diff --git a/hw/buffer_list.c b/hw/buffer_list.c
index 88ba5c5..1e7fbf3 100644
--- a/hw/buffer_list.c
+++ b/hw/buffer_list.c
@@ -79,8 +79,7 @@ retry:
 
   // JPEG is in 16x16 blocks (shrink image to fit) (but adapt to 32x32)
   // And ISP output
-  if (strstr(buf_list->name, "JPEG") || strstr(buf_list->name, "H264") || buf_list->do_capture && strstr(buf_list->name, "ISP")
-    || strstr(buf_list->name, "DECODER")) {
+  if (strstr(buf_list->name, "JPEG") || strstr(buf_list->name, "H264") || buf_list->do_capture && strstr(buf_list->name, "ISP")) {
     width = shrink_to_block(width, 32);
     height = shrink_to_block(height, 32);
     E_LOG_VERBOSE(buf_list, "Adapting size to 32x32 block: %dx%d vs %dx%d", orig_width, orig_height, width, height);
diff --git a/hw/device.c b/hw/device.c
index 4625e1d..29c0ced 100644
--- a/hw/device.c
+++ b/hw/device.c
@@ -181,6 +181,7 @@ int device_set_decoder_start(device_t *dev, bool do_on)
 
   E_LOG_DEBUG(dev, "Setting decoder state %s...", do_on ? "Start" : "Stop");
   E_XIOCTL(dev, dev->fd, VIDIOC_DECODER_CMD, &cmd, "Cannot set decoder state");
+  dev->decoder_started = do_on;
   return 0;
 
 error:
diff --git a/hw/device.h b/hw/device.h
index 459d31b..1d83270 100644
--- a/hw/device.h
+++ b/hw/device.h
@@ -15,6 +15,7 @@ typedef struct device_s {
 
   struct device_s *output_device;
   bool paused;
+  bool decoder_started;
 } device_t;
 
 device_t *device_open(const char *name, const char *path);
diff --git a/hw/links.c b/hw/links.c
index d88a87c..b4d5522 100644
--- a/hw/links.c
+++ b/hw/links.c
@@ -101,6 +101,11 @@ int links_enqueue_from_source(buffer_list_t *buf_list, link_t *link)
     E_LOG_ERROR(buf_list, "No buffer dequeued from source?");
   }
 
+  if (link->callbacks.validate_buffer && !link->callbacks.validate_buffer(link, buf)) {
+    E_LOG_DEBUG(buf_list, "Buffer rejected by validation");
+    return 0;
+  }
+
   for (int j = 0; link->sinks[j]; j++) {
     if (link->sinks[j]->device->paused) {
       continue;
diff --git a/hw/links.h b/hw/links.h
index f5c726c..360e6bd 100644
--- a/hw/links.h
+++ b/hw/links.h
@@ -6,9 +6,11 @@
 
 typedef struct buffer_s buffer_t;
 typedef struct buffer_list_s buffer_list_t;
+typedef struct link_s link_t;
 
 typedef void (*link_on_buffer)(buffer_t *buf);
 typedef bool (*link_check_streaming)();
+typedef bool (*link_validate_buffer)(struct link_s *link, buffer_t *buf);
 
 typedef struct link_s {
   struct buffer_list_s *source; // capture_list
@@ -16,6 +18,7 @@ typedef struct link_s {
   struct {
     link_on_buffer on_buffer;
     link_check_streaming check_streaming;
+    link_validate_buffer validate_buffer;
   } callbacks;
 } link_t;