gstreamer with "rtpvrawpay" fails due to client being unable to prepare media - camera

Question

I have been playing gstreamer to stream video via RTSP and I need help !
At first I wanted to stream video by encoding the data to h264 format so I used x264enc encoder followed by rtph264pay for the payload.
I tried with the following command and it works perfectly:
examples$ ./test-launch --gst-debug=3 '( v4l2src device=/dev/video0 ! video/x-raw,width=640,height=480,framerate=30/1 ! videoconvert ! x264enc tune=zerolatency ! rtph264pay name=pay0 pt=96 )'
But I also want to try sending raw video data over the network without the encoder so I tried with the following command but it fails.
examples$ ./test-launch --gst-debug=3 '( v4l2src device=/dev/video0 ! video/x-raw,width=640,height=480,framerate=30/1 ! rtpvrawpay name=pay0 pt=96 )'
The log is here:
examples$ ./test-launch --gst-debug=3 '( v4l2src device=/dev/video0 ! video/x-raw,width=640,height=480,framerate=30/1 ! rtpvrawpay name=pay0 pt=96 )'
stream ready at rtsp://127.0.0.1:8554/test
0:00:04.246791630 77643 0x7f6464016cc0 FIXME default gstutils.c:3980:gst_pad_create_stream_id_internal:<appsrc0:src> Creating random stream-id, consider implementing a deterministic way of creating a stream-id
0:00:04.246814474 77643 0x7f6464016c60 FIXME default gstutils.c:3980:gst_pad_create_stream_id_internal:<appsrc1:src> Creating random stream-id, consider implementing a deterministic way of creating a stream-id
0:00:04.247156839 77643 0x7f6464016d20 WARN basesrc gstbasesrc.c:3072:gst_base_src_loop:<v4l2src0> error: Internal data stream error.
0:00:04.247209181 77643 0x7f6464016d20 WARN basesrc gstbasesrc.c:3072:gst_base_src_loop:<v4l2src0> error: streaming stopped, reason not-negotiated (-4)
0:00:04.246846899 77643 0x7f646c003400 WARN v4l2src gstv4l2src.c:695:gst_v4l2src_query:<v4l2src0> Can't give latency since framerate isn't fixated !
0:00:04.247422399 77643 0x7f646c003400 WARN v4l2src gstv4l2src.c:695:gst_v4l2src_query:<v4l2src0> Can't give latency since framerate isn't fixated !
0:00:04.249446256 77643 0x7f646c003400 WARN rtspmedia rtsp-media.c:1834:default_handle_message: 0x7f646c034160: got error Internal data stream error. (gstbasesrc.c(3072): gst_base_src_loop (): /GstPipeline:media-pipeline/GstBin:bin0/GstV4l2Src:v4l2src0:
streaming stopped, reason not-negotiated (-4))
0:00:04.249557496 77643 0x561f080aaf60 WARN rtspmedia rtsp-media.c:2127:wait_preroll: failed to preroll pipeline
0:00:04.249603261 77643 0x561f080aaf60 WARN rtspmedia rtsp-media.c:2384:gst_rtsp_media_prepare: failed to preroll pipeline
0:00:04.254686872 77643 0x561f080aaf60 ERROR rtspclient rtsp-client.c:678:find_media: client 0x561f080b58b0: can't prepare media
0:00:04.254996068 77643 0x561f080aaf60 ERROR rtspclient rtsp-client.c:2210:handle_describe_request: client 0x561f080b58b0: no media
0:00:04.271635553 77643 0x7f6464016c00 FIXME default gstutils.c:3980:gst_pad_create_stream_id_internal:<appsrc3:src> Creating random stream-id, consider implementing a deterministic way of creating a stream-id
0:00:04.271635725 77643 0x7f646c003f60 FIXME default gstutils.c:3980:gst_pad_create_stream_id_internal:<appsrc2:src> Creating random stream-id, consider implementing a deterministic way of creating a stream-id
0:00:04.271760281 77643 0x561f080aaf60 WARN v4l2src gstv4l2src.c:695:gst_v4l2src_query:<v4l2src1> Can't give latency since framerate isn't fixated !
0:00:04.272014291 77643 0x7f646c003ea0 WARN basesrc gstbasesrc.c:3072:gst_base_src_loop:<v4l2src1> error: Internal data stream error.
0:00:04.272047911 77643 0x7f646c003ea0 WARN basesrc gstbasesrc.c:3072:gst_base_src_loop:<v4l2src1> error: streaming stopped, reason not-negotiated (-4)
0:00:04.272645141 77643 0x561f080aaf60 WARN rtspmedia rtsp-media.c:1834:default_handle_message: 0x7f646c0348e0: got error Internal data stream error. (gstbasesrc.c(3072): gst_base_src_loop (): /GstPipeline:media-pipeline/GstBin:bin1/GstV4l2Src:v4l2src1:
streaming stopped, reason not-negotiated (-4))
0:00:04.272711585 77643 0x7f646c003400 WARN rtspmedia rtsp-media.c:2127:wait_preroll: failed to preroll pipeline
0:00:04.272742948 77643 0x7f646c003400 WARN rtspmedia rtsp-media.c:2384:gst_rtsp_media_prepare: failed to preroll pipeline
0:00:04.277308540 77643 0x7f646c003400 ERROR rtspclient rtsp-client.c:678:find_media: client 0x561f080b59a0: can't prepare media
0:00:04.277484803 77643 0x7f646c003400 ERROR rtspclient rtsp-client.c:1993:handle_setup_request: client 0x561f080b59a0: media '/test' not found
The camera I am using is a USB camera and from
$ v4l2-ctl -d /dev/video0 --list-formats
ioctl: VIDIOC_ENUM_FMT
Type: Video Capture
[0]: 'YUYV' (YUYV 4:2:2)
[1]: 'MJPG' (Motion-JPEG, compressed)
Why can't I stream raw image data over RTSP ?
Thanks,

Answer 1

These are formats rtpvrawpay accepts as input:
format: { (string)RGB, (string)RGBA, (string)BGR, (string)BGRA, (string)AYUV, (string)UYVY, (string)I420, (string)Y41B, (string)UYVP }
While your camera seems to list YUYV only which is not one of the supported formats. You will probably have to insert a videoconvert in this pipeline too.
YUYV -> UYVY conversion should just be re-arranging the data, so that should be a lossless transformation.