[FFmpeg-devel] [PATCH] avfilter: align data frame when needed

Muhammad Faiz mfcc64 at gmail.com
Fri May 5 17:46:44 EEST 2017

On Fri, May 5, 2017 at 5:00 PM, Nicolas George <george at nsup.org> wrote:
> Le sextidi 16 floréal, an CCXXV, Muhammad Faiz a écrit :
>> This should fix Ticket6349.
>> Since 383057f8e744efeaaa3648a59bc577b25b055835, framequeue may
>> generate unaligned frame data.
>> Signed-off-by: Muhammad Faiz <mfcc64 at gmail.com>
>> ---
>>  libavfilter/avfilter.c | 26 +++++++++++++++++++++++++-
>>  1 file changed, 25 insertions(+), 1 deletion(-)
> Sorry, but no.
> According to the C standard and FFmpeg's developer documentation, the
> current output of libavfilter is correctly aligned, and libmp3lame is
> misbehaving.

If documentation says that data should be aligned to 32-bytes but I
only align it to 4-bytes, then I violate the doc. But if documentation
says that data should be aligned to 4-bytes but I align it to
32-bytes, then there are no violations at all. So what's wrong with
this patch?

This patch does not mean to state that framequeue is wrong. This is a
So I add locally to the commit message and comment in code:
'Workaround for filters and codecs that assume simd aligned data.'

When the framework is ready for simd unaligned data, this patch can be reverted.


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