[FFmpeg-devel] [PATCH] swresample/resample: do not allow odd filter_length

[Muhammad Faiz]

On Thu, Mar 9, 2017 at 1:32 AM, Michael Niedermayer
<michael at niedermayer.cc> wrote:
> On Wed, Mar 08, 2017 at 10:25:42PM +0700, Muhammad Faiz wrote:
>> except filter_length == 1
>>
>> odd filter_length gives worse frequency response,
>> even when compared with shorter filter_length
>>
>> also makes build_filter simpler
>>
>> Signed-off-by: Muhammad Faiz <mfcc64 at gmail.com>
>> ---
>>  libswresample/resample.c     | 56 +++++++++++---------------------
>>  tests/fate/libswresample.mak | 76 ++++++++++++++++++++++----------------------
>>  2 files changed, 56 insertions(+), 76 deletions(-)
>
> why does this change the checksums ?
>
> did they use odd filter lengths ?

Of course, filter_length is not necessarily equal with filter_size.
for example 8000 -> 2626, filter_length = ceil(32/0.97*8000/2626) = 101