[FFmpeg-devel] [PATCH v2] avfilter/delogo: Set default band to 1

Hendrik Leppkes h.leppkes at gmail.com
Thu Oct 8 12:20:25 CEST 2015


On Thu, Oct 8, 2015 at 11:30 AM, Stefano Sabatini <stefasab at gmail.com> wrote:
> On date Wednesday 2015-10-07 15:03:32 +0200, Jean Delvare encoded:
>> The original interpolation algorithm behaved poorly on the borders and
>> did not even guarantee continuity at the borders. For this reason, a
>> second interpolation/blending pass was required on the borders to make
>> them seamless.
>>
>> However, since the interpolation algorithm was improved in June 2013,
>> the border issues no longer exist. The new algorithm does guarantee
>> continuity at the borders, making the second pass useless. A larger
>> band always increases the cumulated interpolation error. In most cases
>> it also increases the average interpolation error, even though the
>> samples in the band are only partially interpolated.
>>
>> For this reason I would like to get rid of the "band" parameter. As a
>> first step, let's change its default value from 4 to 1 and document it
>> as deprecated.
>>
>> I have benchmarked this change on a combination of input sources and
>> realistic logo areas. Lowering the band value from 4 to 1 resulted in
>> 8 to 39 % less interpolation error per frame (or 1 to 34 % less
>> interpolation error per luma sample.)
>>
>> Signed-off-by: Jean Delvare <jdelvare at suse.de>
>> ---
>> Changes since v1:
>>  * Added #ifs so that the deprecated options are dropped automatically
>>    on next major version of libavfilter (suggested by Stefano Sabatini)
>>
>>  doc/filters.texi        |    4 +++-
>>  libavfilter/vf_delogo.c |   17 +++++++++++++++--
>>  2 files changed, 18 insertions(+), 3 deletions(-)
>
> Thanks, applied.

This seems to have broken FATE, ie:
http://fate.ffmpeg.org/report.cgi?time=20151008101706&slot=x86_32-mingw-w64-dll-windows-native


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