[FFmpeg-user] Problem: extracted alpha plane from a grayscale PNG is shifted by 1 pixel to the left

2019-04-06 Thread Mikhail V
I have a strange problem with extracting alpha plane from an grayscale PNG with alpha channel. So I have an image with alpha in it and use this command: ffmpeg -i 1-open-patch.png -vf alphaextract -pix_fmt gray testgray_alpha.png or ffmpeg -i 1-open-patch.png -vf alphaextract

[FFmpeg-user] FFmpeg website (ffmpeg.org)

2018-01-08 Thread Mikhail V
Hi, [Offtopic] I am using the online documentation a lot, especially this page https://ffmpeg.org/ffmpeg-filters.html Frankly, I find the site quite hard to read. (IMO, so please don't take as offense) I have published a userstyle for Firefox (with Stylish plugin) that adresses the issues and

[FFmpeg-user] feature proposal - avoid overwriting the input file

2017-10-10 Thread Mikhail V
James Girotti wrote: > On Tue, Oct 10, 2017 at 4:40 PM, Mikhail V wrote: > > > Currently it is possible to delete the input file if I specify same > > filename in output, > > for example: > > > > ffmpeg -y -i input input > > > > Aren't you specify

[FFmpeg-user] A spelling error in a warning message?

2017-09-21 Thread Mikhail V
Sometimes I get a warning: > Warning: data is not aligned! This can lead to a speedloss "Speedloss" should be "speed loss" I suppose? Mikhail ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To

[FFmpeg-user] Pixel average color filter

2017-07-23 Thread Mikhail V
for all input frame rows So the output frame will be filled with the average color of input frame row-wise. Is there such filter or something similar so I can get similar results? Regards, Mikhail V ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org

Re: [FFmpeg-user] tools for viewing frames and results

2016-10-11 Thread Mikhail V
On 10/11/2016 2:24 PM, Mikhail V wrote: On 10/9/2016 12:24 AM, Xen wrote: Is there any way in Linux to obtain an accurate frame/time number through a GUI that can be used with ffmpeg? I know Avidemux hardly works at all, VLC will not reliably show frames. Pitivi is not an option, I haven't

Re: [FFmpeg-user] tools for viewing frames and results

2016-10-11 Thread Mikhail V
On 10/9/2016 12:24 AM, Xen wrote: Is there any way in Linux to obtain an accurate frame/time number through a GUI that can be used with ffmpeg? I know Avidemux hardly works at all, VLC will not reliably show frames. Pitivi is not an option, I haven't tried Kdenlive because it crashed the

Re: [FFmpeg-user] Selecting/dropping frames without re-encoding

2016-10-10 Thread Mikhail V
On 8 October 2016 at 00:31, Carl Eugen Hoyos <ceffm...@gmail.com> wrote: > 2016-10-08 0:01 GMT+02:00 Mikhail V <mikhail...@gmail.com>: >> BTW after that manipulations a fair question arizes: why >> ffmpeg does not support something like: >> "... -f image2 -i

Re: [FFmpeg-user] Selecting/dropping frames without re-encoding

2016-10-07 Thread Mikhail V
> You can do: > $ ffmpeg -i input -vcodec copy -f image2 frame%4d > > Now make symbolic links to every second frame but > with sequential numbers (Don't ask me how). > $ ffmpeg -f image2 -vcodec dnxhd -i linked_frames%4d -vcodec copy out.mxf > (25fps is the default for the image2 demuxer, use

Re: [FFmpeg-user] Selecting/dropping frames without re-encoding

2016-10-06 Thread Mikhail V
On 6 October 2016 at 10:07, Carl Eugen Hoyos <ceffm...@gmail.com> wrote: > 2016-10-05 23:08 GMT+02:00 Mikhail V <mikhail...@gmail.com>: >> On 5 October 2016 at 19:55, Carl Eugen Hoyos <ceffm...@gmail.com> wrote: >>> 2016-10-05 15:45 GMT+0

Re: [FFmpeg-user] Selecting/dropping frames without re-encoding

2016-10-05 Thread Mikhail V
On 5 October 2016 at 19:55, Carl Eugen Hoyos <ceffm...@gmail.com> wrote: > 2016-10-05 15:45 GMT+02:00 Mikhail V <mikhail...@gmail.com>: > >> Is it possible that ffmpeg cannot do this without re-encoding? > > You can export single frames and delete half of them us

Re: [FFmpeg-user] Selecting/dropping frames without re-encoding

2016-10-05 Thread Mikhail V
On 5 October 2016 at 18:06, Erik Dobberkau wrote: >> Hello, >> >> I have a camera recording which is an MXF file and the codec is DNxHD >> I suppose it is a single-frame codec so literally it is a container of >> images which are independently stored in the file. >>

[FFmpeg-user] Selecting/dropping frames without re-encoding

2016-10-05 Thread Mikhail V
Hello, I have a camera recording which is an MXF file and the codec is DNxHD I suppose it is a single-frame codec so literally it is a container of images which are independently stored in the file. Recordings are taken at 50 fps progressive. Now what I want is to extract only half of the frames,