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Commit 590f52e6 authored by Rémi Denis-Courmont's avatar Rémi Denis-Courmont
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v4l2: rewrite frame rate and resolution negotiation 

 * Enumerate frame sizes once rather than twice.
 * Do not enumerate frame rates if not supported.
 * Get actual frame rate from the device driverr.
 * Get exact fractional frame rate rather than round to single precision
   floating point.

Notes:
 * --v4l2-fps becomes totally redumdant. It should probably be redefined
   to select a maximum capture frame rate.
 * --v4l2-width and --v4l2-height are ignored. This is a regression.
   Maybe they should be redefined as maxima as well as --v4l2-fps.
parent 2a9b79e4
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Showing with 236 additions and 252 deletions
modules/access/v4l2/demux.c
View file @ 590f52e6
......@@ -338,66 +338,20 @@ static int InitVideo (demux_t *demux, int fd)
msg_Dbg (demux, "selected format %4.4s (%4.4s)",
(const char *)&selected->v4l2, (const char *)&selected->vlc);
struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
if (v4l2_ioctl (fd, VIDIOC_G_FMT, &fmt) < 0)
{
msg_Err (demux, "cannot get device default format: %m");
/* Find best resolution and frame rate available */
struct v4l2_format fmt;
struct v4l2_streamparm parm;
if (SetupFormat (demux, fd, selected->v4l2, &fmt, &parm))
return -1;
}
fmt.fmt.pix.pixelformat = selected->v4l2;
#if 0
uint32_t width = var_InheritInteger (demux, CFG_PREFIX"width");
if (width != (uint32_t)-1)
fmt.fmt.pix.width = width; /* override width */
uint32_t height = var_InheritInteger (demux, CFG_PREFIX"height");
if (height != (uint32_t)-1)
fmt.fmt.pix.height = height; /* override height */
if (v4l2_ioctl (fd, VIDIOC_S_FMT, &fmt) < 0)
{
msg_Err (demux, "cannot set format: %m");
return -1;
}
/* Try and find default resolution if not specified */
float fps = 0.;
if (width == (uint32_t)-1 || height == (uint32_t)-1)
{
fps = var_InheritFloat (demux, CFG_PREFIX"fps");
if (fps <= 0.)
{
fps = GetAbsoluteMaxFrameRate (VLC_OBJECT(demux), fd,
fmt.fmt.pix.pixelformat);
msg_Dbg (demux, "Found maximum framerate of %f", fps);
}
uint32_t i_width, i_height;
GetMaxDimensions (VLC_OBJECT(demux), fd, fmt.fmt.pix.pixelformat, fps,
&i_width, &i_height);
if (i_width || i_height)
{
msg_Dbg (demux, "Found optimal dimensions for framerate %f "
"of %ux%u", fps, i_width, i_height);
fmt.fmt.pix.width = i_width;
fmt.fmt.pix.height = i_height;
if (v4l2_ioctl (fd, VIDIOC_S_FMT, &fmt) < 0)
{
msg_Err (demux, "Cannot set size to optimal dimensions %ux%u",
i_width, i_height);
return -1;
}
}
else
{
msg_Warn (demux, "Could not find optimal width and height, "
"falling back to driver default.");
}
}
width = fmt.fmt.pix.width;
height = fmt.fmt.pix.height;
if (v4l2_ioctl (fd, VIDIOC_G_FMT, &fmt) < 0) {;}
#endif
/* Print extra info */
msg_Dbg (demux, "%d bytes maximum for complete image",
......@@ -429,7 +383,7 @@ static int InitVideo (demux_t *demux, int fd)
break;
case V4L2_FIELD_ALTERNATE:
msg_Dbg (demux, "Interlacing setting: alternate fields (TODO)");
height *= 2;
fmt.fmt.pix.height *= 2;
break;
case V4L2_FIELD_INTERLACED_TB:
msg_Dbg (demux, "Interlacing setting: interleaved top bottom");
......@@ -445,12 +399,35 @@ static int InitVideo (demux_t *demux, int fd)
break;
}
/* Look up final fourcc */
/* Declare our unique elementary (video) stream */
es_format_t es_fmt;
es_format_Init (&es_fmt, VIDEO_ES, selected->vlc);
es_fmt.video.i_rmask = selected->red;
es_fmt.video.i_gmask = selected->green;
es_fmt.video.i_bmask = selected->blue;
es_fmt.video.i_width = fmt.fmt.pix.width;
es_fmt.video.i_height = fmt.fmt.pix.height;
es_fmt.video.i_frame_rate = parm.parm.capture.timeperframe.denominator;
es_fmt.video.i_frame_rate_base = parm.parm.capture.timeperframe.numerator;
int ar = 4 * VOUT_ASPECT_FACTOR / 3;
char *str = var_InheritString (demux, CFG_PREFIX"aspect-ratio");
if (likely(str != NULL))
{
const char *delim = strchr (str, ':');
if (delim != NULL)
ar = atoi (str) * VOUT_ASPECT_FACTOR / atoi (delim + 1);
free (str);
}
es_fmt.video.i_sar_num = ar * es_fmt.video.i_height;
es_fmt.video.i_sar_den = VOUT_ASPECT_FACTOR * es_fmt.video.i_width;
msg_Dbg (demux, "added new video es %4.4s %dx%d", (char *)&es_fmt.i_codec,
es_fmt.video.i_width, es_fmt.video.i_height);
msg_Dbg (demux, " frame rate: %u/%u", es_fmt.video.i_frame_rate,
es_fmt.video.i_frame_rate_base);
sys->p_es = es_out_Add (demux->out, &es_fmt);
/* Init I/O method */
switch (sys->io)
......@@ -489,33 +466,6 @@ static int InitVideo (demux_t *demux, int fd)
assert (0);
}
int ar = 4 * VOUT_ASPECT_FACTOR / 3;
char *str = var_InheritString (demux, CFG_PREFIX"aspect-ratio");
if (likely(str != NULL))
{
const char *delim = strchr (str, ':');
if (delim != NULL)
ar = atoi (str) * VOUT_ASPECT_FACTOR / atoi (delim + 1);
free (str);
}
/* Add */
es_fmt.video.i_width = width;
es_fmt.video.i_height = height;
/* Get aspect-ratio */
es_fmt.video.i_sar_num = ar * es_fmt.video.i_height;
es_fmt.video.i_sar_den = VOUT_ASPECT_FACTOR * es_fmt.video.i_width;
/* Framerate */
es_fmt.video.i_frame_rate = lround (fps * 1000000.);
es_fmt.video.i_frame_rate_base = 1000000;
msg_Dbg (demux, "added new video es %4.4s %dx%d", (char *)&es_fmt.i_codec,
es_fmt.video.i_width, es_fmt.video.i_height);
msg_Dbg (demux, " frame rate: %f", fps);
sys->p_es = es_out_Add (demux->out, &es_fmt);
return 0;
}
......@@ -660,174 +610,3 @@ static int Demux( demux_t *demux )
es_out_Send( demux->out, sys->p_es, block );
return 1;
}
static float GetMaxFPS( vlc_object_t *obj, int fd, uint32_t pixel_format,
uint32_t width, uint32_t height )
{
#ifdef VIDIOC_ENUM_FRAMEINTERVALS
/* This is new in Linux 2.6.19 */
struct v4l2_frmivalenum fie = {
.pixel_format = pixel_format,
.width = width,
.height = height,
};
if( v4l2_ioctl( fd, VIDIOC_ENUM_FRAMEINTERVALS, &fie ) < 0 )
return -1.;
switch( fie.type )
{
case V4L2_FRMIVAL_TYPE_DISCRETE:
{
float max = -1.;
do
{
float fps = (float)fie.discrete.denominator
/ (float)fie.discrete.numerator;
if( fps > max )
max = fps;
msg_Dbg( obj, " discrete frame interval %"PRIu32"/%"PRIu32
" supported",
fie.discrete.numerator, fie.discrete.denominator );
fie.index++;
} while( v4l2_ioctl( fd, VIDIOC_ENUM_FRAMEINTERVALS, &fie ) >= 0 );
return max;
}
case V4L2_FRMIVAL_TYPE_STEPWISE:
case V4L2_FRMIVAL_TYPE_CONTINUOUS:
msg_Dbg( obj, " frame intervals from %"PRIu32"/%"PRIu32
"to %"PRIu32"/%"PRIu32" supported",
fie.stepwise.min.numerator, fie.stepwise.min.denominator,
fie.stepwise.max.numerator, fie.stepwise.max.denominator );
if( fie.type == V4L2_FRMIVAL_TYPE_STEPWISE )
msg_Dbg( obj, " with %"PRIu32"/%"PRIu32" step",
fie.stepwise.step.numerator,
fie.stepwise.step.denominator );
return __MAX( (float)fie.stepwise.max.denominator
/ (float)fie.stepwise.max.numerator,
(float)fie.stepwise.min.denominator
/ (float)fie.stepwise.min.numerator );
}
#endif
return -1.;
}
float GetAbsoluteMaxFrameRate( vlc_object_t *obj, int fd,
uint32_t pixel_format )
{
#ifdef VIDIOC_ENUM_FRAMESIZES
/* This is new in Linux 2.6.19 */
struct v4l2_frmsizeenum fse = {
.pixel_format = pixel_format
};
if( v4l2_ioctl( fd, VIDIOC_ENUM_FRAMESIZES, &fse ) < 0 )
return -1.;
float max = -1.;
switch( fse.type )
{
case V4L2_FRMSIZE_TYPE_DISCRETE:
do
{
float fps = GetMaxFPS( obj, fd, pixel_format,
fse.discrete.width, fse.discrete.height );
if( fps > max )
max = fps;
fse.index++;
} while( v4l2_ioctl( fd, VIDIOC_ENUM_FRAMESIZES, &fse ) >= 0 );
break;
case V4L2_FRMSIZE_TYPE_STEPWISE:
case V4L2_FRMSIZE_TYPE_CONTINUOUS:
msg_Dbg( obj, " sizes from %"PRIu32"x%"PRIu32" "
"to %"PRIu32"x%"PRIu32" supported",
fse.stepwise.min_width, fse.stepwise.min_height,
fse.stepwise.max_width, fse.stepwise.max_height );
if( fse.type == V4L2_FRMSIZE_TYPE_STEPWISE )
msg_Dbg( obj, " with %"PRIu32"x%"PRIu32" steps",
fse.stepwise.step_width, fse.stepwise.step_height );
for( uint32_t width = fse.stepwise.min_width;
width <= fse.stepwise.max_width;
width += fse.stepwise.step_width )
for( uint32_t height = fse.stepwise.min_height;
height <= fse.stepwise.max_width;
height += fse.stepwise.step_height )
{
float fps = GetMaxFPS( obj, fd, pixel_format, width, height );
if( fps > max )
max = fps;
}
break;
}
return max;
#else
return -1.;
#endif
}
void GetMaxDimensions( vlc_object_t *obj, int fd, uint32_t pixel_format,
float fps_min, uint32_t *pwidth, uint32_t *pheight )
{
*pwidth = 0;
*pheight = 0;
#ifdef VIDIOC_ENUM_FRAMESIZES
/* This is new in Linux 2.6.19 */
struct v4l2_frmsizeenum fse = {
.pixel_format = pixel_format
};
if( v4l2_ioctl( fd, VIDIOC_ENUM_FRAMESIZES, &fse ) < 0 )
return;
switch( fse.type )
{
case V4L2_FRMSIZE_TYPE_DISCRETE:
do
{
msg_Dbg( obj, " discrete size %"PRIu32"x%"PRIu32" supported",
fse.discrete.width, fse.discrete.height );
float fps = GetMaxFPS( obj, fd, pixel_format,
fse.discrete.width, fse.discrete.height );
if( fps >= fps_min && fse.discrete.width > *pwidth )
{
*pwidth = fse.discrete.width;
*pheight = fse.discrete.height;
}
fse.index++;
}
while( v4l2_ioctl( fd, VIDIOC_ENUM_FRAMESIZES, &fse ) >= 0 );
break;
case V4L2_FRMSIZE_TYPE_STEPWISE:
case V4L2_FRMSIZE_TYPE_CONTINUOUS:
msg_Dbg( obj, " sizes from %"PRIu32"x%"PRIu32" "
"to %"PRIu32"x%"PRIu32" supported",
fse.stepwise.min_width, fse.stepwise.min_height,
fse.stepwise.max_width, fse.stepwise.max_height );
if( fse.type == V4L2_FRMSIZE_TYPE_STEPWISE )
msg_Dbg( obj, " with %"PRIu32"x%"PRIu32" steps",
fse.stepwise.step_width, fse.stepwise.step_height );
for( uint32_t width = fse.stepwise.min_width;
width <= fse.stepwise.max_width;
width += fse.stepwise.step_width )
for( uint32_t height = fse.stepwise.min_height;
height <= fse.stepwise.max_width;
height += fse.stepwise.step_height )
{
float fps = GetMaxFPS( obj, fd, pixel_format, width, height );
if( fps >= fps_min && width > *pwidth )
{
*pwidth = width;
*pheight = height;
}
}
break;
}
#endif
}
modules/access/v4l2/v4l2.h
View file @ 590f52e6
......@@ -103,6 +103,11 @@ struct buffer_t
/* video.c */
void ParseMRL(vlc_object_t *, const char *);
int SetupInput (vlc_object_t *, int fd);
int SetupFormat (vlc_object_t *, int, uint32_t,
struct v4l2_format *, struct v4l2_streamparm *);
#define SetupFormat(o,fd,fcc,fmt,p) \
SetupFormat(VLC_OBJECT(o),fd,fcc,fmt,p)
int InitMmap (vlc_object_t *, demux_sys_t *, int);
block_t* GrabVideo(vlc_object_t *, demux_sys_t *);
......
modules/access/v4l2/video.c
View file @ 590f52e6
......@@ -760,6 +760,206 @@ int SetupInput (vlc_object_t *obj, int fd)
return 0;
}
/** Compares two V4L2 fractions. */
static int64_t fcmp (struct v4l2_fract a, struct v4l2_fract b)
{
return (uint64_t)a.numerator * b.denominator
- (uint64_t)b.numerator * a.denominator;
}
/**
* Finds the highest frame rate possible of a certain V4L2 format.
* @param fmt V4L2 capture format [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)
{
struct v4l2_frmivalenum fie = {
.pixel_format = fmt->fmt.pix.pixelformat,
.width = fmt->fmt.pix.width,
.height = fmt->fmt.pix.height,
};
/* Mind that maximum rate means minimum interval */
struct v4l2_fract min = { 1, 0 }; /* infinity */
if (v4l2_ioctl (fd, VIDIOC_ENUM_FRAMEINTERVALS, &fie) < 0)
{
msg_Dbg (obj, " unknown frame internals: %m");
return -1;
}
switch (fie.type)
{
case V4L2_FRMIVAL_TYPE_DISCRETE:
do
{
if (fcmp (fie.discrete, min) < 0)
min = fie.discrete;
msg_Dbg (obj, " discrete frame interval: %"PRIu32"/%"PRIu32,
fie.discrete.numerator, fie.discrete.denominator);
fie.index++;
}
while (v4l2_ioctl (fd, VIDIOC_ENUM_FRAMEINTERVALS, &fie) >= 0);
msg_Dbg (obj, " best discrete frame interval: %"PRIu32"/%"PRIu32,
min.numerator, min.denominator);
break;
case V4L2_FRMIVAL_TYPE_STEPWISE:
case V4L2_FRMIVAL_TYPE_CONTINUOUS:
msg_Dbg (obj, " frame intervals from %"PRIu32"/%"PRIu32
"to %"PRIu32"/%"PRIu32" supported",
fie.stepwise.min.numerator, fie.stepwise.min.denominator,
fie.stepwise.max.numerator, fie.stepwise.max.denominator);
if (fie.type == V4L2_FRMIVAL_TYPE_STEPWISE)
msg_Dbg (obj, " with %"PRIu32"/%"PRIu32" step",
fie.stepwise.step.numerator,
fie.stepwise.step.denominator);
min = fie.stepwise.min;
break;
}
*it = min;
return 0;
}
#undef SetupFormat
/**
* Finds the best possible frame rate and resolution.
* @param fourcc pixel format
* @param fmt V4L2 capture format [OUT]
* @param parm V4L2 capture streaming parameters [OUT]
* @return 0 on success, -1 on failure.
*/
int SetupFormat (vlc_object_t *obj, int fd, uint32_t fourcc,
struct v4l2_format *restrict fmt,
struct v4l2_streamparm *restrict parm)
{
memset (fmt, 0, sizeof (*fmt));
fmt->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
memset (parm, 0, sizeof (*parm));
parm->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
if (v4l2_ioctl (fd, VIDIOC_G_FMT, fmt) < 0)
{
msg_Err (obj, "cannot get default format: %m");
return -1;
}
fmt->fmt.pix.pixelformat = fourcc;
if (v4l2_ioctl (fd, VIDIOC_G_PARM, parm) < 0)
{
msg_Err (obj, "cannot get streaming parameters: %m");
return -1;
}
struct v4l2_frmsizeenum fse = {
.pixel_format = fourcc,
};
struct v4l2_fract best_it = { 1, 0 }; /* infinity */
uint64_t best_area = 0;
if (v4l2_ioctl (fd, VIDIOC_ENUM_FRAMESIZES, &fse) < 0)
{
/* Fallback to current format, try to maximize frame rate */
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);
}
}
else
switch (fse.type)
{
case V4L2_FRMSIZE_TYPE_DISCRETE:
do
{
struct v4l2_fract cur_it;
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;
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))
{
best_it = cur_it;
best_area = area;
fmt->fmt.pix.width = fse.discrete.width;
fmt->fmt.pix.height = fse.discrete.height;
}
fse.index++;
}
while (v4l2_ioctl (fd, VIDIOC_ENUM_FRAMESIZES, &fse) >= 0);
msg_Dbg (obj, " best discrete frame size: %"PRIu32"x%"PRIu32,
fmt->fmt.pix.width, fmt->fmt.pix.height);
break;
case V4L2_FRMSIZE_TYPE_STEPWISE:
case V4L2_FRMSIZE_TYPE_CONTINUOUS:
msg_Dbg (obj, " frame sizes from %"PRIu32"x%"PRIu32" to "
"%"PRIu32"x%"PRIu32" supported",
fse.stepwise.min_width, fse.stepwise.min_height,
fse.stepwise.max_width, fse.stepwise.max_height);
if (fse.type == V4L2_FRMSIZE_TYPE_STEPWISE)
msg_Dbg (obj, " with %"PRIu32"x%"PRIu32" steps",
fse.stepwise.step_width, fse.stepwise.step_height);
/* FIXME: slow and dumb */
for (uint32_t width = fse.stepwise.min_width;
width <= fse.stepwise.max_width;
width += fse.stepwise.step_width)
for (uint32_t height = fse.stepwise.min_height;
height <= fse.stepwise.max_width;
height += fse.stepwise.step_height)
{
struct v4l2_fract cur_it;
if (FindMaxRate (obj, fd, fmt, &cur_it))
continue;
int64_t c = fcmp (cur_it, best_it);
uint64_t area = width * height;
if (c < 0 || (c == 0 && area > best_area))
{
best_it = cur_it;
best_area = area;
fmt->fmt.pix.width = width;
fmt->fmt.pix.height = height;
}
}
msg_Dbg (obj, " best frame size: %"PRIu32"x%"PRIu32,
fmt->fmt.pix.width, fmt->fmt.pix.height);
break;
}
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;
}
/*****************************************************************************
* GrabVideo: Grab a video frame
*****************************************************************************/
......
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