v4l2: add support for DMABUF

Export dmafd on buffers and use those directly to send to the client.
Do some v4l2 cleanup.

pinos/modules/spa/spa-v4l2-source.c

@@ -199,11 +199,15 @@ on_source_event (SpaHandle *handle, SpaEvent *event, void *user_data)
       pinos_buffer_builder_init_into (&builder, buf, 1024, fdbuf, 8);
       pinos_buffer_builder_add_header (&builder, &hdr);
 
+      if (b->datas[0].type == SPA_DATA_TYPE_FD) {
+        fd = *((int *)b->datas[0].data);
+      } else {
         fd = tmpfile_create (source, b->datas[0].data, b->size);
+      }
       p.fd_index = pinos_buffer_builder_add_fd (&builder, fd);
       p.id = pinos_fd_manager_get_id (priv->fdmanager);
-      p.offset = 0;
+      p.offset = b->datas[0].offset;
-      p.size = b->size;
+      p.size = b->datas[0].size;
       pinos_buffer_builder_add_fd_payload (&builder, &p);
       pinos_buffer_builder_end (&builder, &pbuf);
 
@@ -219,6 +223,7 @@ on_source_event (SpaHandle *handle, SpaEvent *event, void *user_data)
           g_clear_error (&error);
         }
       }
+      pinos_buffer_steal_fds (&pbuf, NULL);
       pinos_buffer_unref (&pbuf);
 
       spa_buffer_unref (b);

spa/plugins/v4l2/v4l2-source.c

@@ -58,6 +58,7 @@ struct _V4l2Buffer {
   bool outstanding;
   struct v4l2_buffer v4l2_buffer;
   V4l2Buffer *next;
+  int dmafd;
 };
 
 typedef struct {
@@ -79,6 +80,7 @@ typedef struct {
   SpaPortInfo info;
   SpaAllocParam *params[1];
   SpaAllocParamBuffers param_buffers;
+  bool export_buf;
   SpaPortStatus status;
 } SpaV4l2State;
 
@@ -598,6 +600,8 @@ v4l2_source_init (const SpaHandleFactory  *factory,
   this->state[0].info.flags = SPA_PORT_INFO_FLAG_NONE;
   this->state[0].status.flags = SPA_PORT_STATUS_FLAG_NONE;
 
+  this->state[0].export_buf = true;
+
   return SPA_RESULT_OK;
 }
 

spa/plugins/v4l2/v4l2-utils.c

@@ -346,7 +346,6 @@ spa_v4l2_close (SpaV4l2Source *this)
 
   state->fd = -1;
   state->opened = false;
-  state->have_buffers = false;
 
   return 0;
 }
@@ -530,6 +529,24 @@ mmap_init (SpaV4l2Source *this)
     b->metas[0].data = &b->header;
     b->metas[0].size = sizeof (b->header);
 
+    if (state->export_buf) {
+      struct v4l2_exportbuffer expbuf;
+
+      CLEAR (expbuf);
+      expbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+      expbuf.index = i;
+      if (xioctl (state->fd, VIDIOC_EXPBUF, &expbuf) < 0) {
+        perror("VIDIOC_EXPBUF");
+        continue;
+      }
+
+      b->dmafd = expbuf.fd;
+      b->datas[0].type = SPA_DATA_TYPE_FD;
+      b->datas[0].data = &b->dmafd;
+      b->datas[0].offset = 0;
+      b->datas[0].size = buf.length;
+      b->datas[0].stride = state->fmt.fmt.pix.bytesperline;
+    } else {
       b->datas[0].type = SPA_DATA_TYPE_MEMPTR;
       b->datas[0].data = mmap (NULL,
                                buf.length,
@@ -540,12 +557,12 @@ mmap_init (SpaV4l2Source *this)
       b->datas[0].offset = 0;
       b->datas[0].size = buf.length;
       b->datas[0].stride = state->fmt.fmt.pix.bytesperline;
-    b->outstanding = true;
-
       if (b->datas[0].data == MAP_FAILED) {
         perror ("mmap");
         continue;
       }
+    }
+    b->outstanding = true;
 
     CLEAR (b->v4l2_buffer);
     b->v4l2_buffer.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
@@ -626,6 +643,7 @@ spa_v4l2_stop (SpaV4l2Source *this)
   SpaV4l2State *state = &this->state[0];
   enum v4l2_buf_type type;
   SpaEvent event;
+  int i;
 
   type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
   if (xioctl (state->fd, VIDIOC_STREAMOFF, &type) < 0) {
@@ -633,6 +651,22 @@ spa_v4l2_stop (SpaV4l2Source *this)
     return -1;
   }
 
+  for (i = 0; i < state->reqbuf.count; i++) {
+    V4l2Buffer *b;
+
+    b = &state->buffers[i];
+    if (b->outstanding) {
+      fprintf (stderr, "queueing outstanding buffer %p\n", b);
+      v4l2_buffer_free (b);
+    }
+    if (state->export_buf) {
+      close (b->dmafd);
+    } else {
+      munmap (b->datas[0].data, b->datas[0].size);
+    }
+  }
+  state->have_buffers = false;
+
   event.refcount = 1;
   event.notify = NULL;
   event.type = SPA_EVENT_TYPE_REMOVE_POLL;