V4L/DVB (5077): Bttv cropping support

Adds the missing VIDIOC_CROPCAP, G_CROP and S_CROP ioctls, permitting 
applications to capture or overlay a subsection of the picture or to 
extend the capture window beyond active video, into the VBI area and the 
horizontal blanking. VBI capturing can start and end on any line, 
including the picture area, and apps can capture different lines of each 
field and single fields.
For compatibility with existing applications, the open() function
resets the cropping and VBI capturing parameters and a VIDIOC_S_CROP
call is necessary to actually enable cropping. 
Regrettably in PAL-M, PAL-N, PAL-Nc and NTSC-JP mode the maximum image 
width will increase from 640 and 768 to 747 and 923 pixels respectively.
Like the VBI changes however, this should only affect applications which 
depend on former driver limitations, such as never getting more than 640 
pixels regardless of the requested width. 
Also, new freedoms require additional checks for conflicts and some 
applications may not expect an EBUSY error from the VIDIOC_QBUF and 
VIDIOCMCAPTURE ioctls. These errors should be rare though.
So far, the patch has been tested on a UP machine with a bt878 in PAL-
BGHI and NTSC-M mode using xawtv, tvtime, mplayer/mencoder, zapping/
libzvbi and these tools: http://zapping.sf.net/bttv-crop-test.tar.bz2
I'd be grateful about comments or bug reports.
Signed-off-by: Michael H. Schimek <mschimek@gmx.at>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/bt8xx/bttv-risc.c

@@ -43,7 +43,8 @@ int
 bttv_risc_packed(struct bttv *btv, struct btcx_riscmem *risc,
 		 struct scatterlist *sglist,
 		 unsigned int offset, unsigned int bpl,
-		 unsigned int padding, unsigned int lines)
+		 unsigned int padding, unsigned int skip_lines,
+		 unsigned int store_lines)
 {
 	u32 instructions,line,todo;
 	struct scatterlist *sg;
@@ -54,9 +55,11 @@ bttv_risc_packed(struct bttv *btv, struct btcx_riscmem *risc,
 	   one write per scan line + sync + jump (all 2 dwords).  padding
 	   can cause next bpl to start close to a page border.  First DMA
 	   region may be smaller than PAGE_SIZE */
-	instructions  = 1 + ((bpl + padding) * lines) / PAGE_SIZE + lines;
-	instructions += 2;
-	if ((rc = btcx_riscmem_alloc(btv->c.pci,risc,instructions*8)) < 0)
+	instructions  = skip_lines * 4;
+	instructions += (1 + ((bpl + padding) * store_lines)
+			 / PAGE_SIZE + store_lines) * 8;
+	instructions += 2 * 8;
+	if ((rc = btcx_riscmem_alloc(btv->c.pci,risc,instructions)) < 0)
 		return rc;
 
 	/* sync instruction */
@@ -64,11 +67,16 @@ bttv_risc_packed(struct bttv *btv, struct btcx_riscmem *risc,
 	*(rp++) = cpu_to_le32(BT848_RISC_SYNC|BT848_FIFO_STATUS_FM1);
 	*(rp++) = cpu_to_le32(0);
 
+	while (skip_lines-- > 0) {
+		*(rp++) = cpu_to_le32(BT848_RISC_SKIP | BT848_RISC_SOL |
+				      BT848_RISC_EOL | bpl);
+	}
+
 	/* scan lines */
 	sg = sglist;
-	for (line = 0; line < lines; line++) {
+	for (line = 0; line < store_lines; line++) {
 		if ((btv->opt_vcr_hack) &&
-		    (line >= (lines - VCR_HACK_LINES)))
+		    (line >= (store_lines - VCR_HACK_LINES)))
 			continue;
 		while (offset && offset >= sg_dma_len(sg)) {
 			offset -= sg_dma_len(sg);
@@ -130,7 +138,8 @@ bttv_risc_planar(struct bttv *btv, struct btcx_riscmem *risc,
 	/* estimate risc mem: worst case is one write per page border +
 	   one write per scan line (5 dwords)
 	   plus sync + jump (2 dwords) */
-	instructions  = (ybpl * ylines * 2) / PAGE_SIZE + ylines;
+	instructions  = ((3 + (ybpl + ypadding) * ylines * 2)
+			 / PAGE_SIZE) + ylines;
 	instructions += 2;
 	if ((rc = btcx_riscmem_alloc(btv->c.pci,risc,instructions*4*5)) < 0)
 		return rc;
@@ -317,10 +326,10 @@ bttv_risc_overlay(struct bttv *btv, struct btcx_riscmem *risc,
 /* ---------------------------------------------------------- */
 
 static void
-bttv_calc_geo(struct bttv *btv, struct bttv_geometry *geo,
-	      int width, int height, int interleaved, int norm)
+bttv_calc_geo_old(struct bttv *btv, struct bttv_geometry *geo,
+		  int width, int height, int interleaved,
+		  const struct bttv_tvnorm *tvnorm)
 {
-	const struct bttv_tvnorm *tvnorm = &bttv_tvnorms[norm];
 	u32 xsf, sr;
 	int vdelay;
 
@@ -360,6 +369,62 @@ bttv_calc_geo(struct bttv *btv, struct bttv_geometry *geo,
 	}
 }
 
+static void
+bttv_calc_geo		(struct bttv *                  btv,
+			 struct bttv_geometry *         geo,
+			 unsigned int                   width,
+			 unsigned int                   height,
+			 int                            both_fields,
+			 const struct bttv_tvnorm *     tvnorm,
+			 const struct v4l2_rect *       crop)
+{
+	unsigned int c_width;
+	unsigned int c_height;
+	u32 sr;
+
+	if ((crop->left == tvnorm->cropcap.defrect.left
+	     && crop->top == tvnorm->cropcap.defrect.top
+	     && crop->width == tvnorm->cropcap.defrect.width
+	     && crop->height == tvnorm->cropcap.defrect.height
+	     && width <= tvnorm->swidth /* see PAL-Nc et al */)
+	    || bttv_tvcards[btv->c.type].muxsel[btv->input] < 0) {
+		bttv_calc_geo_old(btv, geo, width, height,
+				  both_fields, tvnorm);
+		return;
+	}
+
+	/* For bug compatibility the image size checks permit scale
+	   factors > 16. See bttv_crop_calc_limits(). */
+	c_width = min((unsigned int) crop->width, width * 16);
+	c_height = min((unsigned int) crop->height, height * 16);
+
+	geo->width = width;
+	geo->hscale = (c_width * 4096U + (width >> 1)) / width - 4096;
+	/* Even to store Cb first, odd for Cr. */
+	geo->hdelay = ((crop->left * width + c_width) / c_width) & ~1;
+
+	geo->sheight = c_height;
+	geo->vdelay = crop->top - tvnorm->cropcap.bounds.top + MIN_VDELAY;
+	sr = c_height >> !both_fields;
+	sr = (sr * 512U + (height >> 1)) / height - 512;
+	geo->vscale = (0x10000UL - sr) & 0x1fff;
+	geo->vscale |= both_fields ? (BT848_VSCALE_INT << 8) : 0;
+	geo->vtotal = tvnorm->vtotal;
+
+	geo->crop = (((geo->width   >> 8) & 0x03) |
+		     ((geo->hdelay  >> 6) & 0x0c) |
+		     ((geo->sheight >> 4) & 0x30) |
+		     ((geo->vdelay  >> 2) & 0xc0));
+
+	if (btv->opt_combfilter) {
+		geo->vtc  = (width < 193) ? 2 : ((width < 385) ? 1 : 0);
+		geo->comb = (width < 769) ? 1 : 0;
+	} else {
+		geo->vtc  = 0;
+		geo->comb = 0;
+	}
+}
+
 static void
 bttv_apply_geo(struct bttv *btv, struct bttv_geometry *geo, int odd)
 {
@@ -522,16 +587,51 @@ int
 bttv_buffer_activate_vbi(struct bttv *btv,
 			 struct bttv_buffer *vbi)
 {
-	/* vbi capture */
+	struct btcx_riscmem *top;
+	struct btcx_riscmem *bottom;
+	int top_irq_flags;
+	int bottom_irq_flags;
+
+	top = NULL;
+	bottom = NULL;
+	top_irq_flags = 0;
+	bottom_irq_flags = 0;
+
 	if (vbi) {
+		unsigned int crop, vdelay;
+
 		vbi->vb.state = STATE_ACTIVE;
 		list_del(&vbi->vb.queue);
-		bttv_risc_hook(btv, RISC_SLOT_O_VBI, &vbi->top,    0);
-		bttv_risc_hook(btv, RISC_SLOT_E_VBI, &vbi->bottom, 4);
-	} else {
-		bttv_risc_hook(btv, RISC_SLOT_O_VBI, NULL, 0);
-		bttv_risc_hook(btv, RISC_SLOT_E_VBI, NULL, 0);
+
+		/* VDELAY is start of video, end of VBI capturing. */
+		crop = btread(BT848_E_CROP);
+		vdelay = btread(BT848_E_VDELAY_LO) + ((crop & 0xc0) << 2);
+
+		if (vbi->geo.vdelay > vdelay) {
+			vdelay = vbi->geo.vdelay & 0xfe;
+			crop = (crop & 0x3f) | ((vbi->geo.vdelay >> 2) & 0xc0);
+
+			btwrite(vdelay, BT848_E_VDELAY_LO);
+			btwrite(crop,	BT848_E_CROP);
+			btwrite(vdelay, BT848_O_VDELAY_LO);
+			btwrite(crop,	BT848_O_CROP);
 		}
+
+		if (vbi->vbi_count[0] > 0) {
+			top = &vbi->top;
+			top_irq_flags = 4;
+		}
+
+		if (vbi->vbi_count[1] > 0) {
+			top_irq_flags = 0;
+			bottom = &vbi->bottom;
+			bottom_irq_flags = 4;
+		}
+	}
+
+	bttv_risc_hook(btv, RISC_SLOT_O_VBI, top, top_irq_flags);
+	bttv_risc_hook(btv, RISC_SLOT_E_VBI, bottom, bottom_irq_flags);
+
 	return 0;
 }
 
@@ -611,28 +711,31 @@ bttv_buffer_risc(struct bttv *btv, struct bttv_buffer *buf)
 		int bpf = bpl * (buf->vb.height >> 1);
 
 		bttv_calc_geo(btv,&buf->geo,buf->vb.width,buf->vb.height,
-			      V4L2_FIELD_HAS_BOTH(buf->vb.field),buf->tvnorm);
+			      V4L2_FIELD_HAS_BOTH(buf->vb.field),
+			      tvnorm,&buf->crop);
 
 		switch (buf->vb.field) {
 		case V4L2_FIELD_TOP:
 			bttv_risc_packed(btv,&buf->top,buf->vb.dma.sglist,
-					 0,bpl,0,buf->vb.height);
+					 /* offset */ 0,bpl,
+					 /* padding */ 0,/* skip_lines */ 0,
+					 buf->vb.height);
 			break;
 		case V4L2_FIELD_BOTTOM:
 			bttv_risc_packed(btv,&buf->bottom,buf->vb.dma.sglist,
-					 0,bpl,0,buf->vb.height);
+					 0,bpl,0,0,buf->vb.height);
 			break;
 		case V4L2_FIELD_INTERLACED:
 			bttv_risc_packed(btv,&buf->top,buf->vb.dma.sglist,
-					 0,bpl,bpl,buf->vb.height >> 1);
+					 0,bpl,bpl,0,buf->vb.height >> 1);
 			bttv_risc_packed(btv,&buf->bottom,buf->vb.dma.sglist,
-					 bpl,bpl,bpl,buf->vb.height >> 1);
+					 bpl,bpl,bpl,0,buf->vb.height >> 1);
 			break;
 		case V4L2_FIELD_SEQ_TB:
 			bttv_risc_packed(btv,&buf->top,buf->vb.dma.sglist,
-					 0,bpl,0,buf->vb.height >> 1);
+					 0,bpl,0,0,buf->vb.height >> 1);
 			bttv_risc_packed(btv,&buf->bottom,buf->vb.dma.sglist,
-					 bpf,bpl,0,buf->vb.height >> 1);
+					 bpf,bpl,0,0,buf->vb.height >> 1);
 			break;
 		default:
 			BUG();
@@ -662,7 +765,8 @@ bttv_buffer_risc(struct bttv *btv, struct bttv_buffer *buf)
 		switch (buf->vb.field) {
 		case V4L2_FIELD_TOP:
 			bttv_calc_geo(btv,&buf->geo,buf->vb.width,
-				      buf->vb.height,0,buf->tvnorm);
+				      buf->vb.height,/* both_fields */ 0,
+				      tvnorm,&buf->crop);
 			bttv_risc_planar(btv, &buf->top, buf->vb.dma.sglist,
 					 0,buf->vb.width,0,buf->vb.height,
 					 uoffset,voffset,buf->fmt->hshift,
@@ -670,7 +774,8 @@ bttv_buffer_risc(struct bttv *btv, struct bttv_buffer *buf)
 			break;
 		case V4L2_FIELD_BOTTOM:
 			bttv_calc_geo(btv,&buf->geo,buf->vb.width,
-				      buf->vb.height,0,buf->tvnorm);
+				      buf->vb.height,0,
+				      tvnorm,&buf->crop);
 			bttv_risc_planar(btv, &buf->bottom, buf->vb.dma.sglist,
 					 0,buf->vb.width,0,buf->vb.height,
 					 uoffset,voffset,buf->fmt->hshift,
@@ -678,7 +783,8 @@ bttv_buffer_risc(struct bttv *btv, struct bttv_buffer *buf)
 			break;
 		case V4L2_FIELD_INTERLACED:
 			bttv_calc_geo(btv,&buf->geo,buf->vb.width,
-				      buf->vb.height,1,buf->tvnorm);
+				      buf->vb.height,1,
+				      tvnorm,&buf->crop);
 			lines    = buf->vb.height >> 1;
 			ypadding = buf->vb.width;
 			cpadding = buf->vb.width >> buf->fmt->hshift;
@@ -700,7 +806,8 @@ bttv_buffer_risc(struct bttv *btv, struct bttv_buffer *buf)
 			break;
 		case V4L2_FIELD_SEQ_TB:
 			bttv_calc_geo(btv,&buf->geo,buf->vb.width,
-				      buf->vb.height,1,buf->tvnorm);
+				      buf->vb.height,1,
+				      tvnorm,&buf->crop);
 			lines    = buf->vb.height >> 1;
 			ypadding = buf->vb.width;
 			cpadding = buf->vb.width >> buf->fmt->hshift;
@@ -731,11 +838,12 @@ bttv_buffer_risc(struct bttv *btv, struct bttv_buffer *buf)
 		/* build risc code */
 		buf->vb.field = V4L2_FIELD_SEQ_TB;
 		bttv_calc_geo(btv,&buf->geo,tvnorm->swidth,tvnorm->sheight,
-			      1,buf->tvnorm);
+			      1,tvnorm,&buf->crop);
 		bttv_risc_packed(btv, &buf->top,  buf->vb.dma.sglist,
-				 0, RAW_BPL, 0, RAW_LINES);
+				 /* offset */ 0, RAW_BPL, /* padding */ 0,
+				 /* skip_lines */ 0, RAW_LINES);
 		bttv_risc_packed(btv, &buf->bottom, buf->vb.dma.sglist,
-				 buf->vb.size/2 , RAW_BPL, 0, RAW_LINES);
+				 buf->vb.size/2 , RAW_BPL, 0, 0, RAW_LINES);
 	}
 
 	/* copy format info */
@@ -761,7 +869,8 @@ bttv_overlay_risc(struct bttv *btv,
 
 	/* calculate geometry */
 	bttv_calc_geo(btv,&buf->geo,ov->w.width,ov->w.height,
-		      V4L2_FIELD_HAS_BOTH(ov->field), ov->tvnorm);
+		      V4L2_FIELD_HAS_BOTH(ov->field),
+		      &bttv_tvnorms[ov->tvnorm],&buf->crop);
 
 	/* build risc code */
 	switch (ov->field) {

drivers/media/video/bt8xx/bttvp.h

@@ -26,7 +26,7 @@
 #define _BTTVP_H_
 
 #include <linux/version.h>
-#define BTTV_VERSION_CODE KERNEL_VERSION(0,9,16)
+#define BTTV_VERSION_CODE KERNEL_VERSION(0,9,17)
 
 #include <linux/types.h>
 #include <linux/wait.h>
@@ -66,14 +66,22 @@
 #define RISC_SLOT_LOOP        14
 
 #define RESOURCE_OVERLAY       1
-#define RESOURCE_VIDEO         2
+#define RESOURCE_VIDEO_STREAM  2
 #define RESOURCE_VBI           4
+#define RESOURCE_VIDEO_READ    8
 
 #define RAW_LINES            640
 #define RAW_BPL             1024
 
 #define UNSET (-1U)
 
+/* Min. value in VDELAY register. */
+#define MIN_VDELAY 2
+/* Even to get Cb first, odd for Cr. */
+#define MAX_HDELAY (0x3FF & -2)
+/* Limits scaled width, which must be a multiple of 4. */
+#define MAX_HACTIVE (0x3FF & -4)
+
 #define clamp(x, low, high) min (max (low, x), high)
 
 /* ---------------------------------------------------------- */
@@ -92,8 +100,13 @@ struct bttv_tvnorm {
 	u16   vtotal;
 	int   sram;
 	/* ITU-R frame line number of the first VBI line we can
-	   capture, of the first and second field. */
+	   capture, of the first and second field. The last possible line
+	   is determined by cropcap.bounds. */
 	u16   vbistart[2];
+	/* Horizontally this counts fCLKx1 samples following the leading
+	   edge of the horizontal sync pulse, vertically ITU-R frame line
+	   numbers of the first field times two (2, 4, 6, ... 524 or 624). */
+	struct v4l2_cropcap cropcap;
 };
 extern const struct bttv_tvnorm bttv_tvnorms[];
 
@@ -128,6 +141,9 @@ struct bttv_buffer {
 	struct bttv_geometry       geo;
 	struct btcx_riscmem        top;
 	struct btcx_riscmem        bottom;
+	struct v4l2_rect           crop;
+	unsigned int               vbi_skip[2];
+	unsigned int               vbi_count[2];
 };
 
 struct bttv_buffer_set {
@@ -146,6 +162,34 @@ struct bttv_overlay {
 	int                    setup_ok;
 };
 
+struct bttv_vbi_fmt {
+	struct v4l2_vbi_format fmt;
+
+	/* fmt.start[] and count[] refer to this video standard. */
+	const struct bttv_tvnorm *tvnorm;
+
+	/* Earliest possible start of video capturing with this
+	   v4l2_vbi_format, in struct bttv_crop.rect units. */
+	__s32                  end;
+};
+
+/* bttv-vbi.c */
+void bttv_vbi_fmt_reset(struct bttv_vbi_fmt *f, int norm);
+
+struct bttv_crop {
+	/* A cropping rectangle in struct bttv_tvnorm.cropcap units. */
+	struct v4l2_rect       rect;
+
+	/* Scaled image size limits with this crop rect. Divide
+	   max_height, but not min_height, by two when capturing
+	   single fields. See also bttv_crop_reset() and
+	   bttv_crop_adjust() in bttv-driver.c. */
+	__s32                  min_scaled_width;
+	__s32                  min_scaled_height;
+	__s32                  max_scaled_width;
+	__s32                  max_scaled_height;
+};
+
 struct bttv_fh {
 	struct bttv              *btv;
 	int resources;
@@ -160,13 +204,19 @@ struct bttv_fh {
 	int                      width;
 	int                      height;
 
-	/* current settings */
+	/* video overlay */
 	const struct bttv_format *ovfmt;
 	struct bttv_overlay      ov;
 
-	/* video overlay */
+	/* Application called VIDIOC_S_CROP. */
+	int                      do_crop;
+
+	/* vbi capture */
 	struct videobuf_queue    vbi;
-	int                      lines;
+	/* Current VBI capture window as seen through this fh (cannot
+	   be global for compatibility with earlier drivers). Protected
+	   by struct bttv.lock and struct bttv_fh.vbi.lock. */
+	struct bttv_vbi_fmt      vbi_fmt;
 };
 
 /* ---------------------------------------------------------- */
@@ -176,7 +226,8 @@ struct bttv_fh {
 int bttv_risc_packed(struct bttv *btv, struct btcx_riscmem *risc,
 		     struct scatterlist *sglist,
 		     unsigned int offset, unsigned int bpl,
-		     unsigned int pitch, unsigned int lines);
+		     unsigned int pitch, unsigned int skip_lines,
+		     unsigned int store_lines);
 
 /* control dma register + risc main loop */
 void bttv_set_dma(struct bttv *btv, int override);
@@ -202,9 +253,9 @@ int bttv_overlay_risc(struct bttv *btv, struct bttv_overlay *ov,
 /* ---------------------------------------------------------- */
 /* bttv-vbi.c                                                 */
 
-void bttv_vbi_try_fmt(struct bttv_fh *fh, struct v4l2_format *f);
-void bttv_vbi_get_fmt(struct bttv_fh *fh, struct v4l2_format *f);
-void bttv_vbi_setlines(struct bttv_fh *fh, struct bttv *btv, int lines);
+int bttv_vbi_try_fmt(struct bttv_fh *fh, struct v4l2_vbi_format *f);
+void bttv_vbi_get_fmt(struct bttv_fh *fh, struct v4l2_vbi_format *f);
+int bttv_vbi_set_fmt(struct bttv_fh *fh, struct v4l2_vbi_format *f);
 
 extern struct videobuf_queue_ops bttv_vbi_qops;
 
@@ -233,7 +284,6 @@ extern int fini_bttv_i2c(struct bttv *btv);
 #define d2printk if (bttv_debug >= 2) printk
 
 #define BTTV_MAX_FBUF   0x208000
-#define VBIBUF_SIZE     (2048*VBI_MAXLINES*2)
 #define BTTV_TIMEOUT    (HZ/2) /* 0.5 seconds */
 #define BTTV_FREE_IDLE  (HZ)   /* one second */
 
@@ -314,7 +364,6 @@ struct bttv {
 	spinlock_t s_lock;
 	struct mutex lock;
 	int resources;
-	struct mutex reslock;
 #ifdef VIDIOC_G_PRIORITY
 	struct v4l2_prio_state prio;
 #endif
@@ -384,6 +433,21 @@ struct bttv {
 
 	unsigned int users;
 	struct bttv_fh init;
+
+	/* Default (0) and current (1) video capturing and overlay
+	   cropping parameters in bttv_tvnorm.cropcap units. Protected
+	   by bttv.lock. */
+	struct bttv_crop crop[2];
+
+	/* Earliest possible start of video capturing in
+	   bttv_tvnorm.cropcap line units. Set by check_alloc_btres()
+	   and free_btres(). Protected by bttv.lock. */
+	__s32			vbi_end;
+
+	/* Latest possible end of VBI capturing (= crop[x].rect.top when
+	   VIDEO_RESOURCES are locked). Set by check_alloc_btres()
+	   and free_btres(). Protected by bttv.lock. */
+	__s32			crop_start;
 };
 
 /* our devices */