Opened 9 years ago
Closed 9 years ago
#4816 closed defect (fixed)
png: wrong alpha detection
Reported by: | pszemus | Owned by: | |
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Priority: | important | Component: | avcodec |
Version: | git-master | Keywords: | png alpha regression |
Cc: | Blocked By: | ||
Blocking: | Reproduced by developer: | yes | |
Analyzed by developer: | no |
Description
Summary of the bug: alpha channel isn't detected, thus it's being lost after conversion.
How to reproduce:
$ ~/ffmpeg/ffmpeg -i http://storage2.sportowefakty.pl.sds.o2.pl/tags/55c99e750a5fd6_50314226.png ffmpeg version N-74416-gacbd78a Copyright (c) 2000-2015 the FFmpeg developers built with gcc 4.8.3 (GCC) 20140911 (Red Hat 4.8.3-9) configuration: --prefix=/home/pszemus/ffmpeg/build --enable-pic --enable-pthreads --enable-libmp3lame --enable-version3 --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libfaac --enable-gpl --enable-nonfree --enable-libvpx --enable-libvorbis --enable-libx264 --pkg-config-flags=--static --enable-protocol=https --enable-openssl --extra-cflags=-I/opt/WP/common.libs/inc --extra-ldflags='-L/opt/WP/common.libs/lib -ldl' libavutil 54. 30.100 / 54. 30.100 libavcodec 56. 57.100 / 56. 57.100 libavformat 56. 40.101 / 56. 40.101 libavdevice 56. 4.100 / 56. 4.100 libavfilter 5. 33.100 / 5. 33.100 libswscale 3. 1.101 / 3. 1.101 libswresample 1. 2.101 / 1. 2.101 libpostproc 53. 3.100 / 53. 3.100 Input #0, png_pipe, from 'http://storage2.sportowefakty.pl.sds.o2.pl/tags/55c99e750a5fd6_50314226.png': Duration: N/A, bitrate: N/A Stream #0:0: Video: png, rgb24(pc), 330x330, 25 tbr, 25 tbn, 25 tbc At least one output file must be specified
FFmpeg detects pixel format as rgb24(pc)
ignoring the alpha channel.
GraphicsMagick, on the other hand, displays information about 4 channels:
$ gm identify -verbose http://storage2.sportowefakty.pl.sds.o2.pl/tags/55c99e750a5fd6_50314226.png Image: /tmp/gmIhmThX Format: PNG (Portable Network Graphics) Geometry: 330x330 Class: DirectClass Type: true color with transparency Depth: 8 bits-per-pixel component Channel Depths: Red: 8 bits Green: 8 bits Blue: 8 bits Opacity: 1 bits Channel Statistics: Red: Minimum: 0.00 (0.0000) Maximum: 255.00 (1.0000) Mean: 36.07 (0.1414) Standard Deviation: 85.97 (0.3371) Green: Minimum: 0.00 (0.0000) Maximum: 255.00 (1.0000) Mean: 41.85 (0.1641) Standard Deviation: 83.66 (0.3281) Blue: Minimum: 0.00 (0.0000) Maximum: 255.00 (1.0000) Mean: 19.49 (0.0764) Standard Deviation: 56.10 (0.2200) Opacity: Minimum: 0.00 (0.0000) Maximum: 255.00 (1.0000) Mean: 194.13 (0.7613) Standard Deviation: 108.70 (0.4263) Opacity: ( 0, 0, 0,255) #000000FF Filesize: 43.3Ki Interlace: No Orientation: Unknown Background Color: white Border Color: #DFDFDF00 Matte Color: #BDBDBD00 Page geometry: 330x330+0+0 Compose: Over Dispose: Undefined Iterations: 0 Compression: Zip Png:IHDR.color-type-orig: 2 Png:IHDR.bit-depth-orig: 8 Signature: 690a475a4154c72e21cb56c6864e8b37780716ddc7d028661724d29ae6e7f7ac Tainted: False
Attachments (1)
Change History (7)
by , 9 years ago
Attachment: | storage2.sportowefakty.pl.sds.o2.pl_tags_55c99e750a5fd6_50314226.png added |
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comment:2 by , 9 years ago
Component: | undetermined → avcodec |
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Keywords: | png alpha added |
Version: | unspecified → git-master |
comment:5 by , 9 years ago
Keywords: | regression added |
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Priority: | normal → important |
Resolution: | fixed |
Status: | closed → reopened |
Broken since 72eaf726236331e739952806a5fe47b40165ac76
$ ffmpeg -i ../Samples/tickets/ticket4816/55c99e750a5fd6_50314226.png ffmpeg version N-78994-gbd2cc3c Copyright (c) 2000-2016 the FFmpeg developers built with gcc 4.7 (SUSE Linux) configuration: --enable-gpl libavutil 55. 19.100 / 55. 19.100 libavcodec 57. 28.100 / 57. 28.100 libavformat 57. 28.101 / 57. 28.101 libavdevice 57. 0.101 / 57. 0.101 libavfilter 6. 39.102 / 6. 39.102 libswscale 4. 0.100 / 4. 0.100 libswresample 2. 0.101 / 2. 0.101 libpostproc 54. 0.100 / 54. 0.100 Input #0, png_pipe, from '../Samples/tickets/ticket4816/55c99e750a5fd6_50314226.png': Duration: N/A, bitrate: N/A Stream #0:0: Video: png, rgb24(pc), 330x330, 25 tbr, 25 tbn, 25 tbc At least one output file must be specified
comment:6 by , 9 years ago
Reproduced by developer: | set |
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Resolution: | → fixed |
Status: | reopened → closed |
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