/**
* gst_adapter_take_buffer:
* @adapter: a #GstAdapter
* @nbytes: the number of bytes to take
*
* Returns a #GstBuffer containing the first @nbytes bytes of the
* @adapter. The returned bytes will be flushed from the adapter.
* This function is potentially more performant than gst_adapter_take()
* since it can reuse the memory in pushed buffers by subbuffering
* or merging.
*
* Caller owns returned value. gst_buffer_unref() after usage.
*
* Since: 0.10.6
*
* Returns: a #GstBuffer containing the first @nbytes of the adapter,
* or #NULL if @nbytes bytes are not available
*/
GstBuffer *
gst_adapter_take_buffer (GstAdapter * adapter, guint nbytes)
{
GstBuffer *buffer;
GstBuffer *cur;
guint hsize, skip;
guint8 *data;
g_return_val_if_fail (GST_IS_ADAPTER (adapter), NULL);
g_return_val_if_fail (nbytes > 0, NULL);
GST_LOG_OBJECT (adapter, "taking buffer of %u bytes", nbytes);
/* we don't have enough data, return NULL. This is unlikely
* as one usually does an _available() first instead of grabbing a
* random size. */
if (G_UNLIKELY (nbytes > adapter->size))
return NULL;
cur = adapter->buflist->data;
skip = adapter->skip;
hsize = GST_BUFFER_SIZE (cur);
/* our head buffer has enough data left, return it */
if (skip == 0 && hsize == nbytes) {
GST_LOG_OBJECT (adapter, "providing buffer of %d bytes as head buffer",
nbytes);
buffer = gst_buffer_ref (cur);
goto done;
} else if (hsize >= nbytes + skip) {
GST_LOG_OBJECT (adapter, "providing buffer of %d bytes via sub-buffer",
nbytes);
buffer = gst_buffer_create_sub (cur, skip, nbytes);
goto done;
}
if (gst_adapter_try_to_merge_up (adapter, nbytes)) {
/* Merged something, let's try again for sub-buffering */
cur = adapter->buflist->data;
if (GST_BUFFER_SIZE (cur) >= nbytes + skip) {
GST_LOG_OBJECT (adapter, "providing buffer of %d bytes via sub-buffer",
nbytes);
buffer = gst_buffer_create_sub (cur, skip, nbytes);
goto done;
}
}
data = gst_adapter_take_internal (adapter, nbytes);
buffer = gst_buffer_new ();
GST_BUFFER_SIZE (buffer) = nbytes;
GST_BUFFER_DATA (buffer) = data;
GST_BUFFER_MALLOCDATA (buffer) = data;
done:
gst_adapter_flush_unchecked (adapter, nbytes);
return buffer;
}
/**
* gst_adapter_take_buffer:
* @adapter: a #GstAdapter
* @nbytes: the number of bytes to take
*
* Returns a #GstBuffer containing the first @nbytes bytes of the
* @adapter. The returned bytes will be flushed from the adapter.
* This function is potentially more performant than gst_adapter_take()
* since it can reuse the memory in pushed buffers by subbuffering
* or merging.
*
* Note that no assumptions should be made as to whether certain buffer
* flags such as the DISCONT flag are set on the returned buffer, or not.
* The caller needs to explicitly set or unset flags that should be set or
* unset.
*
* Caller owns a reference to the returned buffer. gst_buffer_unref() after
* usage.
*
* Free-function: gst_buffer_unref
*
* Returns: (transfer full): a #GstBuffer containing the first @nbytes of
* the adapter, or #NULL if @nbytes bytes are not available.
* gst_buffer_unref() when no longer needed.
*/
GstBuffer *
gst_adapter_take_buffer (GstAdapter * adapter, gsize nbytes)
{
GstBuffer *buffer;
GstBuffer *cur;
gsize hsize, skip;
guint8 *data;
g_return_val_if_fail (GST_IS_ADAPTER (adapter), NULL);
g_return_val_if_fail (nbytes > 0, NULL);
GST_LOG_OBJECT (adapter, "taking buffer of %" G_GSIZE_FORMAT " bytes",
nbytes);
/* we don't have enough data, return NULL. This is unlikely
* as one usually does an _available() first instead of grabbing a
* random size. */
if (G_UNLIKELY (nbytes > adapter->size))
return NULL;
cur = adapter->buflist->data;
skip = adapter->skip;
hsize = gst_buffer_get_size (cur);
/* our head buffer has enough data left, return it */
if (skip == 0 && hsize == nbytes) {
GST_LOG_OBJECT (adapter, "providing buffer of %" G_GSIZE_FORMAT " bytes"
" as head buffer", nbytes);
buffer = gst_buffer_ref (cur);
goto done;
} else if (hsize >= nbytes + skip) {
GST_LOG_OBJECT (adapter, "providing buffer of %" G_GSIZE_FORMAT " bytes"
" via region copy", nbytes);
buffer = gst_buffer_copy_region (cur, GST_BUFFER_COPY_ALL, skip, nbytes);
goto done;
}
#if 0
if (gst_adapter_try_to_merge_up (adapter, nbytes)) {
/* Merged something, let's try again for sub-buffering */
cur = adapter->buflist->data;
skip = adapter->skip;
if (gst_buffer_get_size (cur) >= nbytes + skip) {
GST_LOG_OBJECT (adapter, "providing buffer of %" G_GSIZE_FORMAT " bytes"
" via sub-buffer", nbytes);
buffer = gst_buffer_copy_region (cur, GST_BUFFER_COPY_ALL, skip, nbytes);
goto done;
}
}
#endif
data = gst_adapter_take_internal (adapter, nbytes);
buffer = gst_buffer_new_wrapped (data, nbytes);
done:
gst_adapter_flush_unchecked (adapter, nbytes);
return buffer;
}
/**
* gst_adapter_take:
* @adapter: a #GstAdapter
* @nbytes: the number of bytes to take
*
* Returns a freshly allocated buffer containing the first @nbytes bytes of the
* @adapter. The returned bytes will be flushed from the adapter.
*
* Caller owns returned value. g_free after usage.
*
* Returns: oven-fresh hot data, or #NULL if @nbytes bytes are not available
*/
guint8 *
gst_adapter_take (GstAdapter * adapter, guint nbytes)
{
guint8 *data;
g_return_val_if_fail (GST_IS_ADAPTER (adapter), NULL);
g_return_val_if_fail (nbytes > 0, NULL);
/* we don't have enough data, return NULL. This is unlikely
* as one usually does an _available() first instead of peeking a
* random size. */
if (G_UNLIKELY (nbytes > adapter->size))
return NULL;
data = gst_adapter_take_internal (adapter, nbytes);
gst_adapter_flush_unchecked (adapter, nbytes);
return data;
}
