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ffmpeg -pix_fmts lists many pixel formats. In my ffmpeg, there are 66 different pixel formats that start with yuv. A few of them are familiar to me (e.g., yuv422p), but most of them are not (e.g., yuva422p16be).

Where are these pixel formats defined?

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    Most are self describing. yuva422p16be YUV are luma and chroma planes. a is the alpha channel. 422 is the plan size descriptions, p means planer, 16be means 16 bits per pixel big endian format. – SlimSCSI Sep 11 '15 at 23:29
  • Thanks @SlimSCSI. Do you know what the j stands for in yuvj440p? – Doug Richardson Sep 12 '15 at 3:32
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    YUV420P uses the range 16 to 239 to describe luminance and chroma values, so values from 0 to 16 get mapped to the same output level, as do values 239-255. YUVJ420P uses the full range from 0 to 255. Not sure why it's J though. – stib Sep 12 '15 at 11:55
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    In libavutil/pixfmt.h: AV_PIX_FMT_YUVJ420P, ///< planar YUV 4:2:0, 12bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV420P and setting color_range. – llogan Sep 12 '15 at 16:53
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If your question was

Where are these pixel formats defined?

Go to http://ffmpeg.org/download.html and download the source of ffmpeg. Then unpack it

tar -xavf FILENAME.tar.*

and descend to the folder in the source code that is called libavutil

cd ffmpeg-*/libavutil/

and open the file pixfmt.h where you will find a description of all pixel formats. A few sample lines

AV_PIX_FMT_YUV420P,   ///< planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)          
AV_PIX_FMT_YUYV422,   ///< packed YUV 4:2:2, 16bpp, Y0 Cb Y1 Cr
AV_PIX_FMT_RGB24,     ///< packed RGB 8:8:8, 24bpp, RGBRGB...
AV_PIX_FMT_BGR24,     ///< packed RGB 8:8:8, 24bpp, BGRBGR...
AV_PIX_FMT_YUV422P,   ///< planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)

Additionally you can read https://en.wikipedia.org/wiki/YUV and it’s cited sources and external links.

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