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basetransform: refine metadata filter and transform

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Add a vmethod to filter metadata that should be passed upstream. By default,
don't pass anything.
Add a vmethod to transform metadata from the input buffer to the output buffer.
By default, nothing is transformed or copied.
This commit is contained in:
Wim Taymans 2012-03-02 17:32:28 +01:00
parent 0d9f22d212
commit 7eae198be2
2 changed files with 112 additions and 10 deletions
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97
libs/gst/base/gstbasetransform.c
View file

@ -802,22 +802,41 @@ gst_base_transform_default_decide_allocation (GstBaseTransform * trans,
GstQuery * query)
{
guint i, n_metas;
GstBaseTransformClass *klass;
klass = GST_BASE_TRANSFORM_GET_CLASS (trans);
n_metas = gst_query_get_n_allocation_metas (query);
for (i = 0; i < n_metas; i++) {
GType api;
gboolean remove;
api = gst_query_parse_nth_allocation_meta (query, i);
/* remove all memory dependent metadata because we are going to have to
* allocate different memory for input and output. */
/* by default we remove all metadata, subclasses should implement a
* filter_meta function */
if (gst_meta_api_type_has_tag (api, GST_META_TAG_MEMORY)) {
GST_LOG_OBJECT (trans, "removing memory metadata %s", g_type_name (api));
/* remove all memory dependent metadata because we are going to have to
* allocate different memory for input and output. */
GST_LOG_OBJECT (trans, "removing memory specific metadata %s",
g_type_name (api));
remove = TRUE;
} else if (G_LIKELY (klass->filter_meta)) {
/* remove if the subclass said so */
remove = !klass->filter_meta (trans, query, api);
GST_LOG_OBJECT (trans, "filter_meta for api %s returned: %s",
g_type_name (api), (remove ? "remove" : "keep"));
} else {
GST_LOG_OBJECT (trans, "removing metadata %s", g_type_name (api));
remove = TRUE;
}
if (remove) {
gst_query_remove_nth_allocation_meta (query, i);
i--;
n_metas--;
}
}
return TRUE;
}
@ -1306,7 +1325,18 @@ gst_base_transform_default_propose_allocation (GstBaseTransform * trans,
GST_DEBUG_OBJECT (trans, "doing passthrough query");
ret = gst_pad_peer_query (trans->srcpad, query);
} else {
ret = FALSE;
guint i, n_metas;
/* non-passthrough, copy all metadata, decide_query does not contain the
* metadata anymore that depends on the buffer memory */
n_metas = gst_query_get_n_allocation_metas (decide_query);
for (i = 0; i < n_metas; i++) {
GType api;
api = gst_query_parse_nth_allocation_meta (decide_query, i);
GST_DEBUG_OBJECT (trans, "proposing metadata %s", g_type_name (api));
gst_query_add_allocation_meta (query, api);
}
ret = TRUE;
}
return ret;
}
@ -1518,11 +1548,62 @@ unknown_size:
}
}
typedef struct
{
GstBaseTransform *trans;
GstBuffer *outbuf;
} CopyMetaData;
static gboolean
foreach_metadata (GstBuffer * inbuf, GstMeta ** meta, gpointer user_data)
{
CopyMetaData *data = user_data;
GstBaseTransform *trans = data->trans;
GstBaseTransformClass *klass;
const GstMetaInfo *info = (*meta)->info;
GstBuffer *outbuf = data->outbuf;
gboolean do_copy;
klass = GST_BASE_TRANSFORM_GET_CLASS (trans);
if (GST_META_FLAG_IS_SET (*meta, GST_META_FLAG_POOLED)) {
/* never call the transform_meta with pool private metadata */
GST_DEBUG_OBJECT (trans, "not copying pooled metadata %s",
g_type_name (info->api));
do_copy = FALSE;
} else if (gst_meta_api_type_has_tag (info->api, GST_META_TAG_MEMORY)) {
/* never call the transform_meta with memory specific metadata */
GST_DEBUG_OBJECT (trans, "not copying memory specific metadata %s",
g_type_name (info->api));
do_copy = FALSE;
} else if (klass->transform_meta) {
do_copy = klass->transform_meta (trans, outbuf, *meta, inbuf);
GST_DEBUG_OBJECT (trans, "transformed metadata %s: copy: %d",
g_type_name (info->api), do_copy);
} else {
do_copy = FALSE;
GST_DEBUG_OBJECT (trans, "not copying metadata %s",
g_type_name (info->api));
}
/* we only copy metadata when the subclass implemented a transform_meta
* function and when it returns TRUE */
if (do_copy) {
GstMetaTransformCopy copy_data = { FALSE, 0, -1 };
GST_DEBUG_OBJECT (trans, "copy metadata %s", g_type_name (info->api));
/* simply copy then */
info->transform_func (outbuf, *meta, inbuf,
_gst_meta_transform_copy, &copy_data);
}
return TRUE;
}
static gboolean
default_copy_metadata (GstBaseTransform * trans,
GstBuffer * inbuf, GstBuffer * outbuf)
{
GstBaseTransformPrivate *priv = trans->priv;
CopyMetaData data;
/* now copy the metadata */
GST_DEBUG_OBJECT (trans, "copying metadata");
@ -1540,6 +1621,12 @@ default_copy_metadata (GstBaseTransform * trans,
if (!priv->gap_aware)
GST_BUFFER_FLAG_UNSET (outbuf, GST_BUFFER_FLAG_GAP);
data.trans = trans;
data.outbuf = outbuf;
gst_buffer_foreach_meta (inbuf, foreach_metadata, &data);
return TRUE;
/* ERRORS */

25
libs/gst/base/gstbasetransform.h
View file

@ -141,16 +141,22 @@ struct _GstBaseTransform {
* @decide_allocation: Setup the allocation parameters for allocating output
* buffers. The passed in query contains the result of the
* downstream allocation query. This function is only called
* when not operating in passthrough mode. the default
* implementation will remove metadata that depends on the
* memory.
* when not operating in passthrough mode. The default
* implementation will remove all memory dependent metadata.
* If there is ia @filter_meta method implementation, it will
* be called for all metadata API in the downstream query,
* otherwise the metadata API is removed.
* @filter_meta: Return TRUE if the metadata API should be proposed in the
* upstream allocation query. The default implementation is NULL
* and will cause all metadata to be removed.
* @propose_allocation: Propose buffer allocation parameters for upstream elements.
* This function must be implemented if the element reads or
* writes the buffer content. The query that was passed to
* the decide_allocation is passed in this method (or NULL
* when the element is in passthrough mode). The default
* implementation will pass the query downstream when in
* passthrough mode.
* passthrough mode and will copy all the filtered metadata
* API in non-passthrough mode.
* @transform_size: Optional. Given the size of a buffer in the given direction
* with the given caps, calculate the size in bytes of a buffer
* on the other pad with the given other caps.
@ -183,6 +189,10 @@ struct _GstBaseTransform {
* Copy the metadata from the input buffer to the output buffer.
* The default implementation will copy the flags, timestamps and
* offsets of the buffer.
* @transform_meta: Optional. Transform the metadata on the input buffer to the
* output buffer. By default this method is NULL and no
* metadata is copied. subclasses can implement this method and
* return TRUE if the metadata is to be copied.
* @before_transform: Optional. Since 0.10.22
* This method is called right before the base class will
* start processing. Dynamic properties or other delayed
@ -221,6 +231,8 @@ struct _GstBaseTransformClass {
/* decide allocation query for output buffers */
gboolean (*decide_allocation) (GstBaseTransform *trans, GstQuery *query);
gboolean (*filter_meta) (GstBaseTransform *trans, GstQuery *query, GType api);
/* propose allocation query parameters for input buffers */
gboolean (*propose_allocation) (GstBaseTransform *trans, GstQuery *decide_query,
GstQuery *query);
@ -245,8 +257,11 @@ struct _GstBaseTransformClass {
GstFlowReturn (*prepare_output_buffer) (GstBaseTransform * trans,
GstBuffer *input, GstBuffer **outbuf);
gboolean (*copy_metadata) (GstBaseTransform * trans, GstBuffer *input,
/* metadata */
gboolean (*copy_metadata) (GstBaseTransform *trans, GstBuffer *input,
GstBuffer *outbuf);
gboolean (*transform_meta) (GstBaseTransform *trans, GstBuffer *outbuf,
GstMeta *meta, GstBuffer *inbuf);
void (*before_transform) (GstBaseTransform *trans, GstBuffer *buffer);