Em 03-02-2012 08:06, Hans Verkuil escreveu:
> From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>
> These new ioctls make it possible for the dv_timings API to replace
> the dv_preset API eventually.
>
> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> ---
> include/linux/videodev2.h | 110 ++++++++++++++++++++++++++++++++++++++++----
> 1 files changed, 100 insertions(+), 10 deletions(-)
>
> diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
> index 0db0503..e59cd02 100644
> --- a/include/linux/videodev2.h
> +++ b/include/linux/videodev2.h
> @@ -987,28 +987,42 @@ struct v4l2_dv_enum_preset {
> */
>
> /* BT.656/BT.1120 timing data */
> +
> +/*
> + * A note regarding vertical interlaced timings: height refers to the total
> + * height of the frame (= two fields). The blanking timings refer
> + * to the blanking of each field. So the height of the active frame is
> + * calculated as follows:
> + *
> + * act_height = height - vfrontporch - vsync - vbackporch -
> + * il_vfrontporch - il_vsync - il_vbackporch
> + *
> + * The active height of each field is act_height / 2.
> + */
> struct v4l2_bt_timings {
> - __u32 width; /* width in pixels */
> - __u32 height; /* height in lines */
> + __u32 width; /* total frame width in pixels */
> + __u32 height; /* total frame height in lines */
> __u32 interlaced; /* Interlaced or progressive */
> __u32 polarities; /* Positive or negative polarity */
> __u64 pixelclock; /* Pixel clock in HZ. Ex. 74.25MHz->74250000 */
> - __u32 hfrontporch; /* Horizpontal front porch in pixels */
> + __u32 hfrontporch; /* Horizontal front porch in pixels */
> __u32 hsync; /* Horizontal Sync length in pixels */
> __u32 hbackporch; /* Horizontal back porch in pixels */
> __u32 vfrontporch; /* Vertical front porch in pixels */
> __u32 vsync; /* Vertical Sync length in lines */
> __u32 vbackporch; /* Vertical back porch in lines */
> - __u32 il_vfrontporch; /* Vertical front porch for bottom field of
> - * interlaced field formats
> + __u32 il_vfrontporch; /* Vertical front porch for the even field
> + * (aka field 2) of interlaced field formats
> */
> - __u32 il_vsync; /* Vertical sync length for bottom field of
> - * interlaced field formats
> + __u32 il_vsync; /* Vertical sync length for the even field
> + * (aka field 2) of interlaced field formats
> */
> - __u32 il_vbackporch; /* Vertical back porch for bottom field of
> - * interlaced field formats
> + __u32 il_vbackporch; /* Vertical back porch for the even field
> + * (aka field 2) of interlaced field formats
> */
> - __u32 reserved[16];
> + __u32 standards; /* Standards the timing belongs to */
> + __u32 flags; /* Flags */
> + __u32 reserved[14];
> } __attribute__ ((packed));
>
> /* Interlaced or progressive format */
> @@ -1019,6 +1033,37 @@ struct v4l2_bt_timings {
> #define V4L2_DV_VSYNC_POS_POL 0x00000001
> #define V4L2_DV_HSYNC_POS_POL 0x00000002
>
> +/* Timings standards */
> +#define V4L2_DV_BT_STD_CEA861 (1 << 0) /* CEA-861 Digital TV Profile */
> +#define V4L2_DV_BT_STD_DMT (1 << 1) /* VESA Discrete Monitor Timings */
> +#define V4L2_DV_BT_STD_CVT (1 << 2) /* VESA Coordinated Video Timings */
> +#define V4L2_DV_BT_STD_GTF (1 << 3) /* VESA Generalized Timings Formula */
> +
> +/* Flags */
> +
> +/* CVT/GTF specific: timing uses reduced blanking (CVT) or the 'Secondary
> + GTF' curve (GTF). In both cases the horizontal and/or vertical blanking
> + intervals are reduced, allowing a higher resolution over the same
> + bandwidth. This is a read-only flag. */
> +#define V4L2_DV_FL_REDUCED_BLANKING (1 << 0)
> +/* CEA-861 specific: set for CEA-861 formats with a framerate of a multiple
> + of six. These formats can be optionally played at 1 / 1.001 speed to
> + be compatible with the normal NTSC framerate of 29.97 frames per second.
> + This is a read-only flag. */
> +#define V4L2_DV_FL_NTSC_COMPATIBLE (1 << 1)
> +/* CEA-861 specific: only valid for video transmitters, the flag is cleared
> + by receivers.
> + If the framerate of the format is a multiple of six, then the pixelclock
> + used to set up the transmitter is divided by 1.001 to make it compatible
> + with NTSC framerates. Otherwise this flag is cleared. If the transmitter
> + can't generate such frequencies, then the flag will also be cleared. */
> +#define V4L2_DV_FL_DIVIDE_CLOCK_BY_1_001 (1 << 2)
The two above have a conceptual problem: NTSC has nothing to do with the frequency.
While, in practice, NTSC is only used on Countries with 60Hz power supply, and a
1000/1001 shift is used there, to avoid flicker with the light bulbs, the
standard doesn't mean a 29.97 Hz frame rate.
If you take a look at CEA-861, it doesn't mention there NTSC (well, except for a
reference for the existing standards), to avoid such conceptual issue.
Besides that, PAL/M (and PAL/60) also uses a 29.97 Hz frame rate, in order to avoid
flicker.
So, please don't call the flag as "NTSC_COMPATIBLE", and please fix the comments
to either not mention NTSC, or to use something more generic, like replacing:
"...be compatible with the normal NTSC framerateof 29.97 frames per second."
with
"...be compatible with 60Hz based standards that use a framerate of 29.97
frames per second, like NTSC and PAL/M."
> +/* Specific to interlaced formats: if set, then field 1 is really one half-line
> + longer and field 2 is really one half-line shorter, so each field has
> + exactly the same number of half-lines. Whether half-lines can be detected
> + or used depends on the hardware. */
> +#define V4L2_DV_FL_HALF_LINE (1 << 0)
> +
>
> /* DV timings */
> struct v4l2_dv_timings {
> @@ -1032,6 +1077,47 @@ struct v4l2_dv_timings {
> /* Values for the type field */
> #define V4L2_DV_BT_656_1120 0 /* BT.656/1120 timing type */
>
> +
> +/* DV timings enumeration */
> +struct v4l2_enum_dv_timings {
> + __u32 index;
> + __u32 reserved[3];
> + struct v4l2_dv_timings timings;
> +};
> +
> +/* BT.656/BT.1120 timing capabilities */
> +struct v4l2_bt_timings_cap {
> + __u32 min_width; /* width in pixels */
> + __u32 max_width; /* width in pixels */
> + __u32 min_height; /* height in lines */
> + __u32 max_height; /* height in lines */
> + __u64 min_pixelclock; /* Pixel clock in HZ. Ex. 74.25MHz->74250000 */
> + __u64 max_pixelclock; /* Pixel clock in HZ. Ex. 74.25MHz->74250000 */
> + __u32 standards; /* Supported standards */
> + __u32 capabilities; /* See below */
> + __u32 reserved[16];
> +} __attribute__ ((packed));
Hmm... why to define a new struct here, instead of just use struct v4l2_bt_timings ?
> +
> +/* Supports interlaced formats */
> +#define V4L2_DV_BT_CAP_INTERLACED (1 << 0)
> +/* Supports progressive formats */
> +#define V4L2_DV_BT_CAP_PROGRESSIVE (1 << 1)
> +/* Supports CVT/GTF reduced blanking */
> +#define V4L2_DV_BT_CAP_REDUCED_BLANKING (1 << 2)
> +/* Supports custom formats */
> +#define V4L2_DV_BT_CAP_CUSTOM (1 << 3)
> +
> +/* DV timings capabilities */
> +struct v4l2_dv_timings_cap {
> + __u32 type;
What are the posible values for type?
Btw, it is a good idea to use kernel-doc-nano to describe the structures:
/**
* struct v4l2_dv_timings_cap - DV timings capabilities
* @type: some description
...
*/
As it documents better what is defined there.
> + __u32 reserved[3];
> + union {
> + struct v4l2_bt_timings_cap bt;
> + __u32 raw_data[32];
> + };
> +};
> +
> +
> /*
> * V I D E O I N P U T S
> */
> @@ -2318,6 +2404,10 @@ struct v4l2_create_buffers {
> #define VIDIOC_G_SELECTION _IOWR('V', 94, struct v4l2_selection)
> #define VIDIOC_S_SELECTION _IOWR('V', 95, struct v4l2_selection)
>
> +#define VIDIOC_ENUM_DV_TIMINGS _IOWR('V', 96, struct v4l2_enum_dv_timings)
> +#define VIDIOC_QUERY_DV_TIMINGS _IOR('V', 97, struct v4l2_dv_timings)
> +#define VIDIOC_DV_TIMINGS_CAP _IOWR('V', 98, struct v4l2_dv_timings_cap)
> +
> /* Reminder: when adding new ioctls please add support for them to
> drivers/media/video/v4l2-compat-ioctl32.c as well! */
>
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