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videolan
vlc
Commits
cd4578a1
Commit
cd4578a1
authored
Apr 07, 2012
by
Rémi Denis-Courmont
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Plain Diff
v4l2: rationalize/factorize frame rate handling
parent
3e73ad2a
Changes
1
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Showing
1 changed file
with
37 additions
and
35 deletions
+37
-35
modules/access/v4l2/video.c
modules/access/v4l2/video.c
+37
-35
No files found.
modules/access/v4l2/video.c
View file @
cd4578a1
...
...
@@ -765,21 +765,25 @@ int SetupInput (vlc_object_t *obj, int fd)
}
/** Compares two V4L2 fractions. */
static
int64_t
fcmp
(
struct
v4l2_fract
a
,
struct
v4l2_fract
b
)
static
int64_t
fcmp
(
const
struct
v4l2_fract
*
a
,
const
struct
v4l2_fract
*
b
)
{
return
(
uint64_t
)
a
.
numerator
*
b
.
denominator
-
(
uint64_t
)
b
.
numerator
*
a
.
denominator
;
return
(
uint64_t
)
a
->
numerator
*
b
->
denominator
-
(
uint64_t
)
b
->
numerator
*
a
->
denominator
;
}
static
const
struct
v4l2_fract
infinity
=
{
1
,
0
};
/**
* Finds the highest frame rate possible of a certain V4L2 format.
* @param fmt V4L2 capture format [IN]
* @param parm V4L2 capture streaming parameters [IN]
* @param it V4L2 frame interval [OUT]
* @return 0 on success, -1 on failure.
*/
static
int
FindMaxRate
(
vlc_object_t
*
obj
,
int
fd
,
const
struct
v4l2_format
*
restrict
fmt
,
struct
v4l2_fract
*
restrict
it
)
static
void
FindMaxRate
(
vlc_object_t
*
obj
,
int
fd
,
const
struct
v4l2_format
*
restrict
fmt
,
const
struct
v4l2_streamparm
*
restrict
parm
,
struct
v4l2_fract
*
restrict
it
)
{
struct
v4l2_frmivalenum
fie
=
{
.
pixel_format
=
fmt
->
fmt
.
pix
.
pixelformat
,
...
...
@@ -787,21 +791,30 @@ static int FindMaxRate (vlc_object_t *obj, int fd,
.
height
=
fmt
->
fmt
.
pix
.
height
,
};
/* Mind that maximum rate means minimum interval */
struct
v4l2_fract
min
=
{
1
,
0
};
/* infinity */
if
(
!
(
parm
->
parm
.
capture
.
capability
&
V4L2_CAP_TIMEPERFRAME
))
{
*
it
=
parm
->
parm
.
capture
.
timeperframe
;
msg_Dbg
(
obj
,
" constant frame interval: %"
PRIu32
"/%"
PRIu32
,
it
->
numerator
,
it
->
denominator
);
}
else
if
(
v4l2_ioctl
(
fd
,
VIDIOC_ENUM_FRAMEINTERVALS
,
&
fie
)
<
0
)
{
msg_Dbg
(
obj
,
" unknown frame internals: %m"
);
return
-
1
;
msg_Warn
(
obj
,
" unknown frame intervals: %m"
);
*
it
=
parm
->
parm
.
capture
.
timeperframe
;
msg_Dbg
(
obj
,
" default frame interval: %"
PRIu32
"/%"
PRIu32
,
it
->
numerator
,
it
->
denominator
);
}
else
switch
(
fie
.
type
)
{
case
V4L2_FRMIVAL_TYPE_DISCRETE
:
*
it
=
infinity
;
do
{
if
(
fcmp
(
fie
.
discrete
,
min
)
<
0
)
min
=
fie
.
discrete
;
if
(
fcmp
(
&
fie
.
discrete
,
it
)
<
0
)
*
it
=
fie
.
discrete
;
msg_Dbg
(
obj
,
" discrete frame interval: %"
PRIu32
"/%"
PRIu32
,
fie
.
discrete
.
numerator
,
fie
.
discrete
.
denominator
);
fie
.
index
++
;
...
...
@@ -809,7 +822,7 @@ static int FindMaxRate (vlc_object_t *obj, int fd,
while
(
v4l2_ioctl
(
fd
,
VIDIOC_ENUM_FRAMEINTERVALS
,
&
fie
)
>=
0
);
msg_Dbg
(
obj
,
" best discrete frame interval: %"
PRIu32
"/%"
PRIu32
,
min
.
numerator
,
min
.
denominator
);
it
->
numerator
,
it
->
denominator
);
break
;
case
V4L2_FRMIVAL_TYPE_STEPWISE
:
...
...
@@ -822,12 +835,9 @@ static int FindMaxRate (vlc_object_t *obj, int fd,
msg_Dbg
(
obj
,
" with %"
PRIu32
"/%"
PRIu32
" step"
,
fie
.
stepwise
.
step
.
numerator
,
fie
.
stepwise
.
step
.
denominator
);
min
=
fie
.
stepwise
.
min
;
*
it
=
fie
.
stepwise
.
min
;
break
;
}
*
it
=
min
;
return
0
;
}
#undef SetupFormat
...
...
@@ -865,7 +875,7 @@ int SetupFormat (vlc_object_t *obj, int fd, uint32_t fourcc,
struct
v4l2_frmsizeenum
fse
=
{
.
pixel_format
=
fourcc
,
};
struct
v4l2_fract
best_it
=
{
1
,
0
};
/* infinity */
struct
v4l2_fract
best_it
=
infinity
;
uint64_t
best_area
=
0
;
if
(
v4l2_ioctl
(
fd
,
VIDIOC_ENUM_FRAMESIZES
,
&
fse
)
<
0
)
...
...
@@ -874,13 +884,7 @@ int SetupFormat (vlc_object_t *obj, int fd, uint32_t fourcc,
msg_Dbg
(
obj
,
" unknown frame sizes: %m"
);
msg_Dbg
(
obj
,
" default frame size: %"
PRIu32
"x%"
PRIu32
,
fmt
->
fmt
.
pix
.
width
,
fmt
->
fmt
.
pix
.
height
);
if
(
!
(
parm
->
parm
.
capture
.
capability
&
V4L2_CAP_TIMEPERFRAME
)
||
FindMaxRate
(
obj
,
fd
,
fmt
,
&
best_it
))
{
best_it
=
parm
->
parm
.
capture
.
timeperframe
;
msg_Dbg
(
obj
,
" constant frame interval: %"
PRIu32
"/%"
PRIu32
,
best_it
.
numerator
,
best_it
.
denominator
);
}
FindMaxRate
(
obj
,
fd
,
fmt
,
parm
,
&
best_it
);
}
else
switch
(
fse
.
type
)
...
...
@@ -892,11 +896,9 @@ int SetupFormat (vlc_object_t *obj, int fd, uint32_t fourcc,
msg_Dbg
(
obj
,
" frame size %"
PRIu32
"x%"
PRIu32
,
fse
.
discrete
.
width
,
fse
.
discrete
.
height
);
if
(
FindMaxRate
(
obj
,
fd
,
fmt
,
&
cur_it
))
/* If frame rate is not known, find largest resolution */
cur_it
.
denominator
=
0
;
FindMaxRate
(
obj
,
fd
,
fmt
,
parm
,
&
cur_it
);
int64_t
c
=
fcmp
(
cur_it
,
best_it
);
int64_t
c
=
fcmp
(
&
cur_it
,
&
best_it
);
uint64_t
area
=
fse
.
discrete
.
width
*
fse
.
discrete
.
height
;
if
(
c
<
0
||
(
c
==
0
&&
area
>
best_area
))
{
...
...
@@ -934,10 +936,9 @@ int SetupFormat (vlc_object_t *obj, int fd, uint32_t fourcc,
{
struct
v4l2_fract
cur_it
;
if
(
FindMaxRate
(
obj
,
fd
,
fmt
,
&
cur_it
))
continue
;
FindMaxRate
(
obj
,
fd
,
fmt
,
parm
,
&
cur_it
);
int64_t
c
=
fcmp
(
cur_it
,
best_it
);
int64_t
c
=
fcmp
(
&
cur_it
,
&
best_it
);
uint64_t
area
=
width
*
height
;
if
(
c
<
0
||
(
c
==
0
&&
area
>
best_area
))
...
...
@@ -954,15 +955,16 @@ int SetupFormat (vlc_object_t *obj, int fd, uint32_t fourcc,
break
;
}
parm
->
parm
.
capture
.
timeperframe
=
best_it
;
if
(
v4l2_ioctl
(
fd
,
VIDIOC_S_FMT
,
fmt
)
<
0
)
{
msg_Err
(
obj
,
"cannot set format: %m"
);
return
-
1
;
}
parm
->
parm
.
capture
.
timeperframe
=
best_it
;
if
(
v4l2_ioctl
(
fd
,
VIDIOC_S_PARM
,
parm
)
<
0
)
msg_Warn
(
obj
,
"cannot set streaming parameters: %m"
);
return
0
;
}
...
...
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