/** * 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); }