decodebin2: Rewrite EOS-handling code

This is now really threadsafe and improves switching
between different groups.
This commit is contained in:
Edward Hervey 2011-07-28 16:44:33 +00:00 committed by Sebastian Dröge
parent 936e87cdcf
commit 9d2bcb08fe

View file

@ -433,7 +433,6 @@ static void gst_decode_group_free (GstDecodeGroup * group);
static GstDecodeGroup *gst_decode_group_new (GstDecodeBin * dbin,
GstDecodeChain * chain);
static gboolean gst_decode_chain_is_complete (GstDecodeChain * chain);
static gboolean gst_decode_chain_handle_eos (GstDecodeChain * chain);
static gboolean gst_decode_chain_expose (GstDecodeChain * chain,
GList ** endpads, gboolean * missing_plugin);
static gboolean gst_decode_chain_is_drained (GstDecodeChain * chain);
@ -3040,95 +3039,152 @@ out:
return complete;
}
static gboolean
drain_and_switch_chains (GstDecodeChain * chain, GstDecodePad * drainpad,
gboolean * last_group, gboolean * drained, gboolean * switched);
/* drain_and_switch_chains/groups:
*
* CALL WITH CHAIN LOCK (or group parent) TAKEN !
*
* Goes down the chains/groups until it finds the chain
* to which the drainpad belongs.
*
* It marks that pad/chain as drained and then will figure
* out which group to switch to or not.
*
* last_chain will be set to TRUE if the group to which the
* pad belongs is the last one.
*
* drained will be set to TRUE if the chain/group is drained.
*
* Returns: TRUE if the chain contained the target pad */
static gboolean
drain_and_switch_group (GstDecodeGroup * group, GstDecodePad * drainpad,
gboolean * last_group, gboolean * drained, gboolean * switched)
{
gboolean handled = FALSE;
gboolean alldrained = TRUE;
GList *tmp;
GST_DEBUG ("Checking group %p (target pad %s:%s)",
group, GST_DEBUG_PAD_NAME (drainpad));
/* Definitely can't be in drained groups */
if (G_UNLIKELY (group->drained)) {
goto beach;
}
/* Figure out if all our chains are drained with the
* new information */
for (tmp = group->children; tmp; tmp = tmp->next) {
GstDecodeChain *chain = (GstDecodeChain *) tmp->data;
gboolean subdrained;
handled |=
drain_and_switch_chains (chain, drainpad, last_group, &subdrained,
switched);
if (!subdrained)
alldrained = FALSE;
}
beach:
GST_DEBUG ("group %p (last_group:%d, drained:%d, switched:%d, handled:%d)",
group, *last_group, alldrained, *switched, handled);
*drained = alldrained;
return handled;
}
static gboolean
drain_and_switch_chains (GstDecodeChain * chain, GstDecodePad * drainpad,
gboolean * last_group, gboolean * drained, gboolean * switched)
{
gboolean handled = FALSE;
GstDecodeBin *dbin = chain->dbin;
GST_DEBUG ("Checking chain %p (target pad %s:%s)",
chain, GST_DEBUG_PAD_NAME (drainpad));
CHAIN_MUTEX_LOCK (chain);
if (chain->endpad) {
/* Check if we're reached the target endchain */
if (chain == drainpad->chain) {
GST_DEBUG ("Found the target chain");
drainpad->drained = TRUE;
handled = TRUE;
}
*drained = chain->endpad->drained;
goto beach;
}
/* We known there are groups to switch to */
if (chain->next_groups)
*last_group = FALSE;
/* Check the active group */
if (chain->active_group) {
gboolean subdrained = FALSE;
handled = drain_and_switch_group (chain->active_group, drainpad,
last_group, &subdrained, switched);
/* The group is drained, see if we can switch to another */
if (handled && subdrained && !*switched) {
if (chain->next_groups) {
/* Switch to next group */
GST_DEBUG_OBJECT (dbin, "Hiding current group %p", chain->active_group);
gst_decode_group_hide (chain->active_group);
chain->old_groups =
g_list_prepend (chain->old_groups, chain->active_group);
GST_DEBUG_OBJECT (dbin, "Switching to next group %p",
chain->next_groups->data);
chain->active_group = chain->next_groups->data;
chain->next_groups =
g_list_delete_link (chain->next_groups, chain->next_groups);
*switched = TRUE;
*drained = FALSE;
} else {
GST_DEBUG ("Group %p was the last in chain %p", chain->active_group,
chain);
*drained = TRUE;
/* We're drained ! */
}
}
}
beach:
CHAIN_MUTEX_UNLOCK (chain);
GST_DEBUG ("Chain %p (handled:%d, last_group:%d, drained:%d, switched:%d)",
chain, handled, *last_group, *drained, *switched);
return handled;
}
/* check if the group is drained, meaning all pads have seen an EOS
* event. */
static gboolean
gst_decode_pad_handle_eos (GstDecodePad * pad)
{
gboolean last_group = TRUE;
gboolean switched = FALSE;
gboolean drained = FALSE;
GstDecodeChain *chain = pad->chain;
GstDecodeBin *dbin = chain->dbin;
GST_LOG_OBJECT (pad->dbin, "chain : %p, pad %p", chain, pad);
pad->drained = TRUE;
return gst_decode_chain_handle_eos (chain);
}
GST_LOG_OBJECT (dbin, "pad %p", pad);
drain_and_switch_chains (dbin->decode_chain, pad, &last_group, &drained,
&switched);
/* gst_decode_chain_handle_eos:
*
* Checks if there are next groups in any parent chain
* to which we can switch or if everything is drained.
*
* If there are groups to switch to, hide the current active
* one and expose the new one.
*
* If a group isn't completely drained (i.e. we received EOS
* only on one of the streams) this function will return FALSE
* to indicate the EOS on the given chain should be dropped
* to avoid it from going downstream.
*
* MT-safe, don't call with chain lock!
*/
static gboolean
gst_decode_chain_handle_eos (GstDecodeChain * eos_chain)
{
GstDecodeBin *dbin = eos_chain->dbin;
GstDecodeGroup *group;
GstDecodeChain *chain = eos_chain;
gboolean drained;
gboolean forward_eos = TRUE;
g_return_val_if_fail (eos_chain->endpad, TRUE);
CHAIN_MUTEX_LOCK (chain);
while ((group = chain->parent)) {
CHAIN_MUTEX_UNLOCK (chain);
chain = group->parent;
CHAIN_MUTEX_LOCK (chain);
if (gst_decode_group_is_drained (group)) {
continue;
}
break;
}
drained = chain->active_group ?
gst_decode_group_is_drained (chain->active_group) : TRUE;
/* Now either group == NULL and chain == dbin->decode_chain
* or chain is the lowest chain that has a non-drained group */
if (chain->active_group && drained && chain->next_groups) {
/* There's an active group which is drained and we have another
* one to switch to. */
GST_DEBUG_OBJECT (dbin, "Hiding current group %p", chain->active_group);
gst_decode_group_hide (chain->active_group);
chain->old_groups = g_list_prepend (chain->old_groups, chain->active_group);
GST_DEBUG_OBJECT (dbin, "Switching to next group %p",
chain->next_groups->data);
chain->active_group = chain->next_groups->data;
chain->next_groups =
g_list_delete_link (chain->next_groups, chain->next_groups);
CHAIN_MUTEX_UNLOCK (chain);
if (switched) {
/* If we resulted in a group switch, expose what's needed */
EXPOSE_LOCK (dbin);
if (gst_decode_chain_is_complete (dbin->decode_chain))
gst_decode_bin_expose (dbin);
EXPOSE_UNLOCK (dbin);
} else if (!chain->active_group || drained) {
/* The group is drained and there isn't a future one */
g_assert (chain == dbin->decode_chain);
CHAIN_MUTEX_UNLOCK (chain);
GST_LOG_OBJECT (dbin, "all groups drained, fire signal");
g_signal_emit (G_OBJECT (dbin), gst_decode_bin_signals[SIGNAL_DRAINED], 0,
NULL);
} else {
CHAIN_MUTEX_UNLOCK (chain);
GST_DEBUG_OBJECT (dbin,
"Current active group in chain %p is not drained yet", chain);
/* Instruct caller to drop EOS event if we have future groups */
if (chain->next_groups)
forward_eos = FALSE;
}
return forward_eos;
return last_group;
}
/* gst_decode_group_is_drained: