[FFmpeg-devel] [PATCH] avcodec/pnm: avoid mirroring PFM images vertically

[Leo Izen]

On 11/29/22 06:14, Anton Khirnov wrote:
> Quoting Leo Izen (2022-11-16 12:43:06)
>> PFM (aka Portable FloatMap) encodes its scanlines from bottom-to-top,
>> not from top-to-bottom, unlike other NetPBM formats. Without this
>> patch, FFmpeg ignores this exception and decodes/encodes PFM images
>> mirrored vertically from their proper orientation.
>>
>> For reference, see the NetPBM tool pfmtopam, which encodes a .pam
>> from a .pfm, using the correct orientation (and which FFmpeg reads
>> correctly). Also compare ffplay to magick display, which shows the
>> correct orientation as well.
>>
>> See: http://www.pauldebevec.com/Research/HDR/PFM/ and see:
>> https://netpbm.sourceforge.net/doc/pfm.html for descriptions of this
>> image format.
>>
>> Signed-off-by: Leo Izen <leo.izen at gmail.com>
>> ---
>>   libavcodec/pnmdec.c          | 10 ++++++++++
>>   libavcodec/pnmenc.c          | 18 ++++++++++--------
>>   tests/ref/lavf/gbrpf32be.pfm |  2 +-
>>   tests/ref/lavf/gbrpf32le.pfm |  2 +-
>>   tests/ref/lavf/grayf32be.pfm |  2 +-
>>   tests/ref/lavf/grayf32le.pfm |  2 +-
>>   6 files changed, 24 insertions(+), 12 deletions(-)
> 
> Looks reasonable, will push soonish.
> 

I got a LGTM, can someone push this? Thanks.

- Leo Izen (thebombzen)