[Camera] Revert Create Video Pipeline change (#40619)
* Revert Create Video Pipeline change
* Update examples/camera-app/linux/src/camera-device.cpp
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
* Address gemini comments
---------
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
diff --git a/examples/camera-app/linux/src/camera-device.cpp b/examples/camera-app/linux/src/camera-device.cpp
index 2d1b4bb..181d7ed 100644
--- a/examples/camera-app/linux/src/camera-device.cpp
+++ b/examples/camera-app/linux/src/camera-device.cpp
@@ -416,24 +416,19 @@
return nullptr; // Here to avoid compiler warnings, should never reach this point.
}
-// Helper function to create a GStreamer pipeline
+// Helper function to create a GStreamer pipeline that ingests MJPEG frames coming
+// from the camera, converted to H.264, and sent to media controller via app sink.
GstElement * CameraDevice::CreateVideoPipeline(const std::string & device, int width, int height, int framerate,
CameraError & error)
{
- width = 640;
- height = 480;
- framerate = 30;
- GstElement * pipeline = gst_pipeline_new("video-pipeline");
- GstElement * capsfilter1 = gst_element_factory_make("capsfilter", "filter1");
- ;
+ GstElement * pipeline = gst_pipeline_new("video-pipeline");
+ GstElement * capsfilter = gst_element_factory_make("capsfilter", "mjpeg_caps");
+ GstElement * jpegdec = gst_element_factory_make("jpegdec", "jpegdec");
GstElement * videoconvert = gst_element_factory_make("videoconvert", "videoconvert");
- GstElement * capsfilter2 = gst_element_factory_make("capsfilter", "filter2");
GstElement * x264enc = gst_element_factory_make("x264enc", "encoder");
GstElement * rtph264pay = gst_element_factory_make("rtph264pay", "rtph264");
GstElement * appsink = gst_element_factory_make("appsink", "appsink");
GstElement * source = nullptr;
- GstCaps * caps1 = nullptr;
- GstCaps * caps2 = nullptr;
#ifdef AV_STREAM_GST_USE_TEST_SRC
source = gst_element_factory_make("videotestsrc", "source");
@@ -447,9 +442,9 @@
const std::vector<std::pair<GstElement *, const char *>> elements = {
{ pipeline, "pipeline" }, //
{ source, "source" }, //
- { capsfilter1, "filter1" }, //
+ { capsfilter, "mjpeg_caps" }, //
+ { jpegdec, "jpegdec" }, //
{ videoconvert, "videoconvert" }, //
- { capsfilter2, "filter2" }, //
{ x264enc, "encoder" }, //
{ rtph264pay, "rtph264" }, //
{ appsink, "appsink" } //
@@ -461,16 +456,30 @@
{
ChipLogError(Camera, "Not all elements could be created.");
// Unreference the elements that were created
- GstreamerPipepline::unrefGstElements(pipeline, source, capsfilter1, videoconvert, capsfilter2, x264enc, rtph264pay,
- appsink);
+ GstreamerPipepline::unrefGstElements(pipeline, source, capsfilter, jpegdec, videoconvert, x264enc, rtph264pay, appsink);
+
error = CameraError::ERROR_INIT_FAILED;
return nullptr;
}
- gst_bin_add_many(GST_BIN(pipeline), source, capsfilter1, videoconvert, capsfilter2, x264enc, appsink, nullptr);
+ // Camera caps request: MJPEG @ WxH @ fps
+ GstCaps * caps = gst_caps_new_simple("image/jpeg", "width", G_TYPE_INT, width, "height", G_TYPE_INT, height, "framerate",
+ GST_TYPE_FRACTION, framerate, 1, nullptr);
+ g_object_set(capsfilter, "caps", caps, nullptr);
+ gst_caps_unref(caps);
- // Link elements: source -> capsfilter1 -> videoconvert -> capsfilter2 -> x264enc -> udpsink
- if (!gst_element_link_many(source, capsfilter1, videoconvert, capsfilter2, x264enc, appsink, nullptr))
+ // Configure encoder for low-latency
+ gst_util_set_object_arg(G_OBJECT(x264enc), "tune", "zerolatency");
+ g_object_set(G_OBJECT(x264enc), "key-int-max", static_cast<guint>(framerate), nullptr);
+
+ // Configure appsink for receiving H.264 RTP data
+ g_object_set(appsink, "emit-signals", TRUE, "sync", FALSE, "async", FALSE, nullptr);
+
+ // Build pipeline: v4l2src → capsfilter → jpegdec → videoconvert → x264enc → rtph264pay → appsink
+ gst_bin_add_many(GST_BIN(pipeline), source, capsfilter, jpegdec, videoconvert, x264enc, rtph264pay, appsink, nullptr);
+
+ // Link the elements
+ if (!gst_element_link_many(source, capsfilter, jpegdec, videoconvert, x264enc, rtph264pay, appsink, nullptr))
{
ChipLogError(Camera, "CreateVideoPipeline: link failed");
@@ -480,21 +489,6 @@
return nullptr;
}
- caps1 = gst_caps_new_simple("video/x-raw", "width", G_TYPE_INT, width, "height", G_TYPE_INT, height, "framerate",
- GST_TYPE_FRACTION, framerate, 1, nullptr);
- g_object_set(capsfilter1, "caps", caps1, nullptr);
- gst_caps_unref(caps1);
-
- // Enforce I420 output
- caps2 = gst_caps_new_simple("video/x-raw", "format", G_TYPE_STRING, "I420", nullptr);
- g_object_set(capsfilter2, "caps", caps2, NULL);
- gst_caps_unref(caps2);
-
- // Add elements in new order
- g_object_set(x264enc, "tune", "zerolatency", "key-int-max", framerate * 1, "profile", "high", NULL);
-
- g_object_set(appsink, "emit-signals", TRUE, NULL);
-
return pipeline;
}
