diff options
author | Sebastian Dröge <sebastian@centricular.com> | 2020-04-14 19:41:24 +0300 |
---|---|---|
committer | Sebastian Dröge <sebastian@centricular.com> | 2020-04-14 20:01:30 +0300 |
commit | f1e3212477a1fcc1b7783fc19d920db2b06c4aa5 (patch) | |
tree | a5e36588fb8750f5d71235e76c12a418c3338d7f /video | |
parent | 70ef91fb4aae23f36ca5c5805f5c60ca93df695f (diff) |
closedcaption: Convert bitfields to uint8_t for portability reasons
Contrary to what one might believe, this actually reduces the size of
the structs due to alignment constraints. On Linux x86-64 clang/gcc it
reduces the size of the caption_frame_t struct from 7760 bytes to 6800
bytes, on Windows x86-64 MSVC from 11600 bytes to 6800 bytes.
It also causes simpler and potentially faster assembly to be generated
as the values can be directly accessed as uint8_t instead of having to
extract the corresponding bits with bitwise operations.
It also gives us the same ABI with clang/gcc and MSVC.
Diffstat (limited to 'video')
-rw-r--r-- | video/closedcaption/src/c/caption.h | 10 | ||||
-rw-r--r-- | video/closedcaption/src/cea608tott_ffi.rs | 188 |
2 files changed, 10 insertions, 188 deletions
diff --git a/video/closedcaption/src/c/caption.h b/video/closedcaption/src/c/caption.h index 508935c1e..c70a8f183 100644 --- a/video/closedcaption/src/c/caption.h +++ b/video/closedcaption/src/c/caption.h @@ -56,8 +56,8 @@ static inline libcaption_stauts_t libcaption_status_update(libcaption_stauts_t o #define SCREEN_COLS 32 typedef struct { - unsigned int uln : 1; //< underline - unsigned int sty : 3; //< style + uint8_t uln; //< underline + uint8_t sty; //< style utf8_char_t data[5]; //< 4 byte utf8 values plus null term } caption_frame_cell_t; @@ -66,9 +66,9 @@ typedef struct { } caption_frame_buffer_t; typedef struct { - unsigned int uln : 1; //< underline - unsigned int sty : 3; //< style - unsigned int rup : 2; //< roll-up line count minus 1 + uint8_t uln; //< underline + uint8_t sty; //< style + uint8_t rup; //< roll-up line count minus 1 int8_t row, col; uint16_t cc_data; } caption_frame_state_t; diff --git a/video/closedcaption/src/cea608tott_ffi.rs b/video/closedcaption/src/cea608tott_ffi.rs index ccbf28d68..97248fda3 100644 --- a/video/closedcaption/src/cea608tott_ffi.rs +++ b/video/closedcaption/src/cea608tott_ffi.rs @@ -1,86 +1,5 @@ /* automatically generated by rust-bindgen */ -#[repr(C)] -#[derive(Copy, Clone, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)] -pub struct __BindgenBitfieldUnit<Storage, Align> { - storage: Storage, - align: [Align; 0], -} -impl<Storage, Align> __BindgenBitfieldUnit<Storage, Align> { - #[inline] - pub const fn new(storage: Storage) -> Self { - Self { storage, align: [] } - } -} -impl<Storage, Align> __BindgenBitfieldUnit<Storage, Align> -where - Storage: AsRef<[u8]> + AsMut<[u8]>, -{ - #[inline] - pub fn get_bit(&self, index: usize) -> bool { - debug_assert!(index / 8 < self.storage.as_ref().len()); - let byte_index = index / 8; - let byte = self.storage.as_ref()[byte_index]; - let bit_index = if cfg!(target_endian = "big") { - 7 - (index % 8) - } else { - index % 8 - }; - let mask = 1 << bit_index; - byte & mask == mask - } - #[inline] - pub fn set_bit(&mut self, index: usize, val: bool) { - debug_assert!(index / 8 < self.storage.as_ref().len()); - let byte_index = index / 8; - let byte = &mut self.storage.as_mut()[byte_index]; - let bit_index = if cfg!(target_endian = "big") { - 7 - (index % 8) - } else { - index % 8 - }; - let mask = 1 << bit_index; - if val { - *byte |= mask; - } else { - *byte &= !mask; - } - } - #[inline] - pub fn get(&self, bit_offset: usize, bit_width: u8) -> u64 { - debug_assert!(bit_width <= 64); - debug_assert!(bit_offset / 8 < self.storage.as_ref().len()); - debug_assert!((bit_offset + (bit_width as usize)) / 8 <= self.storage.as_ref().len()); - let mut val = 0; - for i in 0..(bit_width as usize) { - if self.get_bit(i + bit_offset) { - let index = if cfg!(target_endian = "big") { - bit_width as usize - 1 - i - } else { - i - }; - val |= 1 << index; - } - } - val - } - #[inline] - pub fn set(&mut self, bit_offset: usize, bit_width: u8, val: u64) { - debug_assert!(bit_width <= 64); - debug_assert!(bit_offset / 8 < self.storage.as_ref().len()); - debug_assert!((bit_offset + (bit_width as usize)) / 8 <= self.storage.as_ref().len()); - for i in 0..(bit_width as usize) { - let mask = 1 << i; - let val_bit_is_set = val & mask == mask; - let index = if cfg!(target_endian = "big") { - bit_width as usize - 1 - i - } else { - i - }; - self.set_bit(index + bit_offset, val_bit_is_set); - } - } -} pub const EIA608_CHAR_COUNT: u32 = 176; pub const EIA608_CHAR_NULL: &'static [u8; 1usize] = b"\0"; pub const EIA608_CHAR_SPACE: &'static [u8; 2usize] = b" \0"; @@ -815,124 +734,27 @@ pub const libcaption_stauts_t_LIBCAPTION_READY: libcaption_stauts_t = 2; pub const libcaption_stauts_t_LIBCAPTION_CLEAR: libcaption_stauts_t = 3; pub type libcaption_stauts_t = u32; #[repr(C)] -#[repr(align(4))] #[derive(Debug, Copy, Clone)] pub struct caption_frame_cell_t { - pub _bitfield_1: __BindgenBitfieldUnit<[u8; 1usize], u8>, + pub uln: u8, + pub sty: u8, pub data: [utf8_char_t; 5usize], } -impl caption_frame_cell_t { - #[inline] - pub fn uln(&self) -> ::std::os::raw::c_uint { - unsafe { ::std::mem::transmute(self._bitfield_1.get(0usize, 1u8) as u32) } - } - #[inline] - pub fn set_uln(&mut self, val: ::std::os::raw::c_uint) { - unsafe { - let val: u32 = ::std::mem::transmute(val); - self._bitfield_1.set(0usize, 1u8, val as u64) - } - } - #[inline] - pub fn sty(&self) -> ::std::os::raw::c_uint { - unsafe { ::std::mem::transmute(self._bitfield_1.get(1usize, 3u8) as u32) } - } - #[inline] - pub fn set_sty(&mut self, val: ::std::os::raw::c_uint) { - unsafe { - let val: u32 = ::std::mem::transmute(val); - self._bitfield_1.set(1usize, 3u8, val as u64) - } - } - #[inline] - pub fn new_bitfield_1( - uln: ::std::os::raw::c_uint, - sty: ::std::os::raw::c_uint, - ) -> __BindgenBitfieldUnit<[u8; 1usize], u8> { - let mut __bindgen_bitfield_unit: __BindgenBitfieldUnit<[u8; 1usize], u8> = - Default::default(); - __bindgen_bitfield_unit.set(0usize, 1u8, { - let uln: u32 = unsafe { ::std::mem::transmute(uln) }; - uln as u64 - }); - __bindgen_bitfield_unit.set(1usize, 3u8, { - let sty: u32 = unsafe { ::std::mem::transmute(sty) }; - sty as u64 - }); - __bindgen_bitfield_unit - } -} #[repr(C)] #[derive(Debug, Copy, Clone)] pub struct caption_frame_buffer_t { pub cell: [[caption_frame_cell_t; 32usize]; 15usize], } #[repr(C)] -#[repr(align(4))] #[derive(Debug, Copy, Clone)] pub struct caption_frame_state_t { - pub _bitfield_1: __BindgenBitfieldUnit<[u8; 1usize], u8>, + pub uln: u8, + pub sty: u8, + pub rup: u8, pub row: i8, pub col: i8, pub cc_data: u16, } -impl caption_frame_state_t { - #[inline] - pub fn uln(&self) -> ::std::os::raw::c_uint { - unsafe { ::std::mem::transmute(self._bitfield_1.get(0usize, 1u8) as u32) } - } - #[inline] - pub fn set_uln(&mut self, val: ::std::os::raw::c_uint) { - unsafe { - let val: u32 = ::std::mem::transmute(val); - self._bitfield_1.set(0usize, 1u8, val as u64) - } - } - #[inline] - pub fn sty(&self) -> ::std::os::raw::c_uint { - unsafe { ::std::mem::transmute(self._bitfield_1.get(1usize, 3u8) as u32) } - } - #[inline] - pub fn set_sty(&mut self, val: ::std::os::raw::c_uint) { - unsafe { - let val: u32 = ::std::mem::transmute(val); - self._bitfield_1.set(1usize, 3u8, val as u64) - } - } - #[inline] - pub fn rup(&self) -> ::std::os::raw::c_uint { - unsafe { ::std::mem::transmute(self._bitfield_1.get(4usize, 2u8) as u32) } - } - #[inline] - pub fn set_rup(&mut self, val: ::std::os::raw::c_uint) { - unsafe { - let val: u32 = ::std::mem::transmute(val); - self._bitfield_1.set(4usize, 2u8, val as u64) - } - } - #[inline] - pub fn new_bitfield_1( - uln: ::std::os::raw::c_uint, - sty: ::std::os::raw::c_uint, - rup: ::std::os::raw::c_uint, - ) -> __BindgenBitfieldUnit<[u8; 1usize], u8> { - let mut __bindgen_bitfield_unit: __BindgenBitfieldUnit<[u8; 1usize], u8> = - Default::default(); - __bindgen_bitfield_unit.set(0usize, 1u8, { - let uln: u32 = unsafe { ::std::mem::transmute(uln) }; - uln as u64 - }); - __bindgen_bitfield_unit.set(1usize, 3u8, { - let sty: u32 = unsafe { ::std::mem::transmute(sty) }; - sty as u64 - }); - __bindgen_bitfield_unit.set(4usize, 2u8, { - let rup: u32 = unsafe { ::std::mem::transmute(rup) }; - rup as u64 - }); - __bindgen_bitfield_unit - } -} #[repr(C)] #[derive(Debug, Copy, Clone)] pub struct caption_frame_t { |