/* called after A/V sync to render frame */
static GstFlowReturn
gst_v4l2sink_show_frame (GstBaseSink * bsink, GstBuffer * buf)
{
GstFlowReturn ret;
GstV4l2Sink *v4l2sink = GST_V4L2SINK (bsink);
GstV4l2Object *obj = v4l2sink->v4l2object;
GST_DEBUG_OBJECT (v4l2sink, "render buffer: %p", buf);
if (G_UNLIKELY (obj->pool == NULL))
goto not_negotiated;
ret =
gst_v4l2_buffer_pool_process (GST_V4L2_BUFFER_POOL_CAST (obj->pool), buf);
return ret;
/* ERRORS */
not_negotiated:
{
GST_ERROR_OBJECT (bsink, "not negotiated");
return GST_FLOW_NOT_NEGOTIATED;
}
}
static GstFlowReturn
gst_v4l2src_create (GstPushSrc * src, GstBuffer ** buf)
{
GstV4l2Src *v4l2src = GST_V4L2SRC (src);
GstV4l2Object *obj = v4l2src->v4l2object;
GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL_CAST (obj->pool);
GstFlowReturn ret;
GstClock *clock;
GstClockTime abs_time, base_time, timestamp, duration;
GstClockTime delay;
do {
ret = GST_BASE_SRC_CLASS (parent_class)->alloc (GST_BASE_SRC (src), 0,
obj->info.size, buf);
if (G_UNLIKELY (ret != GST_FLOW_OK))
goto alloc_failed;
ret = gst_v4l2_buffer_pool_process (pool, buf);
} while (ret == GST_V4L2_FLOW_CORRUPTED_BUFFER);
if (G_UNLIKELY (ret != GST_FLOW_OK))
goto error;
timestamp = GST_BUFFER_TIMESTAMP (*buf);
duration = obj->duration;
/* timestamps, LOCK to get clock and base time. */
/* FIXME: element clock and base_time is rarely changing */
GST_OBJECT_LOCK (v4l2src);
if ((clock = GST_ELEMENT_CLOCK (v4l2src))) {
/* we have a clock, get base time and ref clock */
base_time = GST_ELEMENT (v4l2src)->base_time;
gst_object_ref (clock);
} else {
/* no clock, can't set timestamps */
base_time = GST_CLOCK_TIME_NONE;
}
GST_OBJECT_UNLOCK (v4l2src);
/* sample pipeline clock */
if (clock) {
abs_time = gst_clock_get_time (clock);
gst_object_unref (clock);
} else {
abs_time = GST_CLOCK_TIME_NONE;
}
if (timestamp != GST_CLOCK_TIME_NONE) {
struct timespec now;
GstClockTime gstnow;
/* v4l2 specs say to use the system time although many drivers switched to
* the more desirable monotonic time. We first try to use the monotonic time
* and see how that goes */
clock_gettime (CLOCK_MONOTONIC, &now);
gstnow = GST_TIMESPEC_TO_TIME (now);
if (gstnow < timestamp && (timestamp - gstnow) > (10 * GST_SECOND)) {
GTimeVal now;
/* very large diff, fall back to system time */
g_get_current_time (&now);
gstnow = GST_TIMEVAL_TO_TIME (now);
}
if (gstnow > timestamp) {
delay = gstnow - timestamp;
} else {
delay = 0;
}
GST_DEBUG_OBJECT (v4l2src, "ts: %" GST_TIME_FORMAT " now %" GST_TIME_FORMAT
" delay %" GST_TIME_FORMAT, GST_TIME_ARGS (timestamp),
GST_TIME_ARGS (gstnow), GST_TIME_ARGS (delay));
} else {
/* we assume 1 frame latency otherwise */
if (GST_CLOCK_TIME_IS_VALID (duration))
delay = duration;
else
delay = 0;
}
/* set buffer metadata */
GST_BUFFER_OFFSET (*buf) = v4l2src->offset++;
GST_BUFFER_OFFSET_END (*buf) = v4l2src->offset;
if (G_LIKELY (abs_time != GST_CLOCK_TIME_NONE)) {
/* the time now is the time of the clock minus the base time */
timestamp = abs_time - base_time;
/* adjust for delay in the device */
if (timestamp > delay)
timestamp -= delay;
else
timestamp = 0;
} else {
timestamp = GST_CLOCK_TIME_NONE;
}
/* activate settings for next frame */
if (GST_CLOCK_TIME_IS_VALID (duration)) {
v4l2src->ctrl_time += duration;
} else {
/* this is not very good (as it should be the next timestamp),
* still good enough for linear fades (as long as it is not -1)
*/
v4l2src->ctrl_time = timestamp;
}
gst_object_sync_values (GST_OBJECT (src), v4l2src->ctrl_time);
GST_INFO_OBJECT (src, "sync to %" GST_TIME_FORMAT " out ts %" GST_TIME_FORMAT,
GST_TIME_ARGS (v4l2src->ctrl_time), GST_TIME_ARGS (timestamp));
GST_BUFFER_TIMESTAMP (*buf) = timestamp;
GST_BUFFER_DURATION (*buf) = duration;
return ret;
/* ERROR */
alloc_failed:
{
if (ret != GST_FLOW_FLUSHING)
GST_ELEMENT_ERROR (src, RESOURCE, NO_SPACE_LEFT,
("Failed to allocate a buffer"), (NULL));
return ret;
}
error:
{
if (ret == GST_V4L2_FLOW_LAST_BUFFER) {
GST_ELEMENT_ERROR (src, RESOURCE, FAILED,
("Driver returned a buffer with no payload, this most likely "
"indicate a bug in the driver."), (NULL));
ret = GST_FLOW_ERROR;
} else {
GST_DEBUG_OBJECT (src, "error processing buffer %d (%s)", ret,
gst_flow_get_name (ret));
}
return ret;
}
}
static gboolean
gst_v4l2src_query (GstBaseSrc * bsrc, GstQuery * query)
{
GstV4l2Src *src;
GstV4l2Object *obj;
gboolean res = FALSE;
src = GST_V4L2SRC (bsrc);
obj = src->v4l2object;
switch (GST_QUERY_TYPE (query)) {
case GST_QUERY_LATENCY:{
GstClockTime min_latency, max_latency;
guint32 fps_n, fps_d;
guint num_buffers = 0;
/* device must be open */
if (!GST_V4L2_IS_OPEN (obj)) {
GST_WARNING_OBJECT (src,
"Can't give latency since device isn't open !");
goto done;
}
fps_n = GST_V4L2_FPS_N (obj);
fps_d = GST_V4L2_FPS_D (obj);
/* we must have a framerate */
if (fps_n <= 0 || fps_d <= 0) {
GST_WARNING_OBJECT (src,
"Can't give latency since framerate isn't fixated !");
goto done;
}
/* min latency is the time to capture one frame */
min_latency = gst_util_uint64_scale_int (GST_SECOND, fps_d, fps_n);
/* max latency is total duration of the frame buffer */
if (obj->pool != NULL)
num_buffers = GST_V4L2_BUFFER_POOL_CAST (obj->pool)->max_latency;
if (num_buffers == 0)
max_latency = -1;
else
max_latency = num_buffers * min_latency;
GST_DEBUG_OBJECT (bsrc,
"report latency min %" GST_TIME_FORMAT " max %" GST_TIME_FORMAT,
GST_TIME_ARGS (min_latency), GST_TIME_ARGS (max_latency));
/* we are always live, the min latency is 1 frame and the max latency is
* the complete buffer of frames. */
gst_query_set_latency (query, TRUE, min_latency, max_latency);
res = TRUE;
break;
}
default:
res = GST_BASE_SRC_CLASS (parent_class)->query (bsrc, query);
break;
}
done:
return res;
}
static GstFlowReturn
gst_v4l2src_create (GstPushSrc * src, GstBuffer ** buf)
{
GstV4l2Src *v4l2src = GST_V4L2SRC (src);
GstV4l2Object *obj = v4l2src->v4l2object;
GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL_CAST (obj->pool);
GstFlowReturn ret;
GstClock *clock;
GstClockTime abs_time, base_time, timestamp, duration;
GstClockTime delay;
GstMessage *qos_msg;
do {
ret = GST_BASE_SRC_CLASS (parent_class)->alloc (GST_BASE_SRC (src), 0,
obj->info.size, buf);
if (G_UNLIKELY (ret != GST_FLOW_OK))
goto alloc_failed;
ret = gst_v4l2_buffer_pool_process (pool, buf);
} while (ret == GST_V4L2_FLOW_CORRUPTED_BUFFER);
if (G_UNLIKELY (ret != GST_FLOW_OK))
goto error;
timestamp = GST_BUFFER_TIMESTAMP (*buf);
duration = obj->duration;
/* timestamps, LOCK to get clock and base time. */
/* FIXME: element clock and base_time is rarely changing */
GST_OBJECT_LOCK (v4l2src);
if ((clock = GST_ELEMENT_CLOCK (v4l2src))) {
/* we have a clock, get base time and ref clock */
base_time = GST_ELEMENT (v4l2src)->base_time;
gst_object_ref (clock);
} else {
/* no clock, can't set timestamps */
base_time = GST_CLOCK_TIME_NONE;
}
GST_OBJECT_UNLOCK (v4l2src);
/* sample pipeline clock */
if (clock) {
abs_time = gst_clock_get_time (clock);
gst_object_unref (clock);
} else {
abs_time = GST_CLOCK_TIME_NONE;
}
retry:
if (!v4l2src->has_bad_timestamp && timestamp != GST_CLOCK_TIME_NONE) {
struct timespec now;
GstClockTime gstnow;
/* v4l2 specs say to use the system time although many drivers switched to
* the more desirable monotonic time. We first try to use the monotonic time
* and see how that goes */
clock_gettime (CLOCK_MONOTONIC, &now);
gstnow = GST_TIMESPEC_TO_TIME (now);
if (timestamp > gstnow || (gstnow - timestamp) > (10 * GST_SECOND)) {
GTimeVal now;
/* very large diff, fall back to system time */
g_get_current_time (&now);
gstnow = GST_TIMEVAL_TO_TIME (now);
}
/* Detect buggy drivers here, and stop using their timestamp. Failing any
* of these condition would imply a very buggy driver:
* - Timestamp in the future
* - Timestamp is going backward compare to last seen timestamp
* - Timestamp is jumping forward for less then a frame duration
* - Delay is bigger then the actual timestamp
* */
if (timestamp > gstnow) {
GST_WARNING_OBJECT (v4l2src,
"Timestamp in the future detected, ignoring driver timestamps");
v4l2src->has_bad_timestamp = TRUE;
goto retry;
}
if (v4l2src->last_timestamp > timestamp) {
GST_WARNING_OBJECT (v4l2src,
"Timestamp going backward, ignoring driver timestamps");
v4l2src->has_bad_timestamp = TRUE;
goto retry;
}
delay = gstnow - timestamp;
if (delay > timestamp) {
GST_WARNING_OBJECT (v4l2src,
"Timestamp does not correlate with any clock, ignoring driver timestamps");
v4l2src->has_bad_timestamp = TRUE;
goto retry;
}
/* Save last timestamp for sanity checks */
v4l2src->last_timestamp = timestamp;
GST_DEBUG_OBJECT (v4l2src, "ts: %" GST_TIME_FORMAT " now %" GST_TIME_FORMAT
" delay %" GST_TIME_FORMAT, GST_TIME_ARGS (timestamp),
GST_TIME_ARGS (gstnow), GST_TIME_ARGS (delay));
} else {
/* we assume 1 frame latency otherwise */
if (GST_CLOCK_TIME_IS_VALID (duration))
delay = duration;
else
delay = 0;
}
/* set buffer metadata */
if (G_LIKELY (abs_time != GST_CLOCK_TIME_NONE)) {
/* the time now is the time of the clock minus the base time */
timestamp = abs_time - base_time;
/* adjust for delay in the device */
if (timestamp > delay)
timestamp -= delay;
else
timestamp = 0;
} else {
timestamp = GST_CLOCK_TIME_NONE;
}
/* activate settings for next frame */
if (GST_CLOCK_TIME_IS_VALID (duration)) {
v4l2src->ctrl_time += duration;
} else {
/* this is not very good (as it should be the next timestamp),
* still good enough for linear fades (as long as it is not -1)
*/
v4l2src->ctrl_time = timestamp;
}
gst_object_sync_values (GST_OBJECT (src), v4l2src->ctrl_time);
GST_INFO_OBJECT (src, "sync to %" GST_TIME_FORMAT " out ts %" GST_TIME_FORMAT,
GST_TIME_ARGS (v4l2src->ctrl_time), GST_TIME_ARGS (timestamp));
/* use generated offset values only if there are not already valid ones
* set by the v4l2 device */
if (!GST_BUFFER_OFFSET_IS_VALID (*buf) || !GST_BUFFER_OFFSET_END_IS_VALID (*buf)) {
GST_BUFFER_OFFSET (*buf) = v4l2src->offset++;
GST_BUFFER_OFFSET_END (*buf) = v4l2src->offset;
} else {
/* adjust raw v4l2 device sequence, will restart at null in case of renegotiation
* (streamoff/streamon) */
GST_BUFFER_OFFSET (*buf) += v4l2src->renegotiation_adjust;
GST_BUFFER_OFFSET_END (*buf) += v4l2src->renegotiation_adjust;
/* check for frame loss with given (from v4l2 device) buffer offset */
if ((v4l2src->offset != 0) && (GST_BUFFER_OFFSET (*buf) != (v4l2src->offset + 1))) {
guint64 lost_frame_count = GST_BUFFER_OFFSET (*buf) - v4l2src->offset - 1;
GST_WARNING_OBJECT (v4l2src,
"lost frames detected: count = %" G_GUINT64_FORMAT " - ts: %" GST_TIME_FORMAT,
lost_frame_count, GST_TIME_ARGS (timestamp));
qos_msg = gst_message_new_qos (GST_OBJECT_CAST (v4l2src), TRUE,
GST_CLOCK_TIME_NONE, GST_CLOCK_TIME_NONE, timestamp,
GST_CLOCK_TIME_IS_VALID (duration) ? lost_frame_count * duration : GST_CLOCK_TIME_NONE);
gst_element_post_message (GST_ELEMENT_CAST (v4l2src), qos_msg);
}
v4l2src->offset = GST_BUFFER_OFFSET (*buf);
}
GST_BUFFER_TIMESTAMP (*buf) = timestamp;
GST_BUFFER_DURATION (*buf) = duration;
return ret;
/* ERROR */
alloc_failed:
{
if (ret != GST_FLOW_FLUSHING)
GST_ELEMENT_ERROR (src, RESOURCE, NO_SPACE_LEFT,
("Failed to allocate a buffer"), (NULL));
return ret;
}
error:
{
if (ret == GST_V4L2_FLOW_LAST_BUFFER) {
GST_ELEMENT_ERROR (src, RESOURCE, FAILED,
("Driver returned a buffer with no payload, this most likely "
"indicate a bug in the driver."), (NULL));
ret = GST_FLOW_ERROR;
} else {
GST_DEBUG_OBJECT (src, "error processing buffer %d (%s)", ret,
gst_flow_get_name (ret));
}
return ret;
}
}