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| -rw-r--r-- | DOCS/tech/nut.txt | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/DOCS/tech/nut.txt b/DOCS/tech/nut.txt index 631c920556..3aec400baf 100644 --- a/DOCS/tech/nut.txt +++ b/DOCS/tech/nut.txt @@ -901,6 +901,29 @@ backup headers starting at offset 2^x; for each x players SHOULD end their search at a particular offset when any startcode is found (including syncpoint) +Seeking without an index (non-normative): +----------------------------------------- +A. backward seeking + 1. perform a binary search on the syncpoint timestamps finding the one + which is largest and <= the target timestamp +B. forward seeking + 1a. perform a binary search on the syncpoint timestamps finding the one + which is smallest and >= the target timestamp + 1b. perform a binary search on the syncpoint back pointers finding the + smallest one which has a back ptr >= the position of what was found in 1. +2. follow the back pointer to the correspoding syncpoint + +Seeking with an index (non-normative): +-------------------------------------- +The demuxer only has to find the appropriate keyframe in the index and +start demuxing from the previous syncpoint + +Note, more complicated seeking methods exist which are capable of quickly +seeking to the optimal point in the presence of an index even if only a +subset of all streams are active but a muxer SHOULD place syncpoints, +and keyframes if it can affect the placement of keyframes so that simple +low complexity seeking works with fine granularity + Semantic requirements: ====================== |