[vlc-devel] commit: v4l2: rework size detection (Pierre Ynard )

[git version control]

vlc | branch: 1.0-bugfix | Pierre Ynard <linkfanel at yahoo.fr> | Fri Oct 16 19:21:51 2009 +0200| [396918e806738b2786db08c4a39033f9a0399e74] | committer: Pierre Ynard 

v4l2: rework size detection

This fixes my TV card, and should be backported after testing
(cherry picked from commit 881aa894c58b3d4105276088e7b3593677ee2098)

> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=396918e806738b2786db08c4a39033f9a0399e74
---

 modules/access/v4l2.c |   40 +++++++++++++++++++++-------------------
 1 files changed, 21 insertions(+), 19 deletions(-)

diff --git a/modules/access/v4l2.c b/modules/access/v4l2.c
index 113162d..41d3566 100644
--- a/modules/access/v4l2.c
+++ b/modules/access/v4l2.c
@@ -1996,7 +1996,7 @@ static int OpenVideoDev( vlc_object_t *p_obj, demux_sys_t *p_sys, bool b_demux )
     memset( &fmt, 0, sizeof(fmt) );
     fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 
-    if( p_sys->i_width == 0 || p_sys->i_height == 0 )
+    if( p_sys->i_width <= 0 || p_sys->i_height <= 0 )
     {
         /* Use current width and height settings */
         if( v4l2_ioctl( i_fd, VIDIOC_G_FMT, &fmt ) < 0 )
@@ -2005,26 +2005,22 @@ static int OpenVideoDev( vlc_object_t *p_obj, demux_sys_t *p_sys, bool b_demux )
             goto open_failed;
         }
 
-        p_sys->i_width = fmt.fmt.pix.width;
-        p_sys->i_height = fmt.fmt.pix.height;
+        msg_Dbg( p_obj, "found default width and height of %ux%u",
+                 fmt.fmt.pix.width, fmt.fmt.pix.height );
 
-        if( fmt.fmt.pix.field == V4L2_FIELD_ALTERNATE )
+        if( p_sys->i_width < 0 || p_sys->i_height < 0 )
         {
-            p_sys->i_height = p_sys->i_height * 2;
+            msg_Dbg( p_obj, "will try to find optimal width and height." );
         }
     }
-    else if( p_sys->i_width < 0 || p_sys->i_height < 0 )
-    {
-        msg_Dbg( p_obj, "will try to find optimal width and height." );
-    }
     else
     {
         /* Use user specified width and height */
         msg_Dbg( p_obj, "trying specified size %dx%d", p_sys->i_width, p_sys->i_height );
+        fmt.fmt.pix.width = p_sys->i_width;
+        fmt.fmt.pix.height = p_sys->i_height;
     }
 
-    fmt.fmt.pix.width = __MAX(0, p_sys->i_width);
-    fmt.fmt.pix.height = __MAX(0, p_sys->i_height);
     fmt.fmt.pix.field = V4L2_FIELD_NONE;
 
     if (b_demux)
@@ -2108,23 +2104,28 @@ static int OpenVideoDev( vlc_object_t *p_obj, demux_sys_t *p_sys, bool b_demux )
                               &i_width, &i_height );
             if( i_width || i_height )
             {
-                msg_Dbg( p_demux, "Found optimal dimensions for framerate %f of %dx%d",
-                         p_sys->f_fps, i_width, i_height );
+                msg_Dbg( p_demux, "Found optimal dimensions for framerate %f "
+                                  "of %ux%u", p_sys->f_fps, i_width, i_height );
                 fmt.fmt.pix.width = i_width;
                 fmt.fmt.pix.height = i_height;
-                if( v4l2_ioctl( i_fd, VIDIOC_S_FMT, &fmt ) < 0 ) {;}
+                if( v4l2_ioctl( i_fd, VIDIOC_S_FMT, &fmt ) < 0 )
+                {
+                    msg_Err( p_obj, "Cannot set size to optimal dimensions "
+                                    "%ux%u", i_width, i_height );
+                    goto open_failed;
+                }
             }
             else
             {
-                msg_Warn( p_obj, "Could not find optimal width and height." );
+                msg_Warn( p_obj, "Could not find optimal width and height, "
+                                 "falling back to driver default." );
             }
         }
-
-        /* Reassign width, height and chroma incase driver override */
-        p_sys->i_width = fmt.fmt.pix.width;
-        p_sys->i_height = fmt.fmt.pix.height;
     }
 
+    p_sys->i_width = fmt.fmt.pix.width;
+    p_sys->i_height = fmt.fmt.pix.height;
+
     if( v4l2_ioctl( i_fd, VIDIOC_G_FMT, &fmt ) < 0 ) {;}
     /* Print extra info */
     msg_Dbg( p_obj, "Driver requires at most %d bytes to store a complete image", fmt.fmt.pix.sizeimage );
@@ -2151,6 +2152,7 @@ static int OpenVideoDev( vlc_object_t *p_obj, demux_sys_t *p_sys, bool b_demux )
             break;
         case V4L2_FIELD_ALTERNATE:
             msg_Dbg( p_obj, "Interlacing setting: alternate fields" );
+            p_sys->i_height = p_sys->i_height * 2;
             break;
         case V4L2_FIELD_INTERLACED_TB:
             msg_Dbg( p_obj, "Interlacing setting: interleaved top bottom" );