On Friday 30 July 2010 10:49:41 Pawel Osciak wrote:
> Multi-planar API is as a backwards-compatible extension of the V4L2 API,
> which allows video buffers to consist of one or more planes. Planes are
> separate memory buffers; each has its own mapping, backed by usually
> separate physical memory buffers.
>
> Many different uses for the multi-planar API are possible, examples
> include:
> - embedded devices requiring video components to be placed in physically
> separate buffers, e.g. for Samsung S3C/S5P SoC series' video codec,
> Y and interleaved Cb/Cr components reside in buffers in different
> memory banks;
> - applications may receive (or choose to store) video data of one video
> buffer in separate memory buffers; such data would have to be temporarily
> copied together into one buffer before passing it to a V4L2 device;
> - applications or drivers may want to pass metadata related to a buffer and
> it may not be possible to place it in the same buffer, together with video
> data.
>
> Signed-off-by: Pawel Osciak <p.osciak@xxxxxxxxxxx>
> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> Reviewed-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> ---
> drivers/media/video/v4l2-ioctl.c | 2 +
> include/linux/videodev2.h | 126 +++++++++++++++++++++++++++++++++++++-
> 2 files changed, 126 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c
> index 0eeceae..a830bbd 100644
> --- a/drivers/media/video/v4l2-ioctl.c
> +++ b/drivers/media/video/v4l2-ioctl.c
> @@ -168,6 +168,8 @@ const char *v4l2_type_names[] = {
> [V4L2_BUF_TYPE_SLICED_VBI_CAPTURE] = "sliced-vbi-cap",
> [V4L2_BUF_TYPE_SLICED_VBI_OUTPUT] = "sliced-vbi-out",
> [V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY] = "vid-out-overlay",
> + [V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE] = "vid-cap-mplane",
> + [V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE] = "vid-out-mplane",
> };
> EXPORT_SYMBOL(v4l2_type_names);
>
> diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
> index 047f7e6..0379f07 100644
> --- a/include/linux/videodev2.h
> +++ b/include/linux/videodev2.h
> @@ -70,6 +70,7 @@
> * Moved from videodev.h
> */
> #define VIDEO_MAX_FRAME 32
> +#define VIDEO_MAX_PLANES 8
>
> #ifndef __KERNEL__
>
> @@ -157,9 +158,23 @@ enum v4l2_buf_type {
> /* Experimental */
> V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY = 8,
> #endif
> + V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE = 17,
> + V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE = 18,
Why 17 and 18 instead of 9 and 10?
> V4L2_BUF_TYPE_PRIVATE = 0x80,
> };
>
> +#define V4L2_TYPE_IS_MULTIPLANAR(type) \
> + ((type) == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE \
> + || (type) == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
> +
> +#define V4L2_TYPE_IS_OUTPUT(type) \
> + ((type) == V4L2_BUF_TYPE_VIDEO_OUTPUT \
> + || (type) == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE \
> + || (type) == V4L2_BUF_TYPE_VIDEO_OVERLAY \
> + || (type) == V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY \
> + || (type) == V4L2_BUF_TYPE_VBI_OUTPUT \
> + || (type) == V4L2_BUF_TYPE_SLICED_VBI_OUTPUT)
> +
> enum v4l2_tuner_type {
> V4L2_TUNER_RADIO = 1,
> V4L2_TUNER_ANALOG_TV = 2,
> @@ -245,6 +260,11 @@ struct v4l2_capability {
> #define V4L2_CAP_HW_FREQ_SEEK 0x00000400 /* Can do hardware frequency seek */
> #define V4L2_CAP_RDS_OUTPUT 0x00000800 /* Is an RDS encoder */
>
> +/* Is a video capture device that supports multiplanar formats */
> +#define V4L2_CAP_VIDEO_CAPTURE_MPLANE 0x00001000
> +/* Is a video output device that supports multiplanar formats */
> +#define V4L2_CAP_VIDEO_OUTPUT_MPLANE 0x00002000
> +
> #define V4L2_CAP_TUNER 0x00010000 /* has a tuner */
> #define V4L2_CAP_AUDIO 0x00020000 /* has audio support */
> #define V4L2_CAP_RADIO 0x00040000 /* is a radio device */
> @@ -514,6 +534,63 @@ struct v4l2_requestbuffers {
> __u32 reserved[2];
> };
>
> +/**
> + * struct v4l2_plane - plane info for multi-planar buffers
> + * @bytesused: number of bytes occupied by data in the plane (payload)
> + * @mem_offset: when memory in the associated struct v4l2_buffer is
> + * V4L2_MEMORY_MMAP, equals the offset from the start of
> + * the device memory for this plane (or is a "cookie" that
> + * should be passed to mmap() called on the video node)
> + * @userptr: when memory is V4L2_MEMORY_USERPTR, a userspace pointer
> + * pointing
> + * to this plane
Can be put on one line instead of two.
> + * @length: size of this plane (NOT the payload) in bytes
Note: mismatch between the order of the fields here and in the actual struct.
@length should be after @bytesused.
> + * @data_offset: offset in plane to the start of data/end of header,
> + * if relevant
I would rephrase this:
offset in the plane to the start of data. Usually this is 0, unless there is
a header in front of the data.
> + *
> + * Multi-planar buffers consist of one or more planes, e.g. an YCbCr buffer
> + * with two planes can have one plane for Y, and another for interleaved CbCr
> + * components. Each plane can reside in a separate memory buffer, or even in
> + * a completely separate memory node (e.g. in embedded devices).
> + */
> +struct v4l2_plane {
> + __u32 bytesused;
> + __u32 length;
> + union {
> + __u32 mem_offset;
> + unsigned long userptr;
> + } m;
> + __u32 data_offset;
> + __u32 reserved[11];
> +};
> +
> +/**
> + * struct v4l2_buffer - video buffer info
> + * @index: id number of the buffer
> + * @type: buffer type (type == *_MPLANE for multiplanar buffers)
> + * @bytesused: number of bytes occupied by data in the buffer (payload);
> + * unused (set to 0) for multiplanar buffers
> + * @flags: buffer informational flags
> + * @field: field order of the image in the buffer
> + * @timestamp: frame timestamp
> + * @timecode: frame timecode
> + * @sequence: sequence count of this frame
> + * @memory: the method, in which the actual video data is passed
> + * @offset: for non-multiplanar buffers with memory == V4L2_MEMORY_MMAP;
> + * offset from the start of the device memory for this plane,
> + * (or a "cookie" that should be passed to mmap() as offset)
> + * @userptr: for non-multiplanar buffers with memory == V4L2_MEMORY_USERPTR;
> + * a userspace pointer pointing to this buffer
> + * @planes: for multiplanar buffers; userspace pointer to the array of plane
> + * info structs for this buffer
> + * @length: size in bytes of the buffer (NOT its payload) for single-plane
> + * buffers (when type != *_MPLANE); number of planes (and number
> + * of elements in the planes array) for multi-plane buffers
This is confusing. Just write "number of elements in the planes array".
> + * @input: input number from which the video data has has been captured
> + *
> + * Contains data exchanged by application and driver using one of the Streaming
> + * I/O methods.
> + */
> struct v4l2_buffer {
> __u32 index;
> enum v4l2_buf_type type;
> @@ -529,6 +606,7 @@ struct v4l2_buffer {
> union {
> __u32 offset;
> unsigned long userptr;
> + struct v4l2_plane *planes;
Should use the __user attribute.
> } m;
> __u32 length;
> __u32 input;
> @@ -1613,12 +1691,57 @@ struct v4l2_mpeg_vbi_fmt_ivtv {
> * A G G R E G A T E S T R U C T U R E S
> */
>
> -/* Stream data format
> +/**
> + * struct v4l2_plane_pix_format - additional, per-plane format definition
> + * @sizeimage: maximum size in bytes required for data, for which
> + * this plane will be used
> + * @bytesperline: distance in bytes between the leftmost pixels in two
> + * adjacent lines
> + */
> +struct v4l2_plane_pix_format {
> + __u32 sizeimage;
> + __u16 bytesperline;
> + __u16 reserved[7];
> +} __attribute__ ((packed));
> +
> +/**
> + * struct v4l2_pix_format_mplane - multiplanar format definition
> + * @width: image width in pixels
> + * @height: image height in pixels
> + * @pixelformat: little endian four character code (fourcc)
> + * @field: field order (for interlaced video)
> + * @colorspace: supplemental to pixelformat
> + * @plane_fmt: per-plane information
> + * @num_planes: number of planes for this format and number of valid
> + * elements in plane_fmt array
Same problem here: just write "number of planes for this format".
> + */
> +struct v4l2_pix_format_mplane {
> + __u32 width;
> + __u32 height;
> + __u32 pixelformat;
> + enum v4l2_field field;
> + enum v4l2_colorspace colorspace;
> +
> + struct v4l2_plane_pix_format plane_fmt[VIDEO_MAX_PLANES];
> + __u8 num_planes;
> + __u8 reserved[11];
> +} __attribute__ ((packed));
> +
> +/**
> + * struct v4l2_format - stream data format
> + * @type: type of the data stream
> + * @pix: definition of an image format
> + * @pix_mp: definition of a multiplanar image format
> + * @win: definition of an overlaid image
> + * @vbi: raw VBI capture or output parameters
> + * @sliced: sliced VBI capture or output parameters
> + * @raw_data: placeholder for future extensions and custom formats
> */
> struct v4l2_format {
> enum v4l2_buf_type type;
> union {
> struct v4l2_pix_format pix; /* V4L2_BUF_TYPE_VIDEO_CAPTURE */
> + struct v4l2_pix_format_mplane pix_mp; /* V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE */
> struct v4l2_window win; /* V4L2_BUF_TYPE_VIDEO_OVERLAY */
> struct v4l2_vbi_format vbi; /* V4L2_BUF_TYPE_VBI_CAPTURE */
> struct v4l2_sliced_vbi_format sliced; /* V4L2_BUF_TYPE_SLICED_VBI_CAPTURE */
> @@ -1626,7 +1749,6 @@ struct v4l2_format {
> } fmt;
> };
>
> -
> /* Stream type-dependent parameters
> */
> struct v4l2_streamparm {
>
Regards,
Hans
--
Hans Verkuil - video4linux developer - sponsored by TANDBERG, part of Cisco
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