diff options
| author | Giorgio Vazzana <mywing81@gmail.com> | 2013-03-19 19:09:38 +0100 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2013-03-23 13:43:56 +0100 |
| commit | 785b849f1c231698ba66468bc35c393fa99b270c (patch) | |
| tree | 70584e8a05a5a08086a8355e1b07ddddd80cfaf4 | |
| parent | 2a97c5915b8f7ef8048c934b2047912873719568 (diff) | |
| download | ffmpeg-785b849f1c231698ba66468bc35c393fa99b270c.tar.gz | |
lavd/v4l2: honor previously selected input channel
An input channel could have been previously set with another application, like
v4l2-ctl, so if no input channel is specified use the previosly selected one.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
| -rw-r--r-- | doc/indevs.texi | 3 | ||||
| -rw-r--r-- | libavdevice/v4l2.c | 26 |
2 files changed, 20 insertions, 9 deletions
diff --git a/doc/indevs.texi b/doc/indevs.texi index cc5d66622c..63104e22ed 100644 --- a/doc/indevs.texi +++ b/doc/indevs.texi @@ -640,7 +640,8 @@ list of the supported standards, use the @option{list_standards} option. @item channel -Set the input channel number. Default to 0. +Set the input channel number. Default to -1, which means using the +previously selected channel. @item video_size Set the video frame size. The argument must be a string in the form diff --git a/libavdevice/v4l2.c b/libavdevice/v4l2.c index 2d7773a607..c041424952 100644 --- a/libavdevice/v4l2.c +++ b/libavdevice/v4l2.c @@ -894,14 +894,24 @@ static int v4l2_read_header(AVFormatContext *s1) if (s->fd < 0) return s->fd; - /* set tv video input */ - av_log(s1, AV_LOG_DEBUG, "Selecting input_channel: %d\n", s->channel); - if (v4l2_ioctl(s->fd, VIDIOC_S_INPUT, &s->channel) < 0) { - res = AVERROR(errno); - av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_S_INPUT): %s\n", av_err2str(res)); - return res; + if (s->channel != -1) { + /* set video input */ + av_log(s1, AV_LOG_DEBUG, "Selecting input_channel: %d\n", s->channel); + if (v4l2_ioctl(s->fd, VIDIOC_S_INPUT, &s->channel) < 0) { + res = AVERROR(errno); + av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_S_INPUT): %s\n", av_err2str(res)); + return res; + } + } else { + /* get current video input */ + if (v4l2_ioctl(s->fd, VIDIOC_G_INPUT, &s->channel) < 0) { + res = AVERROR(errno); + av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_INPUT): %s\n", av_err2str(res)); + return res; + } } + /* enum input */ input.index = s->channel; if (v4l2_ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) { res = AVERROR(errno); @@ -909,7 +919,7 @@ static int v4l2_read_header(AVFormatContext *s1) return res; } s->std_id = input.std; - av_log(s1, AV_LOG_DEBUG, "input_channel: %d, input_name: %s\n", + av_log(s1, AV_LOG_DEBUG, "Current input_channel: %d, input_name: %s\n", s->channel, input.name); if (s->list_format) { @@ -1045,7 +1055,7 @@ static int v4l2_read_close(AVFormatContext *s1) static const AVOption options[] = { { "standard", "set TV standard, used only by analog frame grabber", OFFSET(standard), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, DEC }, - { "channel", "set TV channel, used only by frame grabber", OFFSET(channel), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, DEC }, + { "channel", "set TV channel, used only by frame grabber", OFFSET(channel), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, INT_MAX, DEC }, { "video_size", "set frame size", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, DEC }, { "pixel_format", "set preferred pixel format", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC }, { "input_format", "set preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC }, |