[FFmpeg-devel] [PATCH] Add support to video4linux2 framerate auto-set. (original) (raw)
Stefano Sabatini stefano.sabatini-lala
Tue Jan 4 21:52:43 CET 2011
- Previous message: [PATCH] In video4linux2, in the case the timebase value in ap is 0/0, read the timebase value already set in the driver, and set it back in the codec stream, rather than leaving the invalid value of 0/0.
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In particular, fix ffmpeg grabbing timestamps when the timebase value is not set through the CLI.
doc/indevs.texi | 8 ++++++-- libavdevice/v4l2.c | 13 +++++++++++++ 2 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/doc/indevs.texi b/doc/indevs.texi index d345833..ce19f91 100644 --- a/doc/indevs.texi +++ b/doc/indevs.texi @@ -146,6 +146,8 @@ devices and the command @file{v4l-info} for Video4Linux2 devices. If the size for the device is set to 0x0, the input device will try to autodetect the size to use. +Only for the video4linux2 device, if the frame rate is set to 0/0 the +the input device will try to autodetect the frame rate to use. Video4Linux support is deprecated since Linux 2.6.30, and will be dropped in later versions. @@ -153,13 +155,15 @@ dropped in later versions. Follow some usage examples of the video4linux devices with the ff* tools. @example -# Grab and show the input of a video4linux device. +# Grab and show the input of a video4linux device, frame rate is set +# to the default of 25/1 ffplay -s 320x240 -f video4linux /dev/video0 # Grab and show the input of a video4linux2 device, autoadjust size. ffplay -f video4linux2 /dev/video0 -# Grab and record the input of a video4linux2 device, autoadjust size. +# Grab and record the input of a video4linux2 device, autoadjust size +# and frame rate ffmpeg -f video4linux2 -i /dev/video0 out.mpeg @end example diff --git a/libavdevice/v4l2.c b/libavdevice/v4l2.c index 5425928..ec52f07 100644 --- a/libavdevice/v4l2.c +++ b/libavdevice/v4l2.c @@ -601,6 +601,19 @@ static int v4l2_read_header(AVFormatContext *s1, AVFormatParameters *ap) return AVERROR(EINVAL); s->frame_format = desired_format; + if (!ap->time_base.num && !ap->time_base.den) { + struct v4l2_streamparm streamparm = { 0 }; + struct v4l2_fract *tpf = &streamparm.parm.capture.timeperframe; + + streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; + if (ioctl(s->fd, VIDIOC_G_PARM, &streamparm) != 0) { + av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_PARM): %s\n", strerror(errno)); + return AVERROR(errno); + } + ap->time_base.num = tpf->numerator; + ap->time_base.den = tpf->denominator; + } + if (v4l2_set_parameters(s1, ap) < 0) return AVERROR(EIO);
1.7.2.3
- Previous message: [PATCH] In video4linux2, in the case the timebase value in ap is 0/0, read the timebase value already set in the driver, and set it back in the codec stream, rather than leaving the invalid value of 0/0.
- Next message: [FFmpeg-devel] [PATCH] Add support to video4linux2 framerate auto-set.
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