On Thu, 12 Apr 2012 11:55:12 -0300, Mauro Carvalho Chehab <mche...@redhat.com>
wrote:
> I can see only two viable fixes for it:
>
> 1) add a typedef for the enum, using the sizeof(enum) in order to select
> the
> size of the used integer.
>
> Pros:
> - Patch is easy to write/easy to review;
> - Won't change the struct size, so applications compiled without
> strong gcc optimization won't break;
> Cons:
> - It will add a typedef, with is ugly;
> - struct size on 32 bits will be different thant he size on 64 bits
> (not really an issue, as v4l2-compat32 will handle that;
> - v4l2-compat32 code may require changes.
>
> 2) just replace it by a 32 bits integer.
>
> Pros:
> - no typedefs;
> - struct size won't change between 32/64 bits (except when they also
> have pointers);
> Cons:
> - will break ABI. So, a compat code is required;
> - will require a "videodev2.h" fork for the legacy API with the enum's;
> - will require a compat code to convert from enum into integer and
> vice-versa.
After reflecting about that, I think that (2) is better at long term. Doing it
won't be easy, as there are 24 ioctl's affected by enum's (if I didn't forget
anything - please double check!).
We'll need to patch for videodev2.h, v4l2-ioctl.h and v4l2-compat-ioctl32.c,
in order to add the compatibility code for handling the old API calls.
If done well, this could be an opportunity to cleanup the code at
v4l2-compat-ioctl32.c,
as, i thesis, only structures with pointers would need compat bits, but the
current implementation forces a compatibility code for everything.
Anyway, the first step is something like the patch bellow.
Comments are welcome.
Regards,
Mauro
[RFC] [media] videodev2: don't use enum's at the public API.
Enum size is not portable and g++ might try to do wrong optimizations
with it.
PS.: Patch is incomplete, as the compatibility bits aren't there.
Signed-off-by: Mauro Carvalho Chehab <mche...@redhat.com>
diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
index e69cacc..37443a9 100644
--- a/include/linux/videodev2.h
+++ b/include/linux/videodev2.h
@@ -292,10 +292,10 @@ struct v4l2_pix_format {
__u32 width;
__u32 height;
__u32 pixelformat;
- enum v4l2_field field;
+ __u32 field; /* enum v4l2_field */
__u32 bytesperline; /* for padding, zero if unused
*/
__u32 sizeimage;
- enum v4l2_colorspace colorspace;
+ __u32 colorspace; /* enum v4l2_colorspace */
__u32 priv; /* private data, depends on
pixelformat */
};
@@ -432,7 +432,7 @@ struct v4l2_pix_format {
*/
struct v4l2_fmtdesc {
__u32 index; /* Format number */
- enum v4l2_buf_type type; /* buffer type */
+ __u32 type; /* buffer type (enum
v4l2_buf_type) */
__u32 flags;
__u8 description[32]; /* Description string */
__u32 pixelformat; /* Format fourcc */
@@ -573,8 +573,8 @@ struct v4l2_jpegcompression {
*/
struct v4l2_requestbuffers {
__u32 count;
- enum v4l2_buf_type type;
- enum v4l2_memory memory;
+ __u32 type; /* enum v4l2_buf_type */
+ __u32 memory; /* enum v4l2_memory */
__u32 reserved[2];
};
@@ -636,16 +636,16 @@ struct v4l2_plane {
*/
struct v4l2_buffer {
__u32 index;
- enum v4l2_buf_type type;
+ __u32 type; /* enum v4l2_buf_type */
__u32 bytesused;
__u32 flags;
- enum v4l2_field field;
+ __u32 field; /* enum v4l2_field */
struct timeval timestamp;
struct v4l2_timecode timecode;
__u32 sequence;
/* memory location */
- enum v4l2_memory memory;
+ __u32 memory; /* enum v4l2_memory */
union {
__u32 offset;
unsigned long userptr;
@@ -708,7 +708,7 @@ struct v4l2_clip {
struct v4l2_window {
struct v4l2_rect w;
- enum v4l2_field field;
+ __u32 field; /* enum v4l2_field */
__u32 chromakey;
struct v4l2_clip __user *clips;
__u32 clipcount;
@@ -745,14 +745,14 @@ struct v4l2_outputparm {
* I N P U T I M A G E C R O P P I N G
*/
struct v4l2_cropcap {
- enum v4l2_buf_type type;
+ __u32 type; /* enum v4l2_buf_type */
struct v4l2_rect bounds;
struct v4l2_rect defrect;
struct v4l2_fract pixelaspect;
};
struct v4l2_crop {
- enum v4l2_buf_type type;
+ __u32 type; /* enum v4l2_buf_type */
struct v4l2_rect c;
};
@@ -1157,7 +1157,7 @@ enum v4l2_ctrl_type {
/* Used in the VIDIOC_QUERYCTRL ioctl for querying controls */
struct v4l2_queryctrl {
__u32 id;
- enum v4l2_ctrl_type type;
+ __u32 type; /* enum v4l2_ctrl_type */
__u8 name[32]; /* Whatever */
__s32 minimum; /* Note signedness */
__s32 maximum;
@@ -1792,7 +1792,7 @@ enum v4l2_jpeg_chroma_subsampling {
struct v4l2_tuner {
__u32 index;
__u8 name[32];
- enum v4l2_tuner_type type;
+ __u32 type; /* enum v4l2_tuner_type */
__u32 capability;
__u32 rangelow;
__u32 rangehigh;
@@ -1842,14 +1842,14 @@ struct v4l2_modulator {
struct v4l2_frequency {
__u32 tuner;
- enum v4l2_tuner_type type;
+ __u32 type; /* enum v4l2_tuner_type */
__u32 frequency;
__u32 reserved[8];
};
struct v4l2_hw_freq_seek {
__u32 tuner;
- enum v4l2_tuner_type type;
+ __u32 type; /* enum v4l2_tuner_type */
__u32 seek_upward;
__u32 wrap_around;
__u32 spacing;
@@ -2060,7 +2060,7 @@ struct v4l2_sliced_vbi_cap {
(equals frame lines 313-336 for 625 line video
standards, 263-286 for 525 line standards) */
__u16 service_lines[2][24];
- enum v4l2_buf_type type;
+ __u32 type; /* enum v4l2_buf_type */
__u32 reserved[3]; /* must be 0 */
};
@@ -2150,8 +2150,8 @@ struct v4l2_pix_format_mplane {
__u32 width;
__u32 height;
__u32 pixelformat;
- enum v4l2_field field;
- enum v4l2_colorspace colorspace;
+ __u32 field; /* enum v4l2_field */
+ __u32 colorspace; /* enum v4l2_colorspace
*/
struct v4l2_plane_pix_format plane_fmt[VIDEO_MAX_PLANES];
__u8 num_planes;
@@ -2169,7 +2169,7 @@ struct v4l2_pix_format_mplane {
* @raw_data: placeholder for future extensions and custom formats
*/
struct v4l2_format {
- enum v4l2_buf_type type;
+ __u32 type; /* enum v4l2_buf_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 */
@@ -2183,7 +2183,7 @@ struct v4l2_format {
/* Stream type-dependent parameters
*/
struct v4l2_streamparm {
- enum v4l2_buf_type type;
+ __u32 type; /* enum v4l2_buf_type */
union {
struct v4l2_captureparm capture;
struct v4l2_outputparm output;
@@ -2303,7 +2303,7 @@ struct v4l2_dbg_chip_ident {
struct v4l2_create_buffers {
__u32 index;
__u32 count;
- enum v4l2_memory memory;
+ __u32 memory; /* enum v4l2_memory */
struct v4l2_format format;
__u32 reserved[8];
};
@@ -2417,4 +2417,213 @@ struct v4l2_create_buffers {
#define BASE_VIDIOC_PRIVATE 192 /* 192-255 are private */
+/*
+ * Backward-compatible IOCTL's to be used by V4L2 core to work with the
+ * old ioctl's defined with "enum's" inside the structures
+ */
+
+#ifdef CONFIG_V4L2_COMPAT
+
+struct v4l2_pix_format_enum {
+ __u32 width;
+ __u32 height;
+ __u32 pixelformat;
+ enum v4l2_field field;
+ __u32 bytesperline; /* for padding, zero if unused
*/
+ __u32 sizeimage;
+ enum v4l2_colorspace colorspace;
+ __u32 priv; /* private data, depends on
pixelformat */
+};
+
+struct v4l2_fmtdesc_enum {
+ __u32 index; /* Format number */
+ enum v4l2_buf_type type; /* buffer type */
+ __u32 flags;
+ __u8 description[32]; /* Description string */
+ __u32 pixelformat; /* Format fourcc */
+ __u32 reserved[4];
+};
+
+struct v4l2_requestbuffers_enum {
+ __u32 count;
+ enum v4l2_buf_type type;
+ enum v4l2_memory memory;
+ __u32 reserved[2];
+};
+
+struct v4l2_buffer_enum {
+ __u32 index;
+ enum v4l2_buf_type type;
+ __u32 bytesused;
+ __u32 flags;
+ enum v4l2_field field;
+ struct timeval timestamp;
+ struct v4l2_timecode timecode;
+ __u32 sequence;
+
+ /* memory location */
+ enum v4l2_memory memory;
+ union {
+ __u32 offset;
+ unsigned long userptr;
+ struct v4l2_plane *planes;
+ } m;
+ __u32 length;
+ __u32 input;
+ __u32 reserved;
+};
+
+struct v4l2_framebuffer_enum {
+ __u32 capability;
+ __u32 flags;
+/* FIXME: in theory we should pass something like PCI device + memory
+ * region + offset instead of some physical address */
+ void *base;
+ struct v4l2_pix_format_enum fmt;
+};
+
+struct v4l2_window_enum {
+ struct v4l2_rect w;
+ enum v4l2_field field;
+ __u32 chromakey;
+ struct v4l2_clip __user *clips;
+ __u32 clipcount;
+ void __user *bitmap;
+ __u8 global_alpha;
+};
+
+struct v4l2_crop_enumcap_enum {
+ enum v4l2_buf_type type;
+ struct v4l2_rect bounds;
+ struct v4l2_rect defrect;
+ struct v4l2_fract pixelaspect;
+};
+
+struct v4l2_crop_enum {
+ enum v4l2_buf_type type;
+ struct v4l2_rect c;
+};
+
+struct v4l2_queryctrl_enum {
+ __u32 id;
+ enum v4l2_ctrl_type type;
+ __u8 name[32]; /* Whatever */
+ __s32 minimum; /* Note signedness */
+ __s32 maximum;
+ __s32 step;
+ __s32 default_value;
+ __u32 flags;
+ __u32 reserved[2];
+};
+
+struct v4l2_tuner_enum {
+ __u32 index;
+ __u8 name[32];
+ enum v4l2_tuner_type type;
+ __u32 capability;
+ __u32 rangelow;
+ __u32 rangehigh;
+ __u32 rxsubchans;
+ __u32 audmode;
+ __s32 signal;
+ __s32 afc;
+ __u32 reserved[4];
+};
+
+struct v4l2_frequency_enum {
+ __u32 tuner;
+ enum v4l2_tuner_type type;
+ __u32 frequency;
+ __u32 reserved[8];
+};
+
+struct v4l2_hw_freq_seek_enum {
+ __u32 tuner;
+ enum v4l2_tuner_type type;
+ __u32 seek_upward;
+ __u32 wrap_around;
+ __u32 spacing;
+ __u32 reserved[7];
+};
+
+struct v4l2_sliced_vbi_cap_enum {
+ __u16 service_set;
+ /* service_lines[0][...] specifies lines 0-23 (1-23 used) of the first
field
+ service_lines[1][...] specifies lines 0-23 (1-23 used) of the second
field
+ (equals frame lines 313-336 for 625 line video
+ standards, 263-286 for 525 line standards) */
+ __u16 service_lines[2][24];
+ enum v4l2_buf_type type;
+ __u32 reserved[3]; /* must be 0 */
+};
+
+struct v4l2_pix_format_mplane_enum {
+ __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_enum {
+ enum v4l2_buf_type type;
+ union {
+ struct v4l2_pix_format_enum pix; /*
V4L2_BUF_TYPE_VIDEO_CAPTURE */
+ struct v4l2_pix_format_mplane_enum pix_mp; /*
V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE */
+ struct v4l2_window_enum 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 */
+ __u8 raw_data[200]; /* user-defined */
+ } fmt;
+};
+
+/* Stream type-dependent parameters
+ */
+struct v4l2_streamparm_enum {
+ enum v4l2_buf_type type;
+ union {
+ struct v4l2_captureparm capture;
+ struct v4l2_outputparm output;
+ __u8 raw_data[200]; /* user-defined */
+ } parm;
+};
+
+struct v4l2_create_buffers_enum {
+ __u32 index;
+ __u32 count;
+ enum v4l2_memory memory;
+ struct v4l2_format_enum format;
+ __u32 reserved[8];
+};
+
+#define VIDIOC_ENUM_FMT_ENUM _IOWR('V', 2, struct v4l2_fmtdesc_enum)
+#define VIDIOC_G_FMT_ENUM _IOWR('V', 4, struct v4l2_format_enum)
+#define VIDIOC_S_FMT_ENUM _IOWR('V', 5, struct v4l2_format_enum)
+#define VIDIOC_REQBUFS_ENUM _IOWR('V', 8, struct
v4l2_requestbuffers_enum)
+#define VIDIOC_QUERYBUF_ENUM _IOWR('V', 9, struct v4l2_buffer_enum)
+#define VIDIOC_G_FBUF_ENUM _IOR('V', 10, struct
v4l2_framebuffer_enum)
+#define VIDIOC_S_FBUF_ENUM _IOW('V', 11, struct
v4l2_framebuffer_enum)
+#define VIDIOC_QBUF_ENUM _IOWR('V', 15, struct v4l2_buffer_enum)
+#define VIDIOC_DQBUF_ENUM _IOWR('V', 17, struct v4l2_buffer_enum)
+#define VIDIOC_G_PARM_ENUM _IOWR('V', 21, struct
v4l2_streamparm_enum)
+#define VIDIOC_S_PARM_ENUM _IOWR('V', 22, struct
v4l2_streamparm_enum)
+#define VIDIOC_G_TUNER_ENUM _IOWR('V', 29, struct v4l2_tuner_enum)
+#define VIDIOC_S_TUNER_ENUM _IOW('V', 30, struct v4l2_tuner_enum)
+#define VIDIOC_QUERYCTRL_ENUM _IOWR('V', 36, struct
v4l2_queryctrl_enum)
+#define VIDIOC_G_FREQUENCY_ENUM _IOWR('V', 56, struct
v4l2_frequency_enum)
+#define VIDIOC_S_FREQUENCY_ENUM _IOW('V', 57, struct
v4l2_frequency_enum)
+#define VIDIOC_CROPCAP_ENUM _IOWR('V', 58, struct
v4l2_crop_enumcap_enum)
+#define VIDIOC_G_CROP_ENUM _IOWR('V', 59, struct v4l2_crop_enum)
+#define VIDIOC_S_CROP_ENUM _IOW('V', 60, struct v4l2_crop_enum)
+#define VIDIOC_TRY_FMT_ENUM _IOWR('V', 64, struct v4l2_format_enum)
+#define VIDIOC_G_SLICED_VBI_CAP_ENUM _IOWR('V', 69, struct
v4l2_sliced_vbi_cap_enum)
+#define VIDIOC_S_HW_FREQ_SEEK_ENUM _IOW('V', 82, struct
v4l2_hw_freq_seek_enum)
+#define VIDIOC_CREATE_BUFS_ENUM _IOWR('V', 92, struct
v4l2_create_buffers_enum)
+#define VIDIOC_PREPARE_BUF_ENUM _IOWR('V', 93, struct
v4l2_buffer_enum)
+#endif /* V4L2_COMPAT */
+
#endif /* __LINUX_VIDEODEV2_H */
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