[FFmpeg-trac] #8898(ffmpeg:new): `-passlogfile` inconsistent behavior on two pass encoding with `file:` prefix

FFmpeg trac at avcodec.org
Thu Sep 17 11:47:41 EEST 2020

#8898: `-passlogfile` inconsistent behavior on two pass encoding with `file:`
             Reporter:  aeris   |                     Type:  defect
               Status:  new     |                 Priority:  normal
            Component:  ffmpeg  |                  Version:  unspecified
             Keywords:          |               Blocked By:
             Blocking:          |  Reproduced by developer:  0
Analyzed by developer:  0       |
 Summary of the bug:

 I try to 2-pass encode files with `:` in filename, so i need to use the
 `file:` prefix to force local file usage instead of remote one.
 But `-passlogfile` acts strangely in this case.

 First pass seems ignore the `file:` prefix and create a real
 `file:xxx.log` file on the filesystem, but the second pass take care of
 the prefix and look for a `xxx.log` file, which doesn't exist.

 How to reproduce:
 ffmpeg -f lavfi -y -i nullsrc=s=1280x720 -filter_complex
 "geq=random(1)*255:128:128;aevalsrc=-2+random(0)" -t 1 "file:input.mp4"
 ffmpeg -y -i "file:input.mp4" -passlogfile "file:output.log" -pass 1 -an
 -f webm /dev/null
 ffmpeg -y -i "file:input.mp4" -passlogfile "file:output.log" -pass 2 -f
 webm "file:output.webm"

 `strace` output to see files access

 First pass
 [pid 48159] openat(AT_FDCWD, "file:output.log-0.log",

 Second pass
 [pid 48223] openat(AT_FDCWD, "output.log-0.log", O_RDONLY) = -1 ENOENT (No
 such file or directory)

Ticket URL: <https://trac.ffmpeg.org/ticket/8898>
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