usbvideo.c

h内核

	up(&uvd->lock);	
	return count;
}

/*
 * Make all of the blocks of data contiguous
 */
static int usbvideo_CompressIsochronous(struct uvd *uvd, struct urb *urb)
{
	char *cdata;
	int i, totlen = 0;

	for (i = 0; i < urb->number_of_packets; i++) {
		int n = urb->iso_frame_desc[i].actual_length;
		int st = urb->iso_frame_desc[i].status;

		cdata = urb->transfer_buffer + urb->iso_frame_desc[i].offset;

		/* Detect and ignore errored packets */
		if (st < 0) {
			if (uvd->debug >= 1)
				err("Data error: packet=%d. len=%d. status=%d.", i, n, st);
			uvd->stats.iso_err_count++;
			continue;
		}

		/* Detect and ignore empty packets */
		if (n <= 0) {
			uvd->stats.iso_skip_count++;
			continue;
		}
		totlen += n;	/* Little local accounting */
		RingQueue_Enqueue(&uvd->dp, cdata, n);
	}
	return totlen;
}

static void usbvideo_IsocIrq(struct urb *urb, struct pt_regs *regs)
{
	int i, ret, len;
	struct uvd *uvd = urb->context;

	/* We don't want to do anything if we are about to be removed! */
	if (!CAMERA_IS_OPERATIONAL(uvd))
		return;
#if 0
	if (urb->actual_length > 0) {
		info("urb=$%p status=%d. errcount=%d. length=%d.",
		     urb, urb->status, urb->error_count, urb->actual_length);
	} else {
		static int c = 0;
		if (c++ % 100 == 0)
			info("No Isoc data");
	}
#endif

	if (!uvd->streaming) {
		if (uvd->debug >= 1)
			info("Not streaming, but interrupt!");
		return;
	}
	
	uvd->stats.urb_count++;
	if (urb->actual_length <= 0)
		goto urb_done_with;

	/* Copy the data received into ring queue */
	len = usbvideo_CompressIsochronous(uvd, urb);
	uvd->stats.urb_length = len;
	if (len <= 0)
		goto urb_done_with;

	/* Here we got some data */
	uvd->stats.data_count += len;
	RingQueue_WakeUpInterruptible(&uvd->dp);

urb_done_with:
	for (i = 0; i < FRAMES_PER_DESC; i++) {
		urb->iso_frame_desc[i].status = 0;
		urb->iso_frame_desc[i].actual_length = 0;
	}
	urb->status = 0;
	urb->dev = uvd->dev;
	ret = usb_submit_urb (urb, GFP_KERNEL);
	if(ret)
		err("usb_submit_urb error (%d)", ret);
	return;
}

/*
 * usbvideo_StartDataPump()
 *
 * History:
 * 27-Jan-2000 Used ibmcam->iface, ibmcam->ifaceAltActive instead
 *             of hardcoded values. Simplified by using for loop,
 *             allowed any number of URBs.
 */
static int usbvideo_StartDataPump(struct uvd *uvd)
{
	struct usb_device *dev = uvd->dev;
	int i, errFlag;

	if (uvd->debug > 1)
		info("%s($%p)", __FUNCTION__, uvd);

	if (!CAMERA_IS_OPERATIONAL(uvd)) {
		err("%s: Camera is not operational", __FUNCTION__);
		return -EFAULT;
	}
	uvd->curframe = -1;

	/* Alternate interface 1 is is the biggest frame size */
	i = usb_set_interface(dev, uvd->iface, uvd->ifaceAltActive);
	if (i < 0) {
		err("%s: usb_set_interface error", __FUNCTION__);
		uvd->last_error = i;
		return -EBUSY;
	}
	if (VALID_CALLBACK(uvd, videoStart))
		GET_CALLBACK(uvd, videoStart)(uvd);
	else 
		err("%s: videoStart not set", __FUNCTION__);

	/* We double buffer the Iso lists */
	for (i=0; i < USBVIDEO_NUMSBUF; i++) {
		int j, k;
		struct urb *urb = uvd->sbuf[i].urb;
		urb->dev = dev;
		urb->context = uvd;
		urb->pipe = usb_rcvisocpipe(dev, uvd->video_endp);
		urb->interval = 1;
		urb->transfer_flags = URB_ISO_ASAP;
		urb->transfer_buffer = uvd->sbuf[i].data;
		urb->complete = usbvideo_IsocIrq;
		urb->number_of_packets = FRAMES_PER_DESC;
		urb->transfer_buffer_length = uvd->iso_packet_len * FRAMES_PER_DESC;
		for (j=k=0; j < FRAMES_PER_DESC; j++, k += uvd->iso_packet_len) {
			urb->iso_frame_desc[j].offset = k;
			urb->iso_frame_desc[j].length = uvd->iso_packet_len;
		}
	}

	/* Submit all URBs */
	for (i=0; i < USBVIDEO_NUMSBUF; i++) {
		errFlag = usb_submit_urb(uvd->sbuf[i].urb, GFP_KERNEL);
		if (errFlag)
			err("%s: usb_submit_isoc(%d) ret %d", __FUNCTION__, i, errFlag);
	}

	uvd->streaming = 1;
	if (uvd->debug > 1)
		info("%s: streaming=1 video_endp=$%02x", __FUNCTION__, uvd->video_endp);
	return 0;
}

/*
 * usbvideo_StopDataPump()
 *
 * This procedure stops streaming and deallocates URBs. Then it
 * activates zero-bandwidth alt. setting of the video interface.
 *
 * History:
 * 22-Jan-2000 Corrected order of actions to work after surprise removal.
 * 27-Jan-2000 Used uvd->iface, uvd->ifaceAltInactive instead of hardcoded values.
 */
static void usbvideo_StopDataPump(struct uvd *uvd)
{
	int i, j;

	if (uvd->debug > 1)
		info("%s($%p)", __FUNCTION__, uvd);

	if ((uvd == NULL) || (!uvd->streaming) || (uvd->dev == NULL))
		return;

	/* Unschedule all of the iso td's */
	for (i=0; i < USBVIDEO_NUMSBUF; i++) {
		usb_kill_urb(uvd->sbuf[i].urb);
	}
	if (uvd->debug > 1)
		info("%s: streaming=0", __FUNCTION__);
	uvd->streaming = 0;

	if (!uvd->remove_pending) {
		/* Invoke minidriver's magic to stop the camera */
		if (VALID_CALLBACK(uvd, videoStop))
			GET_CALLBACK(uvd, videoStop)(uvd);
		else 
			err("%s: videoStop not set", __FUNCTION__);

		/* Set packet size to 0 */
		j = usb_set_interface(uvd->dev, uvd->iface, uvd->ifaceAltInactive);
		if (j < 0) {
			err("%s: usb_set_interface() error %d.", __FUNCTION__, j);
			uvd->last_error = j;
		}
	}
}

/*
 * usbvideo_NewFrame()
 *
 * History:
 * 29-Mar-00 Added copying of previous frame into the current one.
 * 6-Aug-00  Added model 3 video sizes, removed redundant width, height.
 */
static int usbvideo_NewFrame(struct uvd *uvd, int framenum)
{
	struct usbvideo_frame *frame;
	int n;

	if (uvd->debug > 1)
		info("usbvideo_NewFrame($%p,%d.)", uvd, framenum);

	/* If we're not grabbing a frame right now and the other frame is */
	/*  ready to be grabbed into, then use it instead */
	if (uvd->curframe != -1)
		return 0;

	/* If necessary we adjust picture settings between frames */
	if (!uvd->settingsAdjusted) {
		if (VALID_CALLBACK(uvd, adjustPicture))
			GET_CALLBACK(uvd, adjustPicture)(uvd);
		uvd->settingsAdjusted = 1;
	}

	n = (framenum + 1) % USBVIDEO_NUMFRAMES;
	if (uvd->frame[n].frameState == FrameState_Ready)
		framenum = n;

	frame = &uvd->frame[framenum];

	frame->frameState = FrameState_Grabbing;
	frame->scanstate = ScanState_Scanning;
	frame->seqRead_Length = 0;	/* Accumulated in xxx_parse_data() */
	frame->deinterlace = Deinterlace_None;
	frame->flags = 0; /* No flags yet, up to minidriver (or us) to set them */
	uvd->curframe = framenum;

	/*
	 * Normally we would want to copy previous frame into the current one
	 * before we even start filling it with data; this allows us to stop
	 * filling at any moment; top portion of the frame will be new and
	 * bottom portion will stay as it was in previous frame. If we don't
	 * do that then missing chunks of video stream will result in flickering
	 * portions of old data whatever it was before.
	 *
	 * If we choose not to copy previous frame (to, for example, save few
	 * bus cycles - the frame can be pretty large!) then we have an option
	 * to clear the frame before using. If we experience losses in this
	 * mode then missing picture will be black (no flickering).
	 *
	 * Finally, if user chooses not to clean the current frame before
	 * filling it with data then the old data will be visible if we fail
	 * to refill entire frame with new data.
	 */
	if (!(uvd->flags & FLAGS_SEPARATE_FRAMES)) {
		/* This copies previous frame into this one to mask losses */
		int prev = (framenum - 1 + USBVIDEO_NUMFRAMES) % USBVIDEO_NUMFRAMES;
		memmove(frame->data, uvd->frame[prev].data, uvd->max_frame_size);
	} else {
		if (uvd->flags & FLAGS_CLEAN_FRAMES) {
			/* This provides a "clean" frame but slows things down */
			memset(frame->data, 0, uvd->max_frame_size);
		}
	}
	return 0;
}

/*
 * usbvideo_CollectRawData()
 *
 * This procedure can be used instead of 'processData' callback if you
 * only want to dump the raw data from the camera into the output
 * device (frame buffer). You can look at it with V4L client, but the
 * image will be unwatchable. The main purpose of this code and of the
 * mode FLAGS_NO_DECODING is debugging and capturing of datastreams from
 * new, unknown cameras. This procedure will be automatically invoked
 * instead of the specified callback handler when uvd->flags has bit
 * FLAGS_NO_DECODING set. Therefore, any regular build of any driver
 * based on usbvideo can use this feature at any time.
 */
static void usbvideo_CollectRawData(struct uvd *uvd, struct usbvideo_frame *frame)
{
	int n;

	assert(uvd != NULL);
	assert(frame != NULL);

	/* Try to move data from queue into frame buffer */
	n = RingQueue_GetLength(&uvd->dp);
	if (n > 0) {
		int m;
		/* See how much space we have left */
		m = uvd->max_frame_size - frame->seqRead_Length;
		if (n > m)
			n = m;
		/* Now move that much data into frame buffer */
		RingQueue_Dequeue(
			&uvd->dp,
			frame->data + frame->seqRead_Length,
			m);
		frame->seqRead_Length += m;
	}
	/* See if we filled the frame */
	if (frame->seqRead_Length >= uvd->max_frame_size) {
		frame->frameState = FrameState_Done;
		uvd->curframe = -1;
		uvd->stats.frame_num++;
	}
}

static int usbvideo_GetFrame(struct uvd *uvd, int frameNum)
{
	struct usbvideo_frame *frame = &uvd->frame[frameNum];

	if (uvd->debug >= 2)
		info("%s($%p,%d.)", __FUNCTION__, uvd, frameNum);

	switch (frame->frameState) {
        case FrameState_Unused:
		if (uvd->debug >= 2)
			info("%s: FrameState_Unused", __FUNCTION__);
		return -EINVAL;
        case FrameState_Ready:
        case FrameState_Grabbing:
        case FrameState_Error:
        {
		int ntries, signalPending;
	redo:
		if (!CAMERA_IS_OPERATIONAL(uvd)) {
			if (uvd->debug >= 2)
				info("%s: Camera is not operational (1)", __FUNCTION__);
			return -EIO;
		}
		ntries = 0; 
		do {
			RingQueue_InterruptibleSleepOn(&uvd->dp);
			signalPending = signal_pending(current);
			if (!CAMERA_IS_OPERATIONAL(uvd)) {
				if (uvd->debug >= 2)
					info("%s: Camera is not operational (2)", __FUNCTION__);
				return -EIO;
			}
			assert(uvd->fbuf != NULL);
			if (signalPending) {
				if (uvd->debug >= 2)
					info("%s: Signal=$%08x", __FUNCTION__, signalPending);
				if (uvd->flags & FLAGS_RETRY_VIDIOCSYNC) {
					usbvideo_TestPattern(uvd, 1, 0);
					uvd->curframe = -1;
					uvd->stats.frame_num++;
					if (uvd->debug >= 2)
						info("%s: Forced test pattern screen", __FUNCTION__);
					return 0;
				} else {
					/* Standard answer: Interrupted! */
					if (uvd->debug >= 2)
						info("%s: Interrupted!", __FUNCTION__);
					return -EINTR;
				}
			} else {
				/* No signals - we just got new data in dp queue */
				if (uvd->flags & FLAGS_NO_DECODING)
					usbvideo_CollectRawData(uvd, frame);
				else if (VALID_CALLBACK(uvd, processData))
					GET_CALLBACK(uvd, processData)(uvd, frame);
				else 
					err("%s: processData not set", __FUNCTION__);
			}
		} while (frame->frameState == FrameState_Grabbing);
		if (uvd->debug >= 2) {
			info("%s: Grabbing done; state=%d. (%lu. bytes)",
			     __FUNCTION__, frame->frameState, frame->seqRead_Length);
		}
		if (frame->frameState == FrameState_Error) {
			int ret = usbvideo_NewFrame(uvd, frameNum);
			if (ret < 0) {
				err("%s: usbvideo_NewFrame() failed (%d.)", __FUNCTION__, ret);
				return ret;
			}
			goto redo;
		}
		/* Note that we fall through to meet our destiny below */
        }
        case FrameState_Done:
		/*
		 * Do all necessary postprocessing of data prepared in
		 * "interrupt" code and the collecting code above. The
		 * frame gets marked as FrameState_Done by queue parsing code.
		 * This status means that we collected enough data and
		 * most likely processed it as we went through. However
		 * the data may need postprocessing, such as deinterlacing
		 * or picture adjustments implemented in software (horror!)
		 *
		 * As soon as the frame becomes "final" it gets promoted to
		 * FrameState_Done_Hold status where it will remain until the
		 * caller consumed all the video data from the frame. Then
		 * the empty shell of ex-frame is thrown out for dogs to eat.
		 * But we, worried about pets, will recycle the frame!
		 */
		uvd->stats.frame_num++;
		if ((uvd->flags & FLAGS_NO_DECODING) == 0) {
			if (VALID_CALLBACK(uvd, postProcess))
				GET_CALLBACK(uvd, postProcess)(uvd, frame);
			if (frame->flags & USBVIDEO_FRAME_FLAG_SOFTWARE_CONTRAST)
				usbvideo_SoftwareContrastAdjustment(uvd, frame);
		}
		frame->frameState = FrameState_Done_Hold;
		if (uvd->debug >= 2)
			info("%s: Entered FrameState_Done_Hold state.", __FUNCTION__);
		return 0;

	case FrameState_Done_Hold:
		/*
		 * We stay in this state indefinitely until someone external,
		 * like ioctl() or read() call finishes digesting the frame
		 * data. Then it will mark the frame as FrameState_Unused and
		 * it will be released back into the wild to roam freely.
		 */
		if (uvd->debug >= 2)
			info("%s: FrameState_Done_Hold state.", __FUNCTION__);
		return 0;
	}

	/* Catch-all for other cases. We shall not be here. */
	err("%s: Invalid state %d.", __FUNCTION__, frame->frameState);
	frame->frameState = FrameState_Unused;
	return 0;
}

/*
 * usbvideo_DeinterlaceFrame()
 *
 * This procedure deinterlaces the given frame. Some cameras produce
 * only half of scanlines - sometimes only even lines, sometimes only
 * odd lines. The deinterlacing method is stored in frame->deinterlace
 * variable.
 *
 * Here we scan the frame vertically and replace missing scanlines with
 * average between surrounding ones - before and after. If we have no
 * line above then we just copy next line. Similarly, if we need to
 * create a last line then preceding line is used.
 */
void usbvideo_DeinterlaceFrame(struct uvd *uvd, struct usbvideo_frame *frame)
{
	if ((uvd == NULL) || (frame == NULL))
		return;

	if ((frame->deinterlace == Deinterlace_FillEvenLines) ||
	    (frame->deinterlace == Deinterlace_FillOddLines))
	{
		const int v4l_linesize = VIDEOSIZE_X(frame->request) * V4L_BYTES_PER_PIXEL;
		int i = (frame->deinterlace == Deinterlace_FillEvenLines) ? 0 : 1;

		for (; i < VIDEOSIZE_Y(frame->request); i += 2) {
			const unsigned char *fs1, *fs2;
			unsigned char *fd;
			int ip, in, j;	/* Previous and next lines */

			/*
			 * Need to average lines before and after 'i'.
			 * If we go out of bounds seeking those lines then
			 * we point back to existing line.
			 */
			ip = i - 1;	/* First, get rough numbers */
			in = i + 1;

			/* Now validate */
			if (ip < 0)
				ip = in;
			if (in >= VIDEOSIZE_Y(frame->request))
				in = ip;

			/* Sanity check */
			if ((ip < 0) || (in < 0) ||
			    (ip >= VIDEOSIZE_Y(frame->request)) ||
			    (in >= VIDEOSIZE_Y(frame->request)))
			{
				err("Error: ip=%d. in=%d. req.height=%ld.",
				    ip, in, VIDEOSIZE_Y(frame->request));
				break;
			}

			/* Now we need to average lines 'ip' and 'in' to produce line 'i' */
			fs1 = frame->data + (v4l_linesize * ip);
			fs2 = frame->data + (v4l_linesize * in);
			fd = frame->data + (v4l_linesize * i);

			/* Average lines around destination */
			for (j=0; j < v4l_linesize; j++) {
				fd[j] = (unsigned char)((((unsigned) fs1[j]) +
							 ((unsigned)fs2[j])) >> 1);
			}
		}
	}

	/* Optionally display statistics on the screen */
	if (uvd->flags & FLAGS_OVERLAY_STATS)
		usbvideo_OverlayStats(uvd, frame);
}

EXPORT_SYMBOL(usbvideo_DeinterlaceFrame);

/*
 * usbvideo_SoftwareContrastAdjustment()
 *
 * This code adjusts the contrast of the frame, assuming RGB24 format.
 * As most software image processing, this job is CPU-intensive.
 * Get a camera that supports hardware adjustment!
 *
 * History:
 * 09-Feb-2001  Created.
 */
static void usbvideo_SoftwareContrastAdjustment(struct uvd *uvd, 
						struct usbvideo_frame *frame)
{
	int i, j, v4l_linesize;
	signed long adj;
	const int ccm = 128; /* Color correction median - see below */

	if ((uvd == NULL) || (frame == NULL)) {
		err("%s: Illegal call.", __FUNCTION__);
		return;
	}
	adj = (uvd->vpic.contrast - 0x8000) >> 8; /* -128..+127 = -ccm..+(ccm-1)*/
	RESTRICT_TO_RANGE(adj, -ccm, ccm+1);
	if (adj == 0) {
		/* In rare case of no adjustment */
		return;
	}
	v4l_linesize = VIDEOSIZE_X(frame->request) * V4L_BYTES_PER_PIXEL;
	for (i=0; i < VIDEOSIZE_Y(frame->request); i++) {
		unsigned char *fd = frame->data + (v4l_linesize * i);
		for (j=0; j < v4l_linesize; j++) {
			signed long v = (signed long) fd[j];
			/* Magnify up to 2 times, reduce down to zero */
			v = 128 + ((ccm + adj) * (v - 128)) / ccm;
			RESTRICT_TO_RANGE(v, 0, 0xFF); /* Must flatten tails */
			fd[j] = (unsigned char) v;
		}
	}
}

MODULE_LICENSE("GPL");