PDA

View Full Version : MPEG-2 Simple Profile ever used by anything

benwaggoner
18th May 2009, 01:20
Say, is anyone aware of any current usage of MPEG-2 Simple Profile?

The only profiles I ever see in the wild are Main and High.

The Wikipedia page lists it for "Wireless handsets" and "PDA's" and I imagine that some mobile players could do SP in software even. But I can't think of any SP content actually targeting the same. In particular, B-frames seem a hard thing to give up. MPEG-1 is probably more efficient on net; B-frames should beat half-pel motion estimation and the other differences in progressive encoding betwee MPEG-1 and MPEG-2.

But I'm happy to be corrected!

P.S. Semi-related question: does anything require the High 1440 Level other than HDV?
drmpeg
18th May 2009, 02:42
Low-delay never uses B-frames, so you could indicate Simple Profile in the bitstream. However, the real motivation for including Simple Profile in MPEG-2 was memory size. Back in 1994, a decoder with 1 Megabyte of DRAM was significantly cheaper than a decoder with 2 Megabytes.

Same thing with High-1440. With today's memory densities, these Profiles are moot. You won't find a current hardware decoder that's limited to Simple or High-1440 Profile.

Ron
Manao
18th May 2009, 05:39
The only profiles I ever see in the wild are Main and High.I don't think you meant "high", but 4:2:2. High profile in Mpeg2 mandates support for scalability, and I'm not aware of any decoder supporting that. Meanwhile 4:2:2 profile allows higher bitrates than main, and support for 4:2:2 (and that is supported by decoders)

As for Mpeg1 versus Mpeg2 SP, I wouldn't dismiss hpel (vs bframes) that quickly. But as drmpeg said, the point is moot nowadays.
benwaggoner
18th May 2009, 06:52
I don't think you meant "high", but 4:2:2. High profile in Mpeg2 mandates support for scalability, and I'm not aware of any decoder supporting that. Meanwhile 4:2:2 profile allows higher bitrates than main, and support for 4:2:2 (and that is supported by decoders)
I actually meant Main Profile @ High 1440.

As for Mpeg1 versus Mpeg2 SP, I wouldn't dismiss hpel (vs bframes) that quickly. But as drmpeg said, the point is moot nowadays.
I sure hope so :).