Fwd: Re: [ffmbc-discuss] Why does ffmbc auto select a compatible format, even though it is already set to that in a filter?

[Tim Nicholson]

On 14/07/12 00:41, Baptiste Coudurier wrote:
> On 07/13/2012 06:04 AM, Tim Nicholson wrote:
>> On 13/07/12 13:33, Steven Allen wrote:
>>> I'm guessing that is because filters are processed last in the chain.
>
> Yes, that's what happens.
>
>> Really, so you would expect a filter to be processed after the transcode.....
>
> Huh ?
>

If you are filtering and transcoding material then the sequence has to be:-

decode->filter->recode, I don't see how filtering can be processed last?


>>> Have you tried using pix_fmt instead?
>>> -pix_fmt yuv422p10le
>>>
>>
>> Yes, but that doesn't explain why the scale doesn't do as it "says on the tin" and convert the pixel
>> format to that required by the next filter in the chain...
>
> What are you talking about ?
> And why are you using format filter instead of pix_fmt/at all ? What you do here is useless.
>

well according to ffmbc -filters:-

format Convert the input video to one of the specified pixel formats

Since I wanted to convert the input format to a specific output format suitable
for the codec I was using, and I was already using a filter graph it seemed an
appropriate way to do it.

I am wary of using pix_fmt since I don't want auto inserted scale filters to
screw up my interlacing, and the above seemed a neat solution.

I have not yet seen any explanation as to why "What you do here is useless".

It seems perfectly logical based upon the available information, perhaps you
could explain why for the benefit of others as well as myself?

--
Tim

--
Tim Nicholson
Digital Media Services
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