On 6/28/15, Paul B Mahol <[email protected]> wrote: > On 6/28/15, qw <[email protected]> wrote: >> At 2015-06-28 17:11:03, "Paul B Mahol" <[email protected]> wrote: >>>Dana 28. 6. 2015. 09:31 osoba "qw" <[email protected]> napisala je: >>>> >>>> Hi, >>>> >>>> >>>> PNG format supports alpha channel, but some png images don't have alpha >>>channel. How to add alpha channel to those png images and set alpha >>> value? >>>> >>>> >>> >>>See colorkey filter documentation. >>> >> I use the below command to run colorkey filter, and ffmpeg report there >> is >> no colorkey filter: >> ffmpeg -i ./image.png -vf colorkey=green ./output.png >> >> >> ffmpeg version 2.7.1 Copyright (c) 2000-2015 the FFmpeg developers >> built with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-11) >> configuration: --enable-gpl --enable-libx264 >> libavutil 54. 27.100 / 54. 27.100 >> libavcodec 56. 41.100 / 56. 41.100 >> libavformat 56. 36.100 / 56. 36.100 >> libavdevice 56. 4.100 / 56. 4.100 >> libavfilter 5. 16.101 / 5. 16.101 >> libswscale 3. 1.101 / 3. 1.101 >> libswresample 1. 2.100 / 1. 2.100 >> libpostproc 53. 3.100 / 53. 3.100 >> Input #0, png_pipe, from './transparent_3.png': >> Duration: N/A, bitrate: N/A >> Stream #0:0: Video: png, rgba(pc), 256x256, 25 tbr, 25 tbn, 25 tbc >> [AVFilterGraph @ 0x1d1e900] No such filter: 'colorkey' >> Error opening filters! >> >> >> which version of ffmpeg has colorkey filter? >> > > Git version. >
But if image is simple I guess you could use geq filter to replace alpha for similar colors. _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
