onMetaData marker in FLV file

I wanna know how the onMetaData marker in FLV files looks like. When i open FLV files as plain text I get this:

FLV[][][][][](TAB)[][][][][][][]8[][][][][][][][][]  
onMetaData[]  
duration...   

The docs say the first 3 bytes are the signature "FLV" the next byte tells the flv version, the next byte is telling us if audio or video tags are present, the next 4 bytes are the data-offset(the size of the header), which is 9, in ascii its the TAB code. after the TAB starts the body with the fist "previous tag size field" which is 0(4 bytes) next, there is the Tag Type (1 byte) the data size (3 bytes) and the timestamp (4 bytes) the stream id (always 0, 3bytes). After that remains:

[]  
onMetaData[]  
[][][]开发者_如何转开发[][][]  
duration...

I suppose the onMetaData marker is "1byte, newline"onMetaData"1byte,newline) but what are the 7 bytes between onMetaData marker and duration?

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You would need to view this file in a hex editor to get anything useful from it; a text editor will just show you unprintable characters.

The ASCII "onMetaData" bit in the file is the tag header, which is wrapping the "duration" field. The three bytes immediately after "onMetaData" are the BodyLength of the tag (uint24, big-endian), and the next 4 bytes ("\x00\x00\x00\x08") describe the length of the name for the next tag, which is "duration."

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I suggest you to use hexedit tool http://www.hexedit.com/ this will allow you to see all the info in string format.. as well as it has very nice navigation to analyze bytes.

In addition to it, use https://www.adobe.com/content/dam/Adobe/en/devnet/flv/pdfs/video_file_format_spec_v10.pdf to get details about all bytes in an flv file

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Remember that the metadata is encoded using AMF. This means that after the string "onMetaData" you have a 0x08 to signify the start of an array and then 2 bytes to signify the length of the first element as number of character/bytes