Re: [FFmpeg-user] -pix_fmt + pixel format conversions
Nicolas George (2021-07-29): > > Green Koopa (12021-07-29): > > My input file is yuvj420p(pc, bt709). My target output is > > yuv420p(tv, bt709). I would like to use "-pix_fmt +yuv420p" > > to specify the output format, and to force me to be explicit > > in my conversions in the filtergraph. How do I achieve > > explicit conversions? The format filter appears to trigger > > implicit conversions. > > The format filter does not do the conversions, it only forces the format > at a certain point in the filter graph. > > The standard filter for converting between pixel formats is scale. In > certain cases, I hear zscale can be more suited, but I never looked at > the specifics. > > Regards, > > -- > Nicolas George > Thank you, that helps my understanding. Is there a way to know what pix_fmts each filter can accept? ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
[FFmpeg-user] -pix_fmt + pixel format conversions
My input file is yuvj420p(pc, bt709). My target output is yuv420p(tv, bt709). I would like to use "-pix_fmt +yuv420p" to specify the output format, and to force me to be explicit in my conversions in the filtergraph. How do I achieve explicit conversions? The format filter appears to trigger implicit conversions. "crop=2704:1520:0:0,format=yuv420p,eq=saturation=1.2" causes error The filters 'Parsed_crop_0' and 'Parsed_format_1' do not have a common format and automatic conversion is disabled. If I go back to relying on implicit conversions, how do I output these automatically added filters? ffmpeg version 4.4-essentials_build-www.gyan.dev on Windows 10 ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
[FFmpeg-user] processor time
Is there a way to know how much processor time is going to encoding and each of the filters? It would help me in making my commands more efficient if I knew which parts were slow. ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
[FFmpeg-user] Ut Video
Hello everyone- I am new to ffmpeg and am having difficulty locating documentation. I would like to use Ut Video as a video encoding for intermediate files. How do I know if this encoding is supported, and what options are available? ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
[FFmpeg-user] frame rate change w/o changing frames
I have a video from a GoPro Hero8. It was recorded at 29.97 fps. I would like to speed up this video. I figure it would be nice to simply increase the frame rate to 60 fps, so a x2.002 speed-up. Can this be done without re-encoding the video? I tried: ffmpeg -r 60 -i in.mp4 -c:v copy -c:a copy out.mp4 This gave me output that was slightly (1MB, 0.1%) smaller, but the same length in time. ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] output jpeg quality
On 15 Jan 2015, Lou wrote: > On 14 Jan 2015, Green Koopa wrote: > > -q did set the jpeg compression level, making it consistent across > > frames. > > (It had no affect on the png compression level.) Thanks for the tips Lou. > > For PNG you can use -compression_level. Range is 0-100. Default is 100 > (highest compression, IIRC). Thanks again Lou. Any tips on where I could have learned that without bothering everyone with basic questions? ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user
[FFmpeg-user] cutting and splicing
In short order I got ffmpeg to read a video, apply a few filters (crop, color adjustments, sharpness, volume), and output a new file. The extensive documentation is a blessing to this new user. After applying the filters, I would like to edit the video to shorten it. Specifically, I would like to take two non-overlapping segments from the middle of the video and concatenate them, ideally with a fade or other transition. I see -ss, -t, and -to for cutting an input file and the Concat demuxer for merging files. Would this method necessitate writing my filtered file out? I don't see how it could allow for a transition effect. I also see the select, split, and overlay filters. I'm not sure what else I would need or how to put it all together. I have much experience with images (imagemagick is great), but I don't fully grasp how to place clips in time or how to keep audio in sync. I couldn't find any examples of this. Where do I read next? I really appreciate any help! ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user
Re: [FFmpeg-user] output jpeg quality
On 12 Jan 2015, Lou wrote: > On 10 Jan 2015, Green Koopa wrote: > > This creates one image for each second of video: > > ffmpeg -i 00020.MTS -vf fps=fps=1 -f image2 stills-%03d.png > > > > When I change the output format to jpeg, it does the same: > > ffmpeg -i 00020.MTS -vf fps=fps=1 -f image2 stills-%03d.jpeg > > But there is a problem. The quality of the jpegs begin okay, but quickly > > deteriorate. By the tenth image or so, they are unusable. This seems > > strange to me, but this is my first day with ffmpeg. > > Does it look better if you use -qscale:v (or -q:v)? It's a linear scale > of 1-31. A doubling of the value will probably (very) roughly halve the > bitrate. 2-5 are good values to try, but you can experiment. > > You don't need the "-f image2". > -q did set the jpeg compression level, making it consistent across frames. (It had no affect on the png compression level.) Thanks for the tips Lou. When outputting frames like this, is there a way to put the frame number/time in the output file name? Otherwise, it looks like I have to use the drawtext filter to add it to the images. ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user
[FFmpeg-user] output jpeg quality
This creates one image for each second of video: ffmpeg -i 00020.MTS -vf fps=fps=1 -f image2 stills-%03d.png When I change the output format to jpeg, it does the same: ffmpeg -i 00020.MTS -vf fps=fps=1 -f image2 stills-%03d.jpeg But there is a problem. The quality of the jpegs begin okay, but quickly deteriorate. By the tenth image or so, they are unusable. This seems strange to me, but this is my first day with ffmpeg. Same problem when I tried this: ffmpeg -i 00020.MTS -vsync 1 -r 1 -f image2 stills-%03d.jpeg I found -qmin 1 -qmax 1 in an old post. It helped all but the last two images. I can just use png, but I was wondering what is going on here. Thanks for any insight. Console output and sample images: https://googledrive.com/host/0B0-UKhirpea7Sml5OVJpc241bVE/ FFmpeg Win64 static build on 2014-01-22 http://ffmpeg.zeranoe.com/builds/ ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user
