Question about RTMP specification

[scourfish]

Hello,

I have downloaded and read the RTMP specification, and am confused about some of the wording relating to the RTMP Chunk Stream.

Page 19 of the RTMP Chunk Stream specification states that an extended Timestamp must not be present if the timestamp field is not present, then further states that Type 3 chunks must not have this field.  The only Chunk message header that has a timestamp is the Type 0 header.  Types 1 and 2 do not have a Timestamp field (however they have a timestamp delta.)  If applicable, is the extended timestamp only included with a Type 0 chunk, or do Type 1 and Type 2 chunks also include it?

Thanks for your time.

[vgatto · Accepted solution]

Right after section 6.1.2.4 it says:

timestamp delta: 3 bytes

For a type-1 or type-2 chunk, the difference between the previous
chunk's timestamp and the current chunk's timestamp is sent here.
If the delta is greater than or equal to 16777215 (hexadecimal
0x00ffffff), this value MUST be 16777215, and the ‘extended
timestamp header’ MUST be present. Otherwise, this value SHOULD be
the entire delta.

[wdecarne]

Hello i noticed a difference with the 'extended timestamp' in Type 3 chunks. The 'RTMP Specification' on page 19  say 'In the Type 3 chunks MUST NOT have this field.', but i see the 'extended timestamp' in chunks from the flash player. Here my trace with same decoding comments:

06 channelId:6 Type 0 chunk
FF FF FF timestamp
00 BC 48 message length
09 message type id

01 00 00 00 msg stream id
01 64 3D D0 extended timestamp

payload chunk size is 128

12 00 00 84 02 80 9E FE 25 2A 2E F8 30 3F 99 FC

4C AB 6E B7 2F CB CB E2 DE 62 A7 86 9E BC 3E 04

05 73 C3 D1 F0 FB 70 45 12 80 32 CE 4C B3 44 6E

76 37 66 62 C7 A5 84 A0 60 12 C1 80 51 55 E9 41

80 D5 06 01 69 55 53 EB 70 18 06 10 60 1A FC C2

BF 4C B0 03 65 1D E5 FA 6B 57 AE 91 80 C0 25 03

00 A9 E2 EB F0 60 36 01 80 61 B6 65 1D 83 00 D0

0C 03 82 B1 16 C0 52 89 35 7A D3 18 C2 88 F6 CD
C6 channelId:6 Type 3 chunk

01 64 3D D0 (I think tihs is a extended timestamp)

00 FE 03 02 F7 28 19 50 AF F8 55 7D 8C 35 1A 33

0E 3D EE DC F2 75 3B 10 E4 CC 21 7B CF C1 80 11

06 00 64 BF 41 0C 18 00 F0 0C F9 7F F2 DA AC 18

01 10 40 56 3B C5 17 3F 4B BE AD AC B6 E5 DC C1

DC 91 EF 60 C0 4F 03 00 3E 5F B6 83 00 36 0C 00

99 7C A0 C1 88 80 62 A5 3C C0 60 9E 81 80 10 CD

9B 59 83 BE B0 E8 F5 40 C0 22 03 00 A9 00 D8 30

0C 00 C0 36 97 F2 D0 60 5E 02 1D 08 39 F1 EE 03

and the next chunk

C6 channelId:6 Type 3 chunk

01 64 3D D0 (I think tihs is a extended timestamp)

04 F2 07 FB 67 07 6D F6 5B B6 9F 8E A0 C0 20 83

00 B3 E5 14 18 0F 00 84 AF 6A AD A2 58 30 02 A0

C0 0C 04 39 F8 A6 A9 D0 60 3E 41 80 10 2F 6B 16

98 C0 8A E6 AF 2A 12 44 75 73 CA F6 62 90 3F FA

58 08 52 6C 63 AB 64 E1 D8 70 43 FC 9C 2F 2F F5

9B 66 5A 0A AD FB 48 0C 3D E8 18 0A 60 60 09 2D

55 FF 03 00 3A 0C 00 CA 8B C5 70 4B 06 00 60 18

00 F2 FA 8F EA 84 88 5D F9 19 6B E0 59 EF 5E 06

Is this an error in the Flash Player or a mistake in the 'RTMP Specification' ?

[Guest]

Did you ever get a response to this from Adobe?  This seems to be the standard behavior even though it violates the spec.

[wdecarne]

No and I sent an email to the assigned email address, but no answer too. I found out, the flashplayer expected the same behavior, otherwise it close the TCP connection.