GstFlowReturn
gst_ks_video_device_read_frame (GstKsVideoDevice * self, guint8 * buf,
gulong buf_size, gulong * bytes_read, GstClockTime * presentation_time,
gulong * error_code, gchar ** error_str)
{
GstKsVideoDevicePrivate *priv = GST_KS_VIDEO_DEVICE_GET_PRIVATE (self);
guint req_idx;
DWORD wait_ret;
BOOL success;
DWORD bytes_returned;
g_assert (priv->cur_media_type != NULL);
/* First time we're called, submit the requests. */
if (G_UNLIKELY (!priv->requests_submitted)) {
priv->requests_submitted = TRUE;
for (req_idx = 0; req_idx < priv->num_requests; req_idx++) {
ReadRequest *req = &g_array_index (priv->requests, ReadRequest, req_idx);
if (!gst_ks_video_device_request_frame (self, req, error_code, error_str))
goto error_request_failed;
}
}
do {
/* Wait for either a request to complete, a cancel or a timeout */
wait_ret = WaitForMultipleObjects (priv->request_events->len,
(HANDLE *) priv->request_events->data, FALSE, READ_TIMEOUT);
if (wait_ret == WAIT_TIMEOUT)
goto error_timeout;
else if (wait_ret == WAIT_FAILED)
goto error_wait;
/* Stopped? */
if (WaitForSingleObject (priv->cancel_event, 0) == WAIT_OBJECT_0)
goto error_cancel;
*bytes_read = 0;
/* Find the last ReadRequest that finished and get the result, immediately
* re-issuing each request that has completed. */
for (req_idx = wait_ret - WAIT_OBJECT_0;
req_idx < priv->num_requests; req_idx++) {
ReadRequest *req = &g_array_index (priv->requests, ReadRequest, req_idx);
/*
* Completed? WaitForMultipleObjects() returns the lowest index if
* multiple objects are in the signaled state, and we know that requests
* are processed one by one so there's no point in looking further once
* we've found the first that's non-signaled.
*/
if (WaitForSingleObject (req->overlapped.hEvent, 0) != WAIT_OBJECT_0)
break;
success = GetOverlappedResult (priv->pin_handle, &req->overlapped,
&bytes_returned, TRUE);
ResetEvent (req->overlapped.hEvent);
if (success) {
KSSTREAM_HEADER *hdr = &req->params.header;
KS_FRAME_INFO *frame_info = &req->params.frame_info;
GstClockTime timestamp = GST_CLOCK_TIME_NONE;
GstClockTime duration = GST_CLOCK_TIME_NONE;
if (hdr->OptionsFlags & KSSTREAM_HEADER_OPTIONSF_TIMEVALID)
timestamp = hdr->PresentationTime.Time * 100;
if (hdr->OptionsFlags & KSSTREAM_HEADER_OPTIONSF_DURATIONVALID)
duration = hdr->Duration * 100;
/* Assume it's a good frame */
*bytes_read = hdr->DataUsed;
if (G_LIKELY (presentation_time != NULL))
*presentation_time = timestamp;
if (G_UNLIKELY (GST_DEBUG_IS_ENABLED ())) {
gchar *options_flags_str =
ks_options_flags_to_string (hdr->OptionsFlags);
GST_DEBUG ("PictureNumber=%" G_GUINT64_FORMAT ", DropCount=%"
G_GUINT64_FORMAT ", PresentationTime=%" GST_TIME_FORMAT
", Duration=%" GST_TIME_FORMAT ", OptionsFlags=%s: %d bytes",
frame_info->PictureNumber, frame_info->DropCount,
GST_TIME_ARGS (timestamp), GST_TIME_ARGS (duration),
options_flags_str, hdr->DataUsed);
g_free (options_flags_str);
}
/* Protect against old frames. This should never happen, see previous
* comment on last_timestamp. */
if (G_LIKELY (GST_CLOCK_TIME_IS_VALID (timestamp))) {
if (G_UNLIKELY (GST_CLOCK_TIME_IS_VALID (priv->last_timestamp) &&
timestamp < priv->last_timestamp)) {
GST_WARNING ("got an old frame (last_timestamp=%" GST_TIME_FORMAT
", timestamp=%" GST_TIME_FORMAT ")",
GST_TIME_ARGS (priv->last_timestamp),
GST_TIME_ARGS (timestamp));
*bytes_read = 0;
} else {
priv->last_timestamp = timestamp;
}
}
if (*bytes_read > 0) {
/* Grab the frame data */
g_assert (buf_size >= hdr->DataUsed);
memcpy (buf, req->buf, hdr->DataUsed);
if (priv->is_mjpeg) {
/*
* Workaround for cameras/drivers that intermittently provide us
* with incomplete or corrupted MJPEG frames.
*
* Happens with for instance Microsoft LifeCam VX-7000.
*/
gboolean valid = FALSE;
guint padding = 0;
/* JFIF SOI marker */
if (*bytes_read > MJPEG_MAX_PADDING
&& buf[0] == 0xff && buf[1] == 0xd8) {
guint8 *p = buf + *bytes_read - 2;
/* JFIF EOI marker (but skip any padding) */
while (padding < MJPEG_MAX_PADDING - 1 - 2 && !valid) {
if (p[0] == 0xff && p[1] == 0xd9) {
valid = TRUE;
} else {
padding++;
p--;
}
}
}
if (valid)
*bytes_read -= padding;
else
*bytes_read = 0;
}
}
} else if (GetLastError () != ERROR_OPERATION_ABORTED)
goto error_get_result;
/* Submit a new request immediately */
if (!gst_ks_video_device_request_frame (self, req, error_code, error_str))
goto error_request_failed;
}
} while (*bytes_read == 0);
return GST_FLOW_OK;
/* ERRORS */
error_request_failed:
{
return GST_FLOW_ERROR;
}
error_timeout:
{
GST_DEBUG ("IOCTL_KS_READ_STREAM timed out");
if (error_code != NULL)
*error_code = 0;
if (error_str != NULL)
*error_str = NULL;
return GST_FLOW_UNEXPECTED;
}
error_wait:
{
gst_ks_video_device_parse_win32_error ("WaitForMultipleObjects",
GetLastError (), error_code, error_str);
return GST_FLOW_ERROR;
}
error_cancel:
{
if (error_code != NULL)
*error_code = 0;
if (error_str != NULL)
*error_str = NULL;
return GST_FLOW_WRONG_STATE;
}
error_get_result:
{
gst_ks_video_device_parse_win32_error ("GetOverlappedResult",
GetLastError (), error_code, error_str);
return GST_FLOW_ERROR;
}
}
GstFlowReturn
gst_ks_video_device_read_frame (GstKsVideoDevice * self, GstBuffer ** buf,
GstClockTime * presentation_time, gulong * error_code, gchar ** error_str)
{
GstKsVideoDevicePrivate *priv = GST_KS_VIDEO_DEVICE_GET_PRIVATE (self);
guint req_idx;
DWORD wait_ret;
BOOL success;
DWORD bytes_returned;
g_assert (priv->cur_media_type != NULL);
/* First time we're called, submit the requests. */
if (G_UNLIKELY (!priv->requests_submitted)) {
priv->requests_submitted = TRUE;
for (req_idx = 0; req_idx < priv->num_requests; req_idx++) {
ReadRequest *req = &g_array_index (priv->requests, ReadRequest, req_idx);
if (!gst_ks_video_device_request_frame (self, req, error_code, error_str))
goto error_request_failed;
}
}
*buf = NULL;
do {
/* Wait for either a request to complete, a cancel or a timeout */
wait_ret = WaitForMultipleObjects (priv->request_events->len,
(HANDLE *) priv->request_events->data, FALSE, READ_TIMEOUT);
if (wait_ret == WAIT_TIMEOUT)
goto error_timeout;
else if (wait_ret == WAIT_FAILED)
goto error_wait;
/* Stopped? */
if (WaitForSingleObject (priv->cancel_event, 0) == WAIT_OBJECT_0)
goto error_cancel;
/* Find the last ReadRequest that finished and get the result, immediately
* re-issuing each request that has completed. */
for (req_idx = wait_ret - WAIT_OBJECT_0;
req_idx < priv->num_requests; req_idx++) {
ReadRequest *req = &g_array_index (priv->requests, ReadRequest, req_idx);
/*
* Completed? WaitForMultipleObjects() returns the lowest index if
* multiple objects are in the signaled state, and we know that requests
* are processed one by one so there's no point in looking further once
* we've found the first that's non-signaled.
*/
if (WaitForSingleObject (req->overlapped.hEvent, 0) != WAIT_OBJECT_0)
break;
success = GetOverlappedResult (priv->pin_handle, &req->overlapped,
&bytes_returned, TRUE);
ResetEvent (req->overlapped.hEvent);
if (success) {
KSSTREAM_HEADER *hdr = &req->params.header;
KS_FRAME_INFO *frame_info = &req->params.frame_info;
GstClockTime timestamp = GST_CLOCK_TIME_NONE;
GstClockTime duration = GST_CLOCK_TIME_NONE;
if (hdr->OptionsFlags & KSSTREAM_HEADER_OPTIONSF_TIMEVALID)
timestamp = hdr->PresentationTime.Time * 100;
if (hdr->OptionsFlags & KSSTREAM_HEADER_OPTIONSF_DURATIONVALID)
duration = hdr->Duration * 100;
UNREF_BUFFER (buf);
if (G_LIKELY (hdr->DataUsed != 0)) {
/* Assume it's a good frame */
GST_BUFFER_SIZE (req->buf) = hdr->DataUsed;
*buf = gst_buffer_ref (req->buf);
}
if (G_LIKELY (presentation_time != NULL))
*presentation_time = timestamp;
if (G_UNLIKELY (GST_DEBUG_IS_ENABLED ())) {
gchar *options_flags_str =
ks_options_flags_to_string (hdr->OptionsFlags);
GST_DEBUG ("PictureNumber=%" G_GUINT64_FORMAT ", DropCount=%"
G_GUINT64_FORMAT ", PresentationTime=%" GST_TIME_FORMAT
", Duration=%" GST_TIME_FORMAT ", OptionsFlags=%s: %lu bytes",
frame_info->PictureNumber, frame_info->DropCount,
GST_TIME_ARGS (timestamp), GST_TIME_ARGS (duration),
options_flags_str, hdr->DataUsed);
g_free (options_flags_str);
}
/* Protect against old frames. This should never happen, see previous
* comment on last_timestamp. */
if (G_LIKELY (GST_CLOCK_TIME_IS_VALID (timestamp))) {
if (G_UNLIKELY (GST_CLOCK_TIME_IS_VALID (priv->last_timestamp) &&
timestamp < priv->last_timestamp)) {
GST_INFO ("got an old frame (last_timestamp=%" GST_TIME_FORMAT
", timestamp=%" GST_TIME_FORMAT ")",
GST_TIME_ARGS (priv->last_timestamp),
GST_TIME_ARGS (timestamp));
UNREF_BUFFER (buf);
} else {
priv->last_timestamp = timestamp;
}
}
} else if (GetLastError () != ERROR_OPERATION_ABORTED) {
goto error_get_result;
}
/* Submit a new request immediately */
if (!gst_ks_video_device_request_frame (self, req, error_code, error_str))
goto error_request_failed;
}
} while (*buf == NULL);
return GST_FLOW_OK;
/* ERRORS */
error_request_failed:
{
UNREF_BUFFER (buf);
return GST_FLOW_ERROR;
}
error_timeout:
{
GST_DEBUG ("IOCTL_KS_READ_STREAM timed out");
if (error_code != NULL)
*error_code = 0;
if (error_str != NULL)
*error_str = NULL;
return GST_FLOW_UNEXPECTED;
}
error_wait:
{
gst_ks_video_device_parse_win32_error ("WaitForMultipleObjects",
GetLastError (), error_code, error_str);
return GST_FLOW_ERROR;
}
error_cancel:
{
if (error_code != NULL)
*error_code = 0;
if (error_str != NULL)
*error_str = NULL;
return GST_FLOW_FLUSHING;
}
error_get_result:
{
gst_ks_video_device_parse_win32_error ("GetOverlappedResult",
GetLastError (), error_code, error_str);
return GST_FLOW_ERROR;
}
}
