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GStreamer: allow reading raw MJPEG data

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This commit is contained in:
Pavel Rojtberg 2016-03-02 17:22:49 +01:00
parent 7f4a1bcac7
commit ff77f4d9ef
1 changed files with 16 additions and 2 deletions
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18
modules/videoio/src/cap_gstreamer.cpp
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@ -292,18 +292,22 @@ IplImage * CvCapture_GStreamer::retrieveFrame(int)
const gchar* name = gst_structure_get_name(structure);
const gchar* format = gst_structure_get_string(structure, "format");
if (!name || !format)
if (!name)
return 0;
// we support 3 types of data:
// video/x-raw, format=BGR -> 8bit, 3 channels
// video/x-raw, format=GRAY8 -> 8bit, 1 channel
// video/x-bayer -> 8bit, 1 channel
// image/jpeg -> 8bit, mjpeg: buffer_size x 1 x 1
// bayer data is never decoded, the user is responsible for that
// everything is 8 bit, so we just test the caps for bit depth
if (strcasecmp(name, "video/x-raw") == 0)
{
if (!format)
return 0;
if (strcasecmp(format, "BGR") == 0) {
depth = 3;
}
@ -314,6 +318,9 @@ IplImage * CvCapture_GStreamer::retrieveFrame(int)
else if (strcasecmp(name, "video/x-bayer") == 0)
{
depth = 1;
} else if(strcasecmp(name, "image/jpeg") == 0) {
depth = 1;
// the correct size will be set once the first frame arrives
}
#endif
if (depth > 0) {
@ -334,6 +341,13 @@ IplImage * CvCapture_GStreamer::retrieveFrame(int)
// info.data ptr is valid until next grabFrame where the associated sample is unref'd
GstMapInfo info = GstMapInfo();
gboolean success = gst_buffer_map(buffer,&info, (GstMapFlags)GST_MAP_READ);
// with MJPEG streams frame size can change arbitrarily
if(int(info.size) != frame->imageSize) {
cvReleaseImageHeader(&frame);
frame = cvCreateImageHeader(cvSize(info.size, 1), IPL_DEPTH_8U, 1);
}
if (!success){
//something weird went wrong here. abort. abort.
//fprintf(stderr,"GStreamer: unable to map buffer");
@ -797,7 +811,7 @@ bool CvCapture_GStreamer::open( int type, const char* filename )
NULL);
#else
// support 1 and 3 channel 8 bit data, as well as bayer (also 1 channel, 8bit)
caps = gst_caps_from_string("video/x-raw, format=(string){BGR, GRAY8}; video/x-bayer,format=(string){rggb,bggr,grbg,gbrg}");
caps = gst_caps_from_string("video/x-raw, format=(string){BGR, GRAY8}; video/x-bayer,format=(string){rggb,bggr,grbg,gbrg}; image/jpeg");
#endif
gst_app_sink_set_caps(GST_APP_SINK(sink), caps);
gst_caps_unref(caps);