[FFmpeg-devel] [PATCH] lavfi: Port mp=pp7 to libavfilter

Stefano Sabatini stefasab at gmail.com
Wed Jan 7 15:42:16 CET 2015

On date Wednesday 2015-01-07 19:14:49 +0530, arwa arif encoded:
> >
> >
> > Keep in mind that the difference may be due to the QP information
> > missing in mp=pp7. So you should focus on that (try to reset/disable
> > qp processing in pp7 and see if it works the same as mp=pp7).
> >

> For qp=0, the results are bitexact. I am not able to figure out how do I
> take care

Isn't qp=0 the default? How do you get (with which parameters) mp=pp7
and pp7 to issue the same output?

> of the non zero qp case. In the original code, the value is directly
> accessed by
> the frame (mpi->qscale).

> I tried using memset, but it is giving some memory errors. In memset, we use
> the first argument as the pointer to the block and the last as the size of
> the block,
> right?

something like:

memset(qp_table->data, 0, qp_table->size); 

> For documentation, can you provide me with a standard image? Because, the
> one I am using is not giving results which are presentable. There is not
> much
> difference if I vary the parameters (In fact the filters are also giving
> the same result).

I guess this is for the postprocessing comparison document, right? It
is important you use low-quality content (e.g. matrix_bench.mpg
encoded to 200Kbits/s) or you can use the reference images here:

FFmpeg = Faithful and Freak Magnificient Philosophical Elastic Game

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