[FFmpeg-devel] [RFC] Make swscale-test perform only one convertion

Ramiro Polla ramiro.polla
Fri Jan 29 09:16:14 CET 2010

On Fri, Jan 29, 2010 at 2:52 AM, Vitor Sessak <vitor1001 at gmail.com> wrote:
> Stefano Sabatini wrote:
>> this is meant to simplify the testing/debuggin work in lsws, and
>> provide a basis for a future lswstest rule, often it happens that I
>> need to test/debug only a particular conversion, I was using the scale
>> lavfi filter for this but it is way easier this way.
>> I expected the new result to be different from the old one as the
>> random source is different,
> This is easy to work-around, just re-init LFG fo every format pair in the
> unpatched swscale-test and it should give the same results.
>> but I noted that the new result is almost
>> always *worse* than the old one (that is the output obtained with
>> the old swscale-test), can someone explain?
> Have you tried running twice with exactly the same binary to see if there is
> nothing reading uninitialized mem?

The fast bilinear code reads unitialized memory (it always overreads
at least one pixel).

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