/**
* gst_memory_make_mapped:
* @mem: (transfer full): a #GstMemory
* @info: (out): pointer for info
* @flags: mapping flags
*
* Create a #GstMemory object that is mapped with @flags. If @mem is mappable
* with @flags, this function returns the mapped @mem directly. Otherwise a
* mapped copy of @mem is returned.
*
* This function takes ownership of old @mem and returns a reference to a new
* #GstMemory.
*
* Returns: (transfer full) (nullable): a #GstMemory object mapped
* with @flags or %NULL when a mapping is not possible.
*/
GstMemory *
gst_memory_make_mapped (GstMemory * mem, GstMapInfo * info, GstMapFlags flags)
{
GstMemory *result;
if (gst_memory_map (mem, info, flags)) {
result = mem;
} else {
result = gst_memory_copy (mem, 0, -1);
gst_memory_unref (mem);
if (result == NULL)
goto cannot_copy;
if (!gst_memory_map (result, info, flags))
goto cannot_map;
}
return result;
/* ERRORS */
cannot_copy:
{
GST_CAT_DEBUG (GST_CAT_MEMORY, "cannot copy memory %p", mem);
return NULL;
}
cannot_map:
{
GST_CAT_DEBUG (GST_CAT_MEMORY, "cannot map memory %p with flags %d", mem,
flags);
gst_memory_unref (result);
return NULL;
}
}
/* Copy fixed header and extension. Replace current ssrc by ssrc1,
* remove OSN and replace current seq num by OSN.
* Copy memory to avoid to manually copy each rtp buffer field.
*/
static GstBuffer *
_gst_rtp_buffer_new_from_rtx (GstRTPBuffer * rtp, guint32 ssrc1,
guint16 orign_seqnum, guint8 origin_payload_type)
{
GstMemory *mem = NULL;
GstRTPBuffer new_rtp = GST_RTP_BUFFER_INIT;
GstBuffer *new_buffer = gst_buffer_new ();
GstMapInfo map;
guint payload_len = 0;
/* copy fixed header */
mem = gst_memory_copy (rtp->map[0].memory,
(guint8 *) rtp->data[0] - rtp->map[0].data, rtp->size[0]);
gst_buffer_append_memory (new_buffer, mem);
/* copy extension if any */
if (rtp->size[1]) {
mem = gst_memory_copy (rtp->map[1].memory,
(guint8 *) rtp->data[1] - rtp->map[1].data, rtp->size[1]);
gst_buffer_append_memory (new_buffer, mem);
}
/* copy payload and remove OSN */
payload_len = rtp->size[2] - 2;
mem = gst_allocator_alloc (NULL, payload_len, NULL);
gst_memory_map (mem, &map, GST_MAP_WRITE);
if (rtp->size[2])
memcpy (map.data, (guint8 *) rtp->data[2] + 2, payload_len);
gst_memory_unmap (mem, &map);
gst_buffer_append_memory (new_buffer, mem);
/* the sender always constructs rtx packets without padding,
* But the receiver can still receive rtx packets with padding.
* So just copy it.
*/
if (rtp->size[3]) {
guint pad_len = rtp->size[3];
mem = gst_allocator_alloc (NULL, pad_len, NULL);
gst_memory_map (mem, &map, GST_MAP_WRITE);
map.data[pad_len - 1] = pad_len;
gst_memory_unmap (mem, &map);
gst_buffer_append_memory (new_buffer, mem);
}
/* set ssrc and seq num */
gst_rtp_buffer_map (new_buffer, GST_MAP_WRITE, &new_rtp);
gst_rtp_buffer_set_ssrc (&new_rtp, ssrc1);
gst_rtp_buffer_set_seq (&new_rtp, orign_seqnum);
gst_rtp_buffer_set_payload_type (&new_rtp, origin_payload_type);
gst_rtp_buffer_unmap (&new_rtp);
gst_buffer_copy_into (new_buffer, rtp->buffer,
GST_BUFFER_COPY_FLAGS | GST_BUFFER_COPY_TIMESTAMPS, 0, -1);
GST_BUFFER_FLAG_SET (new_buffer, GST_RTP_BUFFER_FLAG_RETRANSMISSION);
return new_buffer;
}
static GstMemory *
_gst_memory_copy (GstMemory * mem)
{
GST_CAT_DEBUG (GST_CAT_MEMORY, "copy memory %p", mem);
return gst_memory_copy (mem, 0, -1);
}
