Show a patch.

GET /api/patches/493/?format=api
HTTP 200 OK
Allow: GET, PUT, PATCH, HEAD, OPTIONS
Content-Type: application/json
Vary: Accept

{
    "id": 493,
    "url": "https://patchwork.libcamera.org/api/patches/493/?format=api",
    "web_url": "https://patchwork.libcamera.org/patch/493/",
    "project": {
        "id": 1,
        "url": "https://patchwork.libcamera.org/api/projects/1/?format=api",
        "name": "libcamera",
        "link_name": "libcamera",
        "list_id": "libcamera_core",
        "list_email": "libcamera-devel@lists.libcamera.org",
        "web_url": "",
        "scm_url": "",
        "webscm_url": ""
    },
    "msgid": "<20190203110102.5663-7-kieran.bingham@ideasonboard.com>",
    "date": "2019-02-03T11:00:57",
    "name": "[libcamera-devel,06/11] libcamera: v4l2_device: Implement stream{On, Off}",
    "commit_ref": null,
    "pull_url": null,
    "state": "superseded",
    "archived": false,
    "hash": "9125b1439670e48298a0c77c8084b0fc422438e6",
    "submitter": {
        "id": 4,
        "url": "https://patchwork.libcamera.org/api/people/4/?format=api",
        "name": "Kieran Bingham",
        "email": "kieran.bingham@ideasonboard.com"
    },
    "delegate": null,
    "mbox": "https://patchwork.libcamera.org/patch/493/mbox/",
    "series": [
        {
            "id": 165,
            "url": "https://patchwork.libcamera.org/api/series/165/?format=api",
            "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=165",
            "date": "2019-02-03T11:00:51",
            "name": "libcamera: V4L2 Streams",
            "version": 1,
            "mbox": "https://patchwork.libcamera.org/series/165/mbox/"
        }
    ],
    "comments": "https://patchwork.libcamera.org/api/patches/493/comments/",
    "check": "pending",
    "checks": "https://patchwork.libcamera.org/api/patches/493/checks/",
    "tags": {},
    "headers": {
        "Return-Path": "<kieran.bingham@ideasonboard.com>",
        "Received": [
            "from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 2D24C60B1B\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tSun,  3 Feb 2019 12:01:08 +0100 (CET)",
            "from localhost.localdomain\n\t(218.182-78-194.adsl-static.isp.belgacom.be [194.78.182.218])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id CADFB41;\n\tSun,  3 Feb 2019 12:01:07 +0100 (CET)"
        ],
        "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1549191667;\n\tbh=0fw5UjSZFZh+JNXV5ehFKNSCl3dpJv03wlB0ejGnFxw=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=d4JlOo9nWB+zXVff09eLt7wMSA3D7HqN2nwHd4WcCPLNXCd5OsnQF7KxuxgCgQMa8\n\tbOGOUUKKOWkaaKJ5hQTdfeAAH4GpL+y8wi4qJnrDvcfItzQETKc4+JTotUdbuihAgi\n\tr0Ul37tvl+m+MBPwAHp8ZcppX9PEsnlUEqEvtafM=",
        "From": "Kieran Bingham <kieran.bingham@ideasonboard.com>",
        "To": "LibCamera Devel <libcamera-devel@lists.libcamera.org>",
        "Date": "Sun,  3 Feb 2019 12:00:57 +0100",
        "Message-Id": "<20190203110102.5663-7-kieran.bingham@ideasonboard.com>",
        "X-Mailer": "git-send-email 2.19.1",
        "In-Reply-To": "<20190203110102.5663-1-kieran.bingham@ideasonboard.com>",
        "References": "<20190203110102.5663-1-kieran.bingham@ideasonboard.com>",
        "MIME-Version": "1.0",
        "Content-Transfer-Encoding": "8bit",
        "Subject": "[libcamera-devel] [PATCH 06/11] libcamera: v4l2_device: Implement\n\tstream{On, Off}",
        "X-BeenThere": "libcamera-devel@lists.libcamera.org",
        "X-Mailman-Version": "2.1.23",
        "Precedence": "list",
        "List-Id": "<libcamera-devel.lists.libcamera.org>",
        "List-Unsubscribe": "<https://lists.libcamera.org/options/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=unsubscribe>",
        "List-Archive": "<https://lists.libcamera.org/pipermail/libcamera-devel/>",
        "List-Post": "<mailto:libcamera-devel@lists.libcamera.org>",
        "List-Help": "<mailto:libcamera-devel-request@lists.libcamera.org?subject=help>",
        "List-Subscribe": "<https://lists.libcamera.org/listinfo/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=subscribe>",
        "X-List-Received-Date": "Sun, 03 Feb 2019 11:01:08 -0000"
    },
    "content": "Support starting and stopping a stream on a V4L2 device. This requires\nhaving buffers queued, thus both queueBuffer() and dequeueBuffer() are\nalso added.\n\nSigned-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>\n---\n src/libcamera/include/v4l2_device.h |   6 ++\n src/libcamera/v4l2_device.cpp       | 134 ++++++++++++++++++++++++++++\n 2 files changed, 140 insertions(+)",
    "diff": "diff --git a/src/libcamera/include/v4l2_device.h b/src/libcamera/include/v4l2_device.h\nindex f445f98f97a4..d3dad355be58 100644\n--- a/src/libcamera/include/v4l2_device.h\n+++ b/src/libcamera/include/v4l2_device.h\n@@ -101,6 +101,12 @@ public:\n \n \tBufferPool *requestBuffers(unsigned int qty = 8);\n \n+\tint queueBuffer(Buffer *frame);\n+\tBuffer *dequeueBuffer();\n+\n+\tint streamOn();\n+\tint streamOff();\n+\n private:\n \tint getFormatSingleplane(V4L2DeviceFormat *fmt);\n \tint setFormatSingleplane(V4L2DeviceFormat *fmt);\ndiff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp\nindex 728478a1ae8f..1fd289137b36 100644\n--- a/src/libcamera/v4l2_device.cpp\n+++ b/src/libcamera/v4l2_device.cpp\n@@ -592,4 +592,138 @@ int V4L2Device::setFormatMultiplane(V4L2DeviceFormat *fmt)\n \treturn 0;\n }\n \n+/**\n+ * \\brief Queue a buffer into the device.\n+ *\n+ * For Capture devices the buffer will be operated on and can be dequeued later\n+ * with active data.\n+ *\n+ * For Output devices the buffer should contain valid data and will be processed\n+ * by the receiving device. The buffer will be available to dequeue when it is\n+ * no longer in use by the Output device.\n+ *\n+ * \\return 0 if the operation completes or a negative error number otherwise\n+ */\n+int V4L2Device::queueBuffer(Buffer *frame)\n+{\n+\tstruct v4l2_buffer buf = {};\n+\tstruct v4l2_plane planes[VIDEO_MAX_PLANES] = {};\n+\tint ret;\n+\n+\tbuf.index = frame->index();\n+\tbuf.type = bufferType_;\n+\tbuf.memory = memoryType_;\n+\n+\tif (V4L2_TYPE_IS_MULTIPLANAR(buf.type)) {\n+\t\tbuf.length = frame->planes().size();\n+\t\tbuf.m.planes = planes;\n+\t}\n+\n+\tLOG(V4L2, Debug) << \"Queueing buffer idx: \" << buf.index;\n+\n+\tret = ioctl(fd_, VIDIOC_QBUF, &buf);\n+\tif (ret < 0) {\n+\t\tret = -errno;\n+\t\tLOG(V4L2, Error)\n+\t\t\t<< \"Failed to queue buffer: \" << strerror(-ret);\n+\t\treturn ret;\n+\t}\n+\n+\treturn 0;\n+}\n+\n+/**\n+ * \\brief dequeue a buffer from the device\n+ *\n+ * For Capture devices the buffer will be contain valid data and can be used for\n+ * further processing. The buffer should be re-queued when it is no longer in\n+ * use.\n+ *\n+ * For Output devices the buffer has been processed by the hardware and can now\n+ * be freely re-used.\n+ *\n+ * \\return A Buffer pointer if the operation completes or a nullptr otherwise\n+ */\n+Buffer *V4L2Device::dequeueBuffer()\n+{\n+\tstruct v4l2_buffer buf = {};\n+\tstruct v4l2_plane planes[VIDEO_MAX_PLANES] = {};\n+\tint ret;\n+\n+\tbuf.type = bufferType_;\n+\tbuf.memory = memoryType_;\n+\n+\tif (V4L2_TYPE_IS_MULTIPLANAR(buf.type)) {\n+\t\tbuf.length = VIDEO_MAX_PLANES;\n+\t\tbuf.m.planes = planes;\n+\t}\n+\n+\tret = ioctl(fd_, VIDIOC_DQBUF, &buf);\n+\tif (ret < 0) {\n+\t\tret = -errno;\n+\t\tLOG(V4L2, Error)\n+\t\t\t<< \"Failed to dequeue buffer: \" << strerror(-ret);\n+\t\treturn nullptr;\n+\t}\n+\n+\tif (buf.index >= bufferPool_->buffers().size()) {\n+\t\tLOG(V4L2, Error) << \"Invalid buffer index dequeued\";\n+\t\treturn nullptr;\n+\t}\n+\n+\treturn bufferPool_->buffers()[buf.index];\n+}\n+\n+/**\n+ * \\brief Request that the V4L2Device commences streaming\n+ *\n+ * Prepares the device to start processing Buffers, and connects the completion\n+ * handler to the bufferAvailable Slot.\n+ *\n+ * \\return 0 if the operation completes or a negative error number otherwise\n+ */\n+int V4L2Device::streamOn()\n+{\n+\tint ret;\n+\n+\tif (caps_.isCapture()) {\n+\t\tfor (Buffer *b : bufferPool_->buffers()) {\n+\t\t\tret = queueBuffer(b);\n+\t\t\tif (ret)\n+\t\t\t\treturn ret;\n+\t\t}\n+\t}\n+\n+\tret = ioctl(fd_, VIDIOC_STREAMON, &bufferType_);\n+\tif (ret < 0) {\n+\t\tret = -errno;\n+\t\tLOG(V4L2, Error)\n+\t\t\t<< \"Failed to start streaming: \" << strerror(-ret);\n+\t\treturn ret;\n+\t}\n+\n+\treturn 0;\n+}\n+\n+/**\n+ * \\brief Request that the V4L2Device stops streaming\n+ *\n+ * Asks the device to halt any current streaming operations.\n+ *\n+ * \\return 0 if the operation completes or a negative error number otherwise\n+ */\n+int V4L2Device::streamOff()\n+{\n+\tint ret;\n+\n+\tret = ioctl(fd_, VIDIOC_STREAMOFF, &bufferType_);\n+\tif (ret < 0) {\n+\t\tLOG(V4L2, Error)\n+\t\t\t<< \"Failed to stop streaming: \" << strerror(errno);\n+\t\treturn ret;\n+\t}\n+\n+\treturn 0;\n+}\n+\n } /* namespace libcamera */\n",
    "prefixes": [
        "libcamera-devel",
        "06/11"
    ]
}