Merge pull request #24243 from kecsap:4.x

Fix gstreamer backend with manual pipelines #24243 - Fix broken seeking in audio/video playback - Fix broken audio playback - Fix unreliable seeking - Estimate frame count if it is not available directly - Return -1 for frame count and fps if it is not available. - Return 0 for fps if the video has variable frame rate - Enable and fix tests ### Pull Request Readiness Checklist See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request - [X] I agree to contribute to the project under Apache 2 License. - [X] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV - [X] The PR is proposed to the proper branch - [-] There is a reference to the original bug report and related work => Reproducible test provided - [-] There is accuracy test, performance test and test data in opencv_extra repository, if applicable Patch to opencv_extra has the same branch name. - [X] The feature is well documented and sample code can be built with the project CMake 1. Download two test videos: ```bash wget https://github.com/ietf-wg-cellar/matroska-test-files/raw/master/test_files/test1.mkv wget https://test-videos.co.uk/vids/jellyfish/mkv/360/Jellyfish_360_10s_5MB.mkv ``` 2. I modified a OpenCV videoio sample to demonstrate the problem, here it is the patch: http://dpaste.com//C9MAT2K6W 3. Build the sample, on Ubuntu: ```bash g++ -g videocapture_audio_combination.cpp -I/usr/include/opencv4 `pkg-config --libs --cflags opencv4` -o videocapture_audio_combination ``` 4. Play an audio stream with seeking BEFORE the fix: ```bash $ ./videocapture_audio_combination --audio "filesrc location=test1.mkv ! queue ! matroskademux name=demux demux.audio_0 ! decodebin ! audioconvert ! appsink"[ERROR:0@0.009] global cap.cpp:164 open VIDEOIO(GSTREAMER): raised OpenCV exception: OpenCV(4.8.0-dev) ./modules/videoio/src/cap_gstreamer.cpp:153: error: (-215:Assertion failed) ptr in function 'get' [ WARN:0@0.009] global cap.cpp:204 open VIDEOIO(GSTREAMER): backend is generally available but can't be used to capture by name ERROR! Can't to open file: filesrc location=test1.mkv ! queue ! matroskademux name=demux demux.audio_0 ! decodebin ! audioconvert ! appsink ``` 5. Play a video stream with seeking BEFORE the fix: ```bash $ ./videocapture_audio_combination --audio "filesrc location=Jellyfish_360_10s_5MB.mkv ! queue ! matroskademux name=demux demux.video_0 ! decodebin ! videoconvert ! video/x-raw, format=BGR ! appsink drop=1" [ WARN:0@0.034] global cap_gstreamer.cpp:1728 open OpenCV | GStreamer warning: Cannot query video position: status=1, value=22, duration=300 CAP_PROP_AUDIO_DATA_DEPTH: CV_16S CAP_PROP_AUDIO_SAMPLES_PER_SECOND: 44100 CAP_PROP_AUDIO_TOTAL_CHANNELS: 0 CAP_PROP_AUDIO_TOTAL_STREAMS: [ WARN:0@0.034] global cap_gstreamer.cpp:1898 getProperty OpenCV | GStreamer: CAP_PROP_AUDIO_TOTAL_STREAMS property is not supported 0 [ WARN:0@0.034] global cap_gstreamer.cpp:1817 getProperty OpenCV | GStreamer: CAP_PROP_POS_MSEC property result may be unrealiable: https://github.com/opencv/opencv/issues/19025 Timestamp: 0.6218 Timestamp: 33.1085 Timestamp: 67.1274 Timestamp: 100.1182 Timestamp: 133.1204 Timestamp: 167.1195 Timestamp: 200.1161 Timestamp: 233.1147 Timestamp: 267.1194 Timestamp: 300.1202 [ WARN:0@0.338] global cap_gstreamer.cpp:1949 setProperty OpenCV | GStreamer warning: GStreamer: unable to seek 0:00:00.338215907 3892572 0x5592899c7580 WARN basesrc gstbasesrc.c:3127:gst_base_src_loop:<filesrc0> error: Internal data stream error. 0:00:00.338235884 3892572 0x5592899c7580 WARN basesrc gstbasesrc.c:3127:gst_base_src_loop:<filesrc0> error: streaming stopped, reason not-linked (-1) 0:00:00.338264287 3892572 0x5592899c7580 WARN queue gstqueue.c:992:gst_queue_handle_sink_event:<queue0> error: Internal data stream error. 0:00:00.338270329 3892572 0x5592899c7580 WARN queue gstqueue.c:992:gst_queue_handle_sink_event:<queue0> error: streaming stopped, reason not-linked (-1) [ WARN:0@0.339] global cap_gstreamer.cpp:2784 handleMessage OpenCV | GStreamer warning: Embedded video playback halted; module filesrc0 reported: Internal data stream error. [ WARN:0@0.339] global cap_gstreamer.cpp:1199 startPipeline OpenCV | GStreamer warning: unable to start pipeline Number of audio samples: 0 Number of video frames: 10 [ WARN:0@0.339] global cap_gstreamer.cpp:1164 isPipelinePlaying OpenCV | GStreamer warning: GStreamer: pipeline have not been created ``` 6. Play an audio stream with seeking AFTER the fix: ```bash $ ./videocapture_audio_combination --audio "filesrc location=test1.mkv ! queue ! matroskademux name=demux demux.audio_0 ! decodebin ! audioconvert ! appsink"CAP_PROP_AUDIO_DATA_DEPTH: CV_16S CAP_PROP_AUDIO_SAMPLES_PER_SECOND: 48000 CAP_PROP_AUDIO_TOTAL_CHANNELS: 2 CAP_PROP_AUDIO_TOTAL_STREAMS: [ WARN:0@0.025] global cap_gstreamer.cpp:1903 getProperty OpenCV | GStreamer: CAP_PROP_AUDIO_TOTAL_STREAMS property is not supported 0 Timestamp: 0.0000 Timestamp: 24.0000 Timestamp: 48.0000 Timestamp: 72.0000 Timestamp: 96.0000 Timestamp: 120.0000 Timestamp: 144.0000 Timestamp: 168.0000 Timestamp: 192.0000 Timestamp: 216.0000 Timestamp: 3500.0000 Timestamp: 3504.0000 Timestamp: 3528.0000 Timestamp: 3552.0000 Timestamp: 3576.0000 Timestamp: 3600.0000 Timestamp: 3624.0000 Timestamp: 3648.0000 Timestamp: 3672.0000 Timestamp: 3696.0000 Timestamp: 3720.0000 Timestamp: 3744.0000 Timestamp: 3768.0000 Timestamp: 3792.0000 Timestamp: 3816.0000 Timestamp: 3840.0000 Timestamp: 3864.0000 Timestamp: 3888.0000 Timestamp: 3912.0000 Timestamp: 3936.0000 ``` 7. Play a video stream with seeking AFTER the fix: ```bash $ ./videocapture_audio_combination --audio "filesrc location=Jellyfish_360_10s_5MB.mkv ! queue ! matroskademux name=demux demux.video_0 ! decodebin ! videoconvert ! video/x-raw, format=BGR ! appsink drop=1" [ WARN:0@0.033] global cap_gstreamer.cpp:1746 open OpenCV | GStreamer warning: Cannot query video position: status=1, value=22, duration=300 CAP_PROP_AUDIO_DATA_DEPTH: CV_16S CAP_PROP_AUDIO_SAMPLES_PER_SECOND: 44100 CAP_PROP_AUDIO_TOTAL_CHANNELS: 0 CAP_PROP_AUDIO_TOTAL_STREAMS: [ WARN:0@0.034] global cap_gstreamer.cpp:1903 getProperty OpenCV | GStreamer: CAP_PROP_AUDIO_TOTAL_STREAMS property is not supported 0 Timestamp: 0.0000 Timestamp: 33.0000 Timestamp: 67.0000 Timestamp: 100.0000 Timestamp: 133.0000 Timestamp: 167.0000 Timestamp: 200.0000 Timestamp: 233.0000 Timestamp: 267.0000 Timestamp: 300.0000 0:00:00.335931693 3893501 0x55bbe76ad920 WARN matroskareadcommon matroska-read-common.c:759:gst_matroska_read_common_parse_skip:<demux:sink> Unknown CueTrackPositions subelement 0xf0 - ignoring 0:00:00.335952823 3893501 0x55bbe76ad920 WARN matroskareadcommon matroska-read-common.c:759:gst_matroska_read_common_parse_skip:<demux:sink> Unknown CueTrackPositions subelement 0xf0 - ignoring 0:00:00.335988029 3893501 0x55bbe76ad920 WARN basesrc gstbasesrc.c:1742:gst_base_src_perform_seek:<filesrc0> duplicate event found 184 Timestamp: 3467.0000 Timestamp: 3500.0000 Timestamp: 3533.0000 Timestamp: 3567.0000 Timestamp: 3600.0000 Timestamp: 3633.0000 Timestamp: 3667.0000 Timestamp: 3700.0000 Timestamp: 3733.0000 Timestamp: 3767.0000 Timestamp: 3800.0000 Timestamp: 3833.0000 Timestamp: 3867.0000 Timestamp: 3900.0000 Timestamp: 3933.0000 Timestamp: 3967.0000 Timestamp: 4000.0000 Timestamp: 4033.0000 Timestamp: 4067.0000 Timestamp: 4100.0000 ```
2026-07-29 23:33:05 +04:00 · 2023-11-08 11:41:50 +01:00
parent 9d0c8a9edb
commit b1e0c4d119
4 changed files with 158 additions and 53 deletions
@@ -114,6 +114,7 @@ template<> inline void GSafePtr_release<GstBuffer>(GstBuffer** pPtr) { if (pPtr)
 template<> inline void GSafePtr_release<GstSample>(GstSample** pPtr) { if (pPtr) { gst_sample_unref(*pPtr); *pPtr = NULL; } }
 template<> inline void GSafePtr_release<GstBus>(GstBus** pPtr) { if (pPtr) { gst_object_unref(G_OBJECT(*pPtr)); *pPtr = NULL; } }
 template<> inline void GSafePtr_release<GstMessage>(GstMessage** pPtr) { if (pPtr) { gst_message_unref(*pPtr); *pPtr = NULL; } }
+template<> inline void GSafePtr_release<GstQuery>(GstQuery** pPtr) { if (pPtr) { gst_query_unref(*pPtr); *pPtr = NULL; } }
 template<> inline void GSafePtr_release<GMainLoop>(GMainLoop** pPtr) { if (pPtr) { g_main_loop_unref(*pPtr); *pPtr = NULL; } }

 template<> inline void GSafePtr_release<GstEncodingVideoProfile>(GstEncodingVideoProfile** pPtr) { if (pPtr) { gst_encoding_profile_unref(*pPtr); *pPtr = NULL; } }
@@ -367,6 +368,7 @@ private:
    gint          audioBitPerFrame;
    gint          audioSampleSize;
    std::string   audioFormat;
+    guint64       timestamp;

    Mat audioFrame;
    std::deque<uint8_t> bufferAudioData;
@@ -433,7 +435,8 @@ GStreamerCapture::GStreamerCapture() :
    audioSamplesPerSecond(44100),
    audioBitPerFrame(0),
    audioSampleSize(0),
-    audioFormat("S16LE")
+    audioFormat("S16LE"),
+    timestamp(0)
    , va_type(VIDEO_ACCELERATION_NONE)
    , hw_device(-1)
 {}
@@ -680,6 +683,11 @@ bool GStreamerCapture::grabVideoFrame()
                stopFlag = true;
                emulatedFrameNumber++;
            }
+            if (usedVideoSample)
+            {
+                auto *buffer = gst_sample_get_buffer((GstSample*)usedVideoSample);
+                timestamp = GST_BUFFER_PTS(buffer);
+            }
            returnFlag = true;
        }
    }
@@ -792,6 +800,7 @@ bool GStreamerCapture::grabAudioFrame()
                CV_LOG_ERROR(NULL, "GStreamer: Failed. Buffer is empty");
                return false;
            }
+            timestamp = GST_BUFFER_PTS(buf);
            if (!gst_buffer_map(buf, &map_info, GST_MAP_READ))
            {
                CV_LOG_ERROR(NULL, "GStreamer: Failed to map GStreamer buffer to system memory");
@@ -1389,6 +1398,7 @@ bool GStreamerCapture::open(const String &filename_, const cv::VideoCaptureParam
    GSafePtr<char> uri;
    GSafePtr<GstBus> bus;

+    GSafePtr<GstElement> queue;
    GSafePtr<GstElement> uridecodebin;
    GSafePtr<GstElement> color;
    GSafePtr<GstElement> convert;
@@ -1493,6 +1503,7 @@ bool GStreamerCapture::open(const String &filename_, const cv::VideoCaptureParam
                    if (strstr(name, "opencvsink") != NULL || strstr(name, "appsink") != NULL)
                    {
                        sink.attach(GST_ELEMENT(gst_object_ref(element)));
+                        audiosink.attach(GST_ELEMENT(gst_object_ref(element)));
                    }
                    else if (strstr(name, COLOR_ELEM_NAME) != NULL)
                    {
@@ -1534,6 +1545,8 @@ bool GStreamerCapture::open(const String &filename_, const cv::VideoCaptureParam

        if (videoStream >= 0)
        {
+            queue.reset(gst_element_factory_make("queue", NULL));
+            CV_Assert(queue);
            sink.reset(gst_element_factory_make("appsink", NULL));
            CV_Assert(sink);
            // videoconvert (in 0.10: ffmpegcolorspace, in 1.x autovideoconvert)
@@ -1541,7 +1554,7 @@ bool GStreamerCapture::open(const String &filename_, const cv::VideoCaptureParam
            color.reset(gst_element_factory_make(COLOR_ELEM, NULL));
            CV_Assert(color);

-            gst_bin_add_many(GST_BIN(pipeline.get()), uridecodebin.get(), color.get(), sink.get(), NULL);
+            gst_bin_add_many(GST_BIN(pipeline.get()), queue.get(), uridecodebin.get(), color.get(), sink.get(), NULL);

            if (element_from_uri)
            {
@@ -1566,6 +1579,8 @@ bool GStreamerCapture::open(const String &filename_, const cv::VideoCaptureParam
        }
        if (audioStream >= 0)
        {
+            queue.reset(gst_element_factory_make("queue", NULL));
+            CV_Assert(queue);
            convert.reset(gst_element_factory_make("audioconvert", NULL));
            resample.reset(gst_element_factory_make("audioresample", NULL));
            audiosink.reset(gst_element_factory_make("appsink", NULL));
@@ -1573,7 +1588,7 @@ bool GStreamerCapture::open(const String &filename_, const cv::VideoCaptureParam
            CV_Assert(resample);
            CV_Assert(audiosink);

-            gst_bin_add_many (GST_BIN (pipeline.get()), uridecodebin.get(), convert.get(), resample.get(), audiosink.get(), NULL);
+            gst_bin_add_many (GST_BIN (pipeline.get()), queue.get(), uridecodebin.get(), convert.get(), resample.get(), audiosink.get(), NULL);
            if (!gst_element_link_many (convert.get(), resample.get(), audiosink.get(), NULL))
            {
                CV_WARN("GStreamer(audio): cannot link convert -> resample -> sink");
@@ -1646,14 +1661,17 @@ bool GStreamerCapture::open(const String &filename_, const cv::VideoCaptureParam
    }
    if (manualpipeline)
    {
-        GSafePtr<GstCaps> peer_caps;
-        GSafePtr<GstPad> sink_pad;
-        sink_pad.attach(gst_element_get_static_pad(sink, "sink"));
-        peer_caps.attach(gst_pad_peer_query_caps(sink_pad, NULL));
-        if (!gst_caps_can_intersect(caps, peer_caps))
+        if (videoStream >= 0)
        {
-            caps.attach(gst_caps_from_string("video/x-raw, format=(string){UYVY,YUY2,YVYU,NV12,NV21,YV12,I420,BGRA,RGBA,BGRx,RGBx,GRAY16_LE,GRAY16_BE}"));
-            CV_Assert(caps);
+            GSafePtr<GstCaps> peer_caps;
+            GSafePtr<GstPad> sink_pad;
+            sink_pad.attach(gst_element_get_static_pad(sink, "sink"));
+            peer_caps.attach(gst_pad_peer_query_caps(sink_pad, NULL));
+            if (!gst_caps_can_intersect(caps, peer_caps))
+            {
+                caps.attach(gst_caps_from_string("video/x-raw, format=(string){UYVY,YUY2,YVYU,NV12,NV21,YV12,I420,BGRA,RGBA,BGRx,RGBx,GRAY16_LE,GRAY16_BE}"));
+                CV_Assert(caps);
+            }
        }
    }
    if (videoStream >= 0)
@@ -1661,6 +1679,7 @@ bool GStreamerCapture::open(const String &filename_, const cv::VideoCaptureParam
        gst_app_sink_set_caps(GST_APP_SINK(sink.get()), caps);
        caps.release();
    }
+
    {
        GST_DEBUG_BIN_TO_DOT_FILE(GST_BIN(pipeline.get()), GST_DEBUG_GRAPH_SHOW_ALL, "pipeline-init");

@@ -1688,18 +1707,6 @@ bool GStreamerCapture::open(const String &filename_, const cv::VideoCaptureParam
            GSafePtr<GstCaps> buffer_caps;
            buffer_caps.attach(gst_pad_get_current_caps(pad));

-            GstFormat format;
-
-            format = GST_FORMAT_DEFAULT;
-            if(!gst_element_query_duration(sink, format, &duration))
-            {
-                handleMessage(pipeline);
-                CV_WARN("unable to query duration of stream");
-                duration = -1;
-            }
-
-            handleMessage(pipeline);
-
            const GstStructure *structure = gst_caps_get_structure(buffer_caps, 0);  // no lifetime transfer
            if (!gst_structure_get_int (structure, "width", &width) ||
                !gst_structure_get_int (structure, "height", &height))
@@ -1708,13 +1715,55 @@ bool GStreamerCapture::open(const String &filename_, const cv::VideoCaptureParam
            }

            gint num = 0, denom=1;
+            bool fps_query_success = true;
+
            if (!gst_structure_get_fraction(structure, "framerate", &num, &denom))
            {
                CV_WARN("cannot query video fps");
+                fps_query_success = false;
            }

            fps = (double)num/(double)denom;

+            // If num == 0 and denom == 1 -> variable frame rate video.
+            if (fps_query_success && !(num == 0 && denom == 1))
+            {
+                GSafePtr<GstQuery> query;
+                query.attach(gst_query_new_duration(GST_FORMAT_DEFAULT));
+
+                gboolean res = gst_element_query(pipeline.get(), query);
+
+                if (res)
+                {
+                    gst_query_parse_duration(query, NULL, &duration);
+                }
+                else if (fps != 0)
+                {
+                    GSafePtr<GstQuery> query2;
+                    query2.attach(gst_query_new_duration(GST_FORMAT_TIME));
+                    gboolean res2 = gst_element_query(pipeline.get(), query2);
+
+                    if (res2)
+                    {
+                        gst_query_parse_duration(query2, NULL, &duration);
+                        duration = static_cast<gint64>((float)duration / GST_SECOND * fps);
+                        CV_WARN("frame count is estimated by duration and fps");
+                    }
+                    else
+                    {
+                        CV_WARN("unable to query duration of stream");
+                        duration = -1;
+                    }
+                }
+                else
+                {
+                    CV_WARN("unable to query frame count of stream and fps are not available to estimate it");
+                    duration = -1;
+                }
+            }
+
+            handleMessage(pipeline);
+
            {
                GstFormat format_;
                gint64 value_ = -1;
@@ -1814,20 +1863,7 @@ double GStreamerCapture::getProperty(int propId) const
    switch(propId)
    {
    case CV_CAP_PROP_POS_MSEC:
-        CV_LOG_ONCE_WARNING(NULL, "OpenCV | GStreamer: CAP_PROP_POS_MSEC property result may be unrealiable: "
-                                  "https://github.com/opencv/opencv/issues/19025");
-        if (audioStream != -1)
-        {
-            return usedVideoSampleTimeNS * 1e-6;
-        }
-        format = GST_FORMAT_TIME;
-        status = gst_element_query_position(sink.get(), CV_GST_FORMAT(format), &value);
-        if(!status) {
-            handleMessage(pipeline);
-            CV_WARN("GStreamer: unable to query position of stream");
-            return 0;
-        }
-        return value * 1e-6; // nano seconds to milli seconds
+        return double(timestamp) / GST_MSECOND;
    case CV_CAP_PROP_POS_FRAMES:
        if (!isPosFramesSupported)
        {
@@ -1859,7 +1895,7 @@ double GStreamerCapture::getProperty(int propId) const
    case CV_CAP_PROP_FPS:
        return fps;
    case CV_CAP_PROP_FRAME_COUNT:
-        return duration;
+        return (double)duration;
    case CV_CAP_PROP_BRIGHTNESS:
    case CV_CAP_PROP_CONTRAST:
    case CV_CAP_PROP_SATURATION:
@@ -1936,13 +1972,15 @@ bool GStreamerCapture::setProperty(int propId, double value)
        return false;
    }

-    bool wasPlaying = this->isPipelinePlaying();
-    if (wasPlaying)
+    bool needRestart = this->isPipelinePlaying() && (propId == CV_CAP_PROP_FRAME_WIDTH || propId == CV_CAP_PROP_FRAME_HEIGHT || propId == CV_CAP_PROP_FPS);
+    if (needRestart) {
        this->stopPipeline();
+    }

    switch(propId)
    {
    case CV_CAP_PROP_POS_MSEC:
+    {
        if(!gst_element_seek_simple(GST_ELEMENT(pipeline.get()), GST_FORMAT_TIME,
                                    flags, (gint64) (value * GST_MSECOND))) {
            handleMessage(pipeline);
@@ -1950,6 +1988,9 @@ bool GStreamerCapture::setProperty(int propId, double value)
        }
        else
        {
+            // Optimistically caching the target timestamp before reading the first frame from the new position since
+            // the timestamp in GStreamer can be reliable extracted from the read frames.
+            timestamp = (gint64)value;
            if (isPosFramesEmulated)
            {
                if (value == 0)
@@ -1963,7 +2004,8 @@ bool GStreamerCapture::setProperty(int propId, double value)
                }
            }
        }
-        break;
+        return true;
+    }
    case CV_CAP_PROP_POS_FRAMES:
    {
        if (!isPosFramesSupported)
@@ -1977,24 +2019,34 @@ bool GStreamerCapture::setProperty(int propId, double value)
                    return true;
                }
            }
-            return false;
            CV_WARN("unable to seek");
+            return false;
        }
+        // Certain mov and mp4 files seek incorrectly if the pipeline is not stopped before.
+        if (this->isPipelinePlaying()) {
+            this->stopPipeline();
+        }
+
        if(!gst_element_seek_simple(GST_ELEMENT(pipeline.get()), GST_FORMAT_DEFAULT,
                                    flags, (gint64) value)) {
            handleMessage(pipeline);
            CV_WARN("GStreamer: unable to seek");
-            break;
+            return false;
        }
        // wait for status update
        gst_element_get_state(pipeline, NULL, NULL, GST_CLOCK_TIME_NONE);
        return true;
    }
    case CV_CAP_PROP_POS_AVI_RATIO:
+    {
+        // https://stackoverflow.com/questions/31290315
+        // GStreamer docs: GST_FORMAT_PERCENT (5) – percentage of stream (few, if any, elements implement this as of May 2009)
+        CV_WARN("GStreamer: seeking by file percent are not supported by most GStreamer elements");
        if(!gst_element_seek_simple(GST_ELEMENT(pipeline.get()), GST_FORMAT_PERCENT,
                                    flags, (gint64) (value * GST_FORMAT_PERCENT_MAX))) {
            handleMessage(pipeline);
            CV_WARN("GStreamer: unable to seek");
+            return false;
        }
        else
        {
@@ -2011,7 +2063,8 @@ bool GStreamerCapture::setProperty(int propId, double value)
                }
            }
        }
-        break;
+        return true;
+    }
    case CV_CAP_PROP_FRAME_WIDTH:
        if(value > 0)
            setFilter("width", G_TYPE_INT, (int) value, 0);
@@ -2099,8 +2152,9 @@ bool GStreamerCapture::setProperty(int propId, double value)
        CV_WARN("GStreamer: unhandled property");
    }

-    if (wasPlaying)
+    if (needRestart) {
        this->startPipeline();
+    }

    return false;
 }
@@ -2572,7 +2626,7 @@ bool CvVideoWriter_GStreamer::open( const std::string &filename, int fourcc,
    if (stateret == GST_STATE_CHANGE_FAILURE)
    {
        handleMessage(pipeline);
-        CV_WARN("GStreamer: cannot put pipeline to play\n");
+        CV_WARN("GStreamer: cannot put pipeline to play");
        pipeline.release();
        return false;
    }
@@ -186,6 +186,7 @@ public:
                double audio_shift = cap.get(CAP_PROP_AUDIO_SHIFT_NSEC);
                double video0_timestamp = cap.get(CAP_PROP_POS_MSEC) * 1e-3;
                audio0_timestamp = video0_timestamp + audio_shift * 1e-9;
+
                std::cout << "video0 timestamp: " << video0_timestamp << "  audio0 timestamp: " << audio0_timestamp << " (audio shift nanoseconds: " << audio_shift << " , seconds: " << audio_shift * 1e-9 << ")" << std::endl;
            }
            ASSERT_TRUE(cap.retrieve(videoFrame));
@@ -228,7 +229,7 @@ public:
                EXPECT_NEAR(
                        cap.get(CAP_PROP_AUDIO_POS) / samplePerSecond + audio0_timestamp,
                        cap.get(CAP_PROP_POS_MSEC) * 1e-3,
-                        (1.0 / fps) * 0.3)
+                        (1.0 / fps) * 0.6)
                    << "CAP_PROP_AUDIO_POS=" << cap.get(CAP_PROP_AUDIO_POS) << " CAP_PROP_POS_MSEC=" << cap.get(CAP_PROP_POS_MSEC);
            }
            if (frame != 0 && frame != numberOfFrames-1 && audioData[0].size() != (size_t)numberOfSamples)
@@ -178,4 +178,47 @@ TEST(videoio_gstreamer, timeout_property)
    }
 }

+//==============================================================================
+// Seeking test with manual GStreamer pipeline
+typedef testing::TestWithParam<string> gstreamer_bunny;
+
+TEST_P(gstreamer_bunny, manual_seek)
+{
+    if (!videoio_registry::hasBackend(CAP_GSTREAMER))
+        throw SkipTestException("GStreamer backend was not found");
+
+    const string video_file = BunnyParameters::getFilename("." + GetParam());
+    const string pipeline = "filesrc location=" + video_file + " ! decodebin ! videoconvert ! video/x-raw, format=BGR ! appsink drop=1";
+    const double target_pos = 3000.0;
+    const float ms_per_frame = 1000 / BunnyParameters::getFps();
+    VideoCapture cap;
+    cap.open(pipeline, CAP_GSTREAMER);
+    ASSERT_TRUE(cap.isOpened());
+    Mat img;
+    for (int i = 0; i < 10; i++)
+    {
+        cap >> img;
+    }
+    EXPECT_FALSE(img.empty());
+    cap.set(CAP_PROP_POS_MSEC, target_pos);
+    cap >> img;
+    EXPECT_FALSE(img.empty());
+    double actual_pos = cap.get(CAP_PROP_POS_MSEC);
+    EXPECT_NEAR(actual_pos, target_pos, ms_per_frame);
+}
+
+static const string bunny_params[] = {
+    // string("wmv"),
+    string("mov"),
+    string("mp4"),
+    // string("mpg"),
+    string("avi"),
+    // string("h264"),
+    // string("h265"),
+    string("mjpg.avi")
+};
+
+INSTANTIATE_TEST_CASE_P(videoio, gstreamer_bunny, testing::ValuesIn(bunny_params));
+
+
 }} // namespace
@@ -67,6 +67,11 @@ public:
            std::cout << "CAP_PROP_FRAME_COUNT is not supported by backend. Assume 50 frames." << std::endl;
            n_frames = 50;
        }
+        // GStreamer can't read frame count of big_buck_bunny.wmv
+        if (apiPref == CAP_GSTREAMER && ext == "wmv")
+        {
+            n_frames = 125;
+        }

        {
            SCOPED_TRACE("consecutive read");
@@ -166,7 +171,7 @@ public:
        EXPECT_NO_THROW(count_prop = (int)cap.get(CAP_PROP_FRAME_COUNT));
        // mpg file reports 5.08 sec * 24 fps => property returns 122 frames
        // but actual number of frames returned is 125
-        if (ext != "mpg")
+        if (ext != "mpg" && !(apiPref == CAP_GSTREAMER && ext == "wmv"))
        {
            if (count_prop > 0)
            {
@@ -200,12 +205,11 @@ public:
        if (!isBackendAvailable(apiPref, cv::videoio_registry::getStreamBackends()))
            throw SkipTestException(cv::String("Backend is not available/disabled: ") + cv::videoio_registry::getBackendName(apiPref));

-        // GStreamer: https://github.com/opencv/opencv/issues/19025
-        if (apiPref == CAP_GSTREAMER)
+        if (((apiPref == CAP_GSTREAMER) && (ext == "avi")))
            throw SkipTestException(cv::String("Backend ") +  cv::videoio_registry::getBackendName(apiPref) +
-                    cv::String(" does not return reliable values for CAP_PROP_POS_MSEC property"));
+                    cv::String(" does not support CAP_PROP_POS_MSEC option"));

-        if (((apiPref == CAP_FFMPEG) && ((ext == "h264") || (ext == "h265"))))
+        if (((apiPref == CAP_FFMPEG || apiPref == CAP_GSTREAMER) && ((ext == "h264") || (ext == "h265"))))
            throw SkipTestException(cv::String("Backend ") +  cv::videoio_registry::getBackendName(apiPref) +
                    cv::String(" does not support CAP_PROP_POS_MSEC option"));

@@ -221,8 +225,8 @@ public:
        // mpg file reports 5.08 sec * 24 fps => property returns 122 frames,but actual number of frames returned is 125
        // HACK: CAP_PROP_FRAME_COUNT is not supported for vmw + MSMF. Just force check for all 125 frames
        if (ext == "mpg")
-            EXPECT_GT(frame_count, 121);
-        else if ((ext == "wmv") && (apiPref == CAP_MSMF))
+            EXPECT_GE(frame_count, 114);
+        else if ((ext == "wmv") && (apiPref == CAP_MSMF || apiPref == CAP_GSTREAMER))
            frame_count = 125;
        else
            EXPECT_EQ(frame_count, 125);
@@ -240,6 +244,9 @@ public:
            if (cvtest::debugLevel > 0)
                std::cout << "i = " << i << ": timestamp = " << timestamp << std::endl;
            const double frame_period = 1000.f/bunny_param.getFps();
+            // big_buck_bunny.mpg starts at 0.500 msec
+            if ((ext == "mpg") && (apiPref == CAP_GSTREAMER))
+                timestamp -= 500.0;
            // NOTE: eps == frame_period, because videoCapture returns frame beginning timestamp or frame end
            // timestamp depending on codec and back-end. So the first frame has timestamp 0 or frame_period.
            EXPECT_NEAR(timestamp, i*frame_period, frame_period) << "i=" << i;