libv4l2: Never be lazy on s_fmt

Before this patch libv4l2 tries to avoid sending an "unnecessary" s_fmt to
the device. So if an app does a s_fmt with parameters which exactly match
what is already in place libv4l2 used to not send the s_fmt to the device.

This means however that if the device was set to a specific framerate
with a s_parm call, that it will stay at this framerate. Where as
normally a s_fmt resets the device to its default framerate.

This patch ensures that app which do a s_fmt always get the default
framerate by always forwarding the s_fmt to the device.

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

diff --git a/lib/libv4l2/libv4l2.c b/lib/libv4l2/libv4l2.c
index 0db7230..9d3a0ef 100644 (file)
--- a/lib/libv4l2/libv4l2.c
+++ b/lib/libv4l2/libv4l2.c
@@ -76,10 +76,9 @@
 #define V4L2_BUFFERS_REQUESTED_BY_READ 0x0200
 #define V4L2_STREAM_CONTROLLED_BY_READ 0x0400
 #define V4L2_SUPPORTS_READ             0x0800
-#define V4L2_IS_UVC                    0x1000
-#define V4L2_STREAM_TOUCHED            0x2000
-#define V4L2_USE_READ_FOR_READ         0x4000
-#define V4L2_SUPPORTS_TIMEPERFRAME     0x8000
+#define V4L2_STREAM_TOUCHED            0x1000
+#define V4L2_USE_READ_FOR_READ         0x2000
+#define V4L2_SUPPORTS_TIMEPERFRAME     0x4000
 
 #define V4L2_MMAP_OFFSET_MAGIC      0xABCDEF00u
 
@@ -679,8 +678,6 @@ no_capture:
                   driver on the first read */
                devices[index].first_frame = V4L2_IGNORE_FIRST_FRAME_ERRORS;
        }
-       if (!strcmp((char *)cap.driver, "uvcvideo"))
-               devices[index].flags |= V4L2_IS_UVC;
        if ((parm.type == V4L2_BUF_TYPE_VIDEO_CAPTURE) &&
            (parm.parm.capture.capability & V4L2_CAP_TIMEPERFRAME))
                devices[index].flags |= V4L2_SUPPORTS_TIMEPERFRAME;
@@ -887,14 +884,6 @@ static int v4l2_s_fmt(int index, struct v4l2_format *dest_fmt)
        struct v4l2_pix_format req_pix_fmt;
        int result;
 
-       /* Don't be lazy on uvc cams, as this triggers a bug in the uvcvideo
-          driver in kernel <= 2.6.28 (with certain cams) */
-       if (!(devices[index].flags & V4L2_IS_UVC) &&
-           v4l2_pix_fmt_compat(&devices[index].dest_fmt, dest_fmt)) {
-               *dest_fmt = devices[index].dest_fmt;
-               return 0;
-       }
-
        if (v4l2_log_file) {
                int pixfmt = dest_fmt->fmt.pix.pixelformat;
 
@@ -924,15 +913,6 @@ static int v4l2_s_fmt(int index, struct v4l2_format *dest_fmt)
                        (pixfmt >> 16) & 0xff, pixfmt >> 24);
        }
 
-       /* Maybe after try format has adjusted width/height etc, to whats
-          available nothing has changed (on the cam side) ? */
-       if (!(devices[index].flags & V4L2_IS_UVC) &&
-           v4l2_pix_fmt_compat(&devices[index].src_fmt, &src_fmt)) {
-               v4l2_set_src_and_dest_format(index, &devices[index].src_fmt,
-                               dest_fmt);
-               return 0;
-       }
-
        result = v4l2_check_buffer_change_ok(index);
        if (result)
                return result;