From f1b449476cd82dd391bd8e078fb93181e2ec881c Mon Sep 17 00:00:00 2001 From: Paul Elder Date: Sat, 4 Jul 2020 17:51:27 +0900 Subject: libcamera: V4L2VideoDevice: Add tryFormat Add tryFormat and its variations (meta, single-plane, multi-plane) to V4L2VideoDevice. Signed-off-by: Paul Elder Reviewed-by: Laurent Pinchart Reviewed-by: Jacopo Mondi --- src/libcamera/v4l2_videodevice.cpp | 50 +++++++++++++++++++++++++++++--------- 1 file changed, 38 insertions(+), 12 deletions(-) (limited to 'src/libcamera/v4l2_videodevice.cpp') diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp index 3614b2ed..e0d22012 100644 --- a/src/libcamera/v4l2_videodevice.cpp +++ b/src/libcamera/v4l2_videodevice.cpp @@ -723,6 +723,26 @@ int V4L2VideoDevice::getFormat(V4L2DeviceFormat *format) return getFormatSingleplane(format); } +/** + * \brief Try an image format on the V4L2 video device + * \param[inout] format The image format to test applicability to the video device + * + * Try the supplied \a format on the video device without applying it, returning + * the format that would be applied. This is equivalent to setFormat(), except + * that the device configuration is not changed. + * + * \return 0 on success or a negative error code otherwise + */ +int V4L2VideoDevice::tryFormat(V4L2DeviceFormat *format) +{ + if (caps_.isMeta()) + return trySetFormatMeta(format, false); + else if (caps_.isMultiplanar()) + return trySetFormatMultiplane(format, false); + else + return trySetFormatSingleplane(format, false); +} + /** * \brief Configure an image format on the V4L2 video device * \param[inout] format The image format to apply to the video device @@ -735,11 +755,11 @@ int V4L2VideoDevice::getFormat(V4L2DeviceFormat *format) int V4L2VideoDevice::setFormat(V4L2DeviceFormat *format) { if (caps_.isMeta()) - return setFormatMeta(format); + return trySetFormatMeta(format, true); else if (caps_.isMultiplanar()) - return setFormatMultiplane(format); + return trySetFormatMultiplane(format, true); else - return setFormatSingleplane(format); + return trySetFormatSingleplane(format, true); } int V4L2VideoDevice::getFormatMeta(V4L2DeviceFormat *format) @@ -765,7 +785,7 @@ int V4L2VideoDevice::getFormatMeta(V4L2DeviceFormat *format) return 0; } -int V4L2VideoDevice::setFormatMeta(V4L2DeviceFormat *format) +int V4L2VideoDevice::trySetFormatMeta(V4L2DeviceFormat *format, bool set) { struct v4l2_format v4l2Format = {}; struct v4l2_meta_format *pix = &v4l2Format.fmt.meta; @@ -774,9 +794,11 @@ int V4L2VideoDevice::setFormatMeta(V4L2DeviceFormat *format) v4l2Format.type = bufferType_; pix->dataformat = format->fourcc; pix->buffersize = format->planes[0].size; - ret = ioctl(VIDIOC_S_FMT, &v4l2Format); + ret = ioctl(set ? VIDIOC_S_FMT : VIDIOC_TRY_FMT, &v4l2Format); if (ret) { - LOG(V4L2, Error) << "Unable to set format: " << strerror(-ret); + LOG(V4L2, Error) + << "Unable to " << (set ? "set" : "try") + << " format: " << strerror(-ret); return ret; } @@ -820,7 +842,7 @@ int V4L2VideoDevice::getFormatMultiplane(V4L2DeviceFormat *format) return 0; } -int V4L2VideoDevice::setFormatMultiplane(V4L2DeviceFormat *format) +int V4L2VideoDevice::trySetFormatMultiplane(V4L2DeviceFormat *format, bool set) { struct v4l2_format v4l2Format = {}; struct v4l2_pix_format_mplane *pix = &v4l2Format.fmt.pix_mp; @@ -838,9 +860,11 @@ int V4L2VideoDevice::setFormatMultiplane(V4L2DeviceFormat *format) pix->plane_fmt[i].sizeimage = format->planes[i].size; } - ret = ioctl(VIDIOC_S_FMT, &v4l2Format); + ret = ioctl(set ? VIDIOC_S_FMT : VIDIOC_TRY_FMT, &v4l2Format); if (ret) { - LOG(V4L2, Error) << "Unable to set format: " << strerror(-ret); + LOG(V4L2, Error) + << "Unable to " << (set ? "set" : "try") + << " format: " << strerror(-ret); return ret; } @@ -883,7 +907,7 @@ int V4L2VideoDevice::getFormatSingleplane(V4L2DeviceFormat *format) return 0; } -int V4L2VideoDevice::setFormatSingleplane(V4L2DeviceFormat *format) +int V4L2VideoDevice::trySetFormatSingleplane(V4L2DeviceFormat *format, bool set) { struct v4l2_format v4l2Format = {}; struct v4l2_pix_format *pix = &v4l2Format.fmt.pix; @@ -895,9 +919,11 @@ int V4L2VideoDevice::setFormatSingleplane(V4L2DeviceFormat *format) pix->pixelformat = format->fourcc; pix->bytesperline = format->planes[0].bpl; pix->field = V4L2_FIELD_NONE; - ret = ioctl(VIDIOC_S_FMT, &v4l2Format); + ret = ioctl(set ? VIDIOC_S_FMT : VIDIOC_TRY_FMT, &v4l2Format); if (ret) { - LOG(V4L2, Error) << "Unable to set format: " << strerror(-ret); + LOG(V4L2, Error) + << "Unable to " << (set ? "set" : "try") + << " format: " << strerror(-ret); return ret; } -- cgit v1.2.1