<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> </head> <body> I have no experience with the NTP timestamp part. But I have successfully appended custom metadata to the EXIF of JPEG. In this way I'm not depend on gstreamer for extracting the metadata again. You need a jpegenc and a jifmux: <div style="color: #d4d4d4;background-color: #1e1e1e;font-family: 'Droid Sans Mono', 'monospace', monospace, 'Droid Sans Fallback';font-weight: normal;font-size: 14px;line-height: 19px;white-space: pre;"><div> g_string_append_printf(pipe_desc,</div><div> "jpegenc name=%s ! jifmux name=%s ! ",</div><div> JPEG_ENCODER_NAME, JIF_MUX_NAME);</div></div> Then add a pad probe to the jpegenc: <div style="color: #d4d4d4;background-color: #1e1e1e;font-family: 'Droid Sans Mono', 'monospace', monospace, 'Droid Sans Fallback';font-weight: normal;font-size: 14px;line-height: 19px;white-space: pre;"><div> //add pad probe to jpeg encoder</div><div> enc = get_elem(bin, JPEG_ENCODER_NAME);</div><div> if (enc != NULL) {</div><div> GstPad *pad = gst_element_get_static_pad(enc, "src");</div> <div> gst_pad_add_probe(pad, GST_PAD_PROBE_TYPE_BUFFER,</div><div> (GstPadProbeCallback) jpeg_encoder_cb, NULL, NULL);</div><div> gst_object_unref(pad);</div><div> }</div><div> gst_object_unref(enc);</div></div> The callback to attach the metadata using the tagsetter: <div style="color: #d4d4d4;background-color: #1e1e1e;font-family: 'Droid Sans Mono', 'monospace', monospace, 'Droid Sans Fallback';font-weight: normal;font-size: 14px;line-height: 19px;white-space: pre;"><div>GstPadProbeReturn</div><div>jpeg_encoder_cb(GstPad *pad, GstPadProbeInfo *info, gpointer user_data)</div><div>{</div><div> GstTagSetter *tagsetter;</div><div> GstElement *mux;</div> <div> struct Pan355_RPC_Data pos0, pos1, tar0, tar1;</div><div> QtecGeometryPoint3d current_xyz, target_xyz;</div> <div> gdouble tof;</div><div> QtecGeometryPoint3d cam_loc;</div><div> struct Pan355Intrinsics intrinsics;</div><div> struct QtecMatrix *cam_rot = NULL;</div> <div> gint width = -1, height = -1;</div><div> gdouble ratio_x = 1, ratio_y = 1, cx, cy, fx, fy, f_mm, px_size_x, px_size_y;</div> <div> //QTEC_DEBUG("jpeg_encoder_cb");</div> <div> pos0.axis = tar0.axis = 0;</div><div> pos1.axis = tar1.axis = 1;</div> <div> mux = get_elem(bin, JIF_MUX_NAME);</div><div> if (!mux)</div><div> return GST_PAD_PROBE_OK;</div> <div> tagsetter = GST_TAG_SETTER(mux);</div> <div> //get position</div><div> if (!get_axis_pos(&pos0) || !get_axis_pos(&pos1) ||</div><div> !get_xyz_pos(pos0.angle, pos1.angle, 0, &current_xyz) ||</div><div> !get_axis_params(&tar0) || !get_axis_params(&tar1) ||</div><div> !get_xyz_pos(tar0.angle, tar1.angle, 0, &target_xyz)) {</div><div> gst_tag_setter_add_tags(tagsetter, GST_TAG_MERGE_REPLACE,</div><div> GST_TAG_ARTIST, <a class="moz-txt-link-rfc2396E" href="mailto:msb@qtec.com">"msb@qtec.com"</a>,</div><div> NULL);</div> <div> gst_object_unref(mux);</div> <div> return GST_PAD_PROBE_OK;</div><div> }</div> <div> get_cam_tilt_offset(&tof);</div><div> get_cam_loc(&cam_loc);</div><div> get_cam_intrinsics(&intrinsics);</div><div> cam_rot = get_cam_rot_matrix();</div> <div> GstCaps *caps = gst_pad_get_current_caps(pad);</div> <div> if (caps != NULL) {</div><div> GstStructure *structure = gst_caps_get_structure(caps, 0);</div> <div> if (structure != NULL) {</div><div> gst_structure_get_int(structure, "width", &width);</div><div> gst_structure_get_int(structure, "height", &height);</div><div> }</div><div> gst_caps_unref(caps);</div><div> }</div> <div> //re-scale principal point and pixel size based on MJPEG size</div><div> if (width > 0)</div><div> ratio_x = FULL_HD_WIDTH / width;</div><div> if (height > 0)</div><div> ratio_y = FULL_HD_HEIGHT / height;</div><div> cx = intrinsics.cx / ratio_x;</div><div> cy = intrinsics.cy / ratio_y;</div><div> fx = intrinsics.fx / ratio_x;</div><div> fy = intrinsics.fy / ratio_y;</div><div> f_mm = intrinsics.fx * DECIMATED_PIXEL_SIZE(SONY_PIXEL_SIZE) / 1000;</div><div> px_size_x = DECIMATED_PIXEL_SIZE(SONY_PIXEL_SIZE) * ratio_x;</div><div> px_size_y = DECIMATED_PIXEL_SIZE(SONY_PIXEL_SIZE) * ratio_y;</div> <div> gchar *metadata = g_strdup_printf(</div><div> "{\"Cur_pos\":{\"x\":%.3f, \"y\":%.3f, \"z\":%.3f}, "</div><div> "\"Tar_pos\":{\"x\":%.3f, \"y\":%.3f, \"z\":%.3f}, "</div><div> "\"T_base\":{\"x\":%.3f, \"y\":%.3f, \"z\":%.3f}, "</div><div> "\"R_base\":[[%.3f, %.3f, %.3f], [%.3f, %.3f, %.3f], [%.3f, %.3f, %.3f]], "</div><div> "\"Tilt_offset\":%.3f, "</div><div> "\"K\":{\"cx\":%.3f, \"cy\":%.3f, \"fx\":%.3f, \"fy\":%.3f, \"px_size_x\":%.3f, \"px_size_y\":%.3f}}",</div><div> current_xyz.x, current_xyz.y, current_xyz.z,</div><div> target_xyz.x, target_xyz.y, target_xyz.z,</div><div> cam_loc.x, cam_loc.y, cam_loc.z,</div><div> QTEC_CORE_MATRIX_AT(cam_rot, 0, 0),</div><div> QTEC_CORE_MATRIX_AT(cam_rot, 0, 1),</div><div> QTEC_CORE_MATRIX_AT(cam_rot, 0, 2),</div><div> QTEC_CORE_MATRIX_AT(cam_rot, 1, 0),</div><div> QTEC_CORE_MATRIX_AT(cam_rot, 1, 1),</div><div> QTEC_CORE_MATRIX_AT(cam_rot, 1, 2),</div><div> QTEC_CORE_MATRIX_AT(cam_rot, 2, 0),</div><div> QTEC_CORE_MATRIX_AT(cam_rot, 2, 1),</div><div> QTEC_CORE_MATRIX_AT(cam_rot, 2, 2),</div><div> tof, cx, cy, fx, fy, px_size_x, px_size_y);</div> <div> gst_tag_setter_add_tags(tagsetter, GST_TAG_MERGE_REPLACE,</div><div> GST_TAG_GEO_LOCATION_ELEVATION, f_mm,</div><div> GST_TAG_GEO_LOCATION_LATITUDE , pos1.angle,</div><div> GST_TAG_GEO_LOCATION_LONGITUDE, pos0.angle,</div><div> GST_TAG_ARTIST, <a class="moz-txt-link-rfc2396E" href="mailto:msb@qtec.com">"msb@qtec.com"</a>,</div><div> GST_TAG_DESCRIPTION, metadata,</div><div> NULL);</div><div> g_free(metadata);</div> <div> gst_object_unref(mux);</div> <div> return GST_PAD_PROBE_OK;</div><div>}</div></div> As you can see I'm using the GPS (ELEVATION, LATITUDE, LONGITUDE) part of EXIF as well as the ARTIST (as author). And then anything else custom has to go into DESCRIPTION Best Regards Marianna <div class="moz-cite-prefix">On 08.12.2021 13.00, <a class="moz-txt-link-abbreviated" href="mailto:gstreamer-devel-request@lists.freedesktop.org">gstreamer-devel-request@lists.freedesktop.org</a> wrote: </div> <blockquote type="cite" cite="mid:mailman.37.1638964803.30359.gstreamer-devel@lists.freedesktop.org"> <pre class="moz-quote-pre" wrap="">Hi all, i have a node js application that uses ffmpeg to receive an h264 stream from a camera and convert to jpeg images. the timestamp is overimpressed on the image and is extracted with an OCR (tesseract.js) My goal is to remove the OCR and extract the NTP timestamp of the frame directly. I was told gstreamer has all i need but it seems too difficult. For now i'm able to build a pipeline to write on file the single jpeg with gst launch. The problems i see are 1)extract the NTP timestamp, 2)synchronize with the jpeg, 3)put the timestamp somewhere (maybe metadata?) 4)Compile the application to be standalone without requiring to install gstreamer i'm not a developer so i need to know if this is doable for me or i need to look elsewhere. Any help is much appreciated Thanks</pre> </blockquote> <pre class="moz-signature" cols="72">-- Best regards / Med venlig hilsen “Marianna Smidth Buschle”</pre> </body> </html>