[FFmpeg-devel] [FFmpeg-cvslog] AAC encoder: tweak PNS usage to be more aggressive

[Claudio Freire]

On Fri, Sep 25, 2015 at 10:39 PM, James Almer <jamrial at gmail.com> wrote:
>> ffmpeg | branch: master | Claudio Freire <klaussfreire at gmail.com> | Fri Sep 25 03:56:32 2015 -0300| [9458a62decfcaa1313b1ba69276466de536d0768] | committer: Claudio Freire
>>
>> AAC encoder: tweak PNS usage to be more aggressive
>>
>> This patch tweaks search_for_pns to be both more
>> aggressive and more careful when applying PNS. On
>> the one side, it will again try to use PNS on zero
>> (or effectively zero) bands. For this, both zeroes
>> and band_type have to be checked (some ZERO bands
>> aren't marked in zeroes). On the other side, a more
>> accurate rate-distortion measure avoids using PNS
>> where it would cause audible distortion.
>>
>> Also fixed a small bug in the computation of freq
>> that caused PNS usage on low-frequency bands during
>> 8-short windows. This allows re-enabling PNS during
>> 8-short.
>
> Clang and gcc's address sanitizer complain about this change
>
> http://fate.ffmpeg.org/report.cgi?time=20150925234050&slot=x86_64-archlinux-gcc-asan
> http://fate.ffmpeg.org/report.cgi?time=20150925220641&slot=x86_64-debian-asan-144800


It was a pre-existing issue that got exposed by that commit, not the
commit itself.

But fixed in any case.

There may be other instances of the bug, so I'll be on the lookout for
this specific case.