Hi again. > So, you fixed the problem with QT player and H.264? Good.
Ahem, I actually switched to mpeg4 for the time being, as it gives acceptable results on the low bit-rates I'm currently using. Of course the best solution is to work it out to work across all the players (please read on). > Unfortunately, real player is closed source, so it's difficult to say > why it does not like a stream... Some time ago, I tried the open source > version of the player (helix player, if I remember well), but it did > not support MPEG4 or H.264 over RTP (I've been told it was because of > patent issues). > > Moreover, are you sure that a real-player powered device can play > MPEG4 or H.264 streams? Don't they only support H.263? Latest handsets (like the N series from Nokia) can play H.264, I suspect it has to do with Symbian update. MPEG4 is supported in almost every 3g device. > > I do not know... Is real player supposed to be compliant with the > standard RFCs? Or only with some special cases/a subset of the > standards? > I have 0 experience with it, but some years ago someone told me that > real player only supported a modified version of RTSP... I think there is a common standard it works according to. > I do not remember what the 3G standards require (but someone is telling > me that such standards are freely available... If you point me to a link > to the correct document, I can have a look). > But I think they require out-of-band global headers (so, your SDP must > contain a "config=" or a "sprop-parameters-set=" entry). I suspect 3G > also requires some additional attributes in the SDP that are not mandated > by the RFCs... Ok, good - it acknowledges what I thought. > Also, I am not sure if H.264 is ok for 3G (I think H.263 is ok, and > maybe MPEG4 video is ok too). Works on N95 for example. > If you have some stream that real player likes, can you post the > corresponding SDP? Here is a good example for live h.264 powered by DSS which: 1) Works on QuickTime *and* on RealPlayer. 2) Works on my mobile (N95). 3) Seems to be powered by VLC encoder (coupled with DSS of course). rtsp://streamer.neoarena.fi/mobile3g.sdp There are several differences between SDP prepared by ffmpeg, and by the one the link uses: FFMPEG SDP: v=0 o=- 0 0 IN IPV4 127.0.0.1 s=test stream c=IN IP4 0.0.0.0 t=0 0 a=tool:libavformat 52.18.0 a=control:* m=video 0 RTP/AVP 96 b=AS:200 a=3GPP-Adaptation-Support:1 a=rtpmap:96 MP4V-ES/90000 a=fmtp:96 profile-level-id=1 a=control:trackID=1 link SDP: v=0 o=- 14720353882026382024 14720353882026382024 IN IP4 neoencoder s=Neo Arena i=Neo Arena c=IN IP4 0.0.0.0 t=0 0 a=tool:vlc 0.9.0 a=recvonly a=type:broadcast a=charset:UTF-8 a=control:* m=video 0 RTP/AVP 96 b=AS:180 b=RR:800 a=rtpmap:96 H264/90000 a=fmtp:96 packetization-mode=1;profile-level-id=42c00c;sprop-parameter-sets=Z0LADJJSAoMvP/4T/hQAIAAAAwAgAAAGUeKFSQ==,aM48gA==; a=framesize:96 320-180 a=control:trackID=1 m=audio 0 RTP/AVP 97 b=AS:64 b=RR:800 a=rtpmap:97 MP4A-LATM/44100 a=fmtp:97 profile-level-id=15; object=2; cpresent=0; config=400024103fc0 a=control:trackID=2 I tried replacing FFMPEG sdp with this one, but it didn't work. Now, I think the following possible reasons: 1) Indeed some required fields are missing from the SDP as you said - question is which are exactly? 2) VLC encodes/transmits the mpeg4/h.264 video in way more compatible with RealPlayer and other players out there (while it uses ffmpeg for encoding, live555 is used for RTP streaming). Hope it gives us some start point to try and pinpoint this issue. _______________________________________________ libav-user mailing list [email protected] https://lists.mplayerhq.hu/mailman/listinfo/libav-user
