[Mp4-tech] B-frame detection?

[Wesley De Neve]

Hi,
harish.vasudeva amd.com wrote:
> Hi,
>
>  Is there any way of detecting (in the decoder) if B-frames are
> present in the sequence? May be by a combination of bits?

The decoder should check for the value of the vop_coding_type syntax element
in case you're talking about an MPEG-4 Visual Elementary Stream:
      vop_coding_type     coding method
      00                            intra-coded (I)
      01                            predictive-coded (P)
      10                            bidirectionally-predictive-coded (B)
      11                            sprite (S)
Best regards,
-Wesley