[FFmpeg-cvslog] r22715 - trunk/libavcodec/bitstream.c

[Måns Rullgård]

Loren Merritt <lorenm at u.washington.edu> writes:

> On Sun, 2 May 2010, M?ns Rullg?rd wrote:
>
>> lorenm <subversion at mplayerhq.hu> writes:
>>
>>> @@ -258,6 +275,9 @@ int init_vlc_sparse(VLC *vlc, int nb_bit
>>>               const void *symbols, int symbols_wrap, int symbols_size,
>>>               int flags)
>>>  {
>>> +    VLCcode buf[nb_codes];
>>
>> Sorry for not noticing this earlier, but is there any way that
>> variable-length array could be removed?  Such beasts are made of pure
>> evil.  We should be slaying them, not helping them spread.
>
> a) malloc.

Would this have any measurable impact on performance?  Is this
function ever called more than once per frame?

> b) unconditionally round it up to 512KB of stack space (that being the
> largest size currently supported).

Out of the question.

> c) unconditionally round it up to 11KB of stack space (that being the
> largest size currently used (not sure of this)).

Fragile, and also out of the question.

-- 
M?ns Rullg?rd
mans at mansr.com