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convert appears to skip some frames when making GIFs
Posted: 2012-10-22T02:56:58-07:00
by CasperVector
When making GIF animation with convert(1) like following:
Code: Select all
$ convert -loop 0 -delay 25 testframe*.png test-convert.gif
some (namely No. 10 and 11 of totally 18) frames are missing from the generated GIF file, while GIF produced from GIMP does have this problem.
I can supply the test files (in a 1.3M tarball) if you permit.
OS: Gentoo amd64 unstable
ImageMagick version: 6.7.9.9.
Re: convert appears to skip some frames when making GIFs
Posted: 2012-10-22T07:37:34-07:00
by glennrp
Maybe those PNG file contain offset info that puts them outside the frame. Look at "identify -verbose testframe*.png" for clues. If that doesn't help then you can mail the tarball to glennrp at gmail dot com and I'll take a look.
Re: convert appears to skip some frames when making GIFs
Posted: 2012-10-22T09:45:18-07:00
by fmw42
try
convert -delay 25 testframe*.png +repage -loop 0 test-convert.gif
Re: convert appears to skip some frames when making GIFs
Posted: 2012-10-22T21:58:40-07:00
by CasperVector
fmw42 wrote:
try
convert -delay 25 testframe*.png +repage -loop 0 test-convert.gif
Tried, but the problem persists
Re: convert appears to skip some frames when making GIFs
Posted: 2012-10-22T22:08:59-07:00
by CasperVector
glennrp wrote:
Maybe those PNG file contain offset info that puts them outside the frame. Look at "identify -verbose testframe*.png" for clues. If that doesn't help then you can mail the tarball to glennrp at gmail dot com and I'll take a look.
Code: Select all
% identify -verbose testframe10.png
Image: testframe10.png
Format: PNG (Portable Network Graphics)
Class: DirectClass
Geometry: 480x480+0+0
Units: Undefined
Type: TrueColor
Endianess: Undefined
Colorspace: sRGB
Depth: 8-bit
Channel depth:
red: 8-bit
green: 8-bit
blue: 8-bit
Channel statistics:
Red:
min: 0 (0)
max: 255 (1)
mean: 204.753 (0.802952)
standard deviation: 36.7577 (0.144148)
kurtosis: 2.38527
skewness: -1.36099
Green:
min: 0 (0)
max: 255 (1)
mean: 204.753 (0.802952)
standard deviation: 36.7577 (0.144148)
kurtosis: 2.38527
skewness: -1.36099
Blue:
min: 1 (0.00392157)
max: 243 (0.952941)
mean: 205.081 (0.804237)
standard deviation: 35.7118 (0.140046)
kurtosis: 1.37428
skewness: -1.18864
Image statistics:
Overall:
min: 0 (0)
max: 255 (1)
mean: 204.862 (0.80338)
standard deviation: 36.4124 (0.142794)
kurtosis: 2.07972
skewness: -1.30751
Rendering intent: Perceptual
Gamma: 0.45455
Chromaticity:
red primary: (0.64,0.33)
green primary: (0.3,0.6)
blue primary: (0.15,0.06)
white point: (0.3127,0.329)
Interlace: None
Background color: white
Border color: srgb(223,223,223)
Matte color: grey74
Transparent color: black
Compose: Over
Page geometry: 480x480+0+0
Dispose: Undefined
Iterations: 0
Compression: Zip
Orientation: Undefined
Properties:
Comment: Render Date: 2012-10-22 08:15:18Z
Platform: x86_64-pc-linux-gnu
Compiler: x86_64-pc-linux-gnu-g++ 4.6.3
date:create: 2012-10-23T12:59:08+08:00
date:modify: 2012-10-22T16:16:16+08:00
png:cHRM : chunk was found (see Chromaticity, above)
png:gAMA : gamma=0.45454544 (See Gamma, above)
png:IHDR.bit_depth : 8
png:IHDR.color_type : 2 (Truecolor)
png:IHDR.interlace_method: 0 (Not interlaced)
png:IHDR.width,height : 480, 480
png:oFFs : x_off=0, y_off=0
png:sRGB : intent=0 (Perceptual Intent)
png:text : 2 tEXt/zTXt/iTXt chunks were found
signature: e8dc3cffef90cd2474349a5df15186ccb2e2e85ac842614620caf33994a188d0
Software: POV-Ray 3.7.0.RC5
Artifacts:
filename: testframe10.png
verbose: true
Tainted: False
Filesize: 26.5KB
Number pixels: 230K
Pixels per second: 11.52MB
User time: 0.010u
Elapsed time: 0:01.019
Version: ImageMagick 6.7.9-9 2012-10-05 Q16 http://www.imagemagick.org
So the offsets (png:oFFs, please correct me if that's wrong, since I'm not familar with these details of the PNG format) seem to be fine.
I have just sent the test files to the mail address you mentioned.
Re: convert appears to skip some frames when making GIFs
Posted: 2012-10-23T05:17:22-07:00
by glennrp
CasperVector wrote:glennrp wrote:
Maybe those PNG file contain offset info that puts them outside the frame. Look at "identify -verbose testframe*.png" for clues. If that doesn't help then you can mail the tarball to glennrp at gmail dot com and I'll take a look.
So the offsets (png:oFFs, please correct me if that's wrong, since I'm not familar with these details of the PNG format) seem to be fine.
I have just sent the test files to the mail address you mentioned.
I don't see anything wrong with test-convert.gif; all 18 frames are present and there aren't any non-zero offsets or anything else unusual about any of the frames. I also reran your convert command with my copy of IM-6.8.0-2 and got the same result but with some slight color differences. With my copy of IM-6.7.9-9 I got an output GIF that is identical to yours. How are you determining that the two frames are missing? "identify" is showing them to me and so is the viewer that I use.
Re: convert appears to skip some frames when making GIFs
Posted: 2012-10-23T18:10:21-07:00
by CasperVector
glennrp wrote:
I don't see anything wrong with test-convert.gif; all 18 frames are present and there aren't any non-zero offsets or anything else unusual about any of the frames. I also reran your convert command with my copy of IM-6.8.0-2 and got the same result but with some slight color differences. With my copy of IM-6.7.9-9 I got an output GIF that is identical to yours. How are you determining that the two frames are missing? "identify" is showing them to me and so is the viewer that I use.
I see, I just discovered that test-convert.gif appears to skip frame No. 10 & 11 in EOG (Eye of GNOME), while looks all right in Windows Image Viewer.
I'll report this to EOG devs and post their feedbacks after they resolved this issue (because I still can not confirm this is a pure EOG issue or an IM issue mixed up with an EOG issue)...