I'm having problem with using udp_multicast transport method using ffmpeg or ffplay as a client to a webcam.
TCP transport works:
ffplay -rtsp_transport tcp rtsp://192.168.1.100/videoinput_1/mjpeg_3/media.stm
UDP transport works:
ffplay -rtsp_transport udp rtsp://192.168.1.100/videoinput_1/mjpeg_3/media.stm
Multicast transport does not work:
ffplay -rtsp_transport udp_multicast rtsp://192.168.1.100/videoinput_1/mjpeg_3/media.stm
The error message when udp_multicast is chosen reads:
[rtsp @ 0x7fd6a8000b80] Could not find codec parameters for stream 0 (Video: mjpeg, none(bt470bg/unknown/unknown)): unspecified size
Run with -v debug: Observe that the UDP multicast information appears in the SDP even though the chosen transport is unicast for this run. The SDP content is unchanged for unicast or multicast.
[tcp @ 0x7f648c002f40] Starting connection attempt to 192.168.1.100 port 554
[tcp @ 0x7f648c002f40] Successfully connected to 192.168.1.100 port 554
[rtsp @ 0x7f648c000b80] SDP:
v=0
o=- 621355968671884050 621355968671884050 IN IP4 192.168.1.100
s=/videoinput_1:0/mjpeg_3/media.stm
c=IN IP4 0.0.0.0
m=video 40004 RTP/AVP 26
c=IN IP4 237.0.0.3/1
a=control:trackID=1
a=range:npt=0-
a=framerate:25.0
Failed to parse interval end specification ''
[rtp @ 0x7f648c008e00] No default whitelist set
[udp @ 0x7f648c009900] No default whitelist set
[udp @ 0x7f648c009900] end receive buffer size reported is 425984
[udp @ 0x7f648c019c80] No default whitelist set
[udp @ 0x7f648c019c80] end receive buffer size reported is 425984
[rtsp @ 0x7f648c000b80] setting jitter buffer size to 500
[rtsp @ 0x7f648c000b80] hello state=0
Failed to parse interval end specification ''
[mjpeg @ 0x7f648c0046c0] marker=d8 avail_size_in_buf=145103
[mjpeg @ 0x7f648c0046c0] marker parser used 0 bytes (0 bits)
[mjpeg @ 0x7f648c0046c0] marker=e0 avail_size_in_buf=145101
[mjpeg @ 0x7f648c0046c0] marker parser used 16 bytes (128 bits)
[mjpeg @ 0x7f648c0046c0] marker=db avail_size_in_buf=145083
[mjpeg @ 0x7f648c0046c0] index=0
[mjpeg @ 0x7f648c0046c0] qscale[0]: 5
[mjpeg @ 0x7f648c0046c0] index=1
[mjpeg @ 0x7f648c0046c0] qscale[1]: 10
[mjpeg @ 0x7f648c0046c0] marker parser used 132 bytes (1056 bits)
[mjpeg @ 0x7f648c0046c0] marker=c4 avail_size_in_buf=144949
[mjpeg @ 0x7f648c0046c0] marker parser used 0 bytes (0 bits)
[mjpeg @ 0x7f648c0046c0] marker=c0 avail_size_in_buf=144529
[mjpeg @ 0x7f648c0046c0] Changing bps from 0 to 8
[mjpeg @ 0x7f648c0046c0] sof0: picture: 1920x1080
[mjpeg @ 0x7f648c0046c0] component 0 2:2 id: 0 quant:0
[mjpeg @ 0x7f648c0046c0] component 1 1:1 id: 1 quant:1
[mjpeg @ 0x7f648c0046c0] component 2 1:1 id: 2 quant:1
[mjpeg @ 0x7f648c0046c0] pix fmt id 22111100
[mjpeg @ 0x7f648c0046c0] Format yuvj420p chosen by get_format().
[mjpeg @ 0x7f648c0046c0] marker parser used 17 bytes (136 bits)
[mjpeg @ 0x7f648c0046c0] escaping removed 676 bytes
[mjpeg @ 0x7f648c0046c0] marker=da avail_size_in_buf=144510
[mjpeg @ 0x7f648c0046c0] marker parser used 143834 bytes (1150672 bits)
[mjpeg @ 0x7f648c0046c0] marker=d9 avail_size_in_buf=2
[mjpeg @ 0x7f648c0046c0] decode frame unused 2 bytes
[rtsp @ 0x7f648c000b80] All info found vq= 0KB sq= 0B f=0/0
[rtsp @ 0x7f648c000b80] rfps: 24.416667 0.018101
Last message repeated 1 times
[rtsp @ 0x7f648c000b80] rfps: 24.500000 0.013298
Last message repeated 1 times
[rtsp @ 0x7f648c000b80] rfps: 24.583333 0.009235
Last message repeated 1 times
[rtsp @ 0x7f648c000b80] rfps: 24.666667 0.005910
Last message repeated 1 times
[rtsp @ 0x7f648c000b80] rfps: 24.750000 0.003324
Last message repeated 1 times
[rtsp @ 0x7f648c000b80] rfps: 24.833333 0.001477
Last message repeated 1 times
[rtsp @ 0x7f648c000b80] rfps: 24.916667 0.000369
Last message repeated 1 times
[rtsp @ 0x7f648c000b80] rfps: 25.000000 0.000000
[rtsp @ 0x7f648c000b80] rfps: 25.083333 0.000370
Last message repeated 1 times
[rtsp @ 0x7f648c000b80] rfps: 25.166667 0.001478
Last message repeated 1 times
[rtsp @ 0x7f648c000b80] rfps: 25.250000 0.003326
Last message repeated 1 times
[rtsp @ 0x7f648c000b80] rfps: 25.333333 0.005912
Last message repeated 1 times
[rtsp @ 0x7f648c000b80] rfps: 25.416667 0.009238
Last message repeated 1 times
[rtsp @ 0x7f648c000b80] rfps: 25.500000 0.013302
Last message repeated 1 times
[rtsp @ 0x7f648c000b80] rfps: 25.583333 0.018105
Last message repeated 1 times
[rtsp @ 0x7f648c000b80] rfps: 50.000000 0.000000
[rtsp @ 0x7f648c000b80] Setting avg frame rate based on r frame rate
Input #0, rtsp, from 'rtsp://192.168.1.100/videoinput_1/mjpeg_3/media.stm':
Metadata:
title : /videoinput_1:0/mjpeg_3/media.stm
Duration: N/A, start: 0.000000, bitrate: N/A
Stream #0:0, 21, 1/90000: Video: mjpeg (Baseline), 1 reference frame, yuvj420p(pc, bt470bg/unknown/unknown, center), 1920x1080 [SAR 1:1 DAR 16:9], 0/1, 25 fps, 25 tbr, 90k tbn, 90k tbc
[mjpeg @ 0x7f648c02ad80] marker=d8 avail_size_in_buf=145103
Here is the same debug section when using udp_multicast. The SDP is identical as mentioned, and the block after the SDP containing [mjpeg] codec info is entirely missing (beginning with marker=d8)--the stream is never identified. This happens (to the eye) instantaneously, there's no indication of a timeout waiting unsuccessfully for an RTP packet, though this, too, could just be insufficient debug info in the driver. Also note that ffmpeg knows that the frames are MJPEG frames and the color primaries are PAL, it just doesn't know the size. Also curious, but not relevant to the problem, the unicast UDP transport destination port utilized for the stream does not appear in the ffmpeg debug dump shown above, meaning part of the RTSP/RTP driver is hiding important information under the kimono, that port number and how it knows that the frames will be MJPEG.
[tcp @ 0x7effe0002f40] Starting connection attempt to 192.168.1.100 port 554
[tcp @ 0x7effe0002f40] Successfully connected to 192.168.1.100 port 554
[rtsp @ 0x7effe0000b80] SDP:aq= 0KB vq= 0KB sq= 0B f=0/0
v=0
o=- 621355968671884050 621355968671884050 IN IP4 192.168.1.100
s=/videoinput_1:0/mjpeg_3/media.stm
c=IN IP4 0.0.0.0
m=video 40004 RTP/AVP 26
c=IN IP4 237.0.0.3/1
a=control:trackID=1
a=range:npt=0-
a=framerate:25.0
Failed to parse interval end specification ''
[rtp @ 0x7effe0008e00] No default whitelist set
[udp @ 0x7effe0009900] No default whitelist set
[udp @ 0x7effe0009900] end receive buffer size reported is 425984
[udp @ 0x7effe0019c40] No default whitelist set
[udp @ 0x7effe0019c40] end receive buffer size reported is 425984
[rtsp @ 0x7effe0000b80] setting jitter buffer size to 500
[rtsp @ 0x7effe0000b80] hello state=0
Failed to parse interval end specification ''
[rtsp @ 0x7effe0000b80] Could not find codec parameters for stream 0 (Video: mjpeg, 1 reference frame, none(bt470bg/unknown/unknown, center)): unspecified size
Consider increasing the value for the 'analyzeduration' (0) and 'probesize' (5000000) options
Input #0, rtsp, from 'rtsp://192.168.1.100/videoinput_1/mjpeg_3/media.stm':
Metadata:
title : /videoinput_1:0/mjpeg_3/media.stm
Duration: N/A, start: 0.000000, bitrate: N/A
Stream #0:0, 0, 1/90000: Video: mjpeg, 1 reference frame, none(bt470bg/unknown/unknown, center), 90k tbr, 90k tbn, 90k tbc
nan M-V: nan fd= 0 aq= 0KB vq= 0KB sq= 0B f=0/0
This is the TCPDUMP of the traffic. The information in both streams appears identical.
19:21:30.703599 IP 192.168.1.100.64271 > 192.168.1.98.5239: UDP, length 60
19:21:30.703734 IP 192.168.1.100.64270 > 192.168.1.98.5238: UDP, length 1400
19:21:30.703852 IP 192.168.1.100.64270 > 192.168.1.98.5238: UDP, length 1400
19:21:30.704326 IP 192.168.1.100.64270 > 192.168.1.98.5238: UDP, length 1400
19:21:30.704326 IP 192.168.1.100.64270 > 192.168.1.98.5238: UDP, length 1400
19:21:30.704327 IP 192.168.1.100.64270 > 192.168.1.98.5238: UDP, length 1400
19:21:30.704327 IP 192.168.1.100.64270 > 192.168.1.98.5238: UDP, length 1400
19:21:30.704504 IP 192.168.1.100.64270 > 192.168.1.98.5238: UDP, length 1400
19:21:30.704813 IP 192.168.1.100.64270 > 192.168.1.98.5238: UDP, length 1400
19:21:30.704814 IP 192.168.1.100.64270 > 192.168.1.98.5238: UDP, length 1400
19:21:30.704872 IP 192.168.1.100.64270 > 192.168.1.98.5238: UDP, length 732
19:21:30.704873 IP 192.168.1.100.59869 > 237.0.0.3.40005: UDP, length 60
19:21:30.705513 IP 192.168.1.100.59868 > 237.0.0.3.40004: UDP, length 1400
19:21:30.705513 IP 192.168.1.100.59868 > 237.0.0.3.40004: UDP, length 1400
19:21:30.705513 IP 192.168.1.100.59868 > 237.0.0.3.40004: UDP, length 1400
19:21:30.705513 IP 192.168.1.100.59868 > 237.0.0.3.40004: UDP, length 1400
19:21:30.705594 IP 192.168.1.100.59868 > 237.0.0.3.40004: UDP, length 1400
19:21:30.705774 IP 192.168.1.100.59868 > 237.0.0.3.40004: UDP, length 1400
19:21:30.706236 IP 192.168.1.100.59868 > 237.0.0.3.40004: UDP, length 1400
19:21:30.706236 IP 192.168.1.100.59868 > 237.0.0.3.40004: UDP, length 1400
19:21:30.706236 IP 192.168.1.100.59868 > 237.0.0.3.40004: UDP, length 1400
19:21:30.706236 IP 192.168.1.100.59868 > 237.0.0.3.40004: UDP, length 732
I hope this is a configuration problem, that I can fix this in my ffplay/ffmpeg line, and it's not a bug in ffmpeg. Thanks for any tips.
