zc030x_isochron.c

AVR单片机视频采集,主要是为了在自主导航的微型机器人里使用。 获取图像后

/* Implementation file for isochronous */
/* Zc030x     -- Driver --      Zc030x */
/* This file is under GPL              */
/* Copyright :
         Martin     Braun         
         Cyril      Russo
---------------------------------------*/

/* Include the header */
#include "zc030x_isochron.h"
/* Include JPEG decoding */
#include "zc030x_jpeg.h"
/* Include allocating urbs */
#include "zc030x_mm.h"
/* Include V4L data */
#include "zc030x_v4l.h"
/* Include gamma things */
#include "zc030x_cameras.h"

// for 2.4 compatibility
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
#define URB_ISO_ASAP USB_ISO_ASAP
#endif 

/* Define the implementation */
DECLARE_TASKLET (decodetasklet,decode_tasklet,(unsigned long)NULL);

/* Return the next free frame to grab into */
zc030x_frame * zc030x_get_free_frame_tmp(struct usb_zc030x *dev)
{
	int iFrameNext;
    /* Return object */
    zc030x_frame * frame=NULL;

	if( dev->frame[dev->curframe].GrabState == FRAME_ERROR) 
    {
        /* recycle the bad one */
		frame=&dev->frame[dev->curframe];
	} else 
    {
		/* Cycle through the frame buffer looking for a free frame to overwrite */
		iFrameNext = (dev->curframe + 1) % ZC030X_NUMFRAMES;
        
		while(frame==NULL && iFrameNext!=(dev->curframe))
		{
            if (dev->frame[iFrameNext].GrabState == FRAME_READY  ||
                dev->frame[iFrameNext].GrabState == FRAME_UNUSED ||
                dev->frame[iFrameNext].GrabState == FRAME_ERROR)
            {
                dev->curframe = iFrameNext;
                frame = &dev->frame[iFrameNext];
                break;
            }
            else
            {
                iFrameNext=(iFrameNext + 1) % ZC030X_NUMFRAMES;
            }
		}
	}

	if(frame==NULL)
	{
		PDEBUG(3,"Can't find a free frame to grab into...using next. "
		         "This is caused by the application not reading fast enough.");
		dev->curframe=(dev->curframe+1)%ZC030X_NUMFRAMES;
		frame = &dev->frame[dev->curframe];
	}


    /* Change its state */
    frame->GrabState = FRAME_GRABBING;
    /* Reset its available compressed size */
    frame->CompLen = 0;
    frame->SeqNumber = 0;
    frame->ScanState = STATE_LINES;
    frame->last_packet=-1;
    /* Release it */
    up(&frame->Lock);
    
    /* Okay, return */
    up(&dev->buf_lock);
    return frame;
}


/* Return the next free frame to grab into */
zc030x_frame * zc030x_get_free_frame_new(struct usb_zc030x *dev)
{
    /* Iterator */
    int    iFrameNext, iNbFrame = 0;
    /* Return object */
    zc030x_frame * frame=NULL;

    /* Check argument */
    if (dev == NULL)
    {
        PDEBUG(2, "[ZCISO] Null argument to this function, exiting!");
        dev->curframe = -1;
        return NULL;
    }
    
    /* Wait until the frame buffer is unlocked */
    if(down_trylock(&dev->buf_lock)) 
    {   
        dev->curframe = -1;
        return NULL;
    }
    
       
    /* Check if a frame is trashed */
    for (iFrameNext = 0; iFrameNext < ZC030X_NUMFRAMES; iFrameNext++)
    {
        /* Lock the frame to look to it*/
        down(&dev->frame[iFrameNext].Lock);
        if (dev->frame[iFrameNext].GrabState == FRAME_ERROR)
        {
            up(&dev->frame[iFrameNext].Lock);
            frame = &dev->frame[iFrameNext];
            dev->curframe = iFrameNext;
            iNbFrame ++;
            break;
        }
        if (dev->frame[iFrameNext].GrabState == FRAME_READY)
        {
            up(&dev->frame[iFrameNext].Lock);
            frame = &dev->frame[iFrameNext];
            dev->curframe = iFrameNext;
            iNbFrame ++;
            break;
        }
        /* Unlock it */
        up(&dev->frame[iFrameNext].Lock);
    }
    

    /* Check if we haven't found a frame */
    if (frame == NULL)
    {
        PDEBUG(4,"ERROR: Can't find a free frame to grab into...using a waiting-to-be-presented frame. ");
        
        /* Check for an unused frame */
        for (iFrameNext = 0; iFrameNext < ZC030X_NUMFRAMES; iFrameNext++)
        {
            /* Lock the frame to look to it*/
            down(&dev->frame[iFrameNext].Lock);
            if (dev->frame[iFrameNext].GrabState == FRAME_DONE)
            {
                up(&dev->frame[iFrameNext].Lock);
                frame = &dev->frame[iFrameNext];
                dev->curframe = iFrameNext;
                iNbFrame ++;
                break;
            }
            /* Unlock it */
            up(&dev->frame[iFrameNext].Lock);
        }
        
        /* Not found a done frame, so leave now */
        if (frame == NULL)
        {
            PDEBUG(4,"ERROR: Can't find a free frame to grab into...using an unused frame. ");
            
            /* Check for an unused frame */
            for (iFrameNext = 0; iFrameNext < ZC030X_NUMFRAMES; iFrameNext++)
            {
                /* Lock the frame to look to it*/
                down(&dev->frame[iFrameNext].Lock);
                if (dev->frame[iFrameNext].GrabState == FRAME_UNUSED)
                {
                    up(&dev->frame[iFrameNext].Lock);
                    frame = &dev->frame[iFrameNext];
                    dev->curframe = iFrameNext;
                    iNbFrame ++;
                    break;
                }
                /* Unlock it */
                up(&dev->frame[iFrameNext].Lock);
            }

            if (frame == NULL)
            {
                /* Cannot get the frame now, so release the driver */
                up(&dev->buf_lock);
                dev->curframe = -1;
                return NULL;
            }
        }
    }
    
    /* Set the frame state */
    /* So lock the frame */
    if(down_trylock(&frame->Lock))
    {   
        /* Cannot get the frame now, so release the driver */
        up(&dev->buf_lock);
        dev->curframe = -1;
        return NULL;
    }

    /* Change its state */
    frame->GrabState = FRAME_GRABBING;
    /* Reset its available compressed size */
    frame->CompLen = 0;
    frame->SeqNumber = 0;
    frame->ScanState = STATE_LINES;
    frame->last_packet=-1;
    /* Release it */
    up(&frame->Lock);
    
    /* Okay, return */
    up(&dev->buf_lock);
    return frame;
}

/* Return the next free frame to grab into */
zc030x_frame * zc030x_get_current_frame(struct usb_zc030x *dev)
{
    /* Check argument */
    if (dev == NULL)
    {
        PDEBUG(2, "[ZCISO] Null argument to this function, exiting!");
        return NULL;
    }
    
    if (dev->curframe == -1)
    {
        return NULL;
    } else
        return &dev->frame[dev->curframe]; 
    
}

/* Tasklet main function */
void decode_tasklet (unsigned long ptr)
{       
    /* Error object */
    int err;

    /* Lock the frame we get */
    zc030x_frame * pFrame = (zc030x_frame *)ptr;
    PDEBUG(4, "decode_tasklet %p", pFrame);
    
    if (pFrame == NULL)
    {
        PDEBUG(2, "Decoding tasklet called without argument - exiting"); 
        return;
    }
    
    if (down_trylock(&pFrame->Lock)) 
    {
        PDEBUG(2, "Someone else is trying to access this frame - exiting"); 
        return;
    }

    /* Debug the received frame */
    PDEBUG(4, "Got Header(%dx%d) frame", pFrame->HeaderWidth, pFrame->HeaderHeight);
    /* And decode it */
    err = zc030x_decode_frame( pFrame, pFrame->Format);
    PDEBUG(4, "zc030x_decodeFrame returned with code=%d",err);
    
    /* Check return */
    if (err == 0)
    {
        PDEBUG(2, "frame decoding failed (%d)", err);
        /* Change its state */
        pFrame->GrabState = FRAME_ERROR;
    } else
    {
        /* Change its state */
        pFrame->GrabState = FRAME_DONE;
    }
   
    /* Release the lock */
    up(&pFrame->Lock);
    
    /* Call next tasklet if needed */
    if (waitqueue_active(&pFrame->wq))
        wake_up_interruptible(&pFrame->wq);
    
    /* Debug this */
    
}




/* Move the isochronous data received to decoder */
int zc030x_move_data (struct usb_zc030x *dev, struct urb *urb)
{
    /* Iterator */
    int i;
    /* The data length */
    int datalength;
    /* The status */
    int st;
    /* Total length of this buffer */
    int totlen = 0;
    /* Next packet buffer */
    unsigned char *cData;  
    /* Frame pointer */
    zc030x_frame * frame = NULL; //Pointer to frame data
    
    /* Lock the buffer pool */
    if(down_trylock(&dev->buf_lock)) 
        return -ENOBUFS;
    
    /* Verify the V4L buffers still exist */
    if(!dev->fbuf)
    {
        up(&dev->buf_lock);
        return -ENOBUFS;
    }
    
    /* Release the buffer lock */
    up(&dev->buf_lock);

    /* Get pointer to a frame */
    frame = zc030x_get_current_frame(dev);
    if (frame == NULL)
    {
        return -ENOBUFS;
    }
    
        
    /* Now copy the packet to the frame */
    for (i = 0; i < urb->number_of_packets; i++)
    {
        datalength = urb->iso_frame_desc[i].actual_length;
                st = urb->iso_frame_desc[i].status;
        
        /* Debug errors if any */
        if (st)