libv4l: Obsolete the V4L2_ENABLE_ENUM_FMT_EMULATION v4l2_fd_open flag

From: Hans de Goede <hdegoede@redhat.com>

The V4L2_ENABLE_ENUM_FMT_EMULATION v4l2_fd_open flag is obsolete, libv4l2
now *always* reports emulated formats through the ENUM_FMT ioctl

Priority: normal

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

4 files changed, 14 insertions, 15 deletions

diff --git a/v4l2-apps/libv4l/ChangeLog b/v4l2-apps/libv4l/ChangeLog
index efdcda093..db2fa02b0 100644
--- a/v4l2-apps/libv4l/ChangeLog
+++ b/v4l2-apps/libv4l/ChangeLog
@@ -14,6 +14,8 @@ libv4l-0.5.98
 * Add the capability to provide 320x240 to apps if the cam can only
   do 320x232 (some zc3xx cams) by adding black borders
 * Add software auto gain / exposure
+* The V4L2_ENABLE_ENUM_FMT_EMULATION v4l2_fd_open flag is obsolete, libv4l2
+  now *always* reports emulated formats through the ENUM_FMT ioctl
 
 libv4l-0.5.97
 -------------
diff --git a/v4l2-apps/libv4l/include/libv4l2.h b/v4l2-apps/libv4l/include/libv4l2.h
index b05b57cb6..b2451dced 100644
--- a/v4l2-apps/libv4l/include/libv4l2.h
+++ b/v4l2-apps/libv4l/include/libv4l2.h
@@ -41,18 +41,12 @@ LIBV4L_PUBLIC extern FILE *v4l2_log_file;
    format which is not supported by the cam, but is supported by libv4lconvert,
    then the try_fmt / set_fmt will succeed as if the cam supports the format
    and on dqbuf / read the data will be converted for you and returned in
-   the request format.
+   the request format. enum_fmt will also report support for the formats to
+   which conversion is possible.
 
    Another difference is that you can make v4l2_read() calls even on devices
    which do not support the regular read() method.
 
-   Note that libv4l2 normally does not interfere with enum_fmt, so enum_fmt
-   will still return the actual formats the hardware supports, and not any
-   formats which may be emulated on top of that. If you pass the
-   V4L2_ENABLE_ENUM_FMT_EMULATION flag to v4l2_fd_open (as the v4l2convert.so
-   wrapper does) then enum_fmt will also report support for the formats to
-   which conversion is possible.
-
    Note the device name passed to v4l2_open must be of a video4linux2 device,
    if it is anything else (including a video4linux1 device), v4l2_open will
    fail.
@@ -89,11 +83,14 @@ LIBV4L_PUBLIC int v4l2_get_control(int fd, int cid);
 
 /* Flags for v4l2_fd_open's v4l2_flags argument */
 
-/* Disable all format conversion done by libv4l2 (reduces libv4l2 functionality
-   to offering v4l2_read() even on devices which don't implement read()) */
+/* Disable all format conversion done by libv4l2, this includes the software
+   whitebalance, gamma correction, flipping, etc. libv4lconvert does. Use this
+   if you want raw frame data, but still want the additional error checks and
+   the read() emulation libv4l2 offers. */
 #define V4L2_DISABLE_CONVERSION 0x01
-/* Report not only real but also emulated formats with the ENUM_FMT ioctl */
-#define V4L2_ENABLE_ENUM_FMT_EMULATION 02
+/* This flag is *OBSOLETE*, since version 0.5.98 libv4l *always* reports
+   emulated formats to ENUM_FMT, except when conversion is disabled. */
+#define V4L2_ENABLE_ENUM_FMT_EMULATION 0x02
 
 /* v4l2_fd_open: open an already opened fd for further use through
    v4l2lib and possibly modify libv4l2's default behavior through the
diff --git a/v4l2-apps/libv4l/libv4l2/libv4l2.c b/v4l2-apps/libv4l/libv4l2/libv4l2.c
index 053e6e28b..382dc405b 100644
--- a/v4l2-apps/libv4l/libv4l2/libv4l2.c
+++ b/v4l2-apps/libv4l/libv4l2/libv4l2.c
@@ -696,12 +696,12 @@ int v4l2_ioctl (int fd, unsigned long int request, ...)
       break;
     case VIDIOC_ENUM_FMT:
       if (((struct v4l2_fmtdesc *)arg)->type == V4L2_BUF_TYPE_VIDEO_CAPTURE &&
-	  (devices[index].flags & V4L2_ENABLE_ENUM_FMT_EMULATION))
+	  !(devices[index].flags & V4L2_DISABLE_CONVERSION))
 	is_capture_request = 1;
       break;
     case VIDIOC_ENUM_FRAMESIZES:
     case VIDIOC_ENUM_FRAMEINTERVALS:
-      if (devices[index].flags & V4L2_ENABLE_ENUM_FMT_EMULATION)
+      if (!(devices[index].flags & V4L2_DISABLE_CONVERSION))
 	is_capture_request = 1;
       break;
     case VIDIOC_TRY_FMT:
diff --git a/v4l2-apps/libv4l/libv4l2/v4l2convert.c b/v4l2-apps/libv4l/libv4l2/v4l2convert.c
index 307a03ce5..b1354772d 100644
--- a/v4l2-apps/libv4l/libv4l2/v4l2convert.c
+++ b/v4l2-apps/libv4l/libv4l2/v4l2convert.c
@@ -92,7 +92,7 @@ LIBV4L_PUBLIC int open (const char *file, int oflag, ...)
 
   /* Try to Register with libv4l2 (in case of failure pass the fd to the
      application as is) */
-  v4l2_fd_open(fd, V4L2_ENABLE_ENUM_FMT_EMULATION);
+  v4l2_fd_open(fd, 0);
 
   return fd;
 }