H264 -Speed Optimization-

[saad]

<areas we can exploit regarding optimzation >

Does someone have any info or update about the optimization of code_from_bitstream_2d{....

// this VLC decoding method is not optimized for speed

...........
} in vlc.c (decoder)

this function is becoming a bottleneck in speed and i m really interested in its optimization ... :confused:

[Magno]

Are you talking about x.264 maybe? If so, X264 hasn't a valid decoder so don't bother about that code.
Maybe you mean that the VLC decoding method isn't optimized in the coder for frame reconstruction, but in that case, the coder hasn't to decode VLCs as it would be a waste of processing (encoding) time: the reconstruction x264 coder do consists of motion compensation + inverse transform, so the code you refer to isn't used either.

[akupenguin]

Trying to optimize JM? good luck ;)

As to that particular function: Yes, it uses a ridiculously inefficient algorithm. Replace the linear search by a couple of table lookups.