static gboolean
gst_ks_read_request_pick_buffer (GstKsVideoDevice * self, ReadRequest * req)
{
GstKsVideoDevicePrivate *priv = GST_KS_VIDEO_DEVICE_GET_PRIVATE (self);
gboolean buffer_found = FALSE;
guint i;
buffer_found = gst_buffer_is_writable (req->buf);
for (i = 0; !buffer_found && i < G_N_ELEMENTS (priv->spare_buffers); i++) {
if (gst_buffer_is_writable (priv->spare_buffers[i])) {
GstBuffer *hold;
hold = req->buf;
req->buf = priv->spare_buffers[i];
priv->spare_buffers[i] = hold;
buffer_found = TRUE;
}
}
if (!buffer_found) {
gst_buffer_unref (req->buf);
req->buf = self->allocfunc (gst_ks_video_device_get_frame_size (self),
KS_BUFFER_ALIGNMENT, self->allocfunc_data);
}
if (req->buf != NULL) {
GST_BUFFER_FLAGS (req->buf) = 0;
return TRUE;
} else {
return FALSE;
}
}
static gboolean
gst_ks_video_device_request_frame (GstKsVideoDevice * self, ReadRequest * req,
gulong * error_code, gchar ** error_str)
{
GstKsVideoDevicePrivate *priv = GST_KS_VIDEO_DEVICE_GET_PRIVATE (self);
HANDLE event;
KSSTREAM_READ_PARAMS *params;
BOOL success;
DWORD bytes_returned = 0;
if (!gst_ks_read_request_pick_buffer (self, req))
goto error_pick_buffer;
/* Reset the OVERLAPPED structure */
event = req->overlapped.hEvent;
memset (&req->overlapped, 0, sizeof (OVERLAPPED));
req->overlapped.hEvent = event;
/* Fill out KSSTREAM_HEADER and KS_FRAME_INFO */
params = &req->params;
memset (params, 0, sizeof (KSSTREAM_READ_PARAMS));
params->header.Size = sizeof (KSSTREAM_HEADER) + sizeof (KS_FRAME_INFO);
params->header.PresentationTime.Numerator = 1;
params->header.PresentationTime.Denominator = 1;
params->header.FrameExtent = gst_ks_video_device_get_frame_size (self);
params->header.Data = GST_BUFFER_DATA (req->buf);
params->frame_info.ExtendedHeaderSize = sizeof (KS_FRAME_INFO);
success = DeviceIoControl (priv->pin_handle, IOCTL_KS_READ_STREAM, NULL, 0,
params, params->header.Size, &bytes_returned, &req->overlapped);
if (!success && GetLastError () != ERROR_IO_PENDING)
goto error_ioctl;
return TRUE;
/* ERRORS */
error_pick_buffer:
{
if (error_code != NULL)
*error_code = 0;
if (error_str != NULL)
*error_str = NULL;
return FALSE;
}
error_ioctl:
{
gst_ks_video_device_parse_win32_error ("DeviceIoControl", GetLastError (),
error_code, error_str);
return FALSE;
}
}
static gboolean
gst_ks_video_device_request_frame (GstKsVideoDevice * self, ReadRequest * req,
gulong * error_code, gchar ** error_str)
{
GstKsVideoDevicePrivate *priv = GST_KS_VIDEO_DEVICE_GET_PRIVATE (self);
HANDLE event;
KSSTREAM_READ_PARAMS *params;
BOOL success;
DWORD bytes_returned = 0;
/* Reset the OVERLAPPED structure */
event = req->overlapped.hEvent;
memset (&req->overlapped, 0, sizeof (OVERLAPPED));
req->overlapped.hEvent = event;
/* Fill out KSSTREAM_HEADER and KS_FRAME_INFO */
params = &req->params;
memset (params, 0, sizeof (KSSTREAM_READ_PARAMS));
params->header.Size = sizeof (KSSTREAM_HEADER) + sizeof (KS_FRAME_INFO);
params->header.PresentationTime.Numerator = 1;
params->header.PresentationTime.Denominator = 1;
params->header.FrameExtent = gst_ks_video_device_get_frame_size (self);
params->header.Data = req->buf;
params->frame_info.ExtendedHeaderSize = sizeof (KS_FRAME_INFO);
/*
* Clear the buffer like DirectShow does
*
* REVISIT: Could probably remove this later, for now it's here to help
* track down the case where we capture old frames. This has been
* observed with UVC cameras, presumably with some system load.
*/
memset (params->header.Data, 0, params->header.FrameExtent);
success = DeviceIoControl (priv->pin_handle, IOCTL_KS_READ_STREAM, NULL, 0,
params, params->header.Size, &bytes_returned, &req->overlapped);
if (!success && GetLastError () != ERROR_IO_PENDING)
goto error_ioctl;
return TRUE;
/* ERRORS */
error_ioctl:
{
gst_ks_video_device_parse_win32_error ("DeviceIoControl", GetLastError (),
error_code, error_str);
return FALSE;
}
}
static void
gst_ks_video_device_prepare_buffers (GstKsVideoDevice * self)
{
GstKsVideoDevicePrivate *priv = GST_KS_VIDEO_DEVICE_GET_PRIVATE (self);
guint i;
guint frame_size;
g_assert (priv->cur_media_type != NULL);
gst_ks_video_device_clear_buffers (self);
priv->requests = g_array_sized_new (FALSE, TRUE, sizeof (ReadRequest),
priv->num_requests);
priv->request_events = g_array_sized_new (FALSE, TRUE, sizeof (HANDLE),
priv->num_requests + 1);
frame_size = gst_ks_video_device_get_frame_size (self);
for (i = 0; i < G_N_ELEMENTS (priv->spare_buffers); i++) {
priv->spare_buffers[i] = self->allocfunc (frame_size, KS_BUFFER_ALIGNMENT,
self->allocfunc_data);
}
for (i = 0; i < priv->num_requests; i++) {
ReadRequest req = { 0, };
req.buf = self->allocfunc (frame_size, KS_BUFFER_ALIGNMENT,
self->allocfunc_data);
req.overlapped.hEvent = CreateEvent (NULL, TRUE, FALSE, NULL);
g_array_append_val (priv->requests, req);
g_array_append_val (priv->request_events, req.overlapped.hEvent);
}
g_array_append_val (priv->request_events, priv->cancel_event);
/*
* REVISIT: Could probably remove this later, for now it's here to help
* track down the case where we capture old frames. This has been
* observed with UVC cameras, presumably with some system load.
*/
priv->last_timestamp = GST_CLOCK_TIME_NONE;
}
static GstFlowReturn
gst_ks_video_src_create (GstPushSrc * pushsrc, GstBuffer ** buffer)
{
GstKsVideoSrc *self = GST_KS_VIDEO_SRC (pushsrc);
GstKsVideoSrcPrivate *priv = GST_KS_VIDEO_SRC_GET_PRIVATE (self);
guint buf_size;
GstCaps *caps;
GstBuffer *buf = NULL;
GstFlowReturn result;
GstClockTime presentation_time;
gulong error_code;
gchar *error_str;
g_assert (priv->device != NULL);
if (!gst_ks_video_device_has_caps (priv->device))
goto error_no_caps;
buf_size = gst_ks_video_device_get_frame_size (priv->device);
g_assert (buf_size);
caps = gst_pad_get_negotiated_caps (GST_BASE_SRC_PAD (self));
if (caps == NULL)
goto error_no_caps;
result = gst_pad_alloc_buffer (GST_BASE_SRC_PAD (self), priv->offset,
buf_size, caps, &buf);
gst_caps_unref (caps);
if (G_UNLIKELY (result != GST_FLOW_OK))
goto error_alloc_buffer;
if (G_UNLIKELY (!priv->running)) {
KS_WORKER_LOCK (priv);
priv->worker_pending_run = TRUE;
KS_WORKER_NOTIFY (priv);
while (priv->worker_pending_run)
KS_WORKER_WAIT_FOR_RESULT (priv);
priv->running = priv->worker_run_result;
KS_WORKER_UNLOCK (priv);
if (!priv->running)
goto error_start_capture;
}
do {
gulong bytes_read;
result = gst_ks_video_device_read_frame (priv->device,
GST_BUFFER_DATA (buf), buf_size, &bytes_read, &presentation_time,
&error_code, &error_str);
if (G_UNLIKELY (result != GST_FLOW_OK))
goto error_read_frame;
GST_BUFFER_SIZE (buf) = bytes_read;
}
while (!gst_ks_video_src_timestamp_buffer (self, buf, presentation_time));
if (G_UNLIKELY (priv->do_stats))
gst_ks_video_src_update_statistics (self);
gst_ks_video_device_postprocess_frame (priv->device,
GST_BUFFER_DATA (buf), GST_BUFFER_SIZE (buf));
*buffer = buf;
return GST_FLOW_OK;
/* ERRORS */
error_no_caps:
{
GST_ELEMENT_ERROR (self, CORE, NEGOTIATION,
("not negotiated"), ("maybe setcaps failed?"));
return GST_FLOW_ERROR;
}
error_start_capture:
{
GST_ELEMENT_ERROR (self, RESOURCE, OPEN_READ,
("could not start capture"),
("failed to change pin state to KSSTATE_RUN"));
return GST_FLOW_ERROR;
}
error_alloc_buffer:
{
GST_ELEMENT_ERROR (self, CORE, PAD, ("alloc_buffer failed"), (NULL));
return result;
}
error_read_frame:
{
if (result != GST_FLOW_WRONG_STATE && result != GST_FLOW_UNEXPECTED) {
GST_ELEMENT_ERROR (self, RESOURCE, READ,
("read failed: %s [0x%08x]", error_str, error_code),
("gst_ks_video_device_read_frame failed"));
}
g_free (error_str);
gst_buffer_unref (buf);
return result;
}
}
