[FFmpeg-soc] [soc] libavsequencer [PATCH 01/08] Music module public API header file.

[Michael Niedermayer]

On Sun, Jul 11, 2010 at 01:27:20AM +0200, Vitor Sessak wrote:
> On 07/11/2010 01:17 AM, Sebastian Vater wrote:
>> Vitor Sessak a écrit :
>>> On 07/11/2010 12:58 AM, Sebastian Vater wrote:
>>>> Vitor Sessak a écrit :
>>>>
>>>>> I don't know what typical values are, but is the folowing doable?
>>>>>
>>>>> #define MAX_INSTRUMENTS [... some value here ...]
>>>>> AVSequencerInstrument *instrument_list[MAX_INSTRUMENTS];
>>>>>
>>>>> Everything access and insertion O(1) and both done in one line of
>>>>> code...
>>>>
>>>> The limit almost always 64k, which would be quite large in that case.
>>>
>>> I don't mean the theoretical limit, I mean the biggest value ever used
>>> in any actual file.
>>
>> Hmm, and how to determine that? Including all the future files that will
>> ever be created?
>
> What was the biggest value you ever encountered? If it's 20, setting it to 
> 100 might be safe. Those who want to try weird experiments with crazy files 
> are free to increase it and recompile ;)
>
>> Another possibility would be simply stick to 2^n size, with a start
>> let's say of 1, and if we add a new instrument which makes the list
>> larger or equal to (2^n) + 1, we increase the size to 2^(n+1).
>>
>> Anyway, when the limit is 64k, we have at worst O(65535) which should
>> even not a problem for 20 year old CPUs. And even if the user has to
>> wait half a second here, we can accept this (in that case, the user
>> would simply add 16 instruments at once to avoid the delay).
>
> That is not important now. If we can not set a maximum value for it we let 
> to whatever code that is going to create this struct to alloc it using the 
> best method for its particular problem...

iam not sure if the MAX_INSTRUMENTS idea is all that great, considering how
we are being hit by MAX_STREAMS currently. But i think an array of pointers
thats allocated somewhere is a big improvent over the tree in terms of
simplicity
[...]
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