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qiqian / webp

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-size and -psnr don't work in webp with the version 0.4.3 #249

Open GoogleCodeExporter opened 8 years ago

GoogleCodeExporter commented 8 years ago 
What steps will reproduce the problem?
1. First encode parameter:  cwebp.exe a_5.jpg -o a_5_enc.webp
2. Second encode parameter: cwebp.exe a_5.jpg  -f 100 -o a_5_enc_f100.webp
3. only different is "-f 100" in the second parameter

What is the expected output? What do you see instead?
It's expected with different PSNR, but I got the same bitstream...
The "-psnr" doesn't work either.

What version of the product are you using? On what operating system?
Version: 0.4.3
OS:x64

Please provide any additional information below.

Original issue reported on code.google.com by denghblz...@gmail.com on 20 May 2015 at 12:01

GoogleCodeExporter commented 8 years ago 
It's the same bitstream with different -size or -psnr value.
I have tried several times, the same as -f above.

Original comment by denghblz...@gmail.com on 20 May 2015 at 12:11

GoogleCodeExporter commented 8 years ago 
The PSNR value displayed doesn't take post-processing into account. It would be 
slow and would make the encoder slightly more complicated.

So, the PSNR value displayed is for "unfiltered output samples", the one you 
would get with -f 0.

Original comment by pascal.m...@gmail.com on 20 May 2015 at 6:21