[FFmpeg-user] preserving YUV color range of 0-255
Rio Kierkels
riokierkels at gmail.com
Fri Mar 7 19:07:40 CET 2014
Hi dave,
You might want to take a look at the Levels and Primaries thread going on
here. Maybe you get some inspiration from it.
Rio
On Mar 7, 2014 6:53 PM, "Dave Rice" <dave at dericed.com> wrote:
>
> On Mar 7, 2014, at 12:37 PM, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:
> > Dave Rice <dave <at> dericed.com> writes:
> >
> >> Given that the test pattern has U and V at 128 I
> >> would expect these two commands to give the same results:
> >>
> >> ffplay 256shades_ntsc.mov
> >> -vf 'histogram=mode=waveform:waveform_mode=column'
> >> ffplay 256shades_ntsc.mov
> >> -vf 'extractplanes=y,histogram=mode=waveform:waveform_mode=column'
> >
> > Is the problem you see reproducible with ffmpeg?
> >
> > ffplay is an application that depends on an external
> > library that is known to contain bugs, so if the
> > problem is reproducible with ffmpeg, please explain
> > how.
> > (Ideally, command line and complete, uncut console
> > output.)
>
> Yes, the issue is the same via ffmpeg.
>
> Here is the output when using histogram=mode=waveform:waveform_mode=column
> on a source that uses full range YUV.
>
> ffmpeg -i 256shades_ntsc.mov -vf
> 'histogram=mode=waveform:waveform_mode=column' -frames:v 1 -y
> histogram_only.jpg
> ffmpeg version 2.2.git Copyright (c) 2000-2014 the FFmpeg developers
> built on Mar 6 2014 20:43:26 with Apple LLVM version 5.0
> (clang-500.2.79) (based on LLVM 3.3svn)
> configuration: --prefix=/usr/local/Cellar/ffmpeg/HEAD --enable-shared
> --enable-pthreads --enable-gpl --enable-version3 --enable-nonfree
> --enable-hardcoded-tables --enable-avresample --enable-vda --cc=clang
> --host-cflags= --host-ldflags= --enable-libx264 --enable-libfaac
> --enable-libmp3lame --enable-libxvid --enable-ffplay
> libavutil 52. 66.101 / 52. 66.101
> libavcodec 55. 52.102 / 55. 52.102
> libavformat 55. 33.101 / 55. 33.101
> libavdevice 55. 11.100 / 55. 11.100
> libavfilter 4. 3.100 / 4. 3.100
> libavresample 1. 2. 0 / 1. 2. 0
> libswscale 2. 5.101 / 2. 5.101
> libswresample 0. 18.100 / 0. 18.100
> libpostproc 52. 3.100 / 52. 3.100
> Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '256shades_ntsc.mov':
> Metadata:
> major_brand : qt
> minor_version : 512
> compatible_brands: qt
> encoder : Lavf55.19.102
> Duration: 00:00:00.03, start: 0.000000, bitrate: 164836 kb/s
> Stream #0:0(eng): Video: rawvideo (2vuy / 0x79757632), uyvy422,
> 720x486, 167793 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 30k tbc (default)
> Metadata:
> handler_name : DataHandler
> [swscaler @ 0x7fa1e3000000] deprecated pixel format used, make sure you
> did set range correctly
> Output #0, image2, to 'histogram_only.jpg':
> Metadata:
> major_brand : qt
> minor_version : 512
> compatible_brands: qt
> encoder : Lavf55.33.101
> Stream #0:0(eng): Video: mjpeg, yuvj422p, 720x768 [SAR 1:1 DAR 15:16],
> q=2-31, 200 kb/s, 90k tbn, 29.97 tbc (default)
> Metadata:
> handler_name : DataHandler
> Stream mapping:
> Stream #0:0 -> #0:0 (rawvideo -> mjpeg)
> Press [q] to stop, [?] for help
> frame= 1 fps=0.0 q=4.0 Lsize=N/A time=00:00:00.03 bitrate=N/A
> video:20kB audio:0kB subtitle:0 data:0 global headers:0kB muxing overhead
> -100.106201%
>
> The resulting file is here
> http://dericed.com/media/extractplanes_then_histogram.jpg. It shows
> essentially a diagonal line in the Y plane representing values 0-255.
>
> Here is the output for the same command as above but adding
> extractplanes=y at the beginning of the filterchain:
>
> ffmpeg -i 256shades_ntsc.mov -vf
> 'extractplanes=y,histogram=mode=waveform:waveform_mode=column' -frames:v 1
> -y extractplanes_then_histogram.jpg
> ffmpeg version 2.2.git Copyright (c) 2000-2014 the FFmpeg developers
> built on Mar 6 2014 20:43:26 with Apple LLVM version 5.0
> (clang-500.2.79) (based on LLVM 3.3svn)
> configuration: --prefix=/usr/local/Cellar/ffmpeg/HEAD --enable-shared
> --enable-pthreads --enable-gpl --enable-version3 --enable-nonfree
> --enable-hardcoded-tables --enable-avresample --enable-vda --cc=clang
> --host-cflags= --host-ldflags= --enable-libx264 --enable-libfaac
> --enable-libmp3lame --enable-libxvid --enable-ffplay
> libavutil 52. 66.101 / 52. 66.101
> libavcodec 55. 52.102 / 55. 52.102
> libavformat 55. 33.101 / 55. 33.101
> libavdevice 55. 11.100 / 55. 11.100
> libavfilter 4. 3.100 / 4. 3.100
> libavresample 1. 2. 0 / 1. 2. 0
> libswscale 2. 5.101 / 2. 5.101
> libswresample 0. 18.100 / 0. 18.100
> libpostproc 52. 3.100 / 52. 3.100
> Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '256shades_ntsc.mov':
> Metadata:
> major_brand : qt
> minor_version : 512
> compatible_brands: qt
> encoder : Lavf55.19.102
> Duration: 00:00:00.03, start: 0.000000, bitrate: 164836 kb/s
> Stream #0:0(eng): Video: rawvideo (2vuy / 0x79757632), uyvy422,
> 720x486, 167793 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 30k tbc (default)
> Metadata:
> handler_name : DataHandler
> [swscaler @ 0x7fb7e8812400] deprecated pixel format used, make sure you
> did set range correctly
> Output #0, image2, to 'extractplanes_then_histogram.jpg':
> Metadata:
> major_brand : qt
> minor_version : 512
> compatible_brands: qt
> encoder : Lavf55.33.101
> Stream #0:0(eng): Video: mjpeg, yuvj444p, 720x768 [SAR 1:1 DAR 15:16],
> q=2-31, 200 kb/s, 90k tbn, 29.97 tbc (default)
> Metadata:
> handler_name : DataHandler
> Stream mapping:
> Stream #0:0 -> #0:0 (rawvideo -> mjpeg)
> Press [q] to stop, [?] for help
> frame= 1 fps=0.0 q=4.0 Lsize=N/A time=00:00:00.03 bitrate=N/A
> video:27kB audio:0kB subtitle:0 data:0 global headers:0kB muxing overhead
> -100.080383%
>
> And here is the resulting image
> http://dericed.com/media/histogram_only.jpg. Instead of the diagonal line
> as before the values from 0-15 and 236-255 are crushed to the same value.
> Best Regards,
> Dave Rice
>
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