Does one benefit of having more than one slice per frame on h264?

[leandro]

I'm concerned mostly with (either for live and vod):

Decoder compatibility (TVs, mobile, tables, desktops... what's the max number of slice to keep the compatibility)
Support (does a decoder uses multi-thread to use it?)
Performance (will it be slower or faster?)



PS: I couldn't find this answer anywhere =/

[sneaker_ger]

There is a slight compression hit. Slices are supposed to make multi-threading easier. 4 slices are required by the Blu-Ray specs for level 4.1. I know some older decoders (notably Playstation 3) can profit from slices but modern decoders usually don't need them. Also, many people only encode to relatively low bitrates (much lower than Blu-Ray) so then even older decoders usually don't need them. Blu-Ray level 4.0 (up to 25 Mbps bitrate) doesn't require slices.

So if you are encoding to high bitrates (> level 4.0) and have some older decoders you can activate 4 slices. Otherwise I would use only no (1) slices. Haven't seen any decoder that cannot decode slices.

[leandro]

There is a slight compression hit. Slices are supposed to make multi-threading easier. 4 slices are required by the Blu-Ray specs for level 4.1. I know some older decoders (notably Playstation 3) can profit from slices but modern decoders usually don't need them. Also, many people only encode to relatively low bitrates (much lower than Blu-Ray) so then even older decoders usually don't need them. Blu-Ray level 4.0 (up to 25 Mbps bitrate) doesn't require slices.

So if you are encoding to high bitrates (> level 4.0) and have some older decoders you can activate 4 slices. Otherwise I would use only no (1) slices. Haven't seen any decoder that cannot decode slices.

Thank you very much @sneaker_ger