From 9bb36ec274da530e509fe2f4010b262c43e812f3 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Tue, 9 Jul 2019 13:56:55 +0300 Subject: libcamera: v4l2_videodevice: Add helper to queue all buffers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When starting the stream on a capture video device it is often needed to queue all the allocated buffers. Add a helper method to do so, and refactor the existing queueBuffer() method to make it clearer. Signed-off-by: Laurent Pinchart Reviewed-by: Niklas Söderlund --- src/libcamera/include/v4l2_videodevice.h | 1 + src/libcamera/pipeline/ipu3/ipu3.cpp | 13 +++---- src/libcamera/v4l2_videodevice.cpp | 62 +++++++++++++++++++++++++++----- 3 files changed, 62 insertions(+), 14 deletions(-) (limited to 'src') diff --git a/src/libcamera/include/v4l2_videodevice.h b/src/libcamera/include/v4l2_videodevice.h index b92df882..2996a609 100644 --- a/src/libcamera/include/v4l2_videodevice.h +++ b/src/libcamera/include/v4l2_videodevice.h @@ -139,6 +139,7 @@ public: int releaseBuffers(); int queueBuffer(Buffer *buffer); + std::vector> queueAllBuffers(); Signal bufferReady; int streamOn(); diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp index 1abd20e5..5a14edb6 100644 --- a/src/libcamera/pipeline/ipu3/ipu3.cpp +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp @@ -131,6 +131,7 @@ public: CameraSensor *sensor_; BufferPool pool_; + std::vector> buffers_; }; class IPU3Stream : public Stream @@ -1430,11 +1431,9 @@ int CIO2Device::start() { int ret; - for (Buffer &buffer : pool_.buffers()) { - ret = output_->queueBuffer(&buffer); - if (ret) - return ret; - } + buffers_ = output_->queueAllBuffers(); + if (buffers_.empty()) + return -EINVAL; ret = output_->streamOn(); if (ret) @@ -1445,7 +1444,9 @@ int CIO2Device::start() int CIO2Device::stop() { - return output_->streamOff(); + int ret = output_->streamOff(); + buffers_.clear(); + return ret; } int CIO2Device::mediaBusToFormat(unsigned int code) diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp index 2d1e87a7..0ab92b3a 100644 --- a/src/libcamera/v4l2_videodevice.cpp +++ b/src/libcamera/v4l2_videodevice.cpp @@ -894,8 +894,8 @@ int V4L2VideoDevice::releaseBuffers() */ int V4L2VideoDevice::queueBuffer(Buffer *buffer) { + struct v4l2_plane v4l2Planes[VIDEO_MAX_PLANES] = {}; struct v4l2_buffer buf = {}; - struct v4l2_plane planes[VIDEO_MAX_PLANES] = {}; int ret; buf.index = buffer->index(); @@ -904,21 +904,20 @@ int V4L2VideoDevice::queueBuffer(Buffer *buffer) buf.field = V4L2_FIELD_NONE; bool multiPlanar = V4L2_TYPE_IS_MULTIPLANAR(buf.type); + const std::vector &planes = buffer->planes(); if (buf.memory == V4L2_MEMORY_DMABUF) { if (multiPlanar) { - for (unsigned int p = 0; - p < buffer->planes().size(); - p++) - planes[p].m.fd = buffer->planes()[p].dmabuf(); + for (unsigned int p = 0; p < planes.size(); ++p) + v4l2Planes[p].m.fd = planes[p].dmabuf(); } else { - buf.m.fd = buffer->planes()[0].dmabuf(); + buf.m.fd = planes[0].dmabuf(); } } if (multiPlanar) { - buf.length = buffer->planes().size(); - buf.m.planes = planes; + buf.length = planes.size(); + buf.m.planes = v4l2Planes; } if (V4L2_TYPE_IS_OUTPUT(bufferType_)) { @@ -944,6 +943,53 @@ int V4L2VideoDevice::queueBuffer(Buffer *buffer) return 0; } +/** + * \brief Queue all buffers into the video device + * + * When starting video capture users of the video device often need to queue + * all allocated buffers to the device. This helper method simplifies the + * implementation of the user by queuing all buffers and returning a vector of + * Buffer instances for each queued buffer. + * + * This method is meant to be used with video capture devices internal to a + * pipeline handler, such as ISP statistics capture devices, or raw CSI-2 + * receivers. For video capture devices facing applications, buffers shall + * instead be queued when requests are received, and for video output devices, + * buffers shall be queued when frames are ready to be output. + * + * The caller shall ensure that the returned buffers vector remains valid until + * all the queued buffers are dequeued, either during capture, or by stopping + * the video device. + * + * Calling this method on an output device or on a device that has buffers + * already queued is an error and will return an empty vector. + * + * \return A vector of queued buffers, which will be empty if an error occurs + */ +std::vector> V4L2VideoDevice::queueAllBuffers() +{ + int ret; + + if (queuedBuffersCount_) + return {}; + + if (V4L2_TYPE_IS_OUTPUT(bufferType_)) + return {}; + + std::vector> buffers; + + for (unsigned int i = 0; i < bufferPool_->count(); ++i) { + Buffer *buffer = new Buffer(); + buffer->index_ = i; + buffers.emplace_back(buffer); + ret = queueBuffer(buffer); + if (ret) + return {}; + } + + return buffers; +} + /** * \brief Dequeue the next available buffer from the video device * -- cgit v1.2.1