<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style></style></head><body lang=KO link="#0563C1" vlink="#954F72" style='word-wrap:break-word'><div class=WordSection1>Hi,<o:p></o:p><o:p> </o:p>GstCudaMemory’s stride is likely different from default one. <o:p></o:p>You will need to use gst_video_frame_map() and GST_VIDEO_FRAME_PLANE_STRIDE(frame, 0), or GstCudaMemory.info.stride[0]<o:p></o:p><o:p> </o:p>Regards,<o:p></o:p>Seungha<o:p></o:p><o:p> </o:p><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'>From: gstreamer-devel <gstreamer-devel-bounces@lists.freedesktop.org> On Behalf Of Richard Pickler via gstreamer-devel Sent: Thursday, June 8, 2023 10:05 PM To: gstreamer-devel@lists.freedesktop.org Cc: Richard Pickler <rpickler@gmail.com> Subject: CUDA GstBuffer output buffer with OpenCV GpuMat<o:p></o:p></div><o:p> </o:p><div><div>I'm struggling to use the recent cuda improvements in gstreamer, using an OpenCV GpuMat to write to a CUDAMemory outbuf. I'm was successful in getting an appropriate buffer through decide/propose_allocation, but simply cannot seem to write to a buffer properly. In my transform function below, I'm able to map the buffer and have the demosaic function run properly, but the output stream comes out garbage. I placed a simple cv::imwrite in the code, and sure enough, the data comes through the function properly, it's just not in a structure that gstreamer is happy with.<o:p></o:p></div><div><o:p> </o:p></div><div>Any ideas? I've been pounding my head against this wall for a couple days now.<o:p></o:p></div><div><o:p> </o:p></div><div>static GstFlowReturn debayer_transform(GstBaseTransform *base, GstBuffer *inbuf, GstBuffer *outbuf) { Debayer *debayer = DEBAYER(base); GstCudaBaseTransform *btrans = GST_CUDA_BASE_TRANSFORM (base); if (gst_buffer_n_memory (outbuf) != 1) { GST_ERROR_OBJECT (debayer, "Invalid output buffer"); return GST_FLOW_ERROR; } GstMemory *mem; mem = gst_buffer_peek_memory (outbuf, 0); if (!gst_is_cuda_memory (mem)) { GST_ERROR_OBJECT (debayer, "Input buffer is not CUDA"); std::cout << "Input buffer is not cuda" << std::endl; return GST_FLOW_ERROR; } GstMapInfo map; if(!gst_buffer_map(inbuf, &map, GST_MAP_READ)) { std::cout << "Can't map" << std::endl; return GST_FLOW_ERROR; } GstMapInfo outmap; if(!gst_buffer_map(outbuf, &outmap, (GstMapFlags)(GST_MAP_WRITE | GST_MAP_CUDA))) { std::cout << "Can't map" << std::endl; return GST_FLOW_ERROR; } cv::Mat in( cv::Size(debayer->info.width, debayer->info.height), CV_8UC1, (char*) map.data); cv::cuda::GpuMat gpu_in; cv::cuda::GpuMat gpu_out( cv::Size(debayer->info.width, debayer->info.height), CV_8UC3, (char*) outmap.data, debayer->info.stride[0]); gpu_in.upload(in); cv::cuda::demosaicing(gpu_in, gpu_out, cv::COLOR_BayerRG2BGR); cv::Mat out(gpu_out); cv::imwrite("foo.jpg", out); gst_buffer_unmap(inbuf, &map); gst_buffer_unmap(outbuf, &outmap); return GST_FLOW_OK; } <o:p></o:p></div><div><o:p> </o:p></div><o:p> </o:p></div></div></body></html>