What's the default behaviour when user not specify scalabilityMode?

[bdrtc]

Do we need add describe about the default scalabilitymode value when user does't specify it via sendencodings api? From my test, L1T1 will be used in none simulcast mode for h264/vp8, and scalabilityMode will be L1T2 by default when h264/vp8 used in simulcast mode .

[Orphis]

The belief is that since this is an optimisation that is codec and implementation dependent, it should probably not be specified not to be too restrictive for current implementation and future developments.

If you do care about having a specific mode used, you should just use the API, otherwise why would you care about the default value?

As for the current defaults, those are the one for current Chrome. They may be different in other browsers or codecs combinations.

[aboba]

The default behavior is specified in Section 4.2.3:

"The default scalabilityMode for each codec is implementation dependent. The default scalabilityMode SHOULD be one of the temporal scalability modes (e.g. ["L1T1"],["L1T2"],["L1T3"], etc.)."

[bdrtc]

The default behavior is specified in Section 4.2.3:

"The default scalabilityMode for each codec is implementation dependent. The default scalabilityMode SHOULD be one of the temporal scalability modes (e.g. ["L1T1"],["L1T2"],["L1T3"], etc.)."

ok，got it, there is only chrome implement this currently, and use diffrent scalabilityMode by default in simulcast and none simucast usage, i think this part should be put in Section 4.2.2。