diff --git a/doc/indevs.texi b/doc/indevs.texi index d34583326d..8e862ff6bc 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 +input device will use the frame rate value already set in the driver. Video4Linux support is deprecated since Linux 2.6.30, and will be dropped in later versions. @@ -153,13 +155,16 @@ 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, +# frame rate value defaults to 0/0 so it is read from the video4linux2 +# driver. ffmpeg -f video4linux2 -i /dev/video0 out.mpeg @end example diff --git a/libavdevice/avdevice.h b/libavdevice/avdevice.h index 9508f2277f..5c3739fdcd 100644 --- a/libavdevice/avdevice.h +++ b/libavdevice/avdevice.h @@ -23,7 +23,7 @@ #define LIBAVDEVICE_VERSION_MAJOR 52 #define LIBAVDEVICE_VERSION_MINOR 2 -#define LIBAVDEVICE_VERSION_MICRO 2 +#define LIBAVDEVICE_VERSION_MICRO 3 #define LIBAVDEVICE_VERSION_INT AV_VERSION_INT(LIBAVDEVICE_VERSION_MAJOR, \ LIBAVDEVICE_VERSION_MINOR, \ diff --git a/libavdevice/v4l2.c b/libavdevice/v4l2.c index 54259284af..26f879a509 100644 --- a/libavdevice/v4l2.c +++ b/libavdevice/v4l2.c @@ -514,6 +514,19 @@ static int v4l2_set_parameters(AVFormatContext *s1, AVFormatParameters *ap) ap->time_base.num = tpf->numerator; ap->time_base.den = tpf->denominator; } + } else { + /* if timebase value is not set in ap, read the timebase value + * from the driver and set it in ap */ + 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; } return 0;