Image acquisition with buffer (Matrox) - c++

I'm new to programming with Matrox (MIL) and C++. I've been wanting to use a camera to its limit (120 Hz frame rate). I'm currently using MIL through Microsoft Visual Studio to program the camera. How my program works currently is using MdigProcess to acquire and save each image using a separate function. However, this slows down the camera to roughly 10Hz since it calls the function every time the to save the image in a buffer when it is ready. If I don't save the images, then the camera works fine. But I won't have any data :/
I am thinking of having the images (100 images for now) in the buffers first once, then save them. Is there a way to do that? Here is my attempt:
#include <mil.h>
#include <stdlib.h>
/* Number of images in the buffering grab queue.
Generally, increasing this number gives a better real-time grab.
*/
#define BUFFERING_SIZE_MAX 5
/* User's processing function prototype. */
MIL_INT MFTYPE ProcessingFunction(MIL_INT HookType, MIL_ID HookId, void*
HookDataPtr);
/* User's processing function hook data structure. */
typedef struct
{
MIL_ID MilDigitizer;
MIL_ID MilImageDisp;
MIL_INT ProcessedImageCount;
} HookDataStruct;
/* Main function. */
/* ---------------*/
int MosMain(void)
{
MIL_ID MilApplication;
MIL_ID MilSystem;
MIL_ID MilDigitizer;
MIL_ID MilDisplay; /* Display identifier. */
MIL_ID MilImageDisp; /* Display Image buffer identifier. */
MIL_ID MilGrabBufferList[BUFFERING_SIZE_MAX] = { 0 };
MIL_INT MilGrabBufferListSize;
MIL_INT ProcessFrameCount = 0, ProcessFrameMissed = 0, ProcessFrameCorrupted = 0;
MIL_DOUBLE ProcessFrameRate = 0;
MIL_DOUBLE FrameRate; // Initializes the FrameRate variable as double
HookDataStruct UserHookData;
MappAlloc(M_NULL, M_DEFAULT, &MilApplication); /* This initializes the MIL library. M_NULL means no cluster manager will be used. M_DEFAULT means reported error message will be displayed. */
MsysAlloc(M_SYSTEM_RAPIXOCL, M_DEFAULT, M_DEFAULT, &MilSystem); /* This allocates a MIL system*/
MdispAlloc(MilSystem, M_DEFAULT, MIL_TEXT("M_DEFAULT"), M_DEFAULT, &MilDisplay); /* M_WINDOWED means it will display at a separate window*/
MdigAlloc(MilSystem, M_DEV0, MIL_TEXT("C:\\Users\\fluids-student\\Documents\\JAI 5000 PMCL.dcf"), M_DEFAULT, &MilDigitizer);
/* Allocate a monochrome display buffer. */
MbufAlloc2d(MilSystem, 2560, 2048, 8 + M_UNSIGNED, M_IMAGE + M_DISP + M_GRAB + M_PROC, &MilImageDisp);
MbufClear(MilImageDisp, M_BLACK);
/* Display the image buffer. */
MdispSelect(MilDisplay, MilImageDisp);
/* This inquires the frame rate */
MdigInquire(MilDigitizer, M_SELECTED_FRAME_RATE, &FrameRate);
MosPrintf(MIL_TEXT("The frame rate is # %0.2f fps.\n"), FrameRate);
/* Print a message. */
MosPrintf(MIL_TEXT("\nMULTIPLE BUFFERED PROCESSING.\n"));
MosPrintf(MIL_TEXT("-----------------------------\n\n"));
MosPrintf(MIL_TEXT("Press <Enter> to start acquisition.\n\n"));
/* Grab continuously on the display and wait for a key press. */
MdigGrabContinuous(MilDigitizer, MilImageDisp);
MosGetch();
/* Halt continuous grab. */
MdigHalt(MilDigitizer);
/* Allocate the grab buffers and clear them. */
MappControl(M_DEFAULT, M_ERROR, M_PRINT_DISABLE);
for (MilGrabBufferListSize = 0; MilGrabBufferListSize < BUFFERING_SIZE_MAX;
MilGrabBufferListSize++)
{
MbufAlloc2d(MilSystem,
MdigInquire(MilDigitizer, M_SIZE_X, M_NULL),
MdigInquire(MilDigitizer, M_SIZE_Y, M_NULL),
8L + M_UNSIGNED,
M_IMAGE + M_GRAB + M_PROC,
&MilGrabBufferList[MilGrabBufferListSize]);
if (MilGrabBufferList[MilGrabBufferListSize])
MbufClear(MilGrabBufferList[MilGrabBufferListSize], 0xFF);
else
break;
}
MappControl(M_DEFAULT, M_ERROR, M_PRINT_ENABLE);
/* Initialize the user's processing function data structure. */
UserHookData.MilDigitizer = MilDigitizer;
UserHookData.MilImageDisp = MilImageDisp;
UserHookData.ProcessedImageCount = 0;
/* Start the processing. The processing function is called with every frame grabbed. */
MdigProcess(MilDigitizer, MilGrabBufferList, MilGrabBufferListSize,
M_SEQUENCE + M_COUNT(100), M_DEFAULT, ProcessingFunction, &UserHookData);
/* Here the main() is free to perform other tasks while the processing is executing. */
/* --------------------------------------------------------------------------------- */
/* Stop the processing. */
MdigProcess(MilDigitizer, MilGrabBufferList, MilGrabBufferListSize,
M_STOP, M_DEFAULT, ProcessingFunction, &UserHookData);
/* Print statistics. */
MdigInquire(MilDigitizer, M_PROCESS_FRAME_COUNT, &ProcessFrameCount);
MdigInquire(MilDigitizer, M_PROCESS_FRAME_RATE, &ProcessFrameRate);
MdigInquire(MilDigitizer, M_PROCESS_FRAME_MISSED, &ProcessFrameMissed);
MdigInquire(MilDigitizer, M_PROCESS_FRAME_CORRUPTED, &ProcessFrameCorrupted);
MosPrintf(MIL_TEXT("\n\n%d frames grabbed at %.1f frames/sec (%.1f ms/frame).\n"),
(int)ProcessFrameCount, ProcessFrameRate, 1000.0 / ProcessFrameRate);
MosPrintf(MIL_TEXT("%ld frames missed.\n"), ProcessFrameMissed);
MosPrintf(MIL_TEXT("%ld frames corrupted.\n"), ProcessFrameCorrupted);
MosPrintf(MIL_TEXT("Press <Enter> to end.\n\n"));
MosPrintf(MIL_TEXT("BufferListSize = %d\n"), MilGrabBufferListSize);
MosGetch();
/* Free the grab buffers. */
while (MilGrabBufferListSize > 0)
MbufFree(MilGrabBufferList[--MilGrabBufferListSize]);
/* Free display buffer. */
MbufFree(MilImageDisp);
/* Release defaults. */
MdigFree(MilDigitizer);
MdispFree(MilDisplay);
MsysFree(MilSystem);
MappFree(MilApplication);
return 0;
}
/* User's processing function called every time a grab buffer is ready. */
/* -------------------------------------------------------------------- */
/* Local defines. */
#define STRING_LENGTH_MAX 20
#define STRING_POS_X 20
#define STRING_POS_Y 20
MIL_INT MFTYPE ProcessingFunction(MIL_INT HookType, MIL_ID HookId, void* HookDataPtr)
{
HookDataStruct* UserHookDataPtr = (HookDataStruct*)HookDataPtr;
MIL_ID ModifiedBufferId;
MIL_TEXT_CHAR Text[STRING_LENGTH_MAX] = { MIL_TEXT('\0'), };
MIL_TEXT_CHAR junkoutput[STRING_LENGTH_MAX] = { MIL_TEXT('\0'), };
/* Retrieve the MIL_ID of the grabbed buffer. */
MdigGetHookInfo(HookId, M_MODIFIED_BUFFER + M_BUFFER_ID, &ModifiedBufferId);
/* Increment the frame counter. */
UserHookDataPtr->ProcessedImageCount++;
/* Print and draw the frame count (remove to reduce CPU usage). */
MosPrintf(MIL_TEXT("Acquiring frame #%d.\r"), (int)UserHookDataPtr->ProcessedImageCount);
MosSprintf(Text, STRING_LENGTH_MAX, MIL_TEXT("%d"),
(int)UserHookDataPtr->ProcessedImageCount);
/* Execute the processing and update the display. */
MbufCopy(ModifiedBufferId, UserHookDataPtr->MilImageDisp); // Remove comment to see the image acquisition. Will slow down the frame rate/ acquisition time
/* Create file name base on the index of the frame that is being processed */
MosSprintf(Text, STRING_LENGTH_MAX, MIL_TEXT("Image%03li.png"), UserHookDataPtr->ProcessedImageCount); // 0-adds zeroes to the naming, 3- three places, l-long integer, i-signed decimal integer
/* Save image to disk */
MbufSave(Text, UserHookDataPtr->MilImageDisp);
return 0;
}
Thanks for all the help I can get!

Related

STM32 HAL I2C DMA not triggering callback function

I try to read and write data to a sensor via i2c with DMA1 in an STM32 Nucleo F401 board where a FreeRTOS is running.
My project is written in C++ and using the stm32 HAL libraries as extern "C".
I can read the sensor data with polling method, and next to the I2C an UART is running with the DMA2 correctly. I have checked and the MX_DMA_Init is running before the MX_I2C1_Init.
When I try to write to the sensor as a master with DMA(HAL_I2C_Master_Transmit_DMA) with the "i2c1 event interrupt" and "i2c1 error interrupt" disabled in the FreeRTOS the parallel tasks are just running fine just the callback HAL_I2C_MasterTxCpltCallback is not triggered.
And when i am enabling the" i2c1 event interrupt" and "i2c1 error interrupt" from the CubeMX two parallel task in the Free RTOS are running at once and then no more parallel scheduling is happening and the HAL_I2C_EV_IRQHandler function is called periodically and leaving the function in the last else branch where the /* Do nothing */ is commented.
" i2c1 event interrupt" and "i2c1 error interrupt" enabled
UART DMA configuration
I2C DMA confuguration
Could you please suggest what could I try to use the i2c with DMA?
I tried to enable and disable the i2c1 event interrupt from CubeMX and expected to trigger the HAL_I2C_MasterTxCpltCallback callback. But only the HAL_I2C_EV_IRQHandler was triggered periodically.
I tried to use the I2C with polling method and it was working correctly.
I tried to use the UART with DMA and it was working correctly too.
I tried to check order of MX_DMA_Init and MX_I2C1_Init, but the order was correct.
I tried if any other I2C callback is triggered, but none other I2C callback is triggered.
I tried to update the Cube MX version from F4 V1.26.2 to F4 V27.1, but i have not found any improvement.
I tried to have all the HAL implementation and callback functions embedded in extern"C". No change has occurred.
I switched to STM32 H723ZG board where at lest the first transfer of the I2C data happened with DMA [FIRST I2C Data transfer][1][1]: https://i.stack.imgur.com/4wsxk.png. But happenes only for 1 cycle and the DMA failes with error code 1. What is the Transfer error.
#define HAL_DMA_ERROR_TE (0x00000001U) /*!< Transfer error */
[DMA Registers]
[2]: https://i.stack.imgur.com/4SH7Z.png
I have seen that in the h= series i need to align the data given to the DMA to be able to send and i tryed to apply the fix for this.
My code now looks like this:
#define TX_LENGTH (16)
uint8_t i2cData[TX_LENGTH];
void I2C_Write8(uint8_t ADDR, uint8_t data)
{
i2cData[0] = ADDR;
i2cData[1] = data;
uint8_t MPUADDR = (MPU_ADDR<<1);
/* Clean D-cache */
/* Make sure the address is 32-byte aligned and add 32-bytes to length, in case it overlaps cacheline */
SCB_CleanDCache_by_Addr((uint32_t*)(((uint32_t)i2cData) & ~(uint32_t)0x1F), TX_LENGTH+32);
HAL_I2C_Master_Transmit_DMA(&i2cHandler, MPUADDR, i2cData, TX_LENGTH);
//HAL_Delay(100);
}
The I2C Init:
static void MX_I2C2_Init(void)
{
/* USER CODE BEGIN I2C2_Init 0 */
/* USER CODE END I2C2_Init 0 */
/* USER CODE BEGIN I2C2_Init 1 */
/* USER CODE END I2C2_Init 1 */
hi2c2.Instance = I2C2;
hi2c2.Init.Timing = 0x60404E72;
hi2c2.Init.OwnAddress1 = 0;
hi2c2.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
hi2c2.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
hi2c2.Init.OwnAddress2 = 0;
hi2c2.Init.OwnAddress2Masks = I2C_OA2_NOMASK;
hi2c2.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
hi2c2.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
if (HAL_I2C_Init(&hi2c2) != HAL_OK)
{
Error_Handler();
}
/** Configure Analogue filter
*/
if (HAL_I2CEx_ConfigAnalogFilter(&hi2c2, I2C_ANALOGFILTER_ENABLE) != HAL_OK)
{
Error_Handler();
}
/** Configure Digital filter
*/
if (HAL_I2CEx_ConfigDigitalFilter(&hi2c2, 0) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN I2C2_Init 2 */
/* USER CODE END I2C2_Init 2 */
}
The DMA Init:
static void MX_DMA_Init(void)
{
/* DMA controller clock enable */
__HAL_RCC_DMA1_CLK_ENABLE();
/* DMA interrupt init */
/* DMA1_Stream0_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Stream0_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(DMA1_Stream0_IRQn);
/* DMA1_Stream1_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Stream1_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(DMA1_Stream1_IRQn);
}
The initialization from the main:
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_DMA_Init();
MX_USART3_UART_Init();
MX_USB_OTG_HS_USB_Init();
MX_SPI1_Init();
MX_ETH_Init();
MX_I2C2_Init();
/* USER CODE BEGIN 2 */
/* USER CODE END 2 */
/* Init scheduler */
osKernelInitialize();
Could you please suggest what I am doing wrongly?
Finally found the solution. I summarise some issues I had:
HAL_I2C_Master_Transmit_DMA(i2cHandler, MPUADDR, i2cData, 2);
The Deliverable data: The deliverable data must be global variable for DMA, otherwise when I am leaving the function/ or calling a destructor of the object the memory is freed and the DMA aburts.
The delivery target in my case the i2cHandler must not be the copy of the original structure/objetc, because the callback function addresses are checked from parallel interrupts based on the original object and updated in the caling HAL_I2C_Master_Transmit_DMA function. If incorrect ending up in a loop in the HAL_I2C_EV_IRQHandler because teh hi2c->XferISR is alvais NULL.
What to check: If the I2C handler is exacly the same in the interrupt handler from the function or the name is different, but the new one only uses a pointer to the old one. In my case thy where not the same from the myin called hi2c1 and the function i2cHandler.
[Name from the main]https://i.stack.imgur.com/OhqJT.png
The solution for me was to use the copy of the pointer only not the contant of the hendler.[Copy of the struct]https://i.stack.imgur.com/JgmTU.png
With the STM32 H7 boards there is a memory allocation issue which is explaind with the solution in the below article.
https://community.st.com/s/article/FAQ-DMA-is-not-working-on-STM32H7-devices

The adc should be able to work well for this kind of applications?

I've been trying to process speech on a stm32f407ve development board for some time now, which makes me wonder if the ADC is really set up to precisely sample the values. CMSIS FFT Functions. But when I try to couple it with the ADC in continuous conversion to sample a sine signal, it doesn't seem to sample well periodically. I put a sine signal into it from a frequency test of a 1khz sine wave from an internet video with a plug that I take out of some headphones, which by the way I already tested that it works correctly with an oscilloscope. So... this one from the development board is obviously not from a DSP but its ADC should work correctly for this type of application? Here is my code, obviously I made sure that the test was emitting voltage before the debug.
#include "main.h"
#include "arm_math.h"
#include "arm_const_structs.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
#define Fs 4096;
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
ADC_HandleTypeDef hadc1;
/* USER CODE BEGIN PV */
#define SIGNAL_BUFFER_LENGTH 4096
float signalBuffer[2*SIGNAL_BUFFER_LENGTH];
float fftBuffer[2*SIGNAL_BUFFER_LENGTH];
float magnitudes[SIGNAL_BUFFER_LENGTH];
/* USER CODE END PV */
uint32_t k;
uint32_t cont1,cont2;
uint32_t start;
uint32_t stopi;
uint32_t delta;
float32_t maxValue; /* Max FFT value is stored here */
uint32_t maxIndex;
float frecuencia=10.0;
float32_t Ts;
float tiempo;
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_ADC1_Init(void);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/**
* #brief The application entry point.
* #retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
#define ARM_CM_DEMCR (*(uint32_t*)0xE000EDFC)
#define ARM_CM_DWT_CTRL (*(uint32_t*)0xE0001000)
#define ARM_CM_DWT_CYCCNT (*(uint32_t*)0xE0001004)
if(ARM_CM_DWT_CTRL !=0){
ARM_CM_DEMCR |= 1<<24;
ARM_CM_DWT_CYCCNT =0;
ARM_CM_DWT_CTRL |= 1<<0;
}
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_ADC1_Init();
/* USER CODE BEGIN 2 */
Ts=1.0/(float)Fs;
HAL_ADC_Start(&hadc1);
for(k=0;k<2*SIGNAL_BUFFER_LENGTH;k+=2 )
{
signalBuffer[k]=HAL_ADC_GetValue(&hadc1);
}
k++;
//signalBuffer[0]=0;
//start= ARM_CM_DWT_CYCCNT;
arm_cfft_f32(&arm_cfft_sR_f32_len4096,signalBuffer,0,1);
signalBuffer[0]=0;
arm_cmplx_mag_f32(signalBuffer,magnitudes,4096);
arm_max_f32(magnitudes, 4096, &maxValue, &maxIndex);
//stopi = ARM_CM_DWT_CYCCNT;
//delta=stopi-start;
//tiempo=delta/8.0E07*1000.0;
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
You are just calling the function to take a single reading over and over in a loop. There is no reason to think that each pass through this loop will take the same amount of time. You need to set the ADC to be triggered from a timer in order to have some kind of reproducible sample rate.
In general the internal ADC is not of suitable quality for audio use. There is an external audio codec fitted to this board, look at the example projects in the Stm32CubeF4 package.

Create an array at different memory locations for each loop

Good morning everyone,
I am currently working on a data acquisition project, where I have to read sensors (at around 10 kHz) and transmit the data via Wi-Fi and the MQTT-protocol. I am using an ESP32 for both of these tasks.
One core is doing the sensor reading and the other core does the transmitting stuff. I also use the FreeRTOS for this.
Now, I want to pass the data as efficient as possible between the task. Currently I'm using the xQueue function built in the FreeRtos. I pass pointers in the Queue which point to an array, where one datapackage is stored.
Task one:
*sensor reading*
for(xx)
{
data_array[x] = sensor_data;
}
if {packageSize == 120}
{
xQueueSend(Queue1, &data_pointer, 0);
}
________________________
Task two:
if( uxQueueMessagesWaiting(Queue1) >= 1)
{
xQueueReceive(Queue1, &received_pointer, 0);
memcpy(data_send, received_pointer, packageSize);
* MQTT-Client sending data_send *
}
You see, my problem isn't the creation of the array with different pointers. The sensor reading task needs to create an array for every package, without overwritting the previous one.
My initial idea was to use the new and delete combination but it gave me strange results.
Is there any way I can change the location of the array on the memory at every loop of task one?
EDIT:
/* general variables*/
const int len = 150;
uint8_t data_received[len];
uint8_t data_send[len];
uint8_t *queue_pointer = 0;
uint8_t *received_pointer = 0;
uint8_t *to_delete_pointer = 0;
uint8_t dummy_data = 0;
int v = 0;
/* multithreading variables */
TaskHandle_t SPI_COM;
TaskHandle_t WIFI;
QueueHandle_t buffer_daten;
/* --------------------- Fake-SPI-Kommunikation auf Core 1 -------------------- */
void SPI_COM_code(void *pvParameters)
{
for (;;)
{
while (v <= 10000)
{
//queue_pointer = new int[len]; // creates a new array
queue_pointer = data_received;
queue_pointer[dummy_data] = dummy_data;
dummy_data++;
delayMicroseconds(100); // Dummy-Interrupt
if (dummy_data == len - 1)
{
dummy_data = 0;
xQueueSend(buffer_daten, &queue_pointer, 0);
v++;
}
}
}
}
/* --------------------- WiFi-Übertragung auf Core 0 --------------------- */
void WIFI_code(void *pvParameters)
{
for (;;)
{
//MQTT_connect();
if (uxQueueMessagesWaiting(buffer_daten) > 0)
{
xQueueReceive(buffer_daten, &received_pointer, 0);
to_delete_pointer = received_pointer;
memcpy(data_send, received_pointer, len);
// Data gets published by MQTT-Client
delayMicroseconds(12);
//delete[] to_delete_pointer; // deletes array, which was send
}
}
}
/* ----------------------------------- Setup ---------------------------------- */
void setup()
{
disableCore0WDT(); // <----- MÖGLICHE PROBLEMQUELLE
Serial.begin(115200);
buffer_daten = xQueueCreate(1000, sizeof(int));
xTaskCreatePinnedToCore(
SPI_COM_code, /* Task function. */
"SPI_COM", /* name of task. */
10000, /* Stack size of task */
NULL, /* parameter of the task */
1, /* priority of the task */
&SPI_COM, /* Task handle to keep track of created task */
1); /* pin task to core 0 */
delay(500);
xTaskCreatePinnedToCore(
WIFI_code, /* Task function. */
"WIFI", /* name of task. */
10000, /* Stack size of task */
NULL, /* parameter of the task */
2, /* priority of the task */
&WIFI, /* Task handle to keep track of created task */
0); /* pin task to core 1 */
delay(500);
}
void loop()
{
}
I would suggest you use a RTOS Message Buffers for this task
With this functions you could copy your array into the buffer and the second task could get it, when the data is available.
In both cases the consumer task should use the timeout '0' to request the data.
If the MQTT task is faster than the data acquisition (and it should be or your buffers will overflow sooner or later) this will lead to invalid pointers:
xQueueReceive(buffer_daten, &received_pointer, 0);
If the is no data available the function will return immediately giving you an invalid received_pointer.
You should either check the return value of xQueueReceive or set the timeout to portMAX_DELAY.

In C, can't change a struct attribute except using #define val

In Minix 3.1.2a I've a struct "struct proc" where the PCB of any process stored,
but I've a problem when adding new attribute "p_currenthash" in the code below to this struct. I can't change its value except using a constant defined by #define directive; otherwise, the system stops responding. For clarity here is the structure:
struct proc {
struct stackframe_s p_reg; /* process' registers saved in stack frame */
#if (CHIP == INTEL)
reg_t p_ldt_sel; /* selector in gdt with ldt base and limit */
struct segdesc_s p_ldt[2+NR_REMOTE_SEGS]; /* CS, DS and remote segments */
#endif
#if (CHIP == M68000)
/* M68000 specific registers and FPU details go here. */
#endif
proc_nr_t p_nr; /* number of this process (for fast access) */
struct priv *p_priv; /* system privileges structure */
short p_rts_flags; /* process is runnable only if zero */
short p_misc_flags; /* flags that do suspend the process */
char p_priority; /* current scheduling priority */
char p_max_priority; /* maximum scheduling priority */
char p_ticks_left; /* number of scheduling ticks left */
char p_quantum_size; /* quantum size in ticks */
struct mem_map p_memmap[NR_LOCAL_SEGS]; /* memory map (T, D, S) */
clock_t p_user_time; /* user time in ticks */
clock_t p_sys_time; /* sys time in ticks */
struct proc *p_nextready; /* pointer to next ready process */
struct proc *p_caller_q; /* head of list of procs wishing to send */
struct proc *p_q_link; /* link to next proc wishing to send */
message *p_messbuf; /* pointer to passed message buffer */
int p_getfrom_e; /* from whom does process want to receive? */
int p_sendto_e; /* to whom does process want to send? */
sigset_t p_pending; /* bit map for pending kernel signals */
char p_name[P_NAME_LEN]; /* name of the process, including \0 */
int p_endpoint; /* endpoint number, generation-aware */
#if DEBUG_SCHED_CHECK
int p_ready, p_found;
#endif
char p_currenthash; /* hash */
};
Now, suppose I want to set its value. Initially I use the constant defined below.
#define NONE -1
register struct proc *rp;
rp->p_currenthash=NONE;
That works fine, but this: rp->p_currenthash=0 ; will cause the program to stop responding.
Any suggestions will be appreciated
Here's the main initialization in main():
/* Start the ball rolling. */
struct boot_image *ip; /* boot image pointer */
register struct proc *rp; /* process pointer */
register struct priv *sp; /* privilege structure pointer */
register int i, s;
int hdrindex; /* index to array of a.out headers */
phys_clicks text_base;
vir_clicks text_clicks, data_clicks;
reg_t ktsb; /* kernel task stack base */
struct exec e_hdr; /* for a copy of an a.out header */
/* Initialize the interrupt controller. */
intr_init(1);
/* Clear the process table. Anounce each slot as empty and set up mappings
* for proc_addr() and proc_nr() macros. Do the same for the table with
* privilege structures for the system processes.
*/
for (rp = BEG_PROC_ADDR, i = -NR_TASKS; rp < END_PROC_ADDR; ++rp, ++i) {
rp->p_rts_flags = SLOT_FREE; /* initialize free slot */
rp->p_nr = i; /* proc number from ptr */
rp->p_currenthash=NONE;
rp->p_endpoint = _ENDPOINT(0, rp->p_nr); /* generation no. 0 */
(pproc_addr + NR_TASKS)[i] = rp; /* proc ptr from number */
}
for (sp = BEG_PRIV_ADDR, i = 0; sp < END_PRIV_ADDR; ++sp, ++i) {
sp->s_proc_nr = NONE; /* initialize as free */
sp->s_id = i; /* priv structure index */
ppriv_addr[i] = sp; /* priv ptr from number */
}
/* Set up proc table entries for processes in boot image. The stacks of the
* kernel tasks are initialized to an array in data space. The stacks
* of the servers have been added to the data segment by the monitor, so
* the stack pointer is set to the end of the data segment. All the
* processes are in low memory on the 8086. On the 386 only the kernel
* is in low memory, the rest is loaded in extended memory.
*/
/* Task stacks. */
ktsb = (reg_t) t_stack;
for (i=0; i < NR_BOOT_PROCS; ++i) {
ip = &image[i]; /* process' attributes */
rp = proc_addr(ip->proc_nr); /* get process pointer */
ip->endpoint = rp->p_endpoint; /* ipc endpoint */
rp->p_max_priority = ip->priority; /* max scheduling priority */
rp->p_priority = ip->priority; /* current priority */
rp->p_quantum_size = ip->quantum; /* quantum size in ticks */
rp->p_ticks_left = ip->quantum; /* current credit */
strncpy(rp->p_name, ip->proc_name, P_NAME_LEN); /* set process name */
(void) get_priv(rp, (ip->flags & SYS_PROC)); /* assign structure */
priv(rp)->s_flags = ip->flags; /* process flags */
priv(rp)->s_trap_mask = ip->trap_mask; /* allowed traps */
priv(rp)->s_call_mask = ip->call_mask; /* kernel call mask */
priv(rp)->s_ipc_to.chunk[0] = ip->ipc_to; /* restrict targets */
if (iskerneln(proc_nr(rp))) { /* part of the kernel? */
if (ip->stksize > 0) { /* HARDWARE stack size is 0 */
rp->p_priv->s_stack_guard = (reg_t *) ktsb;
*rp->p_priv->s_stack_guard = STACK_GUARD;
}
ktsb += ip->stksize; /* point to high end of stack */
rp->p_reg.sp = ktsb; /* this task's initial stack ptr */
text_base = kinfo.code_base >> CLICK_SHIFT;
/* processes that are in the kernel */
hdrindex = 0; /* all use the first a.out header */
} else {
hdrindex = 1 + i-NR_TASKS; /* servers, drivers, INIT */
}
/* The bootstrap loader created an array of the a.out headers at
* absolute address 'aout'. Get one element to e_hdr.
*/
phys_copy(aout + hdrindex * A_MINHDR, vir2phys(&e_hdr),
(phys_bytes) A_MINHDR);
/* Convert addresses to clicks and build process memory map */
text_base = e_hdr.a_syms >> CLICK_SHIFT;
text_clicks = (e_hdr.a_text + CLICK_SIZE-1) >> CLICK_SHIFT;
if (!(e_hdr.a_flags & A_SEP)) text_clicks = 0; /* common I&D */
data_clicks = (e_hdr.a_total + CLICK_SIZE-1) >> CLICK_SHIFT;
rp->p_memmap[T].mem_phys = text_base;
rp->p_memmap[T].mem_len = text_clicks;
rp->p_memmap[D].mem_phys = text_base + text_clicks;
rp->p_memmap[D].mem_len = data_clicks;
rp->p_memmap[S].mem_phys = text_base + text_clicks + data_clicks;
rp->p_memmap[S].mem_vir = data_clicks; /* empty - stack is in data */
/* Set initial register values. The processor status word for tasks
* is different from that of other processes because tasks can
* access I/O; this is not allowed to less-privileged processes
*/
rp->p_reg.pc = (reg_t) ip->initial_pc;
rp->p_reg.psw = (iskernelp(rp)) ? INIT_TASK_PSW : INIT_PSW;
/* Initialize the server stack pointer. Take it down one word
* to give crtso.s something to use as "argc".
*/
if (isusern(proc_nr(rp))) { /* user-space process? */
rp->p_reg.sp = (rp->p_memmap[S].mem_vir +
rp->p_memmap[S].mem_len) << CLICK_SHIFT;
rp->p_reg.sp -= sizeof(reg_t);
}
/* Set ready. The HARDWARE task is never ready. */
if (rp->p_nr != HARDWARE) {
rp->p_rts_flags = 0; /* runnable if no flags */
lock_enqueue(rp); /* add to scheduling queues */
} else {
rp->p_rts_flags = NO_MAP; /* prevent from running */
}
/* Code and data segments must be allocated in protected mode. */
alloc_segments(rp);
}
register struct proc *rp;
rp->p_currenthash=NONE;
rp is an uninitialized pointer; it isn't pointing to a valid struct proc object, and so dereferencing it leads to undefined behavior. The fact that this didn't crash when assigning -1 was pure luck. (bad luck, because it misled you to believe you were doing something meaningful)
acutually the problem not solved ,first the "p_currenthash" initialized in the main as shown above ,later in a function called pic_proc ,i've this code :
register struct proc **xpp; /* iterate over queue */
register struct proc *rp; /* process to run */
int q;
for (q=0; q < NR_SCHED_QUEUES; q++)
{
if ( (rp = rdy_head[q]) != NIL_PROC)
{
for (xpp = &rdy_head[q]; *xpp != NIL_PROC; xpp = &(*xpp)->p_nextready)
{
if ((*xpp)->p_currenthash==NONE)
{
pick_val++;
}
}
}
}
that code works fine ,no inside the if if i changed the attribute "p_currenthash" the problem ocuured as bellow:
register struct proc **xpp; /* iterate over queue */
register struct proc *rp; /* process to run */
int q;
for (q=0; q < NR_SCHED_QUEUES; q++)
{
if ( (rp = rdy_head[q]) != NIL_PROC)
{
for (xpp = &rdy_head[q]; *xpp != NIL_PROC; xpp = &(*xpp)->p_nextready)
{
if ((*xpp)->p_currenthash==NONE)
{
pick_val++;
(*xpp)->p_currenthash=1;
}
}
}
}
i really can't realize the problem.

How to save a JPEG file from RGB buffer in the easiest way (VS2008 C++)?

I've seen many guides and there always seem to be something missing.
If someone can post here a complete "idiot's" guide it will be great!
In any case, I will provide here what I've tried to do so far:
I've tried to download libjpeg and got confused with all the configerations needed and makefiles.
I've downloaded libjpeg-turbo, and currently I'm linking (Successfully) to jpeg.lib and including "jpeglib.h".
I'm using this code that I found on the web (after doing some small modifications to it cause it won't compile), which gives me run-time error ("a buffer overrun has occured") when the block ends (when the last '}' is called)
void TestModel3D::write_JPEG_file(char * filename, int quality, int w, int h)
{
/* This struct contains the JPEG compression parameters and pointers to
* working space (which is allocated as needed by the JPEG library).
* It is possible to have several such structures, representing multiple
* compression/decompression processes, in existence at once. We refer
* to any one struct (and its associated working data) as a "JPEG object".
*/
struct jpeg_compress_struct cinfo;
/* This struct represents a JPEG error handler. It is declared separately
* because applications often want to supply a specialized error handler
* (see the second half of this file for an example). But here we just
* take the easy way out and use the standard error handler, which will
* print a message on stderr and call exit() if compression fails.
* Note that this struct must live as long as the main JPEG parameter
* struct, to avoid dangling-pointer problems.
*/
struct jpeg_error_mgr jerr;
/* More stuff */
FILE * outfile; /* target file */
JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */
int row_stride; /* physical row width in image buffer */
/* Step 1: allocate and initialize JPEG compression object */
/* We have to set up the error handler first, in case the initialization
* step fails. (Unlikely, but it could happen if you are out of memory.)
* This routine fills in the contents of struct jerr, and returns jerr's
* address which we place into the link field in cinfo.
*/
cinfo.err = jpeg_std_error(&jerr);
/* Now we can initialize the JPEG compression object. */
jpeg_create_compress(&cinfo);
/* Step 2: specify data destination (eg, a file) */
/* Note: steps 2 and 3 can be done in either order. */
/* Here we use the library-supplied code to send compressed data to a
* stdio stream. You can also write your own code to do something else.
* VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
* requires it in order to write binary files.
*/
if ((outfile = fopen(filename, "wb")) == NULL) {
fprintf(stderr, "can't open %s\n", filename);
// exit(1);
}
jpeg_stdio_dest(&cinfo, outfile);
/* Step 3: set parameters for compression */
/* First we supply a description of the input image.
* Four fields of the cinfo struct must be filled in:
*/
cinfo.client_data = (void*)&outfile;
cinfo.image_width = w; /* image width and height, in pixels */
cinfo.image_height = h;
cinfo.input_components = 3; /* # of color components per pixel */
cinfo.in_color_space = JCS_RGB; /* colorspace of input image */
/* Now use the library's routine to set default compression parameters.
* (You must set at least cinfo.in_color_space before calling this,
* since the defaults depend on the source color space.)
*/
jpeg_set_defaults(&cinfo);
/* Now you can set any non-default parameters you wish to.
* Here we just illustrate the use of quality (quantization table) scaling:
*/
jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */);
/* Step 4: Start compressor */
/* TRUE ensures that we will write a complete interchange-JPEG file.
* Pass TRUE unless you are very sure of what you're doing.
*/
jpeg_start_compress(&cinfo, TRUE);
/* Step 5: while (scan lines remain to be written) */
/* jpeg_write_scanlines(...); */
/* Here we use the library's state variable cinfo.next_scanline as the
* loop counter, so that we don't have to keep track ourselves.
* To keep things simple, we pass one scanline per call; you can pass
* more if you wish, though.
*/
row_stride = w * 3; /* JSAMPLEs per row in image_buffer */
const int BYTE_SIZE = (160 * 3);
UInt8 lineBuffer[BYTE_SIZE];
for (int y = 0; y < h; y++)
{
int j = 0;
for (int x=0; x < w; x++)
{
//printf("j: %d.\n", (x*3));
float r,g,b;
//if (CVFAILED(grabImage->GetPixel(x,y,r,g,b)))
//{
//printf("GetPixel Error!\n");
//}
//else
//{
lineBuffer[x * 3] = r;
lineBuffer[x * 3 + 1] = g;
lineBuffer[x * 3 + 2] = b;
//}
}
row_pointer[0] = & lineBuffer[0];
(void) jpeg_write_scanlines(&cinfo, row_pointer, 1);
}
/* Step 6: Finish compression */
//jpeg_finish_compress(&cinfo);
/* After finish_compress, we can close the output file. */
fclose(outfile);
/* Step 7: release JPEG compression object */
/* This is an important step since it will release a good deal of memory. */
jpeg_destroy_compress(&cinfo);
/* And we're done! */
}