blivit
28th September 2002, 01:44
I've attached a zip of some avi files that show green pixels in the left most column when played back with Virtualdub. Below is the included description of the bug:
The following three avi files all showed alternating green pixels on the
leftmost column of every frame, but only when played in Virtualdub.
The green pixels persist throughout the entire For The Birds clip that I
took this from, it isn't just this one scene. I was using uManiac's
23.09.2002.0840 build. But I also tried a uManiac build as far back as June,
and a Koepi build from August 3rd, so it looks like the problem has been
around for a while, and is independant of the compiler used. I am using the
latest Virtualdub, and haven't tested older versions.
pixar_green1.avi (Virtualdub encode, default XviD prefs)
pixar_green2.avi (Virtualdub reencode, default XviD prefs)
pixar_divx5_xvid4cc.avi (Virtualdub encode, default DivX 5.02, 900 kbps,
forced fourCC codes to xivd/XVID)
pixar_green1.avi:
Shows green pixels when played with Virtualdub. Windows Media Player plays it
just fine. Avisynth frameserving to Virtualdub (via AVISource()) works just
fine. But Virtualdub decoding with the XviD codec has the green pixels.
Forcing the fourCC codes to divx/DIVX works fine too, in everything.
pixar_green2.avi:
Reencoded pixar_green1 in Virtualdub. Notice that the green pixels are
encoded in the resulting stream, you can see the blocking/blurring/ringing
artifacts that come from them. This shows that it isn't just a display
problem in Virtualdub, but a decoding problem, since the green pixels are
definately in the decoded video stream.
pixar_divx5_xvid4cc.avi:
Encoded original source with Divx5, then changed the fourCC codes to
xvid/XVID. Windows Media Player plays it fine, frameserving Avisynth to
Virtualdub plays it fine. Virtualdub has the green pixels. Original div5
fourCC worked fine in everything.
Summary:
Green pixels show up in Virtualdub if XviD is used to decode. It does not
matter if the avi was encoded with DivX 5.02 or XviD to begin with, so this
doesn't look like an encoding issue. Windows Media Player and Avisynth both
decode using XviD just fine, which points to something screwy with
Virtualdub, or with whatever functions in XviD Virtualdub is calling to
decode. All avi files that exhibit the green pixels in Virtualdub play fine
in everything when the fourCC codes are forced to divx/DIVX. This looks
like an XviD decoding issue and/or Virtualdub decoding issue to me.
Any ideas on which program is at fault, and what to do to fix it?
The following three avi files all showed alternating green pixels on the
leftmost column of every frame, but only when played in Virtualdub.
The green pixels persist throughout the entire For The Birds clip that I
took this from, it isn't just this one scene. I was using uManiac's
23.09.2002.0840 build. But I also tried a uManiac build as far back as June,
and a Koepi build from August 3rd, so it looks like the problem has been
around for a while, and is independant of the compiler used. I am using the
latest Virtualdub, and haven't tested older versions.
pixar_green1.avi (Virtualdub encode, default XviD prefs)
pixar_green2.avi (Virtualdub reencode, default XviD prefs)
pixar_divx5_xvid4cc.avi (Virtualdub encode, default DivX 5.02, 900 kbps,
forced fourCC codes to xivd/XVID)
pixar_green1.avi:
Shows green pixels when played with Virtualdub. Windows Media Player plays it
just fine. Avisynth frameserving to Virtualdub (via AVISource()) works just
fine. But Virtualdub decoding with the XviD codec has the green pixels.
Forcing the fourCC codes to divx/DIVX works fine too, in everything.
pixar_green2.avi:
Reencoded pixar_green1 in Virtualdub. Notice that the green pixels are
encoded in the resulting stream, you can see the blocking/blurring/ringing
artifacts that come from them. This shows that it isn't just a display
problem in Virtualdub, but a decoding problem, since the green pixels are
definately in the decoded video stream.
pixar_divx5_xvid4cc.avi:
Encoded original source with Divx5, then changed the fourCC codes to
xvid/XVID. Windows Media Player plays it fine, frameserving Avisynth to
Virtualdub plays it fine. Virtualdub has the green pixels. Original div5
fourCC worked fine in everything.
Summary:
Green pixels show up in Virtualdub if XviD is used to decode. It does not
matter if the avi was encoded with DivX 5.02 or XviD to begin with, so this
doesn't look like an encoding issue. Windows Media Player and Avisynth both
decode using XviD just fine, which points to something screwy with
Virtualdub, or with whatever functions in XviD Virtualdub is calling to
decode. All avi files that exhibit the green pixels in Virtualdub play fine
in everything when the fourCC codes are forced to divx/DIVX. This looks
like an XviD decoding issue and/or Virtualdub decoding issue to me.
Any ideas on which program is at fault, and what to do to fix it?