Re: [FFmpeg-user] Create high quality JPEGs
Elliott Balsley elliottbalsley at gmail.com writes: Here is a sample TIFF: https://drive.google.com/file/d/0B52QuT8oHvtZZkhSUkswUDhJSlU I tested the following two command lines but I am unable to see any macro blocking in the output files. Where do you see it? $ ffmpeg -i 0.tiff -qscale 0 out1.jpg $ ffmpeg -i 0.tiff -qscale 2 out2.jpg How do you test the output files? Carl Eugen ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user
Re: [FFmpeg-user] Create high quality JPEGs
Carl Eugen Hoyos cehoyos at ag.or.at writes: $ ffmpeg -i 0.tiff -qscale 0 out1.jpg $ ffmpeg -i 0.tiff -qscale 2 out2.jpg Sorry for these sample command lines: The default minimal value for qscale is 2, so these commands produce identical output. To get a bigger output file use: $ ffmpeg -i 0.tiff -qmin 1 -qscale 1 out.jpg Carl Eugen ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user
Re: [FFmpeg-user] Create high quality JPEGs
Moritz Barsnick barsnick at gmx.net writes: ffmpeg with -qscale 0, 1, 2 creates (identical) images which have approximately the same size as a conversion using ImageMagick with libjpeg (albeit very old) with a quality setting of around 89%, which is not generally considered very good. YMMV Could you test again with -qmin 1 -qscale 1 ? Carl Eugen ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user
Re: [FFmpeg-user] Create high quality JPEGs
On Mon, Feb 09, 2015 at 17:56:06 -0800, Elliott Balsley wrote: Here is a sample TIFF: https://drive.google.com/file/d/0B52QuT8oHvtZZkhSUkswUDhJSlU/view?usp=sharing I personally can't see the artifact. I had to subtract or XOR the two images to identify the changes. That said: ffmpeg with -qscale 0, 1, 2 creates (identical) images which have approximately the same size as a conversion using ImageMagick with libjpeg (albeit very old) with a quality setting of around 89%, which is not generally considered very good. YMMV I'm trying to say: At first glance, ffmpeg either compresses much more effectively (which I doubt) or doesn't use a high enough quality setting. Whether that is intended, and whether the various qscale settings should result in identical files, I can't say. Moritz ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user
Re: [FFmpeg-user] Create high quality JPEGs
Moritz Barsnick barsnick at gmx.net writes: -qscale 1:276184 bytes -qscale 1 (or 0) -qmin 1: 608994 bytes I still don't see much of a visual difference, and no blocking or other artifacts. With paint.NET's XOR layer filter, I do see differences and -qmin 1 seems to have less of them. 608994 bytes is close to 95% quality with ImageMagick Could you compare the 95% ImageMagick output with the qscale 1 output? Carl Eugen ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user
