[streaming] Re: Streaming mp4+AAC to mobile phones

[Torben Knerr]

On 12/12/05, PERET Pierre-Hugues <ph.peret at free.fr> wrote:
>
> I fall on a 3gp stream that works on my mobile and it's HE-AAC .
> refer to this message :
> http://lists.apple.com/archives/Streaming-server-dev/2005/Oct/msg00024.html
> so this confirm the fact that this might be a .sdp issue.


...because the mobile tries to load the stream (instead of telling you that
this type of stream is not supported), right? So maybe it is an sdp issue...
One thing to test if aac is supported at all might be:
1) encode a video with mp4/aac using vlc
2) hint the encoded file with mp4box and put it in DSS' streaming dir
3) access the encoded file directly without using an sdp file (e.g.
rtsp://server:port/myfile.mp4) to see if aac sound works.
==> If it does not work, i bet it's the phone not soppurting aac. Then we
are sure that there's nothing wrong with the sdp (because it's not involved
here) and it's also not the fault of VLC's mp4a packetizer (because this one
is not involved when VLC encodes to file)
==> On the other hand, if it works, then there must be something wrong with
either the sdp or the packetize_mp4a method -- or something completely
different :-/

when playing with the sdp file,i can make my mobile phone loading my aac
> stream, but not playing it (player stuck at the end of loading).


Unfortunately I can't test the stream right now, because my current provider
does not allow any other traffic than http :(

looking at the code of the rtp module, i noticed amr / mpa4 sections seems
> inappropriate for mobile streaming (looks normal). unfortunatly i'm not able
> to implement such thing. Maybe i'm completely wrong ...
> correct me in this case.





At 17:48 12/12/2005 +0100, you wrote:
>
> Well,
> back again !
> streaming amr_wb is the same as amr_nb.. it doesn't play in QTplayer
> because it doesn't have the codecs, but the mobile player seems to accept
> it, but no sound is coming.
> switch back to amr_nb and play with the sdp file....
>
>
> At 11:55 12/12/2005 +0100, you wrote:
>
> I came to the same conclusion as you .
> For now, i'm working on the sdp stuff which i think is the problem. Or it
> might be the reflector module of DSS (in this case i doubt i could do
> anything for it).
>
> At 17:02 11/12/2005 -0800, Torben Knerr wrote:
>
>
> On 12/11/05, *PERET Pierre-Hugues* <ph.peret at free.fr> wrote:
>
> Didn't tried with ffmpeg's amr_wb.
> trying with http allways make my operator says wrong url, putting the full
> path or not.
>
> I talked on irc with some guys, and it seems that it's not very possible
> to do what i want , and someone oriented me to helix mobile server and
> mobile encoder, but it's far too expensive....
>
> as i want to take an already running stream and transcode it to 3gp , i
> think i cannot do that with opensource or free software.
>
>
> I think it is possible with vlc+dss, as soon as the sound issue is solved.
> Even though the stream might not be 100% 3gp spec compliant, it worked (at
> least with video only).
>
> I noticed that DSS is not able to stream mp4+aac to mobile phone -> nokia
> 6630 , sound is not working, even with the sample which comes with the
> server. Making aac streaming working on the mobile would be the
> solution.(amr is not my preference).
>
>
> I think that's not possible with the 6630, because it can not play aac
> streams :(
> On the other hand DSS _is able_ to stream mp4+aac (as you can see the
> stream with different players, such as QT), so imho it is definitely the
> mobile, which is _not able_ to play rtsp-streamed aac.
> But you are right, amr_nb is no solution because it is too crappy...
> amr_wb might be okay, even though not as good as aac.
>
> if you know a streaming server that can do that.. pls tell me.
> maybe tomorrow i will try amr_wb . i will keep you informed.
>
> NB : 3gp or mp4 generated by vlc doesn't play on the mobile phone on local
> playback (possibly beacause of the lack of hinted tracks)
>
>
> Right, for local playback you need to hint the files. I used mp4box for
> hinting and got it work to play locally with mp4+aac and mp4+amr (both
> encoded with vlc). Don't remember if it worked with h263 video too, but i
> guess so.
>
> Good luck with the amr_wb stuff!
>
>
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