v4l2: fix step-wise and continuous frame sizes enumeration

Width and height are independent for step-wise frame sizes (yes,
enumerating is slow). Continuous frame sizes are step-size with one
pixel steps for both dimensions (yes, enumerationg is very slow).

A few device drivers use either of those two types, though the discrete
type is much more common.

modules/access/v4l2/demux.c

@@ -284,40 +284,31 @@ float GetAbsoluteMaxFrameRate( vlc_object_t *obj, int fd,
                                    fse.discrete.width, fse.discrete.height );
             if( fps > max )
                 max = fps;
-                msg_Dbg( obj, " discrete size %"PRIu32"x%"PRIu32" supported",
-                         fse.discrete.width, fse.discrete.height );
             fse.index++;
         } while( v4l2_ioctl( fd, VIDIOC_ENUM_FRAMESIZES, &fse ) >= 0 );
         break;
 
       case V4L2_FRMSIZE_TYPE_STEPWISE:
-            for( uint32_t width = fse.stepwise.min_width,
-                          height = fse.stepwise.min_height;
-                 width <= fse.stepwise.max_width
-              && height <= fse.stepwise.max_width;
-                 width += fse.stepwise.step_width,
+      case V4L2_FRMSIZE_TYPE_CONTINUOUS:
+        msg_Dbg( obj, " sizes from %"PRIu32"x%"PRIu32" "
+                 "to %"PRIu32"x%"PRIu32" supported",
+                 fse.stepwise.min_width, fse.stepwise.min_height,
+                 fse.stepwise.max_width, fse.stepwise.max_height );
+        if( fse.type == V4L2_FRMSIZE_TYPE_STEPWISE )
+            msg_Dbg( obj, "  with %"PRIu32"x%"PRIu32" steps",
+                     fse.stepwise.step_width, fse.stepwise.step_height );
+
+        for( uint32_t width =  fse.stepwise.min_width;
+                      width <= fse.stepwise.max_width;
+                      width += fse.stepwise.step_width )
+            for( uint32_t height =  fse.stepwise.min_height;
+                          height <= fse.stepwise.max_width;
                           height += fse.stepwise.step_height )
             {
                 float fps = GetMaxFPS( obj, fd, pixel_format, width, height );
                 if( fps > max )
                     max = fps;
             }
-            msg_Dbg( obj, " sizes from %"PRIu32"x%"PRIu32" to %"PRIu32
-                     "x%"PRIu32" supported with %"PRIu32"x%"PRIu32" steps",
-                     fse.stepwise.min_width, fse.stepwise.min_height,
-                     fse.stepwise.max_width, fse.stepwise.max_height,
-                     fse.stepwise.step_width, fse.stepwise.step_height );
-            break;
-
-        case V4L2_FRMSIZE_TYPE_CONTINUOUS:
-            /* FIXME */
-            msg_Err( obj, "V4L2_FRMSIZE_TYPE_CONTINUOUS support incorrect" );
-            max = GetMaxFPS( obj, fd, pixel_format, fse.stepwise.max_width,
-                             fse.stepwise.max_height );
-            msg_Dbg( obj, " sizes from %"PRIu32"x%"PRIu32" to %"PRIu32
-                     "x%"PRIu32" all supported",
-                     fse.stepwise.min_width, fse.stepwise.min_height,
-                     fse.stepwise.max_width, fse.stepwise.max_height );
         break;
     }
     return max;
@@ -346,6 +337,9 @@ void GetMaxDimensions( vlc_object_t *obj, int fd, uint32_t pixel_format,
       case V4L2_FRMSIZE_TYPE_DISCRETE:
         do
         {
+            msg_Dbg( obj, " discrete size %"PRIu32"x%"PRIu32" supported",
+                     fse.discrete.width, fse.discrete.height );
+
             float fps = GetMaxFPS( obj, fd, pixel_format,
                                    fse.discrete.width, fse.discrete.height );
             if( fps >= fps_min && fse.discrete.width > *pwidth )
@@ -354,15 +348,25 @@ void GetMaxDimensions( vlc_object_t *obj, int fd, uint32_t pixel_format,
                 *pheight = fse.discrete.height;
             }
             fse.index++;
-            } while( v4l2_ioctl( fd, VIDIOC_ENUM_FRAMESIZES, &fse ) >= 0 );
+        }
+        while( v4l2_ioctl( fd, VIDIOC_ENUM_FRAMESIZES, &fse ) >= 0 );
         break;
 
       case V4L2_FRMSIZE_TYPE_STEPWISE:
-            for( uint32_t width = fse.stepwise.min_width,
-                          height = fse.stepwise.min_height;
-                 width <= fse.stepwise.max_width
-              && height <= fse.stepwise.max_width;
-                 width += fse.stepwise.step_width,
+      case V4L2_FRMSIZE_TYPE_CONTINUOUS:
+        msg_Dbg( obj, " sizes from %"PRIu32"x%"PRIu32" "
+                 "to %"PRIu32"x%"PRIu32" supported",
+                 fse.stepwise.min_width, fse.stepwise.min_height,
+                 fse.stepwise.max_width, fse.stepwise.max_height );
+        if( fse.type == V4L2_FRMSIZE_TYPE_STEPWISE )
+            msg_Dbg( obj, "  with %"PRIu32"x%"PRIu32" steps",
+                     fse.stepwise.step_width, fse.stepwise.step_height );
+
+        for( uint32_t width =  fse.stepwise.min_width;
+                      width <= fse.stepwise.max_width;
+                      width += fse.stepwise.step_width )
+            for( uint32_t height = fse.stepwise.min_height;
+                          height <= fse.stepwise.max_width;
                           height += fse.stepwise.step_height )
             {
                 float fps = GetMaxFPS( obj, fd, pixel_format, width, height );
@@ -373,19 +377,6 @@ void GetMaxDimensions( vlc_object_t *obj, int fd, uint32_t pixel_format,
                 }
             }
         break;
-
-        case V4L2_FRMSIZE_TYPE_CONTINUOUS:
-        {
-            float fps = GetMaxFPS( obj, fd, pixel_format,
-                             fse.stepwise.max_width, fse.stepwise.max_height );
-            msg_Err( obj, "V4L2_FRMSIZE_TYPE_CONTINUOUS support incorrect" );
-            if( fps >= fps_min && fse.stepwise.max_width > *pwidth )
-            {
-                *pwidth = fse.stepwise.max_width;
-                *pheight = fse.stepwise.max_height;
-            }
-            break;
-        }
     }
 #endif
 }