gstreamer/sys/v4l2/v4l2src_calls.c

/* GStreamer
 *
 * Copyright (C) 2002 Ronald Bultje <rbultje@ronald.bitfreak.net>
 *               2006 Edgard Lima <edgard.lima@indt.org.br>
 *
 * v4l2src.c - system calls
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <string.h>
#include <errno.h>
#include "v4l2src_calls.h"
#include <sys/time.h>
#include <unistd.h>
#ifdef __sun
/* Needed on older Solaris Nevada builds (72 at least) */
#include <stropts.h>
#include <sys/ioccom.h>
#endif

#include "gstv4l2tuner.h"
#include "gstv4l2bufferpool.h"

#include "gst/gst-i18n-plugin.h"

#define GST_CAT_DEFAULT v4l2src_debug
GST_DEBUG_CATEGORY_EXTERN (GST_CAT_PERFORMANCE);

/* lalala... */
#define GST_V4L2_SET_ACTIVE(element) (element)->buffer = GINT_TO_POINTER (-1)
#define GST_V4L2_SET_INACTIVE(element) (element)->buffer = NULL

/* On some systems MAP_FAILED seems to be missing */
#ifndef MAP_FAILED
#define MAP_FAILED ((caddr_t) -1)
#endif


/* Local functions */

static gboolean
gst_v4l2src_buffer_pool_activate (GstV4l2BufferPool * pool,
    GstV4l2Src * v4l2src)
{
  GstV4l2Buffer *buf;

  while ((buf = gst_v4l2_buffer_pool_get (pool, FALSE)) != NULL)
    if (!gst_v4l2_buffer_pool_qbuf (pool, buf))
      goto queue_failed;

  return TRUE;

  /* ERRORS */
queue_failed:
  {
    GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ,
        (_("Could not enqueue buffers in device '%s'."),
            v4l2src->v4l2object->videodev),
        ("enqueing buffer %d/%d failed: %s",
            buf->vbuffer.index, v4l2src->num_buffers, g_strerror (errno)));
    return FALSE;
  }
}

/******************************************************
 * gst_v4l2src_grab_frame ():
 *   grab a frame for capturing
 * return value: GST_FLOW_OK, GST_FLOW_WRONG_STATE or GST_FLOW_ERROR
 ******************************************************/
GstFlowReturn
gst_v4l2src_grab_frame (GstV4l2Src * v4l2src, GstBuffer ** buf)
{
#define NUM_TRIALS 50
  GstV4l2Object *v4l2object;
  GstV4l2BufferPool *pool;
  gint32 trials = NUM_TRIALS;
  GstBuffer *pool_buffer;
  gboolean need_copy;
  gint ret;

  v4l2object = v4l2src->v4l2object;
  pool = v4l2src->pool;
  if (!pool)
    goto no_buffer_pool;

  GST_DEBUG_OBJECT (v4l2src, "grab frame");

  for (;;) {
    if (v4l2object->can_poll_device) {
      ret = gst_poll_wait (v4l2object->poll, GST_CLOCK_TIME_NONE);
      if (G_UNLIKELY (ret < 0)) {
        if (errno == EBUSY)
          goto stopped;
        if (errno == ENXIO) {
          GST_DEBUG_OBJECT (v4l2src,
              "v4l2 device doesn't support polling. Disabling");
          v4l2object->can_poll_device = FALSE;
        } else {
          if (errno != EAGAIN && errno != EINTR)
            goto select_error;
        }
      }
    }

    pool_buffer = GST_BUFFER (gst_v4l2_buffer_pool_dqbuf (pool));
    if (pool_buffer)
      break;

    GST_WARNING_OBJECT (pool->v4l2elem, "trials=%d", trials);

    /* if the sync() got interrupted, we can retry */
    switch (errno) {
      case EINVAL:
      case ENOMEM:
        /* fatal */
        return GST_FLOW_ERROR;

      case EAGAIN:
      case EIO:
      case EINTR:
      default:
        /* try again, until too many trials */
        break;
    }

    /* check nr. of attempts to capture */
    if (--trials == -1) {
      goto too_many_trials;
    }
  }

  /* if we are handing out the last buffer in the pool, we need to make a
   * copy and bring the buffer back in the pool. */
  need_copy = v4l2src->always_copy
      || !gst_v4l2_buffer_pool_available_buffers (pool);

  if (G_UNLIKELY (need_copy)) {
    if (!v4l2src->always_copy) {
      GST_CAT_LOG_OBJECT (GST_CAT_PERFORMANCE, v4l2src,
          "running out of buffers, making a copy to reuse current one");
    }
    *buf = gst_buffer_copy (pool_buffer);
    GST_BUFFER_FLAG_UNSET (*buf, GST_BUFFER_FLAG_READONLY);
    /* this will requeue */
    gst_buffer_unref (pool_buffer);
  } else {
    *buf = pool_buffer;
  }
  /* we set the buffer metadata in gst_v4l2src_create() */

  return GST_FLOW_OK;

  /* ERRORS */
no_buffer_pool:
  {
    GST_DEBUG ("no buffer pool");
    return GST_FLOW_WRONG_STATE;
  }
select_error:
  {
    GST_ELEMENT_ERROR (pool->v4l2elem, RESOURCE, READ, (NULL),
        ("select error %d: %s (%d)", ret, g_strerror (errno), errno));
    return GST_FLOW_ERROR;
  }
stopped:
  {
    GST_DEBUG ("stop called");
    return GST_FLOW_WRONG_STATE;
  }
too_many_trials:
  {
    GST_ELEMENT_ERROR (pool->v4l2elem, RESOURCE, FAILED,
        (_("Failed trying to get video frames from device '%s'."),
            v4l2object->videodev),
        (_("Failed after %d tries. device %s. system error: %s"),
            NUM_TRIALS, v4l2object->videodev, g_strerror (errno)));
    return GST_FLOW_ERROR;
  }
}

/******************************************************
 * gst_v4l2src_set_capture():
 *   set capture parameters
 * return value: TRUE on success, FALSE on error
 ******************************************************/
gboolean
gst_v4l2src_set_capture (GstV4l2Src * v4l2src, guint32 pixelformat,
    guint32 width, guint32 height, gboolean interlaced,
    guint fps_n, guint fps_d)
{
  gint fd = v4l2src->v4l2object->video_fd;
  struct v4l2_streamparm stream;

  if (pixelformat == GST_MAKE_FOURCC ('M', 'P', 'E', 'G'))
    return TRUE;

  if (!gst_v4l2_object_set_format (v4l2src->v4l2object, pixelformat, width,
          height, interlaced)) {
    /* error already reported */
    return FALSE;
  }

  /* Is there a reason we require the caller to always specify a framerate? */
  GST_DEBUG_OBJECT (v4l2src, "Desired framerate: %u/%u", fps_n, fps_d);

  memset (&stream, 0x00, sizeof (struct v4l2_streamparm));
  stream.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
  if (v4l2_ioctl (fd, VIDIOC_G_PARM, &stream) < 0) {
    GST_ELEMENT_WARNING (v4l2src, RESOURCE, SETTINGS,
        (_("Could not get parameters on device '%s'"),
            v4l2src->v4l2object->videodev), GST_ERROR_SYSTEM);
    goto done;
  }

  /* We used to skip frame rate setup if the camera was already setup
     with the requested frame rate. This breaks some cameras though,
     causing them to not output data (several models of Thinkpad cameras
     have this problem at least).
     So, don't skip. */

  /* We want to change the frame rate, so check whether we can. Some cheap USB
   * cameras don't have the capability */
  if ((stream.parm.capture.capability & V4L2_CAP_TIMEPERFRAME) == 0) {
    GST_DEBUG_OBJECT (v4l2src, "Not setting framerate (not supported)");
    goto done;
  }

  GST_LOG_OBJECT (v4l2src, "Setting framerate to %u/%u", fps_n, fps_d);

  /* Note: V4L2 wants the frame interval, we have the frame rate */
  stream.parm.capture.timeperframe.numerator = fps_d;
  stream.parm.capture.timeperframe.denominator = fps_n;

  /* some cheap USB cam's won't accept any change */
  if (v4l2_ioctl (fd, VIDIOC_S_PARM, &stream) < 0) {
    GST_ELEMENT_WARNING (v4l2src, RESOURCE, SETTINGS,
        (_("Video input device did not accept new frame rate setting.")),
        GST_ERROR_SYSTEM);
    goto done;
  }

  v4l2src->fps_n = fps_n;
  v4l2src->fps_d = fps_d;

  /* if we have a framerate pre-calculate duration */
  if (fps_n > 0 && fps_d > 0) {
    v4l2src->duration = gst_util_uint64_scale_int (GST_SECOND, fps_d, fps_n);
  } else {
    v4l2src->duration = GST_CLOCK_TIME_NONE;
  }

  GST_INFO_OBJECT (v4l2src,
      "Set framerate to %u/%u and duration to %" GST_TIME_FORMAT, fps_n, fps_d,
      GST_TIME_ARGS (v4l2src->duration));
done:

  return TRUE;
}

/******************************************************
 * gst_v4l2src_capture_init():
 *   initialize the capture system
 * return value: TRUE on success, FALSE on error
 ******************************************************/
gboolean
gst_v4l2src_capture_init (GstV4l2Src * v4l2src, GstCaps * caps)
{
  GST_DEBUG_OBJECT (v4l2src, "initializing the capture system");

  GST_V4L2_CHECK_OPEN (v4l2src->v4l2object);
  GST_V4L2_CHECK_NOT_ACTIVE (v4l2src->v4l2object);

  if (v4l2src->v4l2object->vcap.capabilities & V4L2_CAP_STREAMING) {

    /* Map the buffers */
    GST_LOG_OBJECT (v4l2src, "initiating buffer pool");

    if (!(v4l2src->pool = gst_v4l2_buffer_pool_new (GST_ELEMENT (v4l2src),
                v4l2src->v4l2object->video_fd,
                v4l2src->num_buffers, caps, TRUE, V4L2_BUF_TYPE_VIDEO_CAPTURE)))
      goto buffer_pool_new_failed;

    GST_INFO_OBJECT (v4l2src, "capturing buffers via mmap()");
    v4l2src->use_mmap = TRUE;

    if (v4l2src->num_buffers != v4l2src->pool->buffer_count) {
      v4l2src->num_buffers = v4l2src->pool->buffer_count;
      g_object_notify (G_OBJECT (v4l2src), "queue-size");
    }

  } else if (v4l2src->v4l2object->vcap.capabilities & V4L2_CAP_READWRITE) {
    GST_INFO_OBJECT (v4l2src, "capturing buffers via read()");
    v4l2src->use_mmap = FALSE;
    v4l2src->pool = NULL;
  } else {
    goto no_supported_capture_method;
  }

  GST_V4L2_SET_ACTIVE (v4l2src->v4l2object);

  return TRUE;

  /* ERRORS */
buffer_pool_new_failed:
  {
    GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ,
        (_("Could not map buffers from device '%s'"),
            v4l2src->v4l2object->videodev),
        ("Failed to create buffer pool: %s", g_strerror (errno)));
    return FALSE;
  }
no_supported_capture_method:
  {
    GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ,
        (_("The driver of device '%s' does not support any known capture "
                "method."), v4l2src->v4l2object->videodev), (NULL));
    return FALSE;
  }
}


/******************************************************
 * gst_v4l2src_capture_start():
 *   start streaming capture
 * return value: TRUE on success, FALSE on error
 ******************************************************/
gboolean
gst_v4l2src_capture_start (GstV4l2Src * v4l2src)
{
  GST_DEBUG_OBJECT (v4l2src, "starting the capturing");
  //GST_V4L2_CHECK_OPEN (v4l2src->v4l2object);
  GST_V4L2_CHECK_ACTIVE (v4l2src->v4l2object);

  v4l2src->quit = FALSE;

  if (v4l2src->use_mmap) {
    if (!gst_v4l2src_buffer_pool_activate (v4l2src->pool, v4l2src)) {
      return FALSE;
    }

    if (!gst_v4l2_object_start_streaming (v4l2src->v4l2object)) {
      return FALSE;
    }
  }

  v4l2src->is_capturing = TRUE;

  return TRUE;
}

/******************************************************
 * gst_v4l2src_capture_stop():
 *   stop streaming capture
 * return value: TRUE on success, FALSE on error
 ******************************************************/
gboolean
gst_v4l2src_capture_stop (GstV4l2Src * v4l2src)
{
  GST_DEBUG_OBJECT (v4l2src, "stopping capturing");

  if (!GST_V4L2_IS_OPEN (v4l2src->v4l2object)) {
    goto done;
  }
  if (!GST_V4L2_IS_ACTIVE (v4l2src->v4l2object)) {
    goto done;
  }

  if (v4l2src->use_mmap) {
    /* we actually need to sync on all queued buffers but not
     * on the non-queued ones */
    if (!gst_v4l2_object_stop_streaming (v4l2src->v4l2object)) {
      return FALSE;
    }
  }

done:

  /* make an optional pending wait stop */
  v4l2src->quit = TRUE;
  v4l2src->is_capturing = FALSE;

  return TRUE;
}

/******************************************************
 * gst_v4l2src_capture_deinit():
 *   deinitialize the capture system
 * return value: TRUE on success, FALSE on error
 ******************************************************/
gboolean
gst_v4l2src_capture_deinit (GstV4l2Src * v4l2src)
{
  GST_DEBUG_OBJECT (v4l2src, "deinitting capture system");

  if (!GST_V4L2_IS_OPEN (v4l2src->v4l2object)) {
    return TRUE;
  }
  if (!GST_V4L2_IS_ACTIVE (v4l2src->v4l2object)) {
    return TRUE;
  }

  if (v4l2src->pool) {
    gst_v4l2_buffer_pool_destroy (v4l2src->pool);
    v4l2src->pool = NULL;
  }

  GST_V4L2_SET_INACTIVE (v4l2src->v4l2object);

  return TRUE;
}