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

[Sebastian Vater]

Vitor Sessak a écrit :
> On 07/13/2010 11:55 PM, Sebastian Vater wrote:
>> Vitor Sessak a écrit :
>>> On 07/13/2010 10:11 PM, Sebastian Vater wrote:
>>>> Vitor Sessak a écrit :
>>>>> On 07/07/2010 10:46 PM, Sebastian Vater wrote:
>>>
>>> [...]
>>>
>>>>>> /**
>>>>>>    * Opens and registers module to the AVSequencer.
>>>>>>    *
>>>>>>    * @param avctx the AVSequencerContext to store the opened module
>>>>>> into
>>>>>>    * @param module the AVSequencerModule which has been opened to be
>>>>>> registered
>>>>>>    * @return>= 0 on success, a negative error code otherwise
>>>>>>    *
>>>>>>    * @note This is part of the new sequencer API which is still
>>>>>> under
>>>>>> construction.
>>>>>>    *       Thus do not use this yet. It may change at any time,
>>>>>> do not
>>>>>> expect
>>>>>>    *       ABI compatibility yet!
>>>>>>    */
>>>>>> int avseq_module_open(AVSequencerContext *avctx, AVSequencerModule
>>>>>> *module);
>>>>>
>>>>> Hmm, I think I don't really understand what this function do. Suppose
>>>>> you want to write a very short test program to play a MOD file using
>>>>> the libraries. Roughly, what functions it will call, in which order
>>>>> and with which parameters?
>>>>
>>>> To be honest, I added this prototype only for now to see if the way I
>>>> want to add them is compatible with FFmpeg style guide. Wanted just to
>>>> avoid adding functions and all follow a wrong guideline. But the
>>>> suppose
>>>> is to load a module from disc and register it to the module list in
>>>> avctx).
>>>
>>> Guideline-wise it is fine, but I don't think functions should be added
>>> to the BSS structs without a very good reason.
>>
>> That's clear! Just want to mention the point, that the user today
>> expects the feature of having multiple (in this case modules) files
>> opened at once and thus editing them. We're not anymore in the eighties
>> were it was common just to have one file opened at the same time.
>
> And what does it change? Both lavf/ and lavc/ can handle several files
> at the same time (and I mean _really_ at the same time, it is fully
> thread-safe).

Great! Wasn't really aware of this! I have now to find a way to
integrate the lavs base structs in lavs/module.h, as I understand it?

>
>> So I thought of a way of allowing the user exactly that, that's why I
>> plan to add multiple modules to AVSequencerContext. The programmer
>> developing the GUI has to take care of this list though mostly by
>> itself.
>
> In the BSS, it does not make much sense an AVSequencerContext.
>
> Besides that, I agree with Ronald: why not a different player context
> for each file and let the application store them as it wish?
>

This is clearly a until not-yet-known feature of FFmpeg which I didn't
account to until now. Sorry for that! Now I have to guess the best way,
to integrate lavs/avsequencer.h into lavs/module.h instead!?

But let's file that tomorrow, otherwise you will read sth. like that the
next mail:
fjs9teuwJSDUHPuhfp

Because falling on the keyboard for sake of tireness...;-)

-- 

Best regards,
                   :-) Basty/CDGS (-: