About “emulation_prevention_three_byte" of H.264 NAL [Archive]

View Full Version : About “emulation_prevention_three_byte" of H.264 NAL

phdzwei

2nd August 2011, 08:34

Based on the definition of “emulation_prevention_three_byte”， Within NAL, The following bytes sequence
– 0x000000
– 0x000001
– 0x000002
– 0x000003
should convert to following bytes sequence
– 0x00000300
– 0x00000301
– 0x00000302
– 0x00000303

I am confusing the below situation:
If there are normal bytes sequences in H.264 bitstream， such as “0x00000300 “， ”0x00000301“， ”0x00000302"，0x00000303”.

How the decoder differentiates the "normal" one and "converted" one?

Thank you.

Guest

2nd August 2011, 19:34

If there are normal bytes sequences in H.264 bitstream such as “0x00000300 “， ”0x00000301“， ”0x00000302"，0x00000303”. The specification prohibits that.

Sulik

3rd August 2011, 02:12

Actually it doesn't: 0x00,0x00,0x03,0x00 simply becomes 0x00,0x00,0x03,0x03,0x00

phdzwei

3rd August 2011, 09:05

Yes, I got it. Thank you. Neuron2 and Sulik

Guest

3rd August 2011, 14:51

Oops, you are correct Sulik. I misread the spec in haste. :scared: