Lines Matching refs:capture

13 <http://www.webrtc.org/experiments/rtp-hdrext/abs-capture-time>
25 Data layout of the shortened version of `abs-capture-time` with a 1-byte header
31      |  ID   | len=7 |     absolute capture timestamp (bit 0-23)     |
33      |             absolute capture timestamp (bit 24-55)            |
38 Data layout of the extended version of `abs-capture-time` with a 1-byte header +
44      |  ID   | len=15|     absolute capture timestamp (bit 0-23)     |
46      |             absolute capture timestamp (bit 24-55)            |
48      |  ... (56-63)  |   estimated capture clock offset (bit 0-23)   |
50      |           estimated capture clock offset (bit 24-55)          |
56 #### Absolute capture timestamp
58 Absolute capture timestamp is the NTP timestamp of when the first frame in a
61 capture system.
64 a media frame is captured. A capture system MAY postpone the readout until a
65 more convenient time. A capture system SHOULD have known delays (e.g. from
67 close to the actual capture time as possible.
74 #### Estimated capture clock offset
76 Estimated capture clock offset is the sender's estimate of the offset between
77 its own NTP clock and the capture system's NTP clock. The sender is here defined
80 the capture system or a mixer.
85 sender system’s NTP clock, to also estimate the capture system’s NTP clock:
94 it belongs to the capture system. If the CSRC list is empty, then the receiver
95 MUST treat the SSRC as if it belongs to the capture system. Mixers SHOULD put
102 reference clock, if it wants to present itself as a capture system for A/V-sync
107 A sender SHOULD save bandwidth by not sending `abs-capture-time` with every
110 send `abs-capture-time` with the first RTP packet after changing capture system.
112 A receiver SHOULD memorize the capture system (i.e. CSRC/SSRC), capture
113 timestamp, and RTP timestamp of the most recently received `abs-capture-time`
115 with RTP timestamps of packets without `abs-capture-time`, to extrapolate
116 missing capture timestamps.
120 NTP and RTP clock mappings SHOULD send `abs-capture-time` with the first RTP