[Libav-user] errors while processing tiff streams with image2pipe

Carl Eugen Hoyos cehoyos at ag.or.at
Mon May 6 20:11:09 CEST 2013

cyril apan <cyrilapan at ...> writes:

>>cyril apan <cyrilapan <at> ...> writes:
>>> http://www.filmform.com/logo/Filmform_gray-on-blank.tif 
>> stream->codec->pix_fmt == AV_PIX_FMT_RGB24 instead of 
>> being AV_PIX_FMT_RGBA.>Looks like RGB24 to me, why do you 
>> think there is >transparency information?

> Open it with Photoshop CS v12.0.4, and it displays a 
> checkered background.

Both ImageMagick and gimp are not seeing 
the transparency either.
I am not saying Photoshop is wrong, but 
I read it as "RGB" "8bit", so I don't know 
where to find the additional information.
(It may be a Photoshop-specific tag and that 
is what gimp's warnings indicate.)

>> Since you used "image2pipe" in the subject:
>> There is no tiff parser, so you cannot generally use 
>> input format image2pipe with tiff images, but this is 
>> unrelated to the samples.
>> (Patch welcome.)
> I'm not sure to understand. So, image2pipe shouldn't 
> work with tiff files?

Not completely, no.

> So why I can still get something out from the 
> 1st sample?

Possibly because you are only feeding one image?
The idea of image2pipe is usually to feed a 
series of images to ffmpeg, a parser is needed 
to find the beginning of the next image.

Carl Eugen

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