#1261: yellowish color with resize and -pix_fmt pal8 ---------------------------------------+----------------------------------- Reporter: ami_stuff | Owner: Type: defect | Status: open Priority: normal | Component: swscale Version: git-master | Resolution: Keywords: swscale, pal8 | Blocked By: Blocking: | Reproduced by developer: 1 Analyzed by developer: 0 | ---------------------------------------+----------------------------------- Changes (by gdgsdg123): * keywords: => swscale, pal8 Comment: Encountered similar situation when performing a different task... Build from: https://ffmpeg.zeranoe.com/builds/win64/static/win64/static/ffmpeg-20190330-... {{{ ffmpeg started on 2019-04-01 at 10:38:41 Report written to "ffmpeg-20190401-103841.log" Command line: ffmpeg -report -i "C:\\Image-before-scaling.png" -pix_fmt pal8 -sws_flags bicubic+accurate_rnd -vf "scale=iw*2:ih*2" bicubic_text.png ffmpeg version N-93488-g52d8f35b14 Copyright (c) 2000-2019 the FFmpeg developers built with gcc 8.2.1 (GCC) 20190212 configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable- fontconfig --enable-gnutls --enable-iconv --enable-libass --enable- libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable- libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable- nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt libavutil 56. 26.100 / 56. 26.100 libavcodec 58. 47.106 / 58. 47.106 libavformat 58. 26.101 / 58. 26.101 libavdevice 58. 7.100 / 58. 7.100 libavfilter 7. 48.100 / 7. 48.100 libswscale 5. 4.100 / 5. 4.100 libswresample 3. 4.100 / 3. 4.100 libpostproc 55. 4.100 / 55. 4.100 Splitting the commandline. Reading option '-report' ... matched as option 'report' (generate a report) with argument '1'. Reading option '-i' ... matched as input url with argument 'C:\Image- before-scaling.png'. Reading option '-pix_fmt' ... matched as option 'pix_fmt' (set pixel format) with argument 'pal8'. Reading option '-sws_flags' ... matched as AVOption 'sws_flags' with argument 'bicubic+accurate_rnd'. Reading option '-vf' ... matched as option 'vf' (set video filters) with argument 'scale=iw*2:ih*2'. Reading option 'bicubic_text.png' ... matched as output url. Finished splitting the commandline. Parsing a group of options: global . Applying option report (generate a report) with argument 1. Successfully parsed a group of options. Parsing a group of options: input url C:\Image-before-scaling.png. Successfully parsed a group of options. Opening an input file: C:\Image-before-scaling.png. [NULL @ 00000000004f1a80] Opening 'C:\Image-before-scaling.png' for reading [file @ 00000000004f3480] Setting default whitelist 'file,crypto' [png_pipe @ 00000000004f1a80] Format png_pipe probed with size=2048 and score=99 [png_pipe @ 00000000004f1a80] Before avformat_find_stream_info() pos: 0 bytes read:716 seeks:0 nb_streams:1 [png_pipe @ 00000000004f1a80] After avformat_find_stream_info() pos: 716 bytes read:716 seeks:0 frames:1 Input #0, png_pipe, from 'C:\Image-before-scaling.png': Duration: N/A, bitrate: N/A Stream #0:0, 1, 1/25: Video: png, pal8(pc), 109x40, 25 tbr, 25 tbn, 25 tbc Successfully opened the file. Parsing a group of options: output url bicubic_text.png. Applying option pix_fmt (set pixel format) with argument pal8. Applying option vf (set video filters) with argument scale=iw*2:ih*2. Successfully parsed a group of options. Opening an output file: bicubic_text.png. Successfully opened the file. detected 16 logical cores Stream mapping: Stream #0:0 -> #0:0 (png (native) -> png (native)) Press [q] to stop, [?] for help cur_dts is invalid (this is harmless if it occurs once at the start per stream) cur_dts is invalid (this is harmless if it occurs once at the start per stream) [Parsed_scale_0 @ 000000000296f000] Setting 'w' to value 'iw*2' [Parsed_scale_0 @ 000000000296f000] Setting 'h' to value 'ih*2' [Parsed_scale_0 @ 000000000296f000] Setting 'flags' to value 'bicubic' [Parsed_scale_0 @ 000000000296f000] Setting 'sws_flags' to value 'bicubic+accurate_rnd' [Parsed_scale_0 @ 000000000296f000] w:iw*2 h:ih*2 flags:'bicubic' interl:0 [graph 0 input from stream 0:0 @ 0000000002970300] Setting 'video_size' to value '109x40' [graph 0 input from stream 0:0 @ 0000000002970300] Setting 'pix_fmt' to value '11' [graph 0 input from stream 0:0 @ 0000000002970300] Setting 'time_base' to value '1/25' [graph 0 input from stream 0:0 @ 0000000002970300] Setting 'pixel_aspect' to value '0/1' [graph 0 input from stream 0:0 @ 0000000002970300] Setting 'sws_param' to value 'flags=2' [graph 0 input from stream 0:0 @ 0000000002970300] Setting 'frame_rate' to value '25/1' [graph 0 input from stream 0:0 @ 0000000002970300] w:109 h:40 pixfmt:pal8 tb:1/25 fr:25/1 sar:0/1 sws_param:flags=2 [format @ 000000000297a340] Setting 'pix_fmts' to value 'pal8' [AVFilterGraph @ 000000000296e9c0] query_formats: 4 queried, 3 merged, 0 already done, 0 delayed [swscaler @ 000000000297a840] Forcing full internal H chroma due to input having non subsampled chroma [Parsed_scale_0 @ 000000000296f000] w:109 h:40 fmt:pal8 sar:0/1 -> w:218 h:80 fmt:pal8 sar:0/1 flags:0x4 Output #0, image2, to 'bicubic_text.png': Metadata: encoder : Lavf58.26.101 Stream #0:0, 0, 1/25: Video: png, pal8, 218x80, q=2-31, 200 kb/s, 25 fps, 25 tbn, 25 tbc Metadata: encoder : Lavc58.47.106 png Clipping frame in rate conversion by 0.000008 cur_dts is invalid (this is harmless if it occurs once at the start per stream) cur_dts is invalid (this is harmless if it occurs once at the start per stream) [out_0_0 @ 000000000297a180] EOF on sink link out_0_0:default. No more output streams to write to, finishing. [image2 @ 00000000004f35c0] Opening 'bicubic_text.png' for writing [file @ 000000000299dc00] Setting default whitelist 'file,crypto' [AVIOContext @ 000000000a500780] Statistics: 0 seeks, 1 writeouts frame= 1 fps=0.0 q=-0.0 Lsize=N/A time=00:00:00.04 bitrate=N/A speed= 2.5x video:3kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown Input file #0 (C:\Image-before-scaling.png): Input stream #0:0 (video): 1 packets read (716 bytes); 1 frames decoded; Total: 1 packets (716 bytes) demuxed Output file #0 (bicubic_text.png): Output stream #0:0 (video): 1 frames encoded; 1 packets muxed (3380 bytes); Total: 1 packets (3380 bytes) muxed 1 frames successfully decoded, 0 decoding errors [AVIOContext @ 00000000004fb700] Statistics: 716 bytes read, 0 seeks }}} Files attached. Reference group from: https://en.wikipedia.org/wiki/Comparison_gallery_of_image_scaling_algorithms -- Ticket URL: <https://trac.ffmpeg.org/ticket/1261#comment:5> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker