P-VOP: Inter frame compressed data with previous frame
Ratio of I-VOP and P-VOP depends on I-Frame interval setting. Encode page of Web has the setting.
First VOP can be I-VOP or P-VOP. If client want to decode from I-VOP, please skip P-VOP and wait first I-VOP.
Example of MPEG-4 stream
There are VOL, Userdata1, GOV and Userdata2 before each I-VOP.
Data Structure before I-VOP
Item Note
VOL VOL of MPEG-4 Video
Userdata1
Reserved
GOV GOV of MPEG-4 Video
Userdata2
Userdata
Data Structure of Userdata2
Item Example Note
Start Code 0x000001B2 Start code of userdata in MPEG-4 Video
Product Name type = VN-V686 Product Name
Timestamp Timestamp =
20070319161455123UTC
Year, Month, Day, Hour, Minute, Second,
Millisedond, and Time zone
Camera ID camera = Camera01 Camera ID that user can define
Preset Position
Number
position = 0 Indicates preset position number after moving to
preset position. In other cases, position = NA.
Fan status fan = 0 Indicates status of fan. 1 means error.
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