QuickTime Streaming

Hint Information Atom (`'hinf'` )

The hint information atom ('hinf' ) contains a series of child atoms holding statistics about the track, such as its maximum packet size, number of packets, and average data rate. The defined statistics atoms are listed below. Child atoms of unknown type should be ignored.

Table 2 Defined child atoms of 'hinf' user data atoms

Atom type	Data Size	Description
'trpy'	64 bits	Total number of bytes that will be sent, including 12-byte RTP headers, but not including any network headers
'nump'	64 bits	Total number of network packets that will be sent (if the application knows there is a 28-byte network header, it can multiply 28 by this number and add it to the 'trpy' value to get the true number of bytes sent
'tpyl'	64 bits	Total number of bytes that will be sent, not including 12-byte RTP headers
'maxr'	8 bytes Two 32-bit values	Maximum data rate in bits per second. This atom contains two numbers: `g` , followed by `m` (both 32-bit values). `g` is the granularity, in milliseconds. `m` is the maximum data rate for that granularity. For example, if `g` is 1 second, then `m` is the maximum data rate over any 1 second. There may be multiple 'maxr' atoms, with different values for `m` and `g` . The maximum data rate calculation does not include any network headers, but does include 12-byte RTP headers. Currently, movies hinted using the QuickTime hinter component include 'maxr' atoms for 1 second (`m` =1000) and 1 minute (`m` =60000).
'dmed'	64 bits	Total number of bytes from the media track to be sent
'dimm'	64 bits	Number of bytes of immediate data to be sent
'drep'	64 bits	Number of bytes of repeated data to be sent
'tmin'	32 bits	Smallest relative transmission time, in milliseconds. This is a signed 32-bit integer, typically from -2000 to 0. Packets which should be sent earlier than the expected transmission time--for data smoothing, for example--use a negative relative transmission time.
'tmax'	32 bits	Largest relative transmission time, in milliseconds. This is a signed 32-bit integer, typically 0.
'pmax'	32 bits	Largest packet, in bytes, including 12-byte RTP header
'dmax'	32 bits	Longest packet duration, in milliseconds
'payt'	variable	32-bit payload type number, followed by rtpmap payload string (Pascal string)

Hint Information Atom ( 'hinf' )

Hint Information Atom (`'hinf'` )