/* G-Streamer Video4linux2 video-capture plugin - system calls
 * Copyright (C) 2002 Ronald Bultje <rbultje@ronald.bitfreak.net>
 *
 * 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>

#define GST_CAT_DEFAULT v4l2src_debug

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

#define DEBUG(format, args...) \
	GST_CAT_DEBUG_OBJECT (\
		v4l2src_debug, v4l2src, \
		"V4L2SRC: " format, ##args)

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

/******************************************************
 * gst_v4l2src_fill_format_list():
 *   create list of supported capture formats
 * return value: TRUE on success, FALSE on error
 ******************************************************/

gboolean
gst_v4l2src_fill_format_list (GstV4l2Src * v4l2src)
{
  gint n;
  struct v4l2_fmtdesc *format;

  GST_DEBUG_OBJECT (v4l2src, "getting src format enumerations");

  /* format enumeration */
  for (n = 0;; n++) {
    format = g_new (struct v4l2_fmtdesc, 1);

    format->index = n;
    format->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    if (ioctl (GST_V4L2ELEMENT (v4l2src)->video_fd, VIDIOC_ENUM_FMT,
            format) < 0) {
      if (errno == EINVAL) {
        break;                  /* end of enumeration */
      } else {
        GST_ELEMENT_ERROR (v4l2src, RESOURCE, SETTINGS, (NULL),
            ("failed to get number %d in pixelformat enumeration for %s: %s",
                n, GST_V4L2ELEMENT (v4l2src)->device, g_strerror (errno)));
        g_free (format);
        return FALSE;
      }
    }
    GST_LOG_OBJECT (v4l2src, "got format %" GST_FOURCC_FORMAT,
        GST_FOURCC_ARGS (format->pixelformat));
    v4l2src->formats = g_slist_prepend (v4l2src->formats, format);
  }

  return TRUE;
}


/******************************************************
 * gst_v4l2src_clear_format_list():
 *   free list of supported capture formats
 * return value: TRUE on success, FALSE on error
 ******************************************************/

gboolean
gst_v4l2src_clear_format_list (GstV4l2Src * v4l2src)
{
  g_slist_foreach (v4l2src->formats, (GFunc) g_free, NULL);
  g_slist_free (v4l2src->formats);
  v4l2src->formats = NULL;

  return TRUE;
}


/******************************************************
 * gst_v4l2src_queue_frame():
 *   queue a frame for capturing
 * return value: TRUE on success, FALSE on error
 ******************************************************/

gboolean
gst_v4l2src_queue_frame (GstV4l2Src * v4l2src, guint i)
{
  GST_LOG_OBJECT (v4l2src, "queueing frame %u", i);

  if (ioctl (GST_V4L2ELEMENT (v4l2src)->video_fd, VIDIOC_QBUF,
          &v4l2src->pool->buffers[i].buffer) < 0) {
    GST_ELEMENT_ERROR (v4l2src, RESOURCE, WRITE,
        (_("Could not write to device \"%s\"."),
            GST_V4L2ELEMENT (v4l2src)->device),
        ("Error queueing buffer %u on device %s", i, g_strerror (errno)));
    return FALSE;
  }

  return TRUE;
}


/******************************************************
 * gst_v4l2src_grab_frame ():
 *   grab a frame for capturing
 * return value: TRUE on success, FALSE on error
 ******************************************************/

gint
gst_v4l2src_grab_frame (GstV4l2Src * v4l2src)
{
  struct v4l2_buffer buffer;

  buffer.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
  while (ioctl (GST_V4L2ELEMENT (v4l2src)->video_fd, VIDIOC_DQBUF, &buffer) < 0) {
    /* if the sync() got interrupted, we can retry */
    if (errno != EINTR) {
      GST_ELEMENT_ERROR (v4l2src, RESOURCE, SYNC, (NULL),
          ("could not sync on a buffer on device %s: %s",
              GST_V4L2ELEMENT (v4l2src)->device, g_strerror (errno)));
      return -1;
    }
    GST_DEBUG_OBJECT (v4l2src, "grab got interrupted");
  }

  GST_LOG_OBJECT (v4l2src, "grabbed frame %d", buffer.index);

  return buffer.index;
}


/******************************************************
 * gst_v4l2src_get_capture():
 *   get capture parameters
 * return value: TRUE on success, FALSE on error
 ******************************************************/

gboolean
gst_v4l2src_get_capture (GstV4l2Src * v4l2src)
{
  DEBUG ("Getting capture format");

  GST_V4L2_CHECK_OPEN (GST_V4L2ELEMENT (v4l2src));

  v4l2src->format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
  if (ioctl (GST_V4L2ELEMENT (v4l2src)->video_fd, VIDIOC_G_FMT,
          &v4l2src->format) < 0) {
    GST_ELEMENT_ERROR (v4l2src, RESOURCE, SETTINGS, (NULL),
        ("failed to get pixelformat for device %s: %s",
            GST_V4L2ELEMENT (v4l2src)->device, g_strerror (errno)));
    return FALSE;
  }

  return TRUE;
}


/******************************************************
 * gst_v4l2src_set_capture():
 *   set capture parameters
 * return value: TRUE on success, FALSE on error
 ******************************************************/

gboolean
gst_v4l2src_set_capture (GstV4l2Src * v4l2src,
    struct v4l2_fmtdesc * fmt, gint width, gint height)
{
  DEBUG ("Setting capture format to %dx%d, format %s",
      width, height, fmt->description);

  GST_V4L2_CHECK_OPEN (GST_V4L2ELEMENT (v4l2src));
  GST_V4L2_CHECK_NOT_ACTIVE (GST_V4L2ELEMENT (v4l2src));

  memset (&v4l2src->format, 0, sizeof (struct v4l2_format));
  v4l2src->format.fmt.pix.width = width;
  v4l2src->format.fmt.pix.height = height;
  v4l2src->format.fmt.pix.pixelformat = fmt->pixelformat;
  v4l2src->format.fmt.pix.field = V4L2_FIELD_INTERLACED;
  v4l2src->format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

  if (ioctl (GST_V4L2ELEMENT (v4l2src)->video_fd, VIDIOC_S_FMT,
          &v4l2src->format) < 0) {
    GST_ELEMENT_ERROR (v4l2src, RESOURCE, SETTINGS, (NULL),
        ("failed to set pixelformat to %s @ %dx%d for device %s: %s",
            fmt->description, width, height, GST_V4L2ELEMENT (v4l2src)->device,
            g_strerror (errno)));
    return FALSE;
  }

  /* update internal info */
  return gst_v4l2src_get_capture (v4l2src);
}


/******************************************************
 * gst_v4l2src_capture_init():
 *   initialize the capture system
 * return value: TRUE on success, FALSE on error
 ******************************************************/

gboolean
gst_v4l2src_capture_init (GstV4l2Src * v4l2src)
{
  gint n;
  guint buffers;

  GST_DEBUG_OBJECT (v4l2src, "initting the capture system");

  GST_V4L2_CHECK_OPEN (GST_V4L2ELEMENT (v4l2src));
  GST_V4L2_CHECK_NOT_ACTIVE (GST_V4L2ELEMENT (v4l2src));

  /* request buffer info */
  buffers = v4l2src->breq.count;
  if (v4l2src->breq.count > GST_V4L2_MAX_BUFFERS) {
    v4l2src->breq.count = GST_V4L2_MAX_BUFFERS;
  }
  if (v4l2src->breq.count < GST_V4L2_MIN_BUFFERS) {
    v4l2src->breq.count = GST_V4L2_MIN_BUFFERS;
  }
  v4l2src->breq.type = v4l2src->format.type;
  v4l2src->breq.memory = V4L2_MEMORY_MMAP;
  if (ioctl (GST_V4L2ELEMENT (v4l2src)->video_fd, VIDIOC_REQBUFS,
          &v4l2src->breq) < 0) {
    GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ,
        (_("Could not get buffers from device \"%s\"."),
            GST_V4L2ELEMENT (v4l2src)->device),
        ("error requesting %d buffers: %s", v4l2src->breq.count,
            g_strerror (errno)));
    return FALSE;
  }

  if (v4l2src->breq.count < GST_V4L2_MIN_BUFFERS) {
    GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ,
        (_("Could not get enough buffers from device \"%s\"."),
            GST_V4L2ELEMENT (v4l2src)->device),
        ("we received %d, we want at least %d", v4l2src->breq.count,
            GST_V4L2_MIN_BUFFERS));
    v4l2src->breq.count = buffers;
    return FALSE;
  }
  if (v4l2src->breq.count != buffers)
    g_object_notify (G_OBJECT (v4l2src), "num_buffers");

  GST_INFO_OBJECT (v4l2src,
      "Got %d buffers (%" GST_FOURCC_FORMAT ") of size %d KB\n",
      v4l2src->breq.count,
      GST_FOURCC_ARGS (v4l2src->format.fmt.pix.pixelformat),
      v4l2src->format.fmt.pix.sizeimage / 1024);

  /* Map the buffers */
  v4l2src->pool = g_new (GstV4l2BufferPool, 1);
  gst_atomic_int_init (&v4l2src->pool->refcount, 1);
  v4l2src->pool->video_fd = GST_V4L2ELEMENT (v4l2src)->video_fd;
  v4l2src->pool->buffer_count = v4l2src->breq.count;
  v4l2src->pool->buffers = g_new0 (GstV4l2Buffer, v4l2src->breq.count);

  for (n = 0; n < v4l2src->breq.count; n++) {
    GstV4l2Buffer *buffer = &v4l2src->pool->buffers[n];

    gst_atomic_int_init (&buffer->refcount, 1);
    buffer->pool = v4l2src->pool;
    buffer->buffer.index = n;
    buffer->buffer.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    if (ioctl (GST_V4L2ELEMENT (v4l2src)->video_fd, VIDIOC_QUERYBUF,
            &buffer->buffer) < 0) {
      GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ, (NULL),
          ("Could not get buffer properties of buffer %d: %s", n,
              g_strerror (errno)));
      gst_v4l2src_capture_deinit (v4l2src);
      return FALSE;
    }
    buffer->start =
        mmap (0, buffer->buffer.length, PROT_READ | PROT_WRITE, MAP_SHARED,
        GST_V4L2ELEMENT (v4l2src)->video_fd, buffer->buffer.m.offset);
    if (buffer->start == MAP_FAILED) {
      GST_ELEMENT_ERROR (v4l2src, RESOURCE, READ, (NULL),
          ("Could not mmap video buffer %d: %s", n, g_strerror (errno)));
      buffer->start = 0;
      gst_v4l2src_capture_deinit (v4l2src);
      return FALSE;
    }
    buffer->length = buffer->buffer.length;
    if (!gst_v4l2src_queue_frame (v4l2src, n)) {
      gst_v4l2src_capture_deinit (v4l2src);
      return FALSE;
    }
  }

  GST_V4L2_SET_ACTIVE (GST_V4L2ELEMENT (v4l2src));

  return TRUE;
}


/******************************************************
 * gst_v4l2src_capture_start():
 *   start streaming capture
 * return value: TRUE on success, FALSE on error
 ******************************************************/

gboolean
gst_v4l2src_capture_start (GstV4l2Src * v4l2src)
{
  gint type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

  GST_DEBUG_OBJECT (v4l2src, "starting the capturing");

  GST_V4L2_CHECK_OPEN (GST_V4L2ELEMENT (v4l2src));
  if (!GST_V4L2_IS_ACTIVE (GST_V4L2ELEMENT (v4l2src))) {
    gst_pad_renegotiate (v4l2src->srcpad);
  }
  GST_V4L2_CHECK_ACTIVE (GST_V4L2ELEMENT (v4l2src));

  v4l2src->quit = FALSE;

  if (ioctl (GST_V4L2ELEMENT (v4l2src)->video_fd, VIDIOC_STREAMON, &type) < 0) {
    GST_ELEMENT_ERROR (v4l2src, RESOURCE, OPEN_READ, (NULL),
        ("Error starting streaming capture from device %s: %s",
            GST_V4L2ELEMENT (v4l2src)->device, g_strerror (errno)));
    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)
{
  gint type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

  GST_DEBUG_OBJECT (v4l2src, "stopping capturing");
  GST_V4L2_CHECK_OPEN (GST_V4L2ELEMENT (v4l2src));
  GST_V4L2_CHECK_ACTIVE (GST_V4L2ELEMENT (v4l2src));

  /* we actually need to sync on all queued buffers but not
   * on the non-queued ones */
  if (ioctl (GST_V4L2ELEMENT (v4l2src)->video_fd, VIDIOC_STREAMOFF, &type) < 0) {
    GST_ELEMENT_ERROR (v4l2src, RESOURCE, CLOSE, (NULL),
        ("Error stopping streaming capture from device %s: %s",
            GST_V4L2ELEMENT (v4l2src)->device, g_strerror (errno)));
    return FALSE;
  }

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

  return TRUE;
}

static void
gst_v4l2src_buffer_pool_free (GstV4l2BufferPool * pool, gboolean do_close)
{
  guint i;

  for (i = 0; i < pool->buffer_count; i++) {
    gst_atomic_int_destroy (&pool->buffers[i].refcount);
    munmap (pool->buffers[i].start, pool->buffers[i].length);
  }
  g_free (pool->buffers);
  gst_atomic_int_destroy (&pool->refcount);
  if (do_close)
    close (pool->video_fd);
  g_free (pool);
}

void
gst_v4l2src_free_buffer (GstBuffer * buffer)
{
  GstV4l2Buffer *buf = (GstV4l2Buffer *) GST_BUFFER_PRIVATE (buffer);

  GST_LOG ("freeing buffer %p (nr. %d)", buffer, buf->buffer.index);

  if (!gst_atomic_int_dec_and_test (&buf->refcount)) {
    /* we're still in use, add to queue again 
       note: this might fail because the device is already stopped (race) */
    if (ioctl (buf->pool->video_fd, VIDIOC_QBUF, &buf->buffer) < 0)
      GST_INFO ("readding to queue failed, assuming video device is stopped");
  }
  if (gst_atomic_int_dec_and_test (&buf->pool->refcount)) {
    /* we're last thing that used all this */
    gst_v4l2src_buffer_pool_free (buf->pool, TRUE);
  }
}

/******************************************************
 * gst_v4l2src_capture_deinit():
 *   deinitialize the capture system
 * return value: TRUE on success, FALSE on error
 ******************************************************/

gboolean
gst_v4l2src_capture_deinit (GstV4l2Src * v4l2src)
{
  gint i, dequeue = 0;

  GST_DEBUG_OBJECT (v4l2src, "deinitting capture system");

  GST_V4L2_CHECK_OPEN (GST_V4L2ELEMENT (v4l2src));
  GST_V4L2_CHECK_ACTIVE (GST_V4L2ELEMENT (v4l2src));

  /* free the buffers */
  for (i = 0; i < v4l2src->breq.count; i++) {
    if (gst_atomic_int_dec_and_test (&v4l2src->pool->buffers[i].refcount))
      dequeue++;
  }
  for (i = 0; i < dequeue; i++) {
    struct v4l2_buffer buffer;

    buffer.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    if (ioctl (GST_V4L2ELEMENT (v4l2src)->video_fd, VIDIOC_DQBUF, &buffer) < 0)
      GST_WARNING_OBJECT (v4l2src,
          "Could not dequeue buffer on uninitialization");
  }
  if (gst_atomic_int_dec_and_test (&v4l2src->pool->refcount)) {
    /* we're last thing that used all this */
    gst_v4l2src_buffer_pool_free (v4l2src->pool, FALSE);
  }
  v4l2src->pool = NULL;

  GST_V4L2_SET_INACTIVE (GST_V4L2ELEMENT (v4l2src));
  return TRUE;
}


/*

 */

gboolean
gst_v4l2src_get_size_limits (GstV4l2Src * v4l2src,
    struct v4l2_fmtdesc * format,
    gint * min_w, gint * max_w, gint * min_h, gint * max_h)
{
  struct v4l2_format fmt;

  GST_LOG_OBJECT (v4l2src,
      "getting size limits with format %" GST_FOURCC_FORMAT,
      GST_FOURCC_ARGS (format->pixelformat));

  /* get size delimiters */
  memset (&fmt, 0, sizeof (fmt));
  fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
  fmt.fmt.pix.width = 0;
  fmt.fmt.pix.height = 0;
  fmt.fmt.pix.pixelformat = format->pixelformat;
  fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
  if (ioctl (GST_V4L2ELEMENT (v4l2src)->video_fd, VIDIOC_TRY_FMT, &fmt) < 0) {
    return FALSE;
  }

  if (min_w)
    *min_w = fmt.fmt.pix.width;
  if (min_h)
    *min_h = fmt.fmt.pix.height;
  GST_LOG_OBJECT (v4l2src, "got min size %dx%d", fmt.fmt.pix.width,
      fmt.fmt.pix.height);

  fmt.fmt.pix.width = G_MAXINT;
  fmt.fmt.pix.height = 576;
  if (ioctl (GST_V4L2ELEMENT (v4l2src)->video_fd, VIDIOC_TRY_FMT, &fmt) < 0) {
    return FALSE;
  }

  if (max_w)
    *max_w = fmt.fmt.pix.width;
  if (max_h)
    *max_h = fmt.fmt.pix.height;
  GST_LOG_OBJECT (v4l2src, "got max size %dx%d", fmt.fmt.pix.width,
      fmt.fmt.pix.height);

  return TRUE;
}