[FFmpeg-soc] [soc]: r532 - matroska/matroskaenc.c

[David Conrad]

On Jul 28, 2007, at 5:56 PM, Michael Niedermayer wrote:

> Hi
>
> On Sat, Jul 28, 2007 at 04:23:45PM -0400, David Conrad wrote:
>> On Jul 28, 2007, at 3:10 PM, Michael Niedermayer wrote:
>>
>> I don't think it's necessary to try for a completely unique ID, the
>> SHA-1 hash of a couple of frames would be enough imo, given how
>> infrequently these options are used (I'll implement this shortly if
>> there are no objections.) I just didn't want every segment UID to be
>> identical unless the user requests it via bitexact.
>
> no objections ...
> though maybe a crc or adler32 checksum would be a better option
> as they are faster

I wound up using a md5sum of the first 200 bytes of the first frame  
of each cluster since it was the easiest to get 16 bytes without  
repeating the checksum. I couldn't measure any slowdown with this  
method.