camera: add camera_get_scaled_resolution

device/camera/camera.h

@@ -93,6 +93,6 @@ int camera_configure_pipeline(camera_t *camera, buffer_list_t *camera_capture);
 
 buffer_list_t *camera_configure_isp(camera_t *camera, buffer_list_t *src_capture);
 buffer_list_t *camera_configure_decoder(camera_t *camera, buffer_list_t *src_capture);
-unsigned camera_rescaller_align_size(unsigned target_height);
 buffer_list_t *camera_configure_rescaller(camera_t *camera, buffer_list_t *src_capture, const char *name, unsigned target_height, unsigned formats[]);
 int camera_configure_output(camera_t *camera, const char *name, unsigned target_height, unsigned formats[], link_callbacks_t callbacks, device_t **device);
+bool camera_get_scaled_resolution(camera_t *camera, camera_output_options_t *options, buffer_format_t *format);

device/camera/camera_input.c

@@ -70,27 +70,22 @@ static int camera_configure_input_libcamera(camera_t *camera)
     return -1;
   }
 
-  unsigned target_height = camera->options.height;
-
-  if (!camera->options.snapshot.disabled)
-    target_height = camera->options.snapshot.height;
-  else if (!camera->options.stream.disabled)
-    target_height = camera->options.stream.height;
-  else if (!camera->options.video.disabled)
-    target_height = camera->options.video.height;
-
-  target_height = camera_rescaller_align_size(target_height);
-  unsigned target_width = target_height * camera->options.width / camera->options.height;
-  target_width = camera_rescaller_align_size(target_width);
-
   buffer_format_t capture_fmt = {
-    .width = target_width,
+    .width = camera->options.width,
-    .height = target_height,
+    .height = camera->options.height,
     .format = camera->options.format,
     .nbufs = camera->options.nbufs,
     .type = BUFFER_TYPE_IMAGE
   };
 
+  bool found = false;
+
+  found = camera_get_scaled_resolution(camera, &camera->options.snapshot, &capture_fmt);
+  if (!found)
+    found = camera_get_scaled_resolution(camera, &camera->options.stream, &capture_fmt);
+  if (!found)
+    found = camera_get_scaled_resolution(camera, &camera->options.video, &capture_fmt);
+
   buffer_list_t *camera_capture = device_open_buffer_list(camera->camera, true, capture_fmt, true);
   if (!camera_capture) {
     return -1;

device/camera/camera_rescaller.c

@@ -12,12 +12,41 @@
 
 #define MAX_RESCALLER_SIZE 1920
 
-unsigned camera_rescaller_align_size(unsigned size)
+static unsigned camera_rescaller_align_size(unsigned size)
 {
-  size = (size + 31) / 32 * 32;
+  return (size + 31) / 32 * 32;
-  if (size > MAX_RESCALLER_SIZE)
+}
-    return MAX_RESCALLER_SIZE;
+
-  return size;
+static void camera_get_scaled_resolution2(unsigned in_width, unsigned in_height, unsigned proposed_height, unsigned *target_width, unsigned *target_height)
+{
+  proposed_height = MIN(proposed_height, in_height);
+
+  *target_height = camera_rescaller_align_size(proposed_height);
+  *target_height = MIN(*target_height, MAX_RESCALLER_SIZE);
+
+  // maintain aspect ratio on target width
+  *target_width = camera_rescaller_align_size(*target_height * in_width / in_height);
+
+  // if width is larger then rescaller, try to maintain scale down height
+  if (*target_width > MAX_RESCALLER_SIZE) {
+    *target_width = MAX_RESCALLER_SIZE;
+    *target_height = camera_rescaller_align_size(*target_width * in_height / in_width);
+  }
+}
+
+bool camera_get_scaled_resolution(camera_t *camera, camera_output_options_t *options, buffer_format_t *format)
+{
+  if (options->disabled)
+    return false;
+
+  camera_get_scaled_resolution2(
+    camera->options.width,
+    camera->options.height,
+    options->height,
+    &format->width,
+    &format->height
+  );
+  return true;
 }
 
 buffer_list_t *camera_try_rescaller(camera_t *camera, buffer_list_t *src_capture, const char *name, unsigned target_height, unsigned target_format)
@@ -29,15 +58,10 @@ buffer_list_t *camera_try_rescaller(camera_t *camera, buffer_list_t *src_capture
   }
 
   if (target_height > src_capture->fmt.height) {
-    LOG_INFO(src_capture, "Upscaling from %dp to %dp does not make sense.",
+    LOG_INFO(src_capture, "Upscaling from %dp to %dp does not make sense. Lowering to %dp.",
-      src_capture->fmt.height, target_height);
+      src_capture->fmt.height, target_height, src_capture->fmt.height);
-    return NULL;
   }
 
-  target_height = camera_rescaller_align_size(target_height);
-  unsigned target_width = target_height * src_capture->fmt.width / src_capture->fmt.height;
-  target_width = camera_rescaller_align_size(target_width);
-
   char name2[256];
   sprintf(name2, "RESCALLER:%s", name);
 
@@ -47,11 +71,15 @@ buffer_list_t *camera_try_rescaller(camera_t *camera, buffer_list_t *src_capture
     device, src_capture);
 
   buffer_format_t target_fmt = {
-    .width = target_width,
-    .height = target_height,
     .format = target_format
   };
 
+  camera_get_scaled_resolution2(
+    src_capture->fmt.width, src_capture->fmt.height,
+    target_height,
+    &target_fmt.width, &target_fmt.height
+  );
+
   buffer_list_t *rescaller_capture = device_open_buffer_list_capture(
     device, NULL, rescaller_output, target_fmt, true);