio          t140c                                  [RFC4351]
      audio          t38                                    [RFC4612]
      audio          telephone-event                        [RFC4733]
      audio          tone                                   [RFC4733]
      audio          DVI4                                   [RFC4856]
      audio          G722                                   [RFC4856]
      audio          G723                                   [RFC4856]
      audio          G728                                   [RFC4856]
      audio          G729                                   [RFC4856]
      audio          GSM                                    [RFC4856]
      audio          L16                                    [RFC4856]
      audio          LPC                                    [RFC4856]
      audio          PCMA                                   [RFC4856]
      audio          PCMU                                   [RFC4856]
      text           parityfec                              [RFC3009]
      text           red           1000                     [RFC4102]
      text           rtx                                    [RFC4588]
      text           t140          1000                     [RFC4103]
      video          BMPEG         90000                    [RFC2343][RFC3555]
      video          BT656         90000                    [RFC2431][RFC3555]
      video          DV            90000                    [RFC3189]
      video          H263-1998     90000                    [RFC2429][RFC3555]
      video          H263-2000     90000                    [RFC2429][RFC3555]
      video          MP1S          90000                    [RFC2250][RFC3555]
      video          MP2P          90000                    [RFC2250][RFC3555]
      video          MP4V-ES       90000                    [RFC3016]
      video          parityfec                              [RFC3009]
      video          pointer       90000                    [RFC2862]
      video          raw           90000                    [RFC4175]
      video          rtx                                    [RFC4588]
      video          SMPTE292M                              [RFC3497]
      video          vc1           90000                    [RFC4425]

abbrev.    name                       value        Reference
_________  _________________________  ________     _________
           Reserved                   0
           Unassigned                 1-191
FIR        full INTRA-frame request   192          [RFC2032]
NACK       negative acknowledgement   193          [RFC2032]
           Unassigned                 194-199  
SR         sender report              200          [RFC3551]
RR         receiver report            201          [RFC3551]
SDES       source descrīption         202          [RFC3551]
BYE        goodbye                    203          [RFC3551]
APP        application-defined        204          [RFC3551]
RTPFB      Generic RTP Feedback       205          [RFC4585]
PSFB       Payload-specific           206          [RFC4585]
XR         extended report            207          [RFC3611]
           Unassigned                 208-254     
           Reserved                   255


   abbrev.    name                              value
   __________________________________________________
   END        end of SDES list                      0      [RFC3551]
   CNAME      canonical name                        1      [RFC3551]
   NAME       user name                             2      [RFC3551]
   EMAIL      user's electronic mail address        3      [RFC3551]
   PHONE      user's phone number                   4      [RFC3551]
   LOC        geographic user location              5      [RFC3551]
   TOOL       name of application or tool           6      [RFC3551]
   NOTE       notice about the source               7      [RFC3551]
   PRIV       private extensions                    8      [RFC3551]

   H323-CADDR H.323 callable address                9        [Kumar]

Name           Long Name                             Value  Reference
-------------- ---------------------------------     -----  ---------
Generic NACK   Generic negative acknowledgement          1  [RFC4585]
               Reserved                                  2  [RFC-ietf-avt-avpf-ccm-10.txt]
TMMBR          Temporary Maximum Media Stream Bit        3  [RFC-ietf-avt-avpf-ccm-10.txt]
               Rate Request
TMMBN          Temporary Maximum Media Stream Bit        4  [RFC-ietf-avt-avpf-ccm-10.txt]
               Rate Notification
Extension      Reserved for future extensions           31  [RFC4585]

PSFB range
Name           Long Name                             Value  Reference
-------------- ---------------------------------     -----  ---------
PLI            Picture Loss Indication                   1  [RFC4585]
SLI            Slice Loss Indication                     2  [RFC4585]
RPSI           Reference Picture Selection Indication    3  [RFC4585]
FIR            Full Intra Request Command                4  [RFC-ietf-avt-avpf-ccm-10.txt]
TSTR           Temporal-Spatial Trade-off Request        5  [RFC-ietf-avt-avpf-ccm-10.txt]
TSTN           Temporal-Spatial Trade-off Notification   6  [RFC-ietf-avt-avpf-ccm-10.txt]
VBCM           Video Back Channel Message                7  [RFC-ietf-avt-avpf-ccm-10.txt]
AFB            Application Layer Feedback               15  [RFC4585]
Extension      Reserved for future extensions           31  [RFC4585]