[FFmpeg-user] feature request: warn when video bitrate ignored

[James Darnley]

On 2012-10-15 19:15, Roger Pack wrote:
> Hello. Some people get confused when the following occurs--they
> enter a video bitrate, but it is seemingly ignored:
> 
> ffmpeg -i input  -b:v 200k output
> 
> I suppose they're just missing a "bufsize" option, for 1 pass
> encoding. Would it be possible to fail it if it ignores parameters
> like this? Or warn? or fail with a warning (better yet)? Just
> wondering. Thank you.

With a "normal" codec, the bitrate won't be ignored.  The encoder will
try very hard to get to that rate and only at the end will it be able
to say "I was unable to reach this".

Do you have any specific requests on how it should be detected?  I
suppose you could look at whether the encoder was pegged to the
max/min quantiser and then print something.  But then how far off the
target do you start reporting a problem?