[FFmpeg-devel] GSoC VQA v3 vptr decode function implementation

The Deep Explorer thedeepexplorer
Mon Apr 13 07:44:49 CEST 2009


>> Doc's info -->
>>
>> ?010 - Write block number (Val & 0xff) and then write Count blocks
>> ? ? ? ? getting their indexes by reading next Count bytes from
>> ? ? ? ? the VPTR chunk. Count is (((Val/256) & 0x1f)+1)*2.
>> ? ? ? ? Again, the block numbers range from 0-255.
>>
>> ? ? ? ? ? ?block_no = code_buf & 0x1ff;
>> ? ? ? ? ? ?count = (((code_buf/256) & 0x1f)+1)*2;
>>
>> It does not say how many bytes :( . So assuming 1 byte I will read the
>> next byte ( say it is val)
>> and then count will be computed as ?count = (((val/256) & 0x1f)+1)*2;
>
> Count bytes for Count block indexes - do the division yourself.
>

Honestly, I got lost , as to what division you are talking ...,

So, count is  (((Val/256) & 0x1f)+1)*2  and then this many times we
will have to read/fetch
each byte from the vptr chunk.. the byte we read is the index of what ?
Is it the index to the dest buffer where we are writing the block no ?
And every time we read , we have to increment the src index pointer by 1 byte ?

Thanks,
-tde



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