SDL2 - difference between RGB888 and RGB24
As best I understand, both the RGB888 and RGB24 formats put their red components first, followed by green and then blue, and both formats take a total of 24 bits per pixel (because 8+8+8 = 24). Given this information both identifiers appear to describe the exact same format but I can verify that some of my code works with one of the two formats but not the other. What's the difference between the two that makes them incompatible?
sdl-2
asked Nov 27 '15 at 17:30
FlaiseFlaise
31118
add a comment |
As best I understand, both the RGB888 and RGB24 formats put their red components first, followed by green and then blue, and both formats take a total of 24 bits per pixel (because 8+8+8 = 24). Given this information both identifiers appear to describe the exact same format but I can verify that some of my code works with one of the two formats but not the other. What's the difference between the two that makes them incompatible?
sdl-2
asked Nov 27 '15 at 17:30
FlaiseFlaise
31118
I am just guessing. But it is common for systems to use 32 bits to hold RGB24, with 8 bits being completely wasted. This is because it is often easier/faster to the addressing.
– Aron
Nov 27 '15 at 17:45
add a comment |
As best I understand, both the RGB888 and RGB24 formats put their red components first, followed by green and then blue, and both formats take a total of 24 bits per pixel (because 8+8+8 = 24). Given this information both identifiers appear to describe the exact same format but I can verify that some of my code works with one of the two formats but not the other. What's the difference between the two that makes them incompatible?
sdl-2
asked Nov 27 '15 at 17:30
FlaiseFlaise
31118
As best I understand, both the RGB888 and RGB24 formats put their red components first, followed by green and then blue, and both formats take a total of 24 bits per pixel (because 8+8+8 = 24). Given this information both identifiers appear to describe the exact same format but I can verify that some of my code works with one of the two formats but not the other. What's the difference between the two that makes them incompatible?
sdl-2
sdl-2
asked Nov 27 '15 at 17:30
FlaiseFlaise
31118
asked Nov 27 '15 at 17:30
FlaiseFlaise
31118
asked Nov 27 '15 at 17:30
FlaiseFlaise
31118
asked Nov 27 '15 at 17:30
FlaiseFlaise
31118
asked Nov 27 '15 at 17:30
FlaiseFlaise
31118
31118
I am just guessing. But it is common for systems to use 32 bits to hold RGB24, with 8 bits being completely wasted. This is because it is often easier/faster to the addressing.
– Aron
Nov 27 '15 at 17:45
add a comment |
I am just guessing. But it is common for systems to use 32 bits to hold RGB24, with 8 bits being completely wasted. This is because it is often easier/faster to the addressing.
– Aron
Nov 27 '15 at 17:45
I am just guessing. But it is common for systems to use 32 bits to hold RGB24, with 8 bits being completely wasted. This is because it is often easier/faster to the addressing.
– Aron
Nov 27 '15 at 17:45
I am just guessing. But it is common for systems to use 32 bits to hold RGB24, with 8 bits being completely wasted. This is because it is often easier/faster to the addressing.
– Aron
Nov 27 '15 at 17:45
add a comment |
2 Answers
2
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They are different. If you look at SDL2/SDL_pixels.h you'll find:
SDL_PIXELFORMAT_RGB24 =
SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_ARRAYU8, SDL_ARRAYORDER_RGB, 0,
24, 3)
SDL_PIXELFORMAT_RGB888 =
SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_XRGB,
SDL_PACKEDLAYOUT_8888, 24, 4)
SDL_PIXELFORMAT_RGBX8888 =
SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_RGBX,
SDL_PACKEDLAYOUT_8888, 24, 4)
So RGB24 is a tightly packed three byte format (RRGGBB), while RGB888 is a four byte format with the first byte going ignored (XXRRGGBB). So the format is just confusingly named and XRGB8888 would be a more appropriate name.
Don't know why they called it RGB888 instead of XRGB8888, but they leave the leading X away on other formats as well.
answered Nov 16 '18 at 9:13
GrumbelGrumbel
3,24152935
add a comment |
From my understanding RGB24 formats it's data in bit triplets, whereas RGB888 simply concatenates the respective byte for each channel.
RGB24:
RGBRGBRG BRGBRGBR GBRGBRGB
RGB888:
RRRRRRRR GGGGGGGG BBBBBBBB
I highly doubt RGB24 serves a functional or technical benefit, as it would be easier to just load the byte into memory like you would do with RGB888. But I'm not sure.
answered Mar 15 '17 at 20:02
Keyton StanierKeyton Stanier
1
add a comment |
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2 Answers
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2 Answers
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active
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They are different. If you look at SDL2/SDL_pixels.h you'll find:
SDL_PIXELFORMAT_RGB24 =
SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_ARRAYU8, SDL_ARRAYORDER_RGB, 0,
24, 3)
SDL_PIXELFORMAT_RGB888 =
SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_XRGB,
SDL_PACKEDLAYOUT_8888, 24, 4)
SDL_PIXELFORMAT_RGBX8888 =
SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_RGBX,
SDL_PACKEDLAYOUT_8888, 24, 4)
So RGB24 is a tightly packed three byte format (RRGGBB), while RGB888 is a four byte format with the first byte going ignored (XXRRGGBB). So the format is just confusingly named and XRGB8888 would be a more appropriate name.
Don't know why they called it RGB888 instead of XRGB8888, but they leave the leading X away on other formats as well.
answered Nov 16 '18 at 9:13
GrumbelGrumbel
3,24152935
add a comment |
They are different. If you look at SDL2/SDL_pixels.h you'll find:
SDL_PIXELFORMAT_RGB24 =
SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_ARRAYU8, SDL_ARRAYORDER_RGB, 0,
24, 3)
SDL_PIXELFORMAT_RGB888 =
SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_XRGB,
SDL_PACKEDLAYOUT_8888, 24, 4)
SDL_PIXELFORMAT_RGBX8888 =
SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_RGBX,
SDL_PACKEDLAYOUT_8888, 24, 4)
So RGB24 is a tightly packed three byte format (RRGGBB), while RGB888 is a four byte format with the first byte going ignored (XXRRGGBB). So the format is just confusingly named and XRGB8888 would be a more appropriate name.
Don't know why they called it RGB888 instead of XRGB8888, but they leave the leading X away on other formats as well.
answered Nov 16 '18 at 9:13
GrumbelGrumbel
3,24152935
add a comment |
They are different. If you look at SDL2/SDL_pixels.h you'll find:
SDL_PIXELFORMAT_RGB24 =
SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_ARRAYU8, SDL_ARRAYORDER_RGB, 0,
24, 3)
SDL_PIXELFORMAT_RGB888 =
SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_XRGB,
SDL_PACKEDLAYOUT_8888, 24, 4)
SDL_PIXELFORMAT_RGBX8888 =
SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_RGBX,
SDL_PACKEDLAYOUT_8888, 24, 4)
So RGB24 is a tightly packed three byte format (RRGGBB), while RGB888 is a four byte format with the first byte going ignored (XXRRGGBB). So the format is just confusingly named and XRGB8888 would be a more appropriate name.
Don't know why they called it RGB888 instead of XRGB8888, but they leave the leading X away on other formats as well.
answered Nov 16 '18 at 9:13
GrumbelGrumbel
3,24152935
They are different. If you look at SDL2/SDL_pixels.h you'll find:
SDL_PIXELFORMAT_RGB24 =
SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_ARRAYU8, SDL_ARRAYORDER_RGB, 0,
24, 3)
SDL_PIXELFORMAT_RGB888 =
SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_XRGB,
SDL_PACKEDLAYOUT_8888, 24, 4)
SDL_PIXELFORMAT_RGBX8888 =
SDL_DEFINE_PIXELFORMAT(SDL_PIXELTYPE_PACKED32, SDL_PACKEDORDER_RGBX,
SDL_PACKEDLAYOUT_8888, 24, 4)
So RGB24 is a tightly packed three byte format (RRGGBB), while RGB888 is a four byte format with the first byte going ignored (XXRRGGBB). So the format is just confusingly named and XRGB8888 would be a more appropriate name.
Don't know why they called it RGB888 instead of XRGB8888, but they leave the leading X away on other formats as well.
answered Nov 16 '18 at 9:13
GrumbelGrumbel
3,24152935
answered Nov 16 '18 at 9:13
GrumbelGrumbel
3,24152935
answered Nov 16 '18 at 9:13
GrumbelGrumbel
3,24152935
answered Nov 16 '18 at 9:13
GrumbelGrumbel
3,24152935
3,24152935
add a comment |
add a comment |
From my understanding RGB24 formats it's data in bit triplets, whereas RGB888 simply concatenates the respective byte for each channel.
RGB24:
RGBRGBRG BRGBRGBR GBRGBRGB
RGB888:
RRRRRRRR GGGGGGGG BBBBBBBB
I highly doubt RGB24 serves a functional or technical benefit, as it would be easier to just load the byte into memory like you would do with RGB888. But I'm not sure.
answered Mar 15 '17 at 20:02
Keyton StanierKeyton Stanier
1
add a comment |
From my understanding RGB24 formats it's data in bit triplets, whereas RGB888 simply concatenates the respective byte for each channel.
RGB24:
RGBRGBRG BRGBRGBR GBRGBRGB
RGB888:
RRRRRRRR GGGGGGGG BBBBBBBB
I highly doubt RGB24 serves a functional or technical benefit, as it would be easier to just load the byte into memory like you would do with RGB888. But I'm not sure.
answered Mar 15 '17 at 20:02
Keyton StanierKeyton Stanier
1
add a comment |
From my understanding RGB24 formats it's data in bit triplets, whereas RGB888 simply concatenates the respective byte for each channel.
RGB24:
RGBRGBRG BRGBRGBR GBRGBRGB
RGB888:
RRRRRRRR GGGGGGGG BBBBBBBB
I highly doubt RGB24 serves a functional or technical benefit, as it would be easier to just load the byte into memory like you would do with RGB888. But I'm not sure.
answered Mar 15 '17 at 20:02
Keyton StanierKeyton Stanier
1
From my understanding RGB24 formats it's data in bit triplets, whereas RGB888 simply concatenates the respective byte for each channel.
RGB24:
RGBRGBRG BRGBRGBR GBRGBRGB
RGB888:
RRRRRRRR GGGGGGGG BBBBBBBB
I highly doubt RGB24 serves a functional or technical benefit, as it would be easier to just load the byte into memory like you would do with RGB888. But I'm not sure.
answered Mar 15 '17 at 20:02
Keyton StanierKeyton Stanier
1
answered Mar 15 '17 at 20:02
Keyton StanierKeyton Stanier
1
answered Mar 15 '17 at 20:02
Keyton StanierKeyton Stanier
1
answered Mar 15 '17 at 20:02
Keyton StanierKeyton Stanier
1
1
add a comment |
add a comment |
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I am just guessing. But it is common for systems to use 32 bits to hold RGB24, with 8 bits being completely wasted. This is because it is often easier/faster to the addressing.
– Aron
Nov 27 '15 at 17:45