[FFmpeg-devel] [PATCH] avfilter/buffersrc: print relevant info when skipping filter reinit

Gyan ffmpeg at gyani.pro
Sat Jan 26 06:42:18 EET 2019

On 26-01-2019 01:17 AM, Carl Eugen Hoyos wrote:
> 2019-01-25 14:02 GMT+01:00, Gyan <ffmpeg at gyani.pro>:
>> On 25-01-2019 06:25 PM, Carl Eugen Hoyos wrote:
>>> 2019-01-25 13:52 GMT+01:00, Gyan <ffmpeg at gyani.pro>:
>>>> On 25-01-2019 06:11 PM, Carl Eugen Hoyos wrote:
>>>>> 2019-01-25 13:35 GMT+01:00, Gyan <ffmpeg at gyani.pro>:
>>>>>> +        av_log(s, AV_LOG_WARNING, "Changing video frame
>>>>>> properties on the fly is not supported by all filters.\n");\
>>>>> In which situations is this new warning shown?
>>>> e.g.
>>>>         -reinit_filter 0 -i ChangingResolutions.mp4 -vf somefilter  ...
>>> Is it only shown if the filter does not support re-initialization?
>> No. As the existing msgs indicate, it is always printed when
>> _some_ frame properties have changed.
> I may misunderstand but I believe that no warning should be
> shown in this case.

Are you objecting to the loglevel? Because a message was _always_ shown 
- I just added a line with metadata and changed the loglevel of the 
existing message to warning, which the character of the message warrants.

>> The new addition allows the user to discover which properties
>> those are, with timestamp. They can then choose to continue,
>> allow reinit or partition the input (if viable) as appropriate.
> It appears to me that the only thing the message would do is
> to confuse users that do not understand the warning (but see
> above).
Most casual users don't understand most of the warnings. Either users 
grasp the meaning and act upon it themselves, or they can show it to 
others who do.
I see no benefit to fatal or unusual changes remaining opaque. This 
hardly even adds to the verbosity.


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