gstreamer/omx/gstomxbufferpool.c

/*
 * Copyright (C) 2011, Hewlett-Packard Development Company, L.P.
 *   Author: Sebastian Dröge <sebastian.droege@collabora.co.uk>, Collabora Ltd.
 * Copyright (C) 2013, Collabora Ltd.
 *   Author: Sebastian Dröge <sebastian.droege@collabora.co.uk>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation
 * version 2.1 of the License.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
 *
 */

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

#include "gstomxbufferpool.h"

#include <gst/allocators/gstdmabuf.h>

GST_DEBUG_CATEGORY_STATIC (gst_omx_buffer_pool_debug_category);
#define GST_CAT_DEFAULT gst_omx_buffer_pool_debug_category

typedef struct _GstOMXMemory GstOMXMemory;
typedef struct _GstOMXMemoryAllocator GstOMXMemoryAllocator;
typedef struct _GstOMXMemoryAllocatorClass GstOMXMemoryAllocatorClass;

struct _GstOMXMemory
{
  GstMemory mem;

  GstOMXBuffer *buf;
};

struct _GstOMXMemoryAllocator
{
  GstAllocator parent;
};

struct _GstOMXMemoryAllocatorClass
{
  GstAllocatorClass parent_class;
};

#define GST_OMX_MEMORY_TYPE "openmax"

static GstMemory *
gst_omx_memory_allocator_alloc_dummy (GstAllocator * allocator, gsize size,
    GstAllocationParams * params)
{
  g_assert_not_reached ();
  return NULL;
}

static void
gst_omx_memory_allocator_free (GstAllocator * allocator, GstMemory * mem)
{
  GstOMXMemory *omem = (GstOMXMemory *) mem;

  /* TODO: We need to remember which memories are still used
   * so we can wait until everything is released before allocating
   * new memory
   */

  g_slice_free (GstOMXMemory, omem);
}

static gpointer
gst_omx_memory_map (GstMemory * mem, gsize maxsize, GstMapFlags flags)
{
  GstOMXMemory *omem = (GstOMXMemory *) mem;

  return omem->buf->omx_buf->pBuffer + omem->mem.offset;
}

static void
gst_omx_memory_unmap (GstMemory * mem)
{
}

static GstMemory *
gst_omx_memory_share (GstMemory * mem, gssize offset, gssize size)
{
  g_assert_not_reached ();
  return NULL;
}

GType gst_omx_memory_allocator_get_type (void);
G_DEFINE_TYPE (GstOMXMemoryAllocator, gst_omx_memory_allocator,
    GST_TYPE_ALLOCATOR);

#define GST_TYPE_OMX_MEMORY_ALLOCATOR   (gst_omx_memory_allocator_get_type())
#define GST_IS_OMX_MEMORY_ALLOCATOR(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_OMX_MEMORY_ALLOCATOR))

static void
gst_omx_memory_allocator_class_init (GstOMXMemoryAllocatorClass * klass)
{
  GstAllocatorClass *allocator_class;

  allocator_class = (GstAllocatorClass *) klass;

  allocator_class->alloc = gst_omx_memory_allocator_alloc_dummy;
  allocator_class->free = gst_omx_memory_allocator_free;
}

static void
gst_omx_memory_allocator_init (GstOMXMemoryAllocator * allocator)
{
  GstAllocator *alloc = GST_ALLOCATOR_CAST (allocator);

  alloc->mem_type = GST_OMX_MEMORY_TYPE;
  alloc->mem_map = gst_omx_memory_map;
  alloc->mem_unmap = gst_omx_memory_unmap;
  alloc->mem_share = gst_omx_memory_share;

  /* default copy & is_span */

  GST_OBJECT_FLAG_SET (allocator, GST_ALLOCATOR_FLAG_CUSTOM_ALLOC);
}

static GstMemory *
gst_omx_memory_allocator_alloc (GstAllocator * allocator, GstMemoryFlags flags,
    GstOMXBuffer * buf)
{
  GstOMXMemory *mem;
  gint align;

  /* FIXME: We don't allow sharing because we need to know
   * when the memory becomes unused and can only then put
   * it back to the pool. Which is done in the pool's release
   * function
   */
  flags |= GST_MEMORY_FLAG_NO_SHARE;

  /* GStreamer uses a bitmask for the alignment while
   * OMX uses the alignment itself. So we have to convert
   * here */
  align = buf->port->port_def.nBufferAlignment;
  if (align > 0)
    align -= 1;
  if (((align + 1) & align) != 0) {
    GST_WARNING ("Invalid alignment that is not a power of two: %u",
        (guint) buf->port->port_def.nBufferAlignment);
    align = 0;
  }

  mem = g_slice_new (GstOMXMemory);
  /* the shared memory is always readonly */
  gst_memory_init (GST_MEMORY_CAST (mem), flags, allocator, NULL,
      buf->omx_buf->nAllocLen, align, 0, buf->omx_buf->nAllocLen);

  mem->buf = buf;

  return GST_MEMORY_CAST (mem);
}

/* Buffer pool for the buffers of an OpenMAX port.
 *
 * This pool is only used if we either passed buffers from another
 * pool to the OMX port or provide the OMX buffers directly to other
 * elements.
 *
 *
 * A buffer is in the pool if it is currently owned by the port,
 * i.e. after OMX_{Fill,Empty}ThisBuffer(). A buffer is outside
 * the pool after it was taken from the port after it was handled
 * by the port, i.e. {Empty,Fill}BufferDone.
 *
 * Buffers can be allocated by us (OMX_AllocateBuffer()) or allocated
 * by someone else and (temporarily) passed to this pool
 * (OMX_UseBuffer(), OMX_UseEGLImage()). In the latter case the pool of
 * the buffer will be overriden, and restored in free_buffer(). Other
 * buffers are just freed there.
 *
 * The pool always has a fixed number of minimum and maximum buffers
 * and these are allocated while starting the pool and released afterwards.
 * They correspond 1:1 to the OMX buffers of the port, which are allocated
 * before the pool is started.
 *
 * Acquiring a buffer from this pool happens after the OMX buffer has
 * been acquired from the port. gst_buffer_pool_acquire_buffer() is
 * supposed to return the buffer that corresponds to the OMX buffer.
 *
 * For buffers provided to upstream, the buffer will be passed to
 * the component manually when it arrives and then unreffed. If the
 * buffer is released before reaching the component it will be just put
 * back into the pool as if EmptyBufferDone has happened. If it was
 * passed to the component, it will be back into the pool when it was
 * released and EmptyBufferDone has happened.
 *
 * For buffers provided to downstream, the buffer will be returned
 * back to the component (OMX_FillThisBuffer()) when it is released.
 */

static GQuark gst_omx_buffer_data_quark = 0;

#define DEBUG_INIT \
  GST_DEBUG_CATEGORY_INIT (gst_omx_buffer_pool_debug_category, "omxbufferpool", 0, \
      "debug category for gst-omx buffer pool base class");

G_DEFINE_TYPE_WITH_CODE (GstOMXBufferPool, gst_omx_buffer_pool,
    GST_TYPE_BUFFER_POOL, DEBUG_INIT);

static void gst_omx_buffer_pool_free_buffer (GstBufferPool * bpool,
    GstBuffer * buffer);

static gboolean
gst_omx_buffer_pool_start (GstBufferPool * bpool)
{
  GstOMXBufferPool *pool = GST_OMX_BUFFER_POOL (bpool);

  /* Only allow to start the pool if we still are attached
   * to a component and port */
  GST_OBJECT_LOCK (pool);
  if (!pool->component || !pool->port) {
    GST_OBJECT_UNLOCK (pool);
    return FALSE;
  }
  GST_OBJECT_UNLOCK (pool);

  return
      GST_BUFFER_POOL_CLASS (gst_omx_buffer_pool_parent_class)->start (bpool);
}

static gboolean
gst_omx_buffer_pool_stop (GstBufferPool * bpool)
{
  GstOMXBufferPool *pool = GST_OMX_BUFFER_POOL (bpool);
  gint i = 0;

  /* When not using the default GstBufferPool::GstAtomicQueue then
   * GstBufferPool::free_buffer is not called while stopping the pool
   * (because the queue is empty) */
  for (i = 0; i < pool->buffers->len; i++)
    GST_BUFFER_POOL_CLASS (gst_omx_buffer_pool_parent_class)->release_buffer
        (bpool, g_ptr_array_index (pool->buffers, i));

  /* Remove any buffers that are there */
  g_ptr_array_set_size (pool->buffers, 0);

  if (pool->caps)
    gst_caps_unref (pool->caps);
  pool->caps = NULL;

  pool->add_videometa = FALSE;

  return GST_BUFFER_POOL_CLASS (gst_omx_buffer_pool_parent_class)->stop (bpool);
}

static const gchar **
gst_omx_buffer_pool_get_options (GstBufferPool * bpool)
{
  static const gchar *raw_video_options[] =
      { GST_BUFFER_POOL_OPTION_VIDEO_META, NULL };
  static const gchar *options[] = { NULL };
  GstOMXBufferPool *pool = GST_OMX_BUFFER_POOL (bpool);

  GST_OBJECT_LOCK (pool);
  if (pool->port && pool->port->port_def.eDomain == OMX_PortDomainVideo
      && pool->port->port_def.format.video.eCompressionFormat ==
      OMX_VIDEO_CodingUnused) {
    GST_OBJECT_UNLOCK (pool);
    return raw_video_options;
  }
  GST_OBJECT_UNLOCK (pool);

  return options;
}

static gboolean
gst_omx_buffer_pool_set_config (GstBufferPool * bpool, GstStructure * config)
{
  GstOMXBufferPool *pool = GST_OMX_BUFFER_POOL (bpool);
  GstCaps *caps;

  GST_OBJECT_LOCK (pool);

  if (!gst_buffer_pool_config_get_params (config, &caps, NULL, NULL, NULL))
    goto wrong_config;

  if (caps == NULL)
    goto no_caps;

  if (pool->port && pool->port->port_def.eDomain == OMX_PortDomainVideo
      && pool->port->port_def.format.video.eCompressionFormat ==
      OMX_VIDEO_CodingUnused) {
    GstVideoInfo info;

    /* now parse the caps from the config */
    if (!gst_video_info_from_caps (&info, caps))
      goto wrong_video_caps;

    /* enable metadata based on config of the pool */
    pool->add_videometa =
        gst_buffer_pool_config_has_option (config,
        GST_BUFFER_POOL_OPTION_VIDEO_META);

    pool->video_info = info;
  }

  if (pool->caps)
    gst_caps_unref (pool->caps);
  pool->caps = gst_caps_ref (caps);

  GST_OBJECT_UNLOCK (pool);

  return GST_BUFFER_POOL_CLASS (gst_omx_buffer_pool_parent_class)->set_config
      (bpool, config);

  /* ERRORS */
wrong_config:
  {
    GST_OBJECT_UNLOCK (pool);
    GST_WARNING_OBJECT (pool, "invalid config");
    return FALSE;
  }
no_caps:
  {
    GST_OBJECT_UNLOCK (pool);
    GST_WARNING_OBJECT (pool, "no caps in config");
    return FALSE;
  }
wrong_video_caps:
  {
    GST_OBJECT_UNLOCK (pool);
    GST_WARNING_OBJECT (pool,
        "failed getting geometry from caps %" GST_PTR_FORMAT, caps);
    return FALSE;
  }
}

static GstFlowReturn
gst_omx_buffer_pool_alloc_buffer (GstBufferPool * bpool,
    GstBuffer ** buffer, GstBufferPoolAcquireParams * params)
{
  GstOMXBufferPool *pool = GST_OMX_BUFFER_POOL (bpool);
  GstBuffer *buf;
  GstOMXBuffer *omx_buf;

  g_return_val_if_fail (pool->allocating, GST_FLOW_ERROR);

  omx_buf = g_ptr_array_index (pool->port->buffers, pool->current_buffer_index);
  g_return_val_if_fail (omx_buf != NULL, GST_FLOW_ERROR);

  if (pool->other_pool) {
    guint i, n;

    buf = g_ptr_array_index (pool->buffers, pool->current_buffer_index);
    g_assert (pool->other_pool == buf->pool);
    gst_object_replace ((GstObject **) & buf->pool, NULL);

    n = gst_buffer_n_memory (buf);
    for (i = 0; i < n; i++) {
      GstMemory *mem = gst_buffer_peek_memory (buf, i);

      /* FIXME: We don't allow sharing because we need to know
       * when the memory becomes unused and can only then put
       * it back to the pool. Which is done in the pool's release
       * function
       */
      GST_MINI_OBJECT_FLAG_SET (mem, GST_MEMORY_FLAG_NO_SHARE);
    }

    if (pool->add_videometa) {
      GstVideoMeta *meta;

      meta = gst_buffer_get_video_meta (buf);
      if (!meta) {
        gst_buffer_add_video_meta (buf, GST_VIDEO_FRAME_FLAG_NONE,
            GST_VIDEO_INFO_FORMAT (&pool->video_info),
            GST_VIDEO_INFO_WIDTH (&pool->video_info),
            GST_VIDEO_INFO_HEIGHT (&pool->video_info));
      }
    }

    pool->need_copy = FALSE;
  } else {
    GstMemory *mem;
    const guint nstride = pool->port->port_def.format.video.nStride;
    const guint nslice = pool->port->port_def.format.video.nSliceHeight;
    gsize offset[GST_VIDEO_MAX_PLANES] = { 0, };
    gint stride[GST_VIDEO_MAX_PLANES] = { nstride, 0, };

    if (pool->output_mode == GST_OMX_BUFFER_MODE_DMABUF) {
      gint fd;
      GstMapInfo map;

      fd = GPOINTER_TO_INT (omx_buf->omx_buf->pBuffer);

      mem =
          gst_dmabuf_allocator_alloc (pool->allocator, fd,
          omx_buf->omx_buf->nAllocLen);

      if (!gst_caps_features_contains (gst_caps_get_features (pool->caps, 0),
              GST_CAPS_FEATURE_MEMORY_DMABUF)) {
        /* Check if the memory is actually mappable */
        if (!gst_memory_map (mem, &map, GST_MAP_READWRITE)) {
          GST_ERROR_OBJECT (pool,
              "dmabuf memory is not mappable but caps does not have the 'memory:DMABuf' feature");
          gst_memory_unref (mem);
          return GST_FLOW_ERROR;
        }

        gst_memory_unmap (mem, &map);
      }
    } else {
      mem = gst_omx_memory_allocator_alloc (pool->allocator, 0, omx_buf);
    }

    buf = gst_buffer_new ();
    gst_buffer_append_memory (buf, mem);
    g_ptr_array_add (pool->buffers, buf);

    switch (GST_VIDEO_INFO_FORMAT (&pool->video_info)) {
      case GST_VIDEO_FORMAT_ABGR:
      case GST_VIDEO_FORMAT_ARGB:
      case GST_VIDEO_FORMAT_RGB16:
      case GST_VIDEO_FORMAT_BGR16:
      case GST_VIDEO_FORMAT_YUY2:
      case GST_VIDEO_FORMAT_UYVY:
      case GST_VIDEO_FORMAT_YVYU:
      case GST_VIDEO_FORMAT_GRAY8:
        break;
      case GST_VIDEO_FORMAT_I420:
        stride[1] = nstride / 2;
        offset[1] = offset[0] + stride[0] * nslice;
        stride[2] = nstride / 2;
        offset[2] = offset[1] + (stride[1] * nslice / 2);
        break;
      case GST_VIDEO_FORMAT_NV12:
      case GST_VIDEO_FORMAT_NV16:
        stride[1] = nstride;
        offset[1] = offset[0] + stride[0] * nslice;
        break;
      default:
        g_assert_not_reached ();
        break;
    }

    if (pool->add_videometa) {
      pool->need_copy = FALSE;
    } else {
      GstVideoInfo info;
      gboolean need_copy = FALSE;
      gint i;

      gst_video_info_init (&info);
      gst_video_info_set_format (&info,
          GST_VIDEO_INFO_FORMAT (&pool->video_info),
          GST_VIDEO_INFO_WIDTH (&pool->video_info),
          GST_VIDEO_INFO_HEIGHT (&pool->video_info));

      for (i = 0; i < GST_VIDEO_INFO_N_PLANES (&pool->video_info); i++) {
        if (info.stride[i] != stride[i] || info.offset[i] != offset[i]) {
          need_copy = TRUE;
          break;
        }
      }

      pool->need_copy = need_copy;
    }

    if (pool->need_copy || pool->add_videometa) {
      /* We always add the videometa. It's the job of the user
       * to copy the buffer if pool->need_copy is TRUE
       */
      gst_buffer_add_video_meta_full (buf, GST_VIDEO_FRAME_FLAG_NONE,
          GST_VIDEO_INFO_FORMAT (&pool->video_info),
          GST_VIDEO_INFO_WIDTH (&pool->video_info),
          GST_VIDEO_INFO_HEIGHT (&pool->video_info),
          GST_VIDEO_INFO_N_PLANES (&pool->video_info), offset, stride);
    }
  }

  gst_mini_object_set_qdata (GST_MINI_OBJECT_CAST (buf),
      gst_omx_buffer_data_quark, omx_buf, NULL);

  *buffer = buf;

  pool->current_buffer_index++;

  return GST_FLOW_OK;
}

static void
gst_omx_buffer_pool_free_buffer (GstBufferPool * bpool, GstBuffer * buffer)
{
  GstOMXBufferPool *pool = GST_OMX_BUFFER_POOL (bpool);

  /* If the buffers belong to another pool, restore them now */
  GST_OBJECT_LOCK (pool);
  if (pool->other_pool) {
    gst_object_replace ((GstObject **) & buffer->pool,
        (GstObject *) pool->other_pool);
  }
  GST_OBJECT_UNLOCK (pool);

  gst_mini_object_set_qdata (GST_MINI_OBJECT_CAST (buffer),
      gst_omx_buffer_data_quark, NULL, NULL);

  GST_BUFFER_POOL_CLASS (gst_omx_buffer_pool_parent_class)->free_buffer (bpool,
      buffer);
}

static GstFlowReturn
gst_omx_buffer_pool_acquire_buffer (GstBufferPool * bpool,
    GstBuffer ** buffer, GstBufferPoolAcquireParams * params)
{
  GstFlowReturn ret;
  GstOMXBufferPool *pool = GST_OMX_BUFFER_POOL (bpool);

  if (pool->port->port_def.eDir == OMX_DirOutput) {
    GstBuffer *buf;

    g_return_val_if_fail (pool->current_buffer_index != -1, GST_FLOW_ERROR);

    buf = g_ptr_array_index (pool->buffers, pool->current_buffer_index);
    g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
    *buffer = buf;
    ret = GST_FLOW_OK;

    /* If it's our own memory we have to set the sizes */
    if (!pool->other_pool) {
      GstMemory *mem = gst_buffer_peek_memory (*buffer, 0);
      GstOMXBuffer *omx_buf;

      if (pool->output_mode == GST_OMX_BUFFER_MODE_DMABUF) {
        omx_buf =
            gst_mini_object_get_qdata (GST_MINI_OBJECT_CAST (buf),
            gst_omx_buffer_data_quark);
      } else {
        g_assert (mem
            && g_strcmp0 (mem->allocator->mem_type, GST_OMX_MEMORY_TYPE) == 0);
        /* We already have a pointer to the GstOMXBuffer, no need to retrieve it
         * from the qdata */
        omx_buf = ((GstOMXMemory *) mem)->buf;
      }

      mem->size = omx_buf->omx_buf->nFilledLen;
      mem->offset = omx_buf->omx_buf->nOffset;
    }
  } else {
    /* Acquire any buffer that is available to be filled by upstream */
    ret =
        GST_BUFFER_POOL_CLASS (gst_omx_buffer_pool_parent_class)->acquire_buffer
        (bpool, buffer, params);
  }

  return ret;
}

static void
gst_omx_buffer_pool_release_buffer (GstBufferPool * bpool, GstBuffer * buffer)
{
  GstOMXBufferPool *pool = GST_OMX_BUFFER_POOL (bpool);
  OMX_ERRORTYPE err;
  GstOMXBuffer *omx_buf;

  g_assert (pool->component && pool->port);

  if (!pool->allocating && !pool->deactivated) {
    omx_buf =
        gst_mini_object_get_qdata (GST_MINI_OBJECT_CAST (buffer),
        gst_omx_buffer_data_quark);
    if (pool->port->port_def.eDir == OMX_DirOutput && !omx_buf->used) {
      /* Release back to the port, can be filled again */
      err = gst_omx_port_release_buffer (pool->port, omx_buf);
      if (err != OMX_ErrorNone) {
        GST_ELEMENT_ERROR (pool->element, LIBRARY, SETTINGS, (NULL),
            ("Failed to relase output buffer to component: %s (0x%08x)",
                gst_omx_error_to_string (err), err));
      }
    } else if (!omx_buf->used) {
      /* TODO: Implement.
       *
       * If not used (i.e. was not passed to the component) this should do
       * the same as EmptyBufferDone.
       * If it is used (i.e. was passed to the component) this should do
       * nothing until EmptyBufferDone.
       *
       * EmptyBufferDone should release the buffer to the pool so it can
       * be allocated again
       *
       * Needs something to call back here in EmptyBufferDone, like keeping
       * a ref on the buffer in GstOMXBuffer until EmptyBufferDone... which
       * would ensure that the buffer is always unused when this is called.
       */
      g_assert_not_reached ();
      GST_BUFFER_POOL_CLASS (gst_omx_buffer_pool_parent_class)->release_buffer
          (bpool, buffer);
    }
  }
}

static void
gst_omx_buffer_pool_finalize (GObject * object)
{
  GstOMXBufferPool *pool = GST_OMX_BUFFER_POOL (object);

  if (pool->element)
    gst_object_unref (pool->element);
  pool->element = NULL;

  if (pool->buffers)
    g_ptr_array_unref (pool->buffers);
  pool->buffers = NULL;

  if (pool->other_pool)
    gst_object_unref (pool->other_pool);
  pool->other_pool = NULL;

  if (pool->allocator)
    gst_object_unref (pool->allocator);
  pool->allocator = NULL;

  if (pool->caps)
    gst_caps_unref (pool->caps);
  pool->caps = NULL;

  G_OBJECT_CLASS (gst_omx_buffer_pool_parent_class)->finalize (object);
}

static void
gst_omx_buffer_pool_class_init (GstOMXBufferPoolClass * klass)
{
  GObjectClass *gobject_class = (GObjectClass *) klass;
  GstBufferPoolClass *gstbufferpool_class = (GstBufferPoolClass *) klass;

  gst_omx_buffer_data_quark = g_quark_from_static_string ("GstOMXBufferData");

  gobject_class->finalize = gst_omx_buffer_pool_finalize;
  gstbufferpool_class->start = gst_omx_buffer_pool_start;
  gstbufferpool_class->stop = gst_omx_buffer_pool_stop;
  gstbufferpool_class->get_options = gst_omx_buffer_pool_get_options;
  gstbufferpool_class->set_config = gst_omx_buffer_pool_set_config;
  gstbufferpool_class->alloc_buffer = gst_omx_buffer_pool_alloc_buffer;
  gstbufferpool_class->free_buffer = gst_omx_buffer_pool_free_buffer;
  gstbufferpool_class->acquire_buffer = gst_omx_buffer_pool_acquire_buffer;
  gstbufferpool_class->release_buffer = gst_omx_buffer_pool_release_buffer;
}

static void
gst_omx_buffer_pool_init (GstOMXBufferPool * pool)
{
  pool->buffers = g_ptr_array_new ();
}

GstBufferPool *
gst_omx_buffer_pool_new (GstElement * element, GstOMXComponent * component,
    GstOMXPort * port, GstOMXBufferMode output_mode)
{
  GstOMXBufferPool *pool;

  pool = g_object_new (gst_omx_buffer_pool_get_type (), NULL);
  pool->element = gst_object_ref (element);
  pool->component = component;
  pool->port = port;
  pool->output_mode = output_mode;

  switch (output_mode) {
    case GST_OMX_BUFFER_MODE_DMABUF:
      pool->allocator = gst_dmabuf_allocator_new ();
      break;
    case GST_OMX_BUFFER_MODE_SYSTEM_MEMORY:
      pool->allocator =
          g_object_new (gst_omx_memory_allocator_get_type (), NULL);
      break;
    default:
      g_assert_not_reached ();
  }

  return GST_BUFFER_POOL (pool);
}