[FFmpeg-user] DPX bit depth.

[tim nicholson]

On 11/05/15 10:54, tim nicholson wrote:
> The default -pix_fmt for dpx when provided with a  yuv422p10le source
> file appears to be rgb48be, which seems reasonable enough.
> 
> However upon inspection of the created dpx it appears to be only rgb24
> which is not what I would have expected. Can anyone shed light on this?:-
> 

I should add that ffprobe thinks the material is rbg48:-

"Stream #0:0: Video: dpx, rgb48be, 1920x1080 [SAR 1:1 DAR 16:9], 25 tbr,
25 tbn, 25 tbc" but as graphicsmagik is pretty good I am wondering if it
is a case of 8 bit in 10bit becoming 8 bit in 16bit. However i would
expect the padding to be in the lsb not msb or the pictures would be
very dark.

> 
>> ffmpeg -i "prores-HD.mov" -ss 10 -t 1 -c:v dpx -y    -an "dpx-HD-%04d.dpx"
> ffmpeg version N-70593-gf8f324c-by_Tim Copyright (c) 2000-2015 the
> FFmpeg developers
>   built with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
>   configuration: --extra-version=by_Tim --progs-suffix=_Mar-10
> --prefix=/mnt/msds-store-0/tim/ffmpeg-tux/usr/local
> --libdir=/mnt/msds-store-0/tim/ffmpeg-tux/usr/local/lib64
> --extra-cflags='-I/mnt/msds-store-0/tim/ffmpeg-tux/usr/local/include
> -static'
> --extra-ldflags='-L/mnt/msds-store-0/tim/ffmpeg-tux/usr/local/lib64
> -static -ldl' --pkg-config-flags=--static --enable-static
> --disable-shared --enable-runtime-cpudetect --enable-gpl
> --enable-nonfree --enable-version3 --samples=../fate-suite/
> --disable-ffserver --disable-ffplay --enable-libfaac --enable-libfdk-aac
> --enable-libx264 --enable-libx265 --enable-libfreetype
>   libavutil      54. 20.100 / 54. 20.100
>   libavcodec     56. 26.100 / 56. 26.100
>   libavformat    56. 25.101 / 56. 25.101
>   libavdevice    56.  4.100 / 56.  4.100
>   libavfilter     5. 12.100 /  5. 12.100
>   libswscale      3.  1.101 /  3.  1.101
>   libswresample   1.  1.100 /  1.  1.100
>   libpostproc    53.  3.100 / 53.  3.100
> Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'prores-HD.mov':
>   Metadata:
>     major_brand     : qt
>     minor_version   : 537199360
>     compatible_brands: qt
>     creation_time   : 2015-05-05 15:09:43
>   Duration: 00:02:48.29, start: 0.000000, bitrate: 182792 kb/s
>     Stream #0:0(eng): Video: prores (apch / 0x68637061),
> yuv422p10le(bt709), 1920x1080, 173565 kb/s, SAR 1:1 DAR 16:9, 23.98 fps,
> 23.98 tbr, 23976 tbn, 23976 tbc (default)
>     Metadata:
>       creation_time   : 2015-05-05 15:09:43
>       handler_name    : Apple Alias Data Handler
>       encoder         : Apple ProRes 422 (HQ)
> Output #0, image2, to 'dpx-HD-%04d.dpx':
>   Metadata:
>     major_brand     : qt
>     minor_version   : 537199360
>     compatible_brands: qt
>     encoder         : Lavf56.25.101
>     Stream #0:0(eng): Video: dpx, rgb48be, 1920x1080 [SAR 1:1 DAR 16:9],
> q=2-31, 200 kb/s, 23.98 fps, 23.98 tbn, 23.98 tbc (default)
> 
> ==================================================================
> 
>> identify -verbose dpx-HD-0001.dpx
> Image: dpx-HD-0001.dpx
>   Format: DPX (SMPTE 268M-2003 (DPX 2.0))
>   Geometry: 1920x1080
>   Class: DirectClass
>   Type: true color
>   Depth: 8 bits-per-pixel component
>   Channel Depths:
>     Red:      8 bits
>     Green:    8 bits
>     Blue:     8 bits
> 
> 


-- 
Tim.
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