Partial attempt at fixing interlacing support.

First try using no interlacing and fallback to driver's default if it
isn't possible. Might fix some issues. We still need to declare images
as interlaced to VLC afterwards, but that's another problem.

diff --git a/modules/access/v4l2.c b/modules/access/v4l2.c
index b9b44d54d8f3697e3eb09fe8349e600d7982c62a..8ba191a0391257ff8d63d224f5deb87f2cecc6e0 100644 (file)
--- a/modules/access/v4l2.c
+++ b/modules/access/v4l2.c
@@ -1917,7 +1917,20 @@ static int OpenVideoDev( vlc_object_t *p_obj, demux_sys_t *p_sys, bool b_demux )
                 }
             }
             /* Try and set user chroma */
-            if( !IsPixelFormatSupported( p_demux, fmt.fmt.pix.pixelformat ) || ( fmt.fmt.pix.pixelformat && v4l2_ioctl( i_fd, VIDIOC_S_FMT, &fmt ) < 0 ) )
+            bool b_error = !IsPixelFormatSupported( p_demux, fmt.fmt.pix.pixelformat );
+            if( !b_error && fmt.fmt.pix.pixelformat )
+            {
+                if( v4l2_ioctl( i_fd, VIDIOC_S_FMT, &fmt ) < 0 )
+                {
+                    fmt.fmt.pix.field = V4L2_FIELD_ANY;
+                    if( v4l2_ioctl( i_fd, VIDIOC_S_FMT, &fmt ) < 0 )
+                    {
+                        fmt.fmt.pix.field = V4L2_FIELD_NONE;
+                        b_error = true;
+                    }
+                }
+            }
+            if( b_error )
             {
                 msg_Warn( p_demux, "Driver is unable to use specified chroma %s. Trying defaults.", p_sys->psz_requested_chroma );
                 fmt.fmt.pix.pixelformat = 0;
@@ -1932,9 +1945,15 @@ static int OpenVideoDev( vlc_object_t *p_obj, demux_sys_t *p_sys, bool b_demux )
             for( i = 0; i < ARRAY_SIZE( p_chroma_fallbacks ); i++ )
             {
                 fmt.fmt.pix.pixelformat = p_chroma_fallbacks[i];
-                if( IsPixelFormatSupported( p_demux, fmt.fmt.pix.pixelformat )
-                 && v4l2_ioctl( i_fd, VIDIOC_S_FMT, &fmt ) >= 0 )
-                    break;
+                if( IsPixelFormatSupported( p_demux, fmt.fmt.pix.pixelformat ) )
+                {
+                    if( v4l2_ioctl( i_fd, VIDIOC_S_FMT, &fmt ) >= 0 )
+                        break;
+                    fmt.fmt.pix.field = V4L2_FIELD_ANY;
+                    if( v4l2_ioctl( i_fd, VIDIOC_S_FMT, &fmt ) < 0 )
+                        break;
+                    fmt.fmt.pix.field = V4L2_FIELD_NONE;
+                }
             }
             if( i == ARRAY_SIZE( p_chroma_fallbacks ) )
             {