v4l2.c - platform/external/strace - Gitiles

 /*
  * Copyright (c) 2014 Philippe De Muyter <phdm@macqel.be>
  * Copyright (c) 2014 William Manley <will@williammanley.net>
  * Copyright (c) 2011 Peter Zotov <whitequark@whitequark.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. The name of the author may not be used to endorse or promote products
  *    derived from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "defs.h"

 #include <stdint.h>
 #include <sys/ioctl.h>
 #include <linux/types.h>
 #include <linux/videodev2.h>
 /* some historical constants */
 #ifndef V4L2_CID_HCENTER
 #define V4L2_CID_HCENTER (V4L2_CID_BASE+22)
 #endif
 #ifndef V4L2_CID_VCENTER
 #define V4L2_CID_VCENTER (V4L2_CID_BASE+23)
 #endif
 #ifndef V4L2_CID_BAND_STOP_FILTER
 #define V4L2_CID_BAND_STOP_FILTER (V4L2_CID_BASE+33)
 #endif

 #include "xlat/v4l2_device_capabilities_flags.h"
 #include "xlat/v4l2_buf_types.h"
 #include "xlat/v4l2_buf_flags.h"
 #include "xlat/v4l2_framesize_types.h"
 #include "xlat/v4l2_frameinterval_types.h"
 #include "xlat/v4l2_fields.h"
 #include "xlat/v4l2_colorspaces.h"
 #include "xlat/v4l2_format_description_flags.h"
 #include "xlat/v4l2_memories.h"
 #include "xlat/v4l2_control_ids.h"
 #include "xlat/v4l2_control_types.h"
 #include "xlat/v4l2_control_flags.h"
 #include "xlat/v4l2_control_classes.h"
 #include "xlat/v4l2_streaming_capabilities.h"
 #include "xlat/v4l2_capture_modes.h"
 #include "xlat/v4l2_input_types.h"

 #define FMT_FRACT "%u/%u"
 #define ARGS_FRACT(x) ((x).numerator), ((x).denominator)

 #define FMT_RECT "{left=%i, top=%i, width=%i, height=%i}"
 #define ARGS_RECT(x) (x).left, (x).top, (x).width, (x).height

 static void print_pixelformat(uint32_t fourcc)
 {
 	union {
 		uint32_t pixelformat;
 		unsigned char cc[sizeof(uint32_t)];
 	} u = {
 		.pixelformat =
 #if WORDS_BIGENDIAN
 			htole32(fourcc)
 #else
 			fourcc
 #endif
 	};
 	unsigned int i;

 	tprints("v4l2_fourcc(");
 	for (i = 0; i < sizeof(u.cc); ++i) {
 		unsigned int c = u.cc[i];

 		if (i)
 			tprints(", ");
 		if (c == ' ' ||
 		    (c >= '0' && c <= '9') ||
 		    (c >= 'A' && c <= 'Z') ||
 		    (c >= 'a' && c <= 'z')) {
 			char sym[] = {
 				'\'',
 				u.cc[i],
 				'\''
 			};
 			tprints(sym);
 		} else {
 			char hex[] = {
 				'\'',
 				'\\',
 				'x',
 				"0123456789abcdef"[c >> 4],
 				"0123456789abcdef"[c & 0xf],
 				'\'',
 				'\0'
 			};
 			tprints(hex);
 		}
 	}
 	tprints(")");
 }

 static void print_v4l2_format_fmt(const struct v4l2_format *f)
 {
 	tprints("fmt.");
 	switch (f->type) {
 	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
 	case V4L2_BUF_TYPE_VIDEO_OUTPUT: {
 		const struct v4l2_pix_format *pix = &f->fmt.pix;

 		tprintf("pix={width=%u, height=%u, pixelformat=",
 			pix->width, pix->height);
 		print_pixelformat(pix->pixelformat);
 		tprints(", field=");
 		printxval(v4l2_fields, pix->field, "V4L2_FIELD_???");
 		tprintf(", bytesperline=%u, sizeimage=%u, colorspace=",
 			pix->bytesperline, pix->sizeimage);
 		printxval(v4l2_colorspaces, pix->colorspace,
 			  "V4L2_COLORSPACE_???");
 		tprints("}");
 		break;
 	}
 #if HAVE_DECL_V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE
 	case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
 	case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE: {
 		const struct v4l2_pix_format_mplane *pix_mp = &f->fmt.pix_mp;
 		unsigned int i, max;

 		tprintf("pix_mp={width=%u, height=%u, pixelformat=",
 			pix_mp->width, pix_mp->height);
 		print_pixelformat(pix_mp->pixelformat);
 		tprints(", field=");
 		printxval(v4l2_fields, pix_mp->field, "V4L2_FIELD_???");
 		tprints(", colorspace=");
 		printxval(v4l2_colorspaces, pix_mp->colorspace,
 			  "V4L2_COLORSPACE_???");
 		tprints("plane_fmt=[");
 		max = pix_mp->num_planes;
 		if (max > VIDEO_MAX_PLANES)
 			max = VIDEO_MAX_PLANES;
 		for (i = 0; i < max; i++) {
 			if (i > 0)
 				tprints(", ");
 			tprintf("{sizeimage=%u, bytesperline=%u}",
 				pix_mp->plane_fmt[i].sizeimage,
 				pix_mp->plane_fmt[i].bytesperline);
 		}
 		tprintf("], num_planes=%u}", (unsigned) pix_mp->num_planes);
 		break;
 	}
 #endif

 	/* TODO: Complete this switch statement */
 	case V4L2_BUF_TYPE_VIDEO_OVERLAY:
 #if HAVE_DECL_V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY
 	case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY:
 #endif
 		tprints("win={???}");
 		break;

 	case V4L2_BUF_TYPE_VBI_CAPTURE:
 	case V4L2_BUF_TYPE_VBI_OUTPUT:
 		tprints("vbi={???}");
 		break;

 	case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
 	case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
 		tprints("sliced={???}");
 		break;

 	default:
 		tprints("???");
 		break;
 	}
 }

 int
 v4l2_ioctl(struct tcb *tcp, const unsigned int code, long arg)
 {
 	if (!verbose(tcp))
 		return 0;

 	switch (code) {
 	case VIDIOC_QUERYCAP: /* decode on exit */ {
 		struct v4l2_capability caps;

 		if (entering(tcp) || syserror(tcp) || umove(tcp, arg, &caps) < 0)
 			return 0;
 		tprints(", {driver=");
 		print_quoted_string((const char *) caps.driver,
 				    sizeof(caps.driver), QUOTE_0_TERMINATED);
 		tprints(", card=");
 		print_quoted_string((const char *) caps.card,
 				    sizeof(caps.card), QUOTE_0_TERMINATED);
 		tprints(", bus_info=");
 		print_quoted_string((const char *) caps.bus_info,
 				    sizeof(caps.bus_info), QUOTE_0_TERMINATED);
 		tprintf(", version=%u.%u.%u, capabilities=",
 			(caps.version >> 16) & 0xFF,
 			(caps.version >> 8) & 0xFF,
 			caps.version & 0xFF);
 		printflags(v4l2_device_capabilities_flags, caps.capabilities,
 			   "V4L2_CAP_???");
 #ifdef V4L2_CAP_DEVICE_CAPS
 		tprints(", device_caps=");
 		printflags(v4l2_device_capabilities_flags, caps.device_caps,
 			   "V4L2_CAP_???");
 #endif
 		tprints("}");
 		return 1;
 	}

 #ifdef VIDIOC_ENUM_FRAMESIZES
 	case VIDIOC_ENUM_FRAMESIZES: /* decode on exit */ {
 		struct v4l2_frmsizeenum s;

 		if (entering(tcp) || umove(tcp, arg, &s) < 0)
 			return 0;
 		tprintf(", {index=%u, pixel_format=", s.index);
 		print_pixelformat(s.pixel_format);

 		if (!syserror(tcp)) {
 			tprints(", type=");
 			printxval(v4l2_framesize_types, s.type, "V4L2_FRMSIZE_TYPE_???");
 			switch (s.type) {
 			case V4L2_FRMSIZE_TYPE_DISCRETE:
 				tprintf(", discrete={width=%u, height=%u}",
 					s.discrete.width, s.discrete.height);
 				break;
 			case V4L2_FRMSIZE_TYPE_STEPWISE:
 				tprintf(", stepwise={min_width=%u, max_width=%u, "
 					"step_width=%u, min_height=%u, max_height=%u, "
 					"step_height=%u}",
 					s.stepwise.min_width, s.stepwise.max_width,
 					s.stepwise.step_width, s.stepwise.min_height,
 					s.stepwise.max_height, s.stepwise.step_height);
 				break;
 			}
 		}
 		tprints("}");
 		return 1;
 	}
 #endif /* VIDIOC_ENUM_FRAMESIZES */

 	case VIDIOC_G_FMT:
 	case VIDIOC_S_FMT:
 	case VIDIOC_TRY_FMT: {
 		struct v4l2_format f;

 		if (umove(tcp, arg, &f) < 0)
 			return 0;
 		if (entering(tcp)) {
 			tprints(", {type=");
 			printxval(v4l2_buf_types, f.type, "V4L2_BUF_TYPE_???");
 		}
 		if ((entering(tcp) && code != VIDIOC_G_FMT)
 		    || (exiting(tcp) && !syserror(tcp))) {
 			tprints(exiting(tcp) && code != VIDIOC_G_FMT ? " => " : ", ");
 			print_v4l2_format_fmt(&f);
 		}
 		if (exiting(tcp))
 			tprints("}");
 		return 1;
 	}

 	case VIDIOC_ENUM_FMT: {
 		struct v4l2_fmtdesc f;

 		if (entering(tcp) || umove(tcp, arg, &f) < 0)
 			return 0;

 		tprintf(", {index=%u", f.index);
 		if (!syserror(tcp)) {
 			tprints(", type=");
 			printxval(v4l2_buf_types, f.type, "V4L2_BUF_TYPE_???");
 			tprints(", flags=");
 			printflags(v4l2_format_description_flags, f.flags,
 				   "V4L2_FMT_FLAG_???");
 			tprints(", description=");
 			print_quoted_string((const char *) f.description,
 					    sizeof(f.description),
 					    QUOTE_0_TERMINATED);
 			tprints(", pixelformat=");
 			print_pixelformat(f.pixelformat);
 		}
 		tprints("}");
 		return 1;
 	}

 	case VIDIOC_G_PARM:
 	case VIDIOC_S_PARM: {
 		struct v4l2_streamparm s;

 		if (entering(tcp) && code == VIDIOC_G_PARM)
 			return 1;
 		if (exiting(tcp) && syserror(tcp))
 			return code == VIDIOC_S_PARM;
 		if (umove(tcp, arg, &s) < 0)
 			return 0;
 		if (entering(tcp)) {
 			tprints(", {type=");
 			printxval(v4l2_buf_types, s.type, "V4L2_BUF_TYPE_???");
 		}

 		tprints(exiting(tcp) && code == VIDIOC_S_PARM ? " => {" : ", {");
 		if (s.type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
 			struct v4l2_captureparm *cap = &s.parm.capture;

 			tprints("capability=");
 			printflags(v4l2_streaming_capabilities,
 				   cap->capability, "V4L2_CAP_???");

 			tprints(", capturemode=");
 			printflags(v4l2_capture_modes,
 				   cap->capturemode, "V4L2_MODE_???");

 			tprintf(", timeperframe=" FMT_FRACT,
 				ARGS_FRACT(cap->timeperframe));

 			tprintf(", extendedmode=%u, readbuffers=%u",
 				cap->extendedmode,
 				cap->readbuffers);
 		} else
 			tprints("...");
 		tprints("}");
 		if (exiting(tcp))
 			tprints("}");
 		return 1;
 	}

 	case VIDIOC_QUERYCTRL: {
 		struct v4l2_queryctrl c;

 		if (umove(tcp, arg, &c) < 0)
 			return 0;
 		/* 'id' field must be printed :
 		* on enter
 		* on exit if !syserror(tcp) && V4L2_CTRL_FLAG_NEXT_CTRL was set
 		*/
 		if (entering(tcp)
 		    || (exiting(tcp) && tcp->auxstr && !syserror(tcp))) {
 			tprints(exiting(tcp) ? " => " : ", {id=");
 #ifdef V4L2_CTRL_FLAG_NEXT_CTRL
 			tcp->auxstr = (c.id & V4L2_CTRL_FLAG_NEXT_CTRL) ? "" : NULL;
 			if (tcp->auxstr) {
 				tprints("V4L2_CTRL_FLAG_NEXT_CTRL|");
 				c.id &= ~V4L2_CTRL_FLAG_NEXT_CTRL;
 			}
 #endif
 			printxval(v4l2_control_ids, c.id, "V4L2_CID_???");
 		}
 		if (exiting(tcp)) {
 			if (!syserror(tcp)) {
 				tprints(", type=");
 				printxval(v4l2_control_types, c.type,
 					  "V4L2_CTRL_TYPE_???");
 				tprints(", name=");
 				print_quoted_string((const char *) c.name,
 						    sizeof(c.name),
 						    QUOTE_0_TERMINATED);
 				tprintf(", minimum=%i, maximum=%i, step=%i, "
 					"default_value=%i, flags=",
 					c.minimum, c.maximum,
 					c.step, c.default_value);
 				printflags(v4l2_control_flags, c.flags,
 					   "V4L2_CTRL_FLAG_???");
 			}
 			tprints("}");
 		}
 		return 1;
 	}

 	case VIDIOC_G_CTRL:
 	case VIDIOC_S_CTRL: {
 		struct v4l2_control c;

 		if (entering(tcp) || umove(tcp, arg, &c) < 0)
 			return 0;
 		tprints(", {id=");
 		printxval(v4l2_control_ids, c.id, "V4L2_CID_???");
 		if (!syserror(tcp) || code != VIDIOC_G_CTRL)
 			tprintf(", value=%i", c.value);
 		tprints("}");
 		return 1;
 	}

 #ifdef VIDIOC_S_EXT_CTRLS
 	case VIDIOC_S_EXT_CTRLS:
 	case VIDIOC_TRY_EXT_CTRLS:
 	case VIDIOC_G_EXT_CTRLS: {
 		struct v4l2_ext_controls c;
 		unsigned int n;
 		bool must_print_values;

 		if (entering(tcp) && code == VIDIOC_G_EXT_CTRLS)
 			return 0;
 		if (exiting(tcp) && syserror(tcp) && code != VIDIOC_G_EXT_CTRLS)
 			return 0;
 		must_print_values = ((entering(tcp) && code != VIDIOC_G_EXT_CTRLS)
 				     || (exiting(tcp) && !syserror(tcp)));
 		if (umove(tcp, arg, &c) < 0)
 			return 0;
 		tprints(code != VIDIOC_G_EXT_CTRLS && exiting(tcp) ? " => " : ", ");
 		tprints("{ctrl_class=");
 		printxval(v4l2_control_classes, c.ctrl_class,
 			  "V4L2_CTRL_CLASS_???");
 		tprintf(", count=%u", c.count);
 		if (exiting(tcp) && syserror(tcp))
 			tprintf(", error_idx=%u", c.error_idx);
 		tprints(", controls=[");
 		for (n = 0; n < c.count; ++n) {
 			struct v4l2_ext_control ctrl;

 			if (n > 0)
 				tprints(", ");
 			if (umove(tcp, (long) (c.controls + n), &ctrl) < 0)
 				break;
 			if (abbrev(tcp) && n == 2) {
 				tprints("...");
 				break;
 			}
 			tprints("{id=");
 			printxval(v4l2_control_ids, ctrl.id, "V4L2_CID_???");
 # if HAVE_DECL_V4L2_CTRL_TYPE_STRING
 			tprintf(", size=%u", ctrl.size);
 			if (ctrl.size > 0) {
 				if (must_print_values) {
 					tprints(", string=");
 					printstr(tcp, (long) ctrl.string, ctrl.size);
 				}
 			} else
 # endif
 			{
 				if (must_print_values) {
 					tprintf(", value=%i, value64=%lld", ctrl.value,
 						(long long) ctrl.value64);
 				}
 			}
 			tprints("}");
 		}
 		tprints("]}");
 		return 1;
 	}
 #endif /* VIDIOC_S_EXT_CTRLS */

 	case VIDIOC_ENUMSTD: {
 		struct v4l2_standard s;

 		if (umove(tcp, arg, &s) < 0)
 			return 0;
 		if (entering(tcp))
 			tprintf(", {index=%i", s.index);
 		else {
 			if (!syserror(tcp)) {
 				tprints(", name=");
 				print_quoted_string((const char *) s.name,
 						    sizeof(s.name),
 						    QUOTE_0_TERMINATED);
 				tprintf(", frameperiod=" FMT_FRACT, ARGS_FRACT(s.frameperiod));
 				tprintf(", framelines=%i", s.framelines);
 			}
 			tprints("}");
 		}
 		return 1;
 	}

 	case VIDIOC_G_STD:
 	case VIDIOC_S_STD: {
 		v4l2_std_id s;

 		if (code == VIDIOC_G_STD && exiting(tcp) && syserror(tcp))
 			return 0;
 		if (umove(tcp, arg, &s) < 0)
 			return 0;
 		if ((code == VIDIOC_S_STD) == entering(tcp))
 			tprintf(", std=%#llx", (unsigned long long) s);
 		return 1;
 	}

 	case VIDIOC_ENUMINPUT: {
 		struct v4l2_input i;

 		if (entering(tcp) || umove(tcp, arg, &i) < 0)
 			return 0;
 		tprintf(", {index=%i", i.index);
 		if (!syserror(tcp)) {
 			tprints(", name=");
 			print_quoted_string((const char *) i.name,
 					    sizeof(i.name), QUOTE_0_TERMINATED);
 			tprints(", type=");
 			printxval(v4l2_input_types, i.type,
 				  "V4L2_INPUT_TYPE_???");
 		}
 		tprints("}");
 		return 1;
 	}

 	case VIDIOC_G_INPUT:
 	case VIDIOC_S_INPUT: {
 		int index;

 		if (entering(tcp) || syserror(tcp) || umove(tcp, arg, &index) < 0)
 			return 0;

 		tprintf(", index=%i", index);
 		return 1;
 	}

 #ifdef VIDIOC_ENUM_FRAMEINTERVALS
 	case VIDIOC_ENUM_FRAMEINTERVALS: {
 		struct v4l2_frmivalenum f;

 		if (entering(tcp) || umove(tcp, arg, &f) < 0)
 			return 0;
 		tprintf(", {index=%i, pixel_format=", f.index);
 		print_pixelformat(f.pixel_format);
 		tprintf(", width=%u, height=%u", f.width, f.height);
 		if (!syserror(tcp)) {
 			tprints(", type=");
 			printxval(v4l2_frameinterval_types, f.type,
 				  "V4L2_FRMIVAL_TYPE_???");
 			switch (f.type) {
 			case V4L2_FRMIVAL_TYPE_DISCRETE:
 				tprintf(", discrete=" FMT_FRACT,
 					ARGS_FRACT(f.discrete));
 				break;
 			case V4L2_FRMIVAL_TYPE_STEPWISE:
 			case V4L2_FRMSIZE_TYPE_CONTINUOUS:
 				tprintf(", stepwise={min=" FMT_FRACT ", max="
 					FMT_FRACT ", step=" FMT_FRACT "}",
 					ARGS_FRACT(f.stepwise.min),
 					ARGS_FRACT(f.stepwise.max),
 					ARGS_FRACT(f.stepwise.step));
 				break;
 			}
 		}
 		tprints("}");
 		return 1;
 	}
 #endif /* VIDIOC_ENUM_FRAMEINTERVALS */

 	case VIDIOC_CROPCAP: {
 		struct v4l2_cropcap c;

 		if (entering(tcp) || umove(tcp, arg, &c) < 0)
 			return 0;
 		tprints(", {type=");
 		printxval(v4l2_buf_types, c.type, "V4L2_BUF_TYPE_???");
 		if (!syserror(tcp))
 			tprintf(", bounds=" FMT_RECT ", defrect=" FMT_RECT ", "
 				"pixelaspect=" FMT_FRACT, ARGS_RECT(c.bounds),
 				ARGS_RECT(c.defrect), ARGS_FRACT(c.pixelaspect));
 		tprints("}");
 		return 1;
 	}

 	case VIDIOC_S_CROP: {
 		struct v4l2_crop c;

 		if (exiting(tcp) || umove(tcp, arg, &c) < 0)
 			return 0;
 		tprints(", {type=");
 		printxval(v4l2_buf_types, c.type, "V4L2_BUF_TYPE_???");
 		tprintf(", c=" FMT_RECT "}", ARGS_RECT(c.c));
 		return 1;
 	}

 	case VIDIOC_G_FBUF:
 	case VIDIOC_S_FBUF: {
 		struct v4l2_framebuffer b;

 		if (syserror(tcp) && code == VIDIOC_G_FBUF)
 			return 0;
 		if (entering(tcp) || umove(tcp, arg, &b) < 0)
 			return 0;
 		tprintf(", {capability=%x, flags=%x, base=%p}",
 			b.capability, b.flags, b.base);
 		return 1;
 	}

 #ifdef VIDIOC_CREATE_BUFS
 	case VIDIOC_CREATE_BUFS: {
 		struct v4l2_create_buffers b;

 		if (exiting(tcp) && syserror(tcp))
 			return 1;
 		if (umove(tcp, arg, &b) < 0)
 			return 0;
 		if (entering(tcp)) {
 			tprintf(", {count=%u, memory=", b.count);
 			printxval(v4l2_memories, b.memory, "V4L2_MEMORY_???");
 			tprints(", format={type=");
 			printxval(v4l2_buf_types, b.format.type, "V4L2_BUF_TYPE_???");
 			tprints(", ");
 			print_v4l2_format_fmt(&b.format);
 			tprints("}}");
 			return 1;
 		} else {
 			static const char fmt[] = "{index=%u, count=%u}";
 			static char outstr[sizeof(fmt) + sizeof(int) * 6];

 			sprintf(outstr, fmt, b.index, b.count);
 			tcp->auxstr = outstr;
 			return 1 + RVAL_STR;
 		}
 	}
 #endif /* VIDIOC_CREATE_BUFS */

 	case VIDIOC_REQBUFS: {
 		struct v4l2_requestbuffers reqbufs;

 		if (umove(tcp, arg, &reqbufs) < 0)
 			return 0;
 		if (entering(tcp)) {
 			tprintf(", {count=%u, type=", reqbufs.count);
 			printxval(v4l2_buf_types, reqbufs.type, "V4L2_BUF_TYPE_???");
 			tprints(", memory=");
 			printxval(v4l2_memories, reqbufs.memory, "V4L2_MEMORY_???");
 			tprints("}");
 			return 1;
 		} else if (syserror(tcp))
 			return 1;
 		else {
 			static char outstr[sizeof("{count=}") + sizeof(int) * 3];

 			sprintf(outstr, "{count=%u}", reqbufs.count);
 			tcp->auxstr = outstr;
 			return 1 + RVAL_STR;
 		}
 	}

 	case VIDIOC_QUERYBUF:
 	case VIDIOC_QBUF:
 	case VIDIOC_DQBUF: {
 		struct v4l2_buffer b;

 		if (umove(tcp, arg, &b) < 0)
 			return 0;
 		if (entering(tcp)) {
 			tprints(", {type=");
 			printxval(v4l2_buf_types, b.type, "V4L2_BUF_TYPE_???");
 			if (code != VIDIOC_DQBUF)
 				tprintf(", index=%u", b.index);
 		} else {
 			if (!syserror(tcp)) {
 				if (code == VIDIOC_DQBUF)
 					tprintf(", index=%u", b.index);
 				tprints(", memory=");
 				printxval(v4l2_memories, b.memory, "V4L2_MEMORY_???");

 				if (b.memory == V4L2_MEMORY_MMAP) {
 					tprintf(", m.offset=%#x", b.m.offset);
 				} else if (b.memory == V4L2_MEMORY_USERPTR) {
 					tprintf(", m.userptr=%#lx", b.m.userptr);
 				}

 				tprintf(", length=%u, bytesused=%u, flags=",
 					b.length, b.bytesused);
 				printflags(v4l2_buf_flags, b.flags, "V4L2_BUF_FLAG_???");
 				if (code == VIDIOC_DQBUF)
 					tprintf(", timestamp = {%ju.%06ju}",
 						(uintmax_t)b.timestamp.tv_sec,
 						(uintmax_t)b.timestamp.tv_usec);
 				tprints(", ...");
 			}
 			tprints("}");
 		}
 		return 1;
 	}

 	case VIDIOC_STREAMON:
 	case VIDIOC_STREAMOFF: {
 		int type;

 		if (umove(tcp, arg, &type) < 0)
 			return 0;
 		if (entering(tcp)) {
 			tprints(", ");
 			printxval(v4l2_buf_types, type, "V4L2_BUF_TYPE_???");
 		}
 		return 1;
 	}

 	default: /* decode on exit */
 		return 0;
 	}
 }
	/*
	* Copyright (c) 2014 Philippe De Muyter <phdm@macqel.be>
	* Copyright (c) 2014 William Manley <will@williammanley.net>
	* Copyright (c) 2011 Peter Zotov <whitequark@whitequark.org>
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* 3. The name of the author may not be used to endorse or promote products
	* derived from this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "defs.h"

	#include <stdint.h>
	#include <sys/ioctl.h>
	#include <linux/types.h>
	#include <linux/videodev2.h>
	/* some historical constants */
	#ifndef V4L2_CID_HCENTER
	#define V4L2_CID_HCENTER (V4L2_CID_BASE+22)
	#endif
	#ifndef V4L2_CID_VCENTER
	#define V4L2_CID_VCENTER (V4L2_CID_BASE+23)
	#endif
	#ifndef V4L2_CID_BAND_STOP_FILTER
	#define V4L2_CID_BAND_STOP_FILTER (V4L2_CID_BASE+33)
	#endif

	#include "xlat/v4l2_device_capabilities_flags.h"
	#include "xlat/v4l2_buf_types.h"
	#include "xlat/v4l2_buf_flags.h"
	#include "xlat/v4l2_framesize_types.h"
	#include "xlat/v4l2_frameinterval_types.h"
	#include "xlat/v4l2_fields.h"
	#include "xlat/v4l2_colorspaces.h"
	#include "xlat/v4l2_format_description_flags.h"
	#include "xlat/v4l2_memories.h"
	#include "xlat/v4l2_control_ids.h"
	#include "xlat/v4l2_control_types.h"
	#include "xlat/v4l2_control_flags.h"
	#include "xlat/v4l2_control_classes.h"
	#include "xlat/v4l2_streaming_capabilities.h"
	#include "xlat/v4l2_capture_modes.h"
	#include "xlat/v4l2_input_types.h"

	#define FMT_FRACT "%u/%u"
	#define ARGS_FRACT(x) ((x).numerator), ((x).denominator)

	#define FMT_RECT "{left=%i, top=%i, width=%i, height=%i}"
	#define ARGS_RECT(x) (x).left, (x).top, (x).width, (x).height

	static void print_pixelformat(uint32_t fourcc)
	{
	union {
	uint32_t pixelformat;
	unsigned char cc[sizeof(uint32_t)];
	} u = {
	.pixelformat =
	#if WORDS_BIGENDIAN
	htole32(fourcc)
	#else
	fourcc
	#endif
	};
	unsigned int i;

	tprints("v4l2_fourcc(");
	for (i = 0; i < sizeof(u.cc); ++i) {
	unsigned int c = u.cc[i];

	if (i)
	tprints(", ");
	if (c == ' ' \|\|
	(c >= '0' && c <= '9') \|\|
	(c >= 'A' && c <= 'Z') \|\|
	(c >= 'a' && c <= 'z')) {
	char sym[] = {
	'\'',
	u.cc[i],
	'\''
	};
	tprints(sym);
	} else {
	char hex[] = {
	'\'',
	'\\',
	'x',
	"0123456789abcdef"[c >> 4],
	"0123456789abcdef"[c & 0xf],
	'\'',
	'\0'
	};
	tprints(hex);
	}
	}
	tprints(")");
	}

	static void print_v4l2_format_fmt(const struct v4l2_format *f)
	{
	tprints("fmt.");
	switch (f->type) {
	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
	case V4L2_BUF_TYPE_VIDEO_OUTPUT: {
	const struct v4l2_pix_format *pix = &f->fmt.pix;

	tprintf("pix={width=%u, height=%u, pixelformat=",
	pix->width, pix->height);
	print_pixelformat(pix->pixelformat);
	tprints(", field=");
	printxval(v4l2_fields, pix->field, "V4L2_FIELD_???");
	tprintf(", bytesperline=%u, sizeimage=%u, colorspace=",
	pix->bytesperline, pix->sizeimage);
	printxval(v4l2_colorspaces, pix->colorspace,
	"V4L2_COLORSPACE_???");
	tprints("}");
	break;
	}
	#if HAVE_DECL_V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE
	case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
	case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE: {
	const struct v4l2_pix_format_mplane *pix_mp = &f->fmt.pix_mp;
	unsigned int i, max;

	tprintf("pix_mp={width=%u, height=%u, pixelformat=",
	pix_mp->width, pix_mp->height);
	print_pixelformat(pix_mp->pixelformat);
	tprints(", field=");
	printxval(v4l2_fields, pix_mp->field, "V4L2_FIELD_???");
	tprints(", colorspace=");
	printxval(v4l2_colorspaces, pix_mp->colorspace,
	"V4L2_COLORSPACE_???");
	tprints("plane_fmt=[");
	max = pix_mp->num_planes;
	if (max > VIDEO_MAX_PLANES)
	max = VIDEO_MAX_PLANES;
	for (i = 0; i < max; i++) {
	if (i > 0)
	tprints(", ");
	tprintf("{sizeimage=%u, bytesperline=%u}",
	pix_mp->plane_fmt[i].sizeimage,
	pix_mp->plane_fmt[i].bytesperline);
	}
	tprintf("], num_planes=%u}", (unsigned) pix_mp->num_planes);
	break;
	}
	#endif

	/* TODO: Complete this switch statement */
	case V4L2_BUF_TYPE_VIDEO_OVERLAY:
	#if HAVE_DECL_V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY
	case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY:
	#endif
	tprints("win={???}");
	break;

	case V4L2_BUF_TYPE_VBI_CAPTURE:
	case V4L2_BUF_TYPE_VBI_OUTPUT:
	tprints("vbi={???}");
	break;

	case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
	case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
	tprints("sliced={???}");
	break;

	default:
	tprints("???");
	break;
	}
	}

	int
	v4l2_ioctl(struct tcb *tcp, const unsigned int code, long arg)
	{
	if (!verbose(tcp))
	return 0;

	switch (code) {
	case VIDIOC_QUERYCAP: /* decode on exit */ {
	struct v4l2_capability caps;

	if (entering(tcp) \|\| syserror(tcp) \|\| umove(tcp, arg, &caps) < 0)
	return 0;
	tprints(", {driver=");
	print_quoted_string((const char *) caps.driver,
	sizeof(caps.driver), QUOTE_0_TERMINATED);
	tprints(", card=");
	print_quoted_string((const char *) caps.card,
	sizeof(caps.card), QUOTE_0_TERMINATED);
	tprints(", bus_info=");
	print_quoted_string((const char *) caps.bus_info,
	sizeof(caps.bus_info), QUOTE_0_TERMINATED);
	tprintf(", version=%u.%u.%u, capabilities=",
	(caps.version >> 16) & 0xFF,
	(caps.version >> 8) & 0xFF,
	caps.version & 0xFF);
	printflags(v4l2_device_capabilities_flags, caps.capabilities,
	"V4L2_CAP_???");
	#ifdef V4L2_CAP_DEVICE_CAPS
	tprints(", device_caps=");
	printflags(v4l2_device_capabilities_flags, caps.device_caps,
	"V4L2_CAP_???");
	#endif
	tprints("}");
	return 1;
	}

	#ifdef VIDIOC_ENUM_FRAMESIZES
	case VIDIOC_ENUM_FRAMESIZES: /* decode on exit */ {
	struct v4l2_frmsizeenum s;

	if (entering(tcp) \|\| umove(tcp, arg, &s) < 0)
	return 0;
	tprintf(", {index=%u, pixel_format=", s.index);
	print_pixelformat(s.pixel_format);

	if (!syserror(tcp)) {
	tprints(", type=");
	printxval(v4l2_framesize_types, s.type, "V4L2_FRMSIZE_TYPE_???");
	switch (s.type) {
	case V4L2_FRMSIZE_TYPE_DISCRETE:
	tprintf(", discrete={width=%u, height=%u}",
	s.discrete.width, s.discrete.height);
	break;
	case V4L2_FRMSIZE_TYPE_STEPWISE:
	tprintf(", stepwise={min_width=%u, max_width=%u, "
	"step_width=%u, min_height=%u, max_height=%u, "
	"step_height=%u}",
	s.stepwise.min_width, s.stepwise.max_width,
	s.stepwise.step_width, s.stepwise.min_height,
	s.stepwise.max_height, s.stepwise.step_height);
	break;
	}
	}
	tprints("}");
	return 1;
	}
	#endif /* VIDIOC_ENUM_FRAMESIZES */

	case VIDIOC_G_FMT:
	case VIDIOC_S_FMT:
	case VIDIOC_TRY_FMT: {
	struct v4l2_format f;

	if (umove(tcp, arg, &f) < 0)
	return 0;
	if (entering(tcp)) {
	tprints(", {type=");
	printxval(v4l2_buf_types, f.type, "V4L2_BUF_TYPE_???");
	}
	if ((entering(tcp) && code != VIDIOC_G_FMT)
	\|\| (exiting(tcp) && !syserror(tcp))) {
	tprints(exiting(tcp) && code != VIDIOC_G_FMT ? " => " : ", ");
	print_v4l2_format_fmt(&f);
	}
	if (exiting(tcp))
	tprints("}");
	return 1;
	}

	case VIDIOC_ENUM_FMT: {
	struct v4l2_fmtdesc f;

	if (entering(tcp) \|\| umove(tcp, arg, &f) < 0)
	return 0;

	tprintf(", {index=%u", f.index);
	if (!syserror(tcp)) {
	tprints(", type=");
	printxval(v4l2_buf_types, f.type, "V4L2_BUF_TYPE_???");
	tprints(", flags=");
	printflags(v4l2_format_description_flags, f.flags,
	"V4L2_FMT_FLAG_???");
	tprints(", description=");
	print_quoted_string((const char *) f.description,
	sizeof(f.description),
	QUOTE_0_TERMINATED);
	tprints(", pixelformat=");
	print_pixelformat(f.pixelformat);
	}
	tprints("}");
	return 1;
	}

	case VIDIOC_G_PARM:
	case VIDIOC_S_PARM: {
	struct v4l2_streamparm s;

	if (entering(tcp) && code == VIDIOC_G_PARM)
	return 1;
	if (exiting(tcp) && syserror(tcp))
	return code == VIDIOC_S_PARM;
	if (umove(tcp, arg, &s) < 0)
	return 0;
	if (entering(tcp)) {
	tprints(", {type=");
	printxval(v4l2_buf_types, s.type, "V4L2_BUF_TYPE_???");
	}

	tprints(exiting(tcp) && code == VIDIOC_S_PARM ? " => {" : ", {");
	if (s.type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
	struct v4l2_captureparm *cap = &s.parm.capture;

	tprints("capability=");
	printflags(v4l2_streaming_capabilities,
	cap->capability, "V4L2_CAP_???");

	tprints(", capturemode=");
	printflags(v4l2_capture_modes,
	cap->capturemode, "V4L2_MODE_???");

	tprintf(", timeperframe=" FMT_FRACT,
	ARGS_FRACT(cap->timeperframe));

	tprintf(", extendedmode=%u, readbuffers=%u",
	cap->extendedmode,
	cap->readbuffers);
	} else
	tprints("...");
	tprints("}");
	if (exiting(tcp))
	tprints("}");
	return 1;
	}

	case VIDIOC_QUERYCTRL: {
	struct v4l2_queryctrl c;

	if (umove(tcp, arg, &c) < 0)
	return 0;
	/* 'id' field must be printed :
	* on enter
	* on exit if !syserror(tcp) && V4L2_CTRL_FLAG_NEXT_CTRL was set
	*/
	if (entering(tcp)
	\|\| (exiting(tcp) && tcp->auxstr && !syserror(tcp))) {
	tprints(exiting(tcp) ? " => " : ", {id=");
	#ifdef V4L2_CTRL_FLAG_NEXT_CTRL
	tcp->auxstr = (c.id & V4L2_CTRL_FLAG_NEXT_CTRL) ? "" : NULL;
	if (tcp->auxstr) {
	tprints("V4L2_CTRL_FLAG_NEXT_CTRL\|");
	c.id &= ~V4L2_CTRL_FLAG_NEXT_CTRL;
	}
	#endif
	printxval(v4l2_control_ids, c.id, "V4L2_CID_???");
	}
	if (exiting(tcp)) {
	if (!syserror(tcp)) {
	tprints(", type=");
	printxval(v4l2_control_types, c.type,
	"V4L2_CTRL_TYPE_???");
	tprints(", name=");
	print_quoted_string((const char *) c.name,
	sizeof(c.name),
	QUOTE_0_TERMINATED);
	tprintf(", minimum=%i, maximum=%i, step=%i, "
	"default_value=%i, flags=",
	c.minimum, c.maximum,
	c.step, c.default_value);
	printflags(v4l2_control_flags, c.flags,
	"V4L2_CTRL_FLAG_???");
	}
	tprints("}");
	}
	return 1;
	}

	case VIDIOC_G_CTRL:
	case VIDIOC_S_CTRL: {
	struct v4l2_control c;

	if (entering(tcp) \|\| umove(tcp, arg, &c) < 0)
	return 0;
	tprints(", {id=");
	printxval(v4l2_control_ids, c.id, "V4L2_CID_???");
	if (!syserror(tcp) \|\| code != VIDIOC_G_CTRL)
	tprintf(", value=%i", c.value);
	tprints("}");
	return 1;
	}

	#ifdef VIDIOC_S_EXT_CTRLS
	case VIDIOC_S_EXT_CTRLS:
	case VIDIOC_TRY_EXT_CTRLS:
	case VIDIOC_G_EXT_CTRLS: {
	struct v4l2_ext_controls c;
	unsigned int n;
	bool must_print_values;

	if (entering(tcp) && code == VIDIOC_G_EXT_CTRLS)
	return 0;
	if (exiting(tcp) && syserror(tcp) && code != VIDIOC_G_EXT_CTRLS)
	return 0;
	must_print_values = ((entering(tcp) && code != VIDIOC_G_EXT_CTRLS)
	\|\| (exiting(tcp) && !syserror(tcp)));
	if (umove(tcp, arg, &c) < 0)
	return 0;
	tprints(code != VIDIOC_G_EXT_CTRLS && exiting(tcp) ? " => " : ", ");
	tprints("{ctrl_class=");
	printxval(v4l2_control_classes, c.ctrl_class,
	"V4L2_CTRL_CLASS_???");
	tprintf(", count=%u", c.count);
	if (exiting(tcp) && syserror(tcp))
	tprintf(", error_idx=%u", c.error_idx);
	tprints(", controls=[");
	for (n = 0; n < c.count; ++n) {
	struct v4l2_ext_control ctrl;

	if (n > 0)
	tprints(", ");
	if (umove(tcp, (long) (c.controls + n), &ctrl) < 0)
	break;
	if (abbrev(tcp) && n == 2) {
	tprints("...");
	break;
	}
	tprints("{id=");
	printxval(v4l2_control_ids, ctrl.id, "V4L2_CID_???");
	# if HAVE_DECL_V4L2_CTRL_TYPE_STRING
	tprintf(", size=%u", ctrl.size);
	if (ctrl.size > 0) {
	if (must_print_values) {
	tprints(", string=");
	printstr(tcp, (long) ctrl.string, ctrl.size);
	}
	} else
	# endif
	{
	if (must_print_values) {
	tprintf(", value=%i, value64=%lld", ctrl.value,
	(long long) ctrl.value64);
	}
	}
	tprints("}");
	}
	tprints("]}");
	return 1;
	}
	#endif /* VIDIOC_S_EXT_CTRLS */

	case VIDIOC_ENUMSTD: {
	struct v4l2_standard s;

	if (umove(tcp, arg, &s) < 0)
	return 0;
	if (entering(tcp))
	tprintf(", {index=%i", s.index);
	else {
	if (!syserror(tcp)) {
	tprints(", name=");
	print_quoted_string((const char *) s.name,
	sizeof(s.name),
	QUOTE_0_TERMINATED);
	tprintf(", frameperiod=" FMT_FRACT, ARGS_FRACT(s.frameperiod));
	tprintf(", framelines=%i", s.framelines);
	}
	tprints("}");
	}
	return 1;
	}

	case VIDIOC_G_STD:
	case VIDIOC_S_STD: {
	v4l2_std_id s;

	if (code == VIDIOC_G_STD && exiting(tcp) && syserror(tcp))
	return 0;
	if (umove(tcp, arg, &s) < 0)
	return 0;
	if ((code == VIDIOC_S_STD) == entering(tcp))
	tprintf(", std=%#llx", (unsigned long long) s);
	return 1;
	}

	case VIDIOC_ENUMINPUT: {
	struct v4l2_input i;

	if (entering(tcp) \|\| umove(tcp, arg, &i) < 0)
	return 0;
	tprintf(", {index=%i", i.index);
	if (!syserror(tcp)) {
	tprints(", name=");
	print_quoted_string((const char *) i.name,
	sizeof(i.name), QUOTE_0_TERMINATED);
	tprints(", type=");
	printxval(v4l2_input_types, i.type,
	"V4L2_INPUT_TYPE_???");
	}
	tprints("}");
	return 1;
	}

	case VIDIOC_G_INPUT:
	case VIDIOC_S_INPUT: {
	int index;

	if (entering(tcp) \|\| syserror(tcp) \|\| umove(tcp, arg, &index) < 0)
	return 0;

	tprintf(", index=%i", index);
	return 1;
	}

	#ifdef VIDIOC_ENUM_FRAMEINTERVALS
	case VIDIOC_ENUM_FRAMEINTERVALS: {
	struct v4l2_frmivalenum f;

	if (entering(tcp) \|\| umove(tcp, arg, &f) < 0)
	return 0;
	tprintf(", {index=%i, pixel_format=", f.index);
	print_pixelformat(f.pixel_format);
	tprintf(", width=%u, height=%u", f.width, f.height);
	if (!syserror(tcp)) {
	tprints(", type=");
	printxval(v4l2_frameinterval_types, f.type,
	"V4L2_FRMIVAL_TYPE_???");
	switch (f.type) {
	case V4L2_FRMIVAL_TYPE_DISCRETE:
	tprintf(", discrete=" FMT_FRACT,
	ARGS_FRACT(f.discrete));
	break;
	case V4L2_FRMIVAL_TYPE_STEPWISE:
	case V4L2_FRMSIZE_TYPE_CONTINUOUS:
	tprintf(", stepwise={min=" FMT_FRACT ", max="
	FMT_FRACT ", step=" FMT_FRACT "}",
	ARGS_FRACT(f.stepwise.min),
	ARGS_FRACT(f.stepwise.max),
	ARGS_FRACT(f.stepwise.step));
	break;
	}
	}
	tprints("}");
	return 1;
	}
	#endif /* VIDIOC_ENUM_FRAMEINTERVALS */

	case VIDIOC_CROPCAP: {
	struct v4l2_cropcap c;

	if (entering(tcp) \|\| umove(tcp, arg, &c) < 0)
	return 0;
	tprints(", {type=");
	printxval(v4l2_buf_types, c.type, "V4L2_BUF_TYPE_???");
	if (!syserror(tcp))
	tprintf(", bounds=" FMT_RECT ", defrect=" FMT_RECT ", "
	"pixelaspect=" FMT_FRACT, ARGS_RECT(c.bounds),
	ARGS_RECT(c.defrect), ARGS_FRACT(c.pixelaspect));
	tprints("}");
	return 1;
	}

	case VIDIOC_S_CROP: {
	struct v4l2_crop c;

	if (exiting(tcp) \|\| umove(tcp, arg, &c) < 0)
	return 0;
	tprints(", {type=");
	printxval(v4l2_buf_types, c.type, "V4L2_BUF_TYPE_???");
	tprintf(", c=" FMT_RECT "}", ARGS_RECT(c.c));
	return 1;
	}

	case VIDIOC_G_FBUF:
	case VIDIOC_S_FBUF: {
	struct v4l2_framebuffer b;

	if (syserror(tcp) && code == VIDIOC_G_FBUF)
	return 0;
	if (entering(tcp) \|\| umove(tcp, arg, &b) < 0)
	return 0;
	tprintf(", {capability=%x, flags=%x, base=%p}",
	b.capability, b.flags, b.base);
	return 1;
	}

	#ifdef VIDIOC_CREATE_BUFS
	case VIDIOC_CREATE_BUFS: {
	struct v4l2_create_buffers b;

	if (exiting(tcp) && syserror(tcp))
	return 1;
	if (umove(tcp, arg, &b) < 0)
	return 0;
	if (entering(tcp)) {
	tprintf(", {count=%u, memory=", b.count);
	printxval(v4l2_memories, b.memory, "V4L2_MEMORY_???");
	tprints(", format={type=");
	printxval(v4l2_buf_types, b.format.type, "V4L2_BUF_TYPE_???");
	tprints(", ");
	print_v4l2_format_fmt(&b.format);
	tprints("}}");
	return 1;
	} else {
	static const char fmt[] = "{index=%u, count=%u}";
	static char outstr[sizeof(fmt) + sizeof(int) * 6];

	sprintf(outstr, fmt, b.index, b.count);
	tcp->auxstr = outstr;
	return 1 + RVAL_STR;
	}
	}
	#endif /* VIDIOC_CREATE_BUFS */

	case VIDIOC_REQBUFS: {
	struct v4l2_requestbuffers reqbufs;

	if (umove(tcp, arg, &reqbufs) < 0)
	return 0;
	if (entering(tcp)) {
	tprintf(", {count=%u, type=", reqbufs.count);
	printxval(v4l2_buf_types, reqbufs.type, "V4L2_BUF_TYPE_???");
	tprints(", memory=");
	printxval(v4l2_memories, reqbufs.memory, "V4L2_MEMORY_???");
	tprints("}");
	return 1;
	} else if (syserror(tcp))
	return 1;
	else {
	static char outstr[sizeof("{count=}") + sizeof(int) * 3];

	sprintf(outstr, "{count=%u}", reqbufs.count);
	tcp->auxstr = outstr;
	return 1 + RVAL_STR;
	}
	}

	case VIDIOC_QUERYBUF:
	case VIDIOC_QBUF:
	case VIDIOC_DQBUF: {
	struct v4l2_buffer b;

	if (umove(tcp, arg, &b) < 0)
	return 0;
	if (entering(tcp)) {
	tprints(", {type=");
	printxval(v4l2_buf_types, b.type, "V4L2_BUF_TYPE_???");
	if (code != VIDIOC_DQBUF)
	tprintf(", index=%u", b.index);
	} else {
	if (!syserror(tcp)) {
	if (code == VIDIOC_DQBUF)
	tprintf(", index=%u", b.index);
	tprints(", memory=");
	printxval(v4l2_memories, b.memory, "V4L2_MEMORY_???");

	if (b.memory == V4L2_MEMORY_MMAP) {
	tprintf(", m.offset=%#x", b.m.offset);
	} else if (b.memory == V4L2_MEMORY_USERPTR) {
	tprintf(", m.userptr=%#lx", b.m.userptr);
	}

	tprintf(", length=%u, bytesused=%u, flags=",
	b.length, b.bytesused);
	printflags(v4l2_buf_flags, b.flags, "V4L2_BUF_FLAG_???");
	if (code == VIDIOC_DQBUF)
	tprintf(", timestamp = {%ju.%06ju}",
	(uintmax_t)b.timestamp.tv_sec,
	(uintmax_t)b.timestamp.tv_usec);
	tprints(", ...");
	}
	tprints("}");
	}
	return 1;
	}

	case VIDIOC_STREAMON:
	case VIDIOC_STREAMOFF: {
	int type;

	if (umove(tcp, arg, &type) < 0)
	return 0;
	if (entering(tcp)) {
	tprints(", ");
	printxval(v4l2_buf_types, type, "V4L2_BUF_TYPE_???");
	}
	return 1;
	}

	default: /* decode on exit */
	return 0;
	}
	}