[FFmpeg-trac] #5668(avcodec:new): webp : lossy decoding have lower quality than official decoder

[FFmpeg]

#5668: webp : lossy decoding have lower quality than official decoder
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             Reporter:  mvignali    |                     Type:  defect
               Status:  new         |                 Priority:  normal
            Component:  avcodec     |                  Version:  git-master
             Keywords:  webm lossy  |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
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 Summary of the bug:
 How to reproduce:
 {{{
 ./ffmpeg -i ./rgb_webp_q80.webp res3.png
 ffmpeg version N-80681-g4cc896e Copyright (c) 2000-2016 the FFmpeg
 developers
   built with Apple LLVM version 6.0 (clang-600.0.56) (based on LLVM
 3.5svn)
   configuration: --prefix=../build --disable-yasm --disable-ffplay
 --disable-ffprobe --disable-ffserver
   libavutil      55. 26.100 / 55. 26.100
   libavcodec     57. 46.100 / 57. 46.100
   libavformat    57. 40.101 / 57. 40.101
   libavdevice    57.  0.101 / 57.  0.101
   libavfilter     6. 46.102 /  6. 46.102
   libswscale      4.  1.100 /  4.  1.100
   libswresample   2.  1.100 /  2.  1.100
 Input #0, webp_pipe, from './rgb_webp_q80.webp':
   Duration: N/A, bitrate: N/A
     Stream #0:0: Video: webp, yuv420p(tv, bt470bg/unknown/unknown), 12x8,
 25 tbr, 25 tbn, 25 tbc
 [image2 @ 0x7f8ef1013800] Using AVStream.codec to pass codec parameters to
 muxers is deprecated, use AVStream.codecpar instead.
 Output #0, image2, to 'res3.png':
   Metadata:
     encoder         : Lavf57.40.101
     Stream #0:0: Video: png, rgb24, 12x8, q=2-31, 200 kb/s, 25 fps, 25
 tbn, 25 tbc
     Metadata:
       encoder         : Lavc57.46.100 png
 Stream mapping:
   Stream #0:0 -> #0:0 (webp (native) -> png (native))
 Press [q] to stop, [?] for help
 frame=    1 fps=0.0 q=-0.0 Lsize=N/A time=00:00:00.04 bitrate=N/A speed=
 24x
 video:0kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB
 muxing overhead: unknown
 }}}
 Patches should be submitted to the ffmpeg-devel mailing list and not this
 bug tracker.

--
Ticket URL: <https://trac.ffmpeg.org/ticket/5668>
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