[FFmpeg-devel] [PATCH] avcodec/aaccoder: Limit sf_idx difference for all cases

Claudio Freire klaussfreire at gmail.com
Thu Nov 17 01:18:14 EET 2016


On Wed, Nov 16, 2016 at 8:09 PM, Michael Niedermayer
<michael at niedermayer.cc> wrote:
>> Sorry for the delay, it turned out to be more complex than that.
>>
>> There were a few potential violations that I had already identified in
>> a WIP patch but they did not apply to the fuzzed sample. That sample
>> triggered an interaction with TNS and trellis band type coding that
>> resulted in zeroed bands reappearing and thus invalidating all delta
>> scalefactor validations.
>>
>> The attached patch series fixes most of the delta scalefactor
>> violation risks I could find, including that one.
>>
>> It hasn't been thoroughly tested for quality regressions/improvements.
>> It's possible that it does change quality since it changes key
>> decision points that conduce to the violations but also to lots of
>> audible artifacts. So I believe it should improve quality, but one
>> never knows without proper ABX testing, which I'll be conducting, at
>> least in a limited way, in the following days.
>>
>> In the meantime, I'm attaching the patch series for review.
>
> ping

Is that ping for me?

It's a significant patch so I'd rather have a little review before
pushing, waiting for that.

Well, not really waiting. I did some tests too and found some not so
desirable side effects that I hadn't fully fixed when RL decided to
rob me of most of my free time, so I haven't pushed it yet to prevent
even more serious regressions, but still I'd rather not push without
some form of review.

So, ccing Rostislav in case he just missed the original patch (he's
the most likely to review anyway)


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