[FFmpeg-trac] #4017(avfilter:new): noise filter breaks when combined with scaling

[FFmpeg]

#4017: noise filter breaks when combined with scaling
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             Reporter:  rmk       |                     Type:  defect
               Status:  new       |                 Priority:  normal
            Component:  avfilter  |                  Version:  unspecified
             Keywords:            |               Blocked By:
             Blocking:            |  Reproduced by developer:  0
Analyzed by developer:  0         |
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 The following command line generates a video which has only noise in the
 right half of the picture and the noise has patterns that are completely
 different from the filter's behaviour when used without scaling:

  ./ffmpeg -f lavfi -i testsrc=s=1920x1080 -vf
 format=pix_fmts=yuv422p10le,scale=3840:2160,noise=c0s=10:allf=t -vcodec
 prores -q:v 0 -t 1
 /Volumes/LPTest4_Mac/playground/transcoding/noise_upscale_ffmpeg.mov
 ffmpeg version N-66701-g33db995 Copyright (c) 2000-2014 the FFmpeg
 developers
   built on Oct  8 2014 19:07:01 with Apple LLVM version 6.0
 (clang-600.0.51) (based on LLVM 3.5svn)
   configuration:
   libavutil      54.  9.100 / 54.  9.100
   libavcodec     56.  3.101 / 56.  3.101
   libavformat    56.  7.104 / 56.  7.104
   libavdevice    56.  1.100 / 56.  1.100
   libavfilter     5.  1.103 /  5.  1.103
   libswscale      3.  1.100 /  3.  1.100
   libswresample   1.  1.100 /  1.  1.100
 Input #0, lavfi, from 'testsrc=s=1920x1080':
   Duration: N/A, start: 0.000000, bitrate: N/A
     Stream #0:0: Video: rawvideo (RGB[24] / 0x18424752), rgb24, 1920x1080
 [SAR 1:1 DAR 16:9], 25 tbr, 25 tbn, 25 tbc
 File
 '/Volumes/LPTest4_Mac/playground/transcoding/noise_upscale_ffmpeg.mov'
 already exists. Overwrite ? [y/N] y
 [prores @ 0x7fd260881400] encoding with ProRes standard (apcn) profile
 [prores @ 0x7fd260865a00] encoding with ProRes standard (apcn) profile
 [prores @ 0x7fd260838200] encoding with ProRes standard (apcn) profile
 [prores @ 0x7fd260838800] encoding with ProRes standard (apcn) profile
 [prores @ 0x7fd26081b200] encoding with ProRes standard (apcn) profile
 [prores @ 0x7fd26081b800] encoding with ProRes standard (apcn) profile
 [prores @ 0x7fd2608e8e00] encoding with ProRes standard (apcn) profile
 [prores @ 0x7fd2608eb600] encoding with ProRes standard (apcn) profile
 [prores @ 0x7fd261002200] encoding with ProRes standard (apcn) profile
 Output #0, mov, to
 '/Volumes/LPTest4_Mac/playground/transcoding/noise_upscale_ffmpeg.mov':
   Metadata:
     encoder         : Lavf56.7.104
     Stream #0:0: Video: prores (apcn) (apcn / 0x6E637061), yuv422p10le,
 3840x2160 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 25 fps, 12800 tbn, 25 tbc
     Metadata:
       encoder         : Lavc56.3.101 prores
 Stream mapping:
   Stream #0:0 -> #0:0 (rawvideo (native) -> prores (native))
 Press [q] to stop, [?] for help
 frame=   25 fps=8.5 q=0.0 Lsize=   77807kB time=00:00:01.00
 bitrate=637393.6kbits/s
 video:77806kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB
 muxing overhead: 0.001156%

 For comparison, the same command line without the scaling results in the
 expected evenly distributed luma noise without those patterns. I used this
 pixel format because I am simulating the case where I ran into this, i.e.
 while transcoding and upscaling a prores 422 file.

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Ticket URL: <https://trac.ffmpeg.org/ticket/4017>
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