granicus.if.org Git - strace/blob - v4l2.c

   1 /*
   2  * Copyright (c) 2014 Philippe De Muyter <phdm@macqel.be>
   3  * Copyright (c) 2014 William Manley <will@williammanley.net>
   4  * Copyright (c) 2011 Peter Zotov <whitequark@whitequark.org>
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. The name of the author may not be used to endorse or promote products
  16  *    derived from this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #include "defs.h"
  31
  32 #include <stdint.h>
  33 #include <sys/ioctl.h>
  34 #include <linux/videodev2.h>
  35 /* some historical constants */
  36 #ifndef V4L2_CID_HCENTER
  37 #define V4L2_CID_HCENTER (V4L2_CID_BASE+22)
  38 #endif
  39 #ifndef V4L2_CID_VCENTER
  40 #define V4L2_CID_VCENTER (V4L2_CID_BASE+23)
  41 #endif
  42 #ifndef V4L2_CID_BAND_STOP_FILTER
  43 #define V4L2_CID_BAND_STOP_FILTER (V4L2_CID_BASE+33)
  44 #endif
  45
  46 #include "xlat/v4l2_device_capabilities_flags.h"
  47 #include "xlat/v4l2_buf_types.h"
  48 #include "xlat/v4l2_buf_flags.h"
  49 #include "xlat/v4l2_framesize_types.h"
  50 #include "xlat/v4l2_frameinterval_types.h"
  51 #include "xlat/v4l2_fields.h"
  52 #include "xlat/v4l2_colorspaces.h"
  53 #include "xlat/v4l2_format_description_flags.h"
  54 #include "xlat/v4l2_memories.h"
  55 #include "xlat/v4l2_control_ids.h"
  56 #include "xlat/v4l2_control_types.h"
  57 #include "xlat/v4l2_control_flags.h"
  58 #include "xlat/v4l2_control_classes.h"
  59 #include "xlat/v4l2_streaming_capabilities.h"
  60 #include "xlat/v4l2_capture_modes.h"
  61 #include "xlat/v4l2_input_types.h"
  62
  63 #define FMT_FRACT "%u/%u"
  64 #define ARGS_FRACT(x) ((x).numerator), ((x).denominator)
  65
  66 #define FMT_RECT "{left=%i, top=%i, width=%i, height=%i}"
  67 #define ARGS_RECT(x) (x).left, (x).top, (x).width, (x).height
  68
  69 static void print_pixelformat(uint32_t fourcc)
  70 {
  71 #if WORDS_BIGENDIAN
  72         fourcc = htole32(fourcc);
  73 #endif
  74         tprintf("%.4s", (char*)&fourcc);
  75 }
  76
  77 static void print_v4l2_format_fmt(const struct v4l2_format *f)
  78 {
  79         tprints("fmt.");
  80         switch (f->type) {
  81         case V4L2_BUF_TYPE_VIDEO_CAPTURE:
  82         case V4L2_BUF_TYPE_VIDEO_OUTPUT: {
  83                 const struct v4l2_pix_format *pix = &f->fmt.pix;
  84
  85                 tprintf("pix={width=%u, height=%u, pixelformat=",
  86                         pix->width, pix->height);
  87                 print_pixelformat(pix->pixelformat);
  88                 tprints(", field=");
  89                 printxval(v4l2_fields, pix->field, "V4L2_FIELD_???");
  90                 tprintf(", bytesperline=%u, sizeimage=%u, colorspace=",
  91                         pix->bytesperline, pix->sizeimage);
  92                 printxval(v4l2_colorspaces, pix->colorspace,
  93                           "V4L2_COLORSPACE_???");
  94                 tprints("}");
  95                 break;
  96         }
  97 #if HAVE_DECL_V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE
  98         case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
  99         case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE: {
 100                 const struct v4l2_pix_format_mplane *pix_mp = &f->fmt.pix_mp;
 101                 unsigned int i, max;
 102
 103                 tprintf("pix_mp={width=%u, height=%u, pixelformat=",
 104                         pix_mp->width, pix_mp->height);
 105                 print_pixelformat(pix_mp->pixelformat);
 106                 tprints(", field=");
 107                 printxval(v4l2_fields, pix_mp->field, "V4L2_FIELD_???");
 108                 tprints(", colorspace=");
 109                 printxval(v4l2_colorspaces, pix_mp->colorspace,
 110                           "V4L2_COLORSPACE_???");
 111                 tprints("plane_fmt=[");
 112                 max = pix_mp->num_planes;
 113                 if (max > VIDEO_MAX_PLANES)
 114                         max = VIDEO_MAX_PLANES;
 115                 for (i = 0; i < max; i++) {
 116                         if (i > 0)
 117                                 tprints(", ");
 118                         tprintf("{sizeimage=%u, bytesperline=%u}",
 119                                 pix_mp->plane_fmt[i].sizeimage,
 120                                 pix_mp->plane_fmt[i].bytesperline);
 121                 }
 122                 tprintf("], num_planes=%u}", (unsigned) pix_mp->num_planes);
 123                 break;
 124         }
 125 #endif
 126
 127         /* TODO: Complete this switch statement */
 128         case V4L2_BUF_TYPE_VIDEO_OVERLAY:
 129         case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY:
 130                 tprints("win={???}");
 131                 break;
 132
 133         case V4L2_BUF_TYPE_VBI_CAPTURE:
 134         case V4L2_BUF_TYPE_VBI_OUTPUT:
 135                 tprints("vbi={???}");
 136                 break;
 137
 138         case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE:
 139         case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
 140                 tprints("sliced={???}");
 141                 break;
 142
 143         default:
 144                 tprints("???");
 145                 break;
 146         }
 147 }
 148
 149 int
 150 v4l2_ioctl(struct tcb *tcp, unsigned long code, long arg)
 151 {
 152         if (!verbose(tcp))
 153                 return 0;
 154
 155         switch (code) {
 156         case VIDIOC_QUERYCAP: /* decode on exit */ {
 157                 struct v4l2_capability caps;
 158
 159                 if (entering(tcp) || syserror(tcp) || umove(tcp, arg, &caps) < 0)
 160                         return 0;
 161                 tprintf(", {driver=\"%s\", card=\"%s\", bus_info=\"%s\", "
 162                         "version=%u.%u.%u, capabilities=", caps.driver, caps.card,
 163                         caps.bus_info, (caps.version >> 16) & 0xFF,
 164                         (caps.version >> 8) & 0xFF, caps.version & 0xFF);
 165                 printflags(v4l2_device_capabilities_flags, caps.capabilities,
 166                            "V4L2_CAP_???");
 167 #ifdef V4L2_CAP_DEVICE_CAPS
 168                 tprints(", device_caps=");
 169                 printflags(v4l2_device_capabilities_flags, caps.device_caps,
 170                            "V4L2_CAP_???");
 171 #endif
 172                 tprints("}");
 173                 return 1;
 174         }
 175
 176         case VIDIOC_ENUM_FRAMESIZES: /* decode on exit */ {
 177                 struct v4l2_frmsizeenum s;
 178
 179                 if (entering(tcp) || umove(tcp, arg, &s) < 0)
 180                         return 0;
 181                 tprintf(", {index=%u, pixel_format=", s.index);
 182                 print_pixelformat(s.pixel_format);
 183
 184                 if (!syserror(tcp)) {
 185                         tprints(", type=");
 186                         printxval(v4l2_framesize_types, s.type, "V4L2_FRMSIZE_TYPE_???");
 187                         switch (s.type) {
 188                         case V4L2_FRMSIZE_TYPE_DISCRETE:
 189                                 tprintf(", discrete={width=%u, height=%u}",
 190                                         s.discrete.width, s.discrete.height);
 191                                 break;
 192                         case V4L2_FRMSIZE_TYPE_STEPWISE:
 193                                 tprintf(", stepwise={min_width=%u, max_width=%u, "
 194                                         "step_width=%u, min_height=%u, max_height=%u, "
 195                                         "step_height=%u}",
 196                                         s.stepwise.min_width, s.stepwise.max_width,
 197                                         s.stepwise.step_width, s.stepwise.min_height,
 198                                         s.stepwise.max_height, s.stepwise.step_height);
 199                                 break;
 200                         }
 201                 }
 202                 tprints("}");
 203                 return 1;
 204         }
 205
 206         case VIDIOC_G_FMT:
 207         case VIDIOC_S_FMT:
 208         case VIDIOC_TRY_FMT: {
 209                 struct v4l2_format f;
 210
 211                 if (umove(tcp, arg, &f) < 0)
 212                         return 0;
 213                 if (entering(tcp)) {
 214                         tprints(", {type=");
 215                         printxval(v4l2_buf_types, f.type, "V4L2_BUF_TYPE_???");
 216                 }
 217                 if ((entering(tcp) && code != VIDIOC_G_FMT)
 218                     || (exiting(tcp) && !syserror(tcp))) {
 219                         tprints(exiting(tcp) && code != VIDIOC_G_FMT ? " => " : ", ");
 220                         print_v4l2_format_fmt(&f);
 221                 }
 222                 if (exiting(tcp))
 223                         tprints("}");
 224                 return 1;
 225         }
 226
 227         case VIDIOC_ENUM_FMT: {
 228                 struct v4l2_fmtdesc f;
 229
 230                 if (entering(tcp) || umove(tcp, arg, &f) < 0)
 231                         return 0;
 232
 233                 tprintf(", {index=%u", f.index);
 234                 if (!syserror(tcp)) {
 235                         tprints(", type=");
 236                         printxval(v4l2_buf_types, f.type, "V4L2_BUF_TYPE_???");
 237                         tprints(", flags=");
 238                         printflags(v4l2_format_description_flags, f.flags,
 239                                    "V4L2_FMT_FLAG_???");
 240                         tprintf(", description=\"%s\", pixelformat=",
 241                                 f.description);
 242                         print_pixelformat(f.pixelformat);
 243                 }
 244                 tprints("}");
 245                 return 1;
 246         }
 247
 248         case VIDIOC_G_PARM:
 249         case VIDIOC_S_PARM: {
 250                 struct v4l2_streamparm s;
 251
 252                 if (entering(tcp) && code == VIDIOC_G_PARM)
 253                         return 1;
 254                 if (exiting(tcp) && syserror(tcp))
 255                         return code == VIDIOC_S_PARM;
 256                 if (umove(tcp, arg, &s) < 0)
 257                         return 0;
 258                 if (entering(tcp)) {
 259                         tprints(", {type=");
 260                         printxval(v4l2_buf_types, s.type, "V4L2_BUF_TYPE_???");
 261                 }
 262
 263                 tprints(exiting(tcp) && code == VIDIOC_S_PARM ? " => {" : ", {");
 264                 if (s.type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
 265                         struct v4l2_captureparm *cap = &s.parm.capture;
 266
 267                         tprints("capability=");
 268                         printflags(v4l2_streaming_capabilities,
 269                                    cap->capability, "V4L2_CAP_???");
 270
 271                         tprints(", capturemode=");
 272                         printflags(v4l2_capture_modes,
 273                                    cap->capturemode, "V4L2_MODE_???");
 274
 275                         tprintf(", timeperframe=" FMT_FRACT,
 276                                 ARGS_FRACT(cap->timeperframe));
 277
 278                         tprintf(", extendedmode=%u, readbuffers=%u",
 279                                 cap->extendedmode,
 280                                 cap->readbuffers);
 281                 } else
 282                         tprints("...");
 283                 tprints("}");
 284                 if (exiting(tcp))
 285                         tprints("}");
 286                 return 1;
 287         }
 288
 289         case VIDIOC_QUERYCTRL: {
 290                 struct v4l2_queryctrl c;
 291
 292                 if (umove(tcp, arg, &c) < 0)
 293                         return 0;
 294                 /* 'id' field must be printed :
 295                 * on enter
 296                 * on exit if !syserror(tcp) && V4L2_CTRL_FLAG_NEXT_CTRL was set
 297                 */
 298                 if (entering(tcp)
 299                     || (exiting(tcp) && tcp->auxstr && !syserror(tcp))) {
 300                         tprints(exiting(tcp) ? " => " : ", {id=");
 301                         tcp->auxstr = (c.id & V4L2_CTRL_FLAG_NEXT_CTRL) ? "" : NULL;
 302                         if (tcp->auxstr) {
 303                                 tprints("V4L2_CTRL_FLAG_NEXT_CTRL|");
 304                                 c.id &= ~V4L2_CTRL_FLAG_NEXT_CTRL;
 305                         }
 306                         printxval(v4l2_control_ids, c.id, "V4L2_CID_???");
 307                 }
 308                 if (exiting(tcp)) {
 309                         if (!syserror(tcp)) {
 310                                 tprints(", type=");
 311                                 printxval(v4l2_control_types, c.type,
 312                                           "V4L2_CTRL_TYPE_???");
 313                                 tprintf(", name=\"%s\", minimum=%i, maximum=%i, step=%i, "
 314                                         "default_value=%i, flags=",
 315                                         c.name, c.minimum, c.maximum,
 316                                         c.step, c.default_value);
 317                                 printflags(v4l2_control_flags, c.flags,
 318                                            "V4L2_CTRL_FLAG_???");
 319                         }
 320                         tprints("}");
 321                 }
 322                 return 1;
 323         }
 324
 325         case VIDIOC_G_CTRL:
 326         case VIDIOC_S_CTRL: {
 327                 struct v4l2_control c;
 328
 329                 if (entering(tcp) || umove(tcp, arg, &c) < 0)
 330                         return 0;
 331                 tprints(", {id=");
 332                 printxval(v4l2_control_ids, c.id, "V4L2_CID_???");
 333                 if (!syserror(tcp) || code != VIDIOC_G_CTRL)
 334                         tprintf(", value=%i", c.value);
 335                 tprints("}");
 336                 return 1;
 337         }
 338
 339         case VIDIOC_S_EXT_CTRLS:
 340         case VIDIOC_TRY_EXT_CTRLS:
 341         case VIDIOC_G_EXT_CTRLS: {
 342                 struct v4l2_ext_controls c;
 343                 unsigned int n;
 344                 bool must_print_values;
 345
 346                 if (entering(tcp) && code == VIDIOC_G_EXT_CTRLS)
 347                         return 0;
 348                 if (exiting(tcp) && syserror(tcp) && code != VIDIOC_G_EXT_CTRLS)
 349                         return 0;
 350                 must_print_values = ((entering(tcp) && code != VIDIOC_G_EXT_CTRLS)
 351                                      || (exiting(tcp) && !syserror(tcp)));
 352                 if (umove(tcp, arg, &c) < 0)
 353                         return 0;
 354                 tprints(code != VIDIOC_G_EXT_CTRLS && exiting(tcp) ? " => " : ", ");
 355                 tprints("{ctrl_class=");
 356                 printxval(v4l2_control_classes, c.ctrl_class,
 357                           "V4L2_CTRL_CLASS_???");
 358                 tprintf(", count=%u", c.count);
 359                 if (exiting(tcp) && syserror(tcp))
 360                         tprintf(", error_idx=%u", c.error_idx);
 361                 tprints(", controls=[");
 362                 for (n = 0; n < c.count; ++n) {
 363                         struct v4l2_ext_control ctrl;
 364
 365                         if (n > 0)
 366                                 tprints(", ");
 367                         if (umove(tcp, (long) (c.controls + n), &ctrl) < 0)
 368                                 break;
 369                         if (abbrev(tcp) && n == 2) {
 370                                 tprints("...");
 371                                 break;
 372                         }
 373                         tprints("{id=");
 374                         printxval(v4l2_control_ids, ctrl.id, "V4L2_CID_???");
 375 #if HAVE_DECL_V4L2_CTRL_TYPE_STRING
 376                         tprintf(", size=%u", ctrl.size);
 377                         if (ctrl.size > 0) {
 378                                 if (must_print_values) {
 379                                         tprints(", string=");
 380                                         printstr(tcp, (long) ctrl.string, ctrl.size);
 381                                 }
 382                         } else
 383 #endif
 384                         {
 385                                 if (must_print_values) {
 386                                         tprintf(", value=%i, value64=%lli", ctrl.value,
 387                                                 ctrl.value64);
 388                                 }
 389                         }
 390                         tprints("}");
 391                 }
 392                 tprints("]}");
 393                 return 1;
 394         }
 395
 396         case VIDIOC_ENUMSTD: {
 397                 struct v4l2_standard s;
 398
 399                 if (umove(tcp, arg, &s) < 0)
 400                         return 0;
 401                 if (entering(tcp))
 402                         tprintf(", {index=%i", s.index);
 403                 else {
 404                         if (!syserror(tcp)) {
 405                                 tprintf(", name=\"%s\"", s.name);
 406                                 tprintf(", frameperiod=" FMT_FRACT, ARGS_FRACT(s.frameperiod));
 407                                 tprintf(", framelines=%i", s.framelines);
 408                         }
 409                         tprints("}");
 410                 }
 411                 return 1;
 412         }
 413
 414         case VIDIOC_G_STD:
 415         case VIDIOC_S_STD: {
 416                 v4l2_std_id s;
 417
 418                 if (code == VIDIOC_G_STD && exiting(tcp) && syserror(tcp))
 419                         return 0;
 420                 if (umove(tcp, arg, &s) < 0)
 421                         return 0;
 422                 if ((code == VIDIOC_S_STD) == entering(tcp))
 423                         tprintf(", std=%#llx", s);
 424                 return 1;
 425         }
 426
 427         case VIDIOC_ENUMINPUT: {
 428                 struct v4l2_input i;
 429
 430                 if (entering(tcp) || umove(tcp, arg, &i) < 0)
 431                         return 0;
 432                 tprintf(", {index=%i", i.index);
 433                 if (!syserror(tcp)) {
 434                         tprintf(", name=\"%s\", type=", i.name);
 435                         printxval(v4l2_input_types, i.type,
 436                                   "V4L2_INPUT_TYPE_???");
 437                 }
 438                 tprints("}");
 439                 return 1;
 440         }
 441
 442         case VIDIOC_G_INPUT:
 443         case VIDIOC_S_INPUT: {
 444                 int index;
 445
 446                 if (entering(tcp) || syserror(tcp) || umove(tcp, arg, &index) < 0)
 447                         return 0;
 448
 449                 tprintf(", index=%i", index);
 450                 return 1;
 451         }
 452
 453         case VIDIOC_ENUM_FRAMEINTERVALS: {
 454                 struct v4l2_frmivalenum f;
 455
 456                 if (entering(tcp) || umove(tcp, arg, &f) < 0)
 457                         return 0;
 458                 tprintf(", {index=%i, pixel_format=", f.index);
 459                 print_pixelformat(f.pixel_format);
 460                 tprintf(", width=%u, height=%u", f.width, f.height);
 461                 if (!syserror(tcp)) {
 462                         tprints(", type=");
 463                         printxval(v4l2_frameinterval_types, f.type,
 464                                   "V4L2_FRMIVAL_TYPE_???");
 465                         switch (f.type) {
 466                         case V4L2_FRMIVAL_TYPE_DISCRETE:
 467                                 tprintf(", discrete=" FMT_FRACT,
 468                                         ARGS_FRACT(f.discrete));
 469                                 break;
 470                         case V4L2_FRMIVAL_TYPE_STEPWISE:
 471                         case V4L2_FRMSIZE_TYPE_CONTINUOUS:
 472                                 tprintf(", stepwise={min=" FMT_FRACT ", max="
 473                                         FMT_FRACT ", step=" FMT_FRACT "}",
 474                                         ARGS_FRACT(f.stepwise.min),
 475                                         ARGS_FRACT(f.stepwise.max),
 476                                         ARGS_FRACT(f.stepwise.step));
 477                                 break;
 478                         }
 479                 }
 480                 tprints("}");
 481                 return 1;
 482         }
 483
 484         case VIDIOC_CROPCAP: {
 485                 struct v4l2_cropcap c;
 486
 487                 if (entering(tcp) || umove(tcp, arg, &c) < 0)
 488                         return 0;
 489                 tprints(", type=");
 490                 printxval(v4l2_buf_types, c.type, "V4L2_BUF_TYPE_???");
 491                 if (syserror(tcp))
 492                         return 1;
 493                 tprintf(", bounds=" FMT_RECT ", defrect=" FMT_RECT ", "
 494                         "pixelaspect=" FMT_FRACT, ARGS_RECT(c.bounds),
 495                         ARGS_RECT(c.defrect), ARGS_FRACT(c.pixelaspect));
 496                 return 1;
 497         }
 498
 499         case VIDIOC_G_FBUF:
 500         case VIDIOC_S_FBUF: {
 501                 struct v4l2_framebuffer b;
 502
 503                 if (syserror(tcp) && code == VIDIOC_G_FBUF)
 504                         return 0;
 505                 if (entering(tcp) || umove(tcp, arg, &b) < 0)
 506                         return 0;
 507                 tprintf(", {capability=%x, flags=%x, base=%p}",
 508                         b.capability, b.flags, b.base);
 509                 return 1;
 510         }
 511
 512         case VIDIOC_REQBUFS: {
 513                 struct v4l2_requestbuffers reqbufs;
 514
 515                 if (umove(tcp, arg, &reqbufs) < 0)
 516                         return 0;
 517                 if (entering(tcp)) {
 518                         tprintf(", {count=%u, type=", reqbufs.count);
 519                         printxval(v4l2_buf_types, reqbufs.type, "V4L2_BUF_TYPE_???");
 520                         tprints(", memory=");
 521                         printxval(v4l2_memories, reqbufs.memory, "V4L2_MEMORY_???");
 522                         tprints("}");
 523                         return 1;
 524                 } else if (syserror(tcp))
 525                         return 1;
 526                 else {
 527                         static char outstr[sizeof("{count=}") + sizeof(int) * 3];
 528
 529                         sprintf(outstr, "{count=%u}", reqbufs.count);
 530                         tcp->auxstr = outstr;
 531                         return 1 + RVAL_STR;
 532                 }
 533         }
 534
 535         case VIDIOC_QUERYBUF:
 536         case VIDIOC_QBUF:
 537         case VIDIOC_DQBUF: {
 538                 struct v4l2_buffer b;
 539
 540                 if (umove(tcp, arg, &b) < 0)
 541                         return 0;
 542                 if (entering(tcp)) {
 543                         tprints(", {type=");
 544                         printxval(v4l2_buf_types, b.type, "V4L2_BUF_TYPE_???");
 545                         if (code != VIDIOC_DQBUF)
 546                                 tprintf(", index=%u", b.index);
 547                 } else {
 548                         if (!syserror(tcp)) {
 549                                 if (code == VIDIOC_DQBUF)
 550                                         tprintf(", index=%u", b.index);
 551                                 tprints(", memory=");
 552                                 printxval(v4l2_memories, b.memory, "V4L2_MEMORY_???");
 553
 554                                 if (b.memory == V4L2_MEMORY_MMAP) {
 555                                         tprintf(", m.offset=%#x", b.m.offset);
 556                                 } else if (b.memory == V4L2_MEMORY_USERPTR) {
 557                                         tprintf(", m.userptr=%#lx", b.m.userptr);
 558                                 }
 559
 560                                 tprintf(", length=%u, bytesused=%u, flags=",
 561                                         b.length, b.bytesused);
 562                                 printflags(v4l2_buf_flags, b.flags, "V4L2_BUF_FLAG_???");
 563                                 if (code == VIDIOC_DQBUF)
 564                                         tprintf(", timestamp = {%lu.%06lu}",
 565                                                 b.timestamp.tv_sec,
 566                                                 b.timestamp.tv_usec);
 567                                 tprints(", ...");
 568                         }
 569                         tprints("}");
 570                 }
 571                 return 1;
 572         }
 573
 574         case VIDIOC_STREAMON:
 575         case VIDIOC_STREAMOFF: {
 576                 int type;
 577
 578                 if (umove(tcp, arg, &type) < 0)
 579                         return 0;
 580                 if (entering(tcp)) {
 581                         tprints(", ");
 582                         printxval(v4l2_buf_types, type, "V4L2_BUF_TYPE_???");
 583                 }
 584                 return 1;
 585         }
 586
 587         default: /* decode on exit */
 588                 return 0;
 589         }
 590 }