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PTP/IP


This document briefly describes the PTP/IP transfer layer, as reverse engineered from ethereal packet dumps and glanced from the sparely available online documentation.

It operates on top of a normal IP networkstack, the connections are simple TCP/IP socket connection.

Default port is 15740 (same as the ISO standard number for PTP).

There are 2 connections used:

  • control & data connection (Initiator (computer) driven)
  • event connection (Responder (camera) driven)

The participants communicate in packets, their layout is:

LengthVariableNotes
4length (little endian)Length of the whole packet including the header
4type (little endian)Type, listed below
length - 8dataspecific on type

Observed types:

TypeDirectionNameNext reply(s)Payload
1 I->R Init_Command_Request 2 or 5
  • 16 byte GUID
  • xx byte WCHAR computername with terminating \0
2 R->I Init_Command_Ack 5 or MAINLOOP
  • 4 byte ID (session id, to be used for event connection startup)
  • 16 byte GUID (MAC is used here for my camera, and repeated)
  • xx byte WCHAR Camera Name with terminating \0
3 I->R Init_Event_Request 4 or 5
  • 4 byte ID (from Init_Command_Ack)
4 R->I Init_Event_Ack EVENTLOOP
  • No payload.
5 I->R Init_Fail End of communication
  • 4 byte error code (unclear meaning)
6 I->R Cmd_Request 9 -> A/C or 7
  • 4 byte unknown. set to 1 currently.
  • 2 byte PTP command code
  • 4 byte Transaction ID
  • n x 4 byte PTP command arguments
7 R->I Cmd_Response MAINLOOP
  • 2 bytes PTP response code
  • 4 bytes Transaction ID
  • nr*4 bytes arguments (depending on length of response)
8 R->I Event EVENTLOOP
  • 2 byte PTP event code
  • ...
Not fully investigated, but similar to PTP event.
9 R<->I Start_Data_Packet 10,12
  • 4 byte Transaction ID
  • 4 byte Total data download size (without headers)
10 R<->I Data_Packet 10,12
  • 4 byte Transaction ID
  • length-4-8 bytes payload data
11 I->R Cancel_Transaction 7 ? (Untested yet.)
  • 4 bytes Transaction ID
12 R<->I End_Data_Packet 7 ?
  • 4 byte Transaction ID
  • length-4-8 bytes payload data
13 R<->I Ping 14
  • No payload.
13 R<->I Pong EVENTLOOP
  • No payload.

State transitions:

Initial Phase:

Command Connection:

1-> 2-> MAINLOOP
   \ 5-> EXIT

Event Connection:

3-> 4-> EVENTLOOP
   \ 5-> EXIT
Cameras using PTP/IP:
  • Nikon CoolPix P1
  • Nikon CoolPix P2
  • Nikon CoolPix P3
  • Nikon CoolPix P4
  • Nikon CoolPix S6
  • Kodak EasyShare One
  • Canon PowerShot SD430

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