GP2X
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| + | ==How to map memory== | ||
| + | First, open "/dev/mem" with the 'open' function, using O_RDWR. | ||
| + | |||
| + | ===Magic Eyes Registers=== | ||
| + | mmap(0, 0x10000, PROT_READ|PROT_WRITE, MAP_SHARED, ''/dev/mem fd'', 0xc0000000) | ||
| + | |||
| + | Remember that most of the registers seem to be 16-bit so you may want to use a (Uint16 *) pointer (you'll have to divide all offsets by 2 of you do). | ||
| + | |||
| + | ===Video Memory=== | ||
| + | mmap(0, 0x4B000, PROT_READ|PROT_WRITE, MAP_SHARED, ''/dev/mem fd'', 0x4000000 - 0x4B000) | ||
| + | |||
| + | The above is what Rlyeh does in his code. The 0x4b000 is 320x240x4. He may start at 0x3FFB5000 because of a wiki post here [http://wiki.gp2x.org/wiki/Development_FAQ#Memory_Layout] . | ||
| + | |||
==FDC== | ==FDC== | ||
===Frame Dimension Converter (13.2)=== | ===Frame Dimension Converter (13.2)=== | ||
Revision as of 23:38, 25 June 2007
How to map memory
First, open "/dev/mem" with the 'open' function, using O_RDWR.
Magic Eyes Registers
mmap(0, 0x10000, PROT_READ|PROT_WRITE, MAP_SHARED, /dev/mem fd, 0xc0000000)
Remember that most of the registers seem to be 16-bit so you may want to use a (Uint16 *) pointer (you'll have to divide all offsets by 2 of you do).
Video Memory
mmap(0, 0x4B000, PROT_READ|PROT_WRITE, MAP_SHARED, /dev/mem fd, 0x4000000 - 0x4B000)
The above is what Rlyeh does in his code. The 0x4b000 is 320x240x4. He may start at 0x3FFB5000 because of a wiki post here [1] .
FDC
Frame Dimension Converter (13.2)
(from the Magic Eyes PDF) "The Frame Dimension Converter (FDC) transforms 2-D data made during the process of Encoding/Decoding MPEG into the 1-D data format. During this work, 4:2:0 to 4:2:2 format conversion, Rotation are performed."
ie 2D frame to 1D frame
2D separated 4:2:0, 4:2:2, or 4:4:4 --> YUY2 4:2:2
Rotation (0, 90, 180, 270 degrees).
Registers:
Control Register FDC_CNTL
Frame Size Register FDC_FRAME_SIZE
Source Address Registers FDC_LUMA_OFFSET FDC_CB_OFFSET FDC_CR_OFFSET
Destination Address Registers FDC_DST_BASE_L FDB_DST_BASE_H
Status Register FDC_STATUS (can indicate when FDC is busy)
Other Regs FDC_DERING FDC_OCC_CNTL
SC
Scale Processor (13.3)
Receives data from external memory, the ISP, or the Frame Dimensional Convertor (FDC).
Supports Coarse scale and fine scale.
Scale is split into Pre-scale and Post-scale.
PreScale
Coarse scale without filtering, more than 2x down scaling is exclusively possible.
SC_PRE_VRATIO SC_PRE_HRATIO SC_SRC_PXL_WIDTH SC_SRC_PXL_REQCNT
PostScale
Up/Down scale with filtering.
SC_POST_VRATIO SC_POST_HRATIO
Field/Frame Function
SC_SRC_ODD_ADDR SC_SRC_EVEN_ADDR SC_DST_ADDR SC_DST_WPXL_WIDTH
Y/Cb/Cr Separating Function
Only seems to be needed for mpeg or jpeg encoding.
SC_SEP_ADDR SC_DST_PXL_WIDTH
Mirror
SC_MIRROR
bits: 0 - src horizontal mirror (0 = disable, 1 = mirror) 1 - src vertical mirror 2 - dst horizontal mirror 3 - dst vertical mirror 4-5 - scale _source_ data format (0 = yuy2, 1 = yvyu, 2 = uyvy, 3 = vyuy)
Scale Status
SC_STATUS (has "busy" and "done" bits)
Output
Outputs to either external memory or the external display directly.
Other Registers
SC_CMD (Scale control register) SC_SEP_LUMA_ADDR SC_SEP_CB_ADDR SC_SEP_CR_ADDR SC_DELAY SC_MEM_CNTR SC_IRQ
MLC (Multi Layer Controller)
Inputs
Receives data from Scale Processor, Frame Dimensional Converter, and External Memory. (see MLC_YUV_CNTL for where to set this for YUV)
Data Format
Y/Cr/Cb, RGB, indexed color, OSD/sub-picture/cursor data format.
Mirroring
Controls 4-division display of Y/Cr/Cb data. The mirror function can only be enabled when the source is memory (section 13-25).
Color Correction
Does brightness/contrast for luminance, and hue/saturation for chrominance. Does dithering and gamma correction for RGB.
Color Space Conversion
Converts Y/Cr/Cb to RGB.
Scaling
for Y/Cr/Cb and RGB: coarse scaling only (see 13.4.2.10) Registers for YUV Region A (top): MLC_YUVA_TP_HSC (section 13-64), MLC_YUVA_TP_VSC (see 13.4.2.10 for others)
Algorithm:
horizontal scale value = (W / 320) * 1024
vertical scale value = (H / 240) * MLC_VLA_TP_PXW (MLC_VLA_TP_PXW _may_ be equal to 320 * 2 according to ryleh's code)
YUV Layer
Handles only Y/Cr/Cb data. Supports scaling, mirroring, and 4-division display.
Input: Receives data from scale processor, FDC, or external memory.
Divided into Region A and Region B. Each Region is divided into Top Region and Bottom Region. The bottom regions can only be enabled when the source is memory (section 13-25).
Region Differences (this is why you'd have to choose one or the other)
Region A receives data from external memory and scale processor.
Region B receives data from external memory and Frame Dimension Converter.
Y/Cr/Cb format
Basically this seems to be just regular YUY2.
Region Dimensions Example
YUV Region A (top) MLC_YUVA_STX (section 13-64) : starting X (horizontal) MLC_YUVA_ENDX (section 13-65) : ending X MLC_YUVA_TP_STY (section 13-65) : starting Y (vertical) MLC_YUVA_TP_ENDY (13-65) : ending Y
Interlaced/Progressive Display
Section 13.4.2.11, this may be neecessary to explicitly set
Source Addresses (where image data comes from, I presume)
MLC_YUVA_TP_OADR[L/H] (13-65) - Odd Field Source Address of Top Region A MLC_YUVA_TP_EADR[L/H] (13-65) - Even Field Source Address ot Top Region A
Other Registers
MLC_OVLAY_CNTR (overlay control register) - used to enable/disable RGB regions, and YUV regions
MLC_YUV_EFFECT (13-63) - controls mirroring and whether to divide regions into top/bottom
MLC_YUV_CNTL (13-63) - controls whether Region A inputs from external memory or scale processor, whether Region B inputs from external memory or FDC, and whether region A or region B has priority. Also controls primitive down scaling (by skipping pixels, 1/2, 1/3 or 1/4 down scaling).
MLC_YUVA_TP_PXW (13-64) - horizontal pixel width (I'm not sure what this does)
RGB Stuff
MLC_STL_CNTL (13-68) - still image control register (still image seems equivalent to RGB)
MLC_STL_MIXMUX (13-68) - STL, color key, alpha blending stuff
MLC_STL_ALPHA[L/H] (13-68) - alpha blending stuff
MLC_STL_OADR[L/H] (13-71) - odd field source address of RGB layer
MLC_STL_EADR[L/H] (13-72) - even field source address of RGB layer
Hardware Cursor
see section 13-72
Luminance and Chrominance Enhancement
see section 13-73
