The VideoLAN Forums

Posted: **02 Dec 2004 02:38**

Just wondered if anyone knew of the best settings they've found so far to stream various videos over their standard broadband connection (256kbit/s upload) ..

I've settled on this at the moment

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:sout=#transcode{vcodec=mp4v,vb=110,scale=0.5,acodec=vorb,ab=32,channels=2}:duplicate{dst=std{access=http,mux=ogg,url=:8000}}

{ tho i'm still using the gui i think i'll be moving over to the command line very soon as i'm sick of having to put my settings in via the gui every time i rerun the program

}

but as i mention elsewhere problems with ogg means that the ab parameter isn't used (correctly, quality is the best way to control ogg for quality's sake) and when i look at the stream info in a 2nd vlc listening to the streaming one i spot that my audio is taking up 80kbit/s ... HUGE compared to my ~128kbit/s for the video... I've used the default mpeg audio encoder and it respects the bitrates better.. but doesn't sound anywhere near what ogg sounds like at similar rates, also it doesn't work below 32k/s and again as i mention in my other post about audio problems it nor any other codec will work with the channels set to mono..

Anyone got any other video/audio codecs, settings that seem to have good results!??!

THis is for a dvd with widescreen.. the black bars really help keep the rates low.. 4:3 content seems to be much more difficult, as you'd expect really..

Posted: **08 Dec 2004 10:28**

i would switch to the DIV3 video protocol.. it just looks better at comparable bitrates (for me).. also, maybe try mpg4a for audio.. to be honest, i really cut audio to give myself a better picture.. really reduce the rate-- i think you'll find it's really bearable at lower rates..

Posted: **09 Dec 2004 15:28**

lower fps rate, use hq encoding
1 channel for audio segfaults on 0.8.1 here

depending on client, rtp/rtsp stream would probably be better idea

try:
vlc -H --advanced |grep sout

Posted: **09 Dec 2004 15:38**

If you don't require high frame rate, or don't have large source frame size, try the h264 video CODEC -- better quality than mp4v or DIV3 at lower bitrates. (the reason for lower frame rate is that it's quite processor intensive on the TX side, right now, as h264 in VLC is work-in-progress).

I've done initial tests with live CCTV, pretty decent video at 128 and 192K, 320x240

Posted: **09 Dec 2004 22:15**

Thanks for the replies guys.. I'm working from DVD resolution files mostly at the moment... I wanted to try h264 but whenever i select it i get the following errors in the messages

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stream_out_transcode error: cannot create chain
main error: stream chained failed for `transcode{vcodec=DIV3,vb=128,scale=0.75,acodec=mpga,ab=32,channels=2}'
main error: cannot start stream output instance, aborting
main error: cannot add this stream
main error: cannot create packetizer output
ffmpeg error: cannot find encoder h264
stream_out_transcode error: cannot find encoder
stream_out_transcode error: cannot create video chain
main error: cannot create packetizer output

I doubt i have the power to do anything good with it.. i was going to try latest nero recode to see if it could do any better, it has h264 encoding i believe now..

The lack of being able to encode mono audio is a real pain.. that you can't seem to drive ogg down to really low rates (below quality 1) is also a pain... if you select 16kbit/s for the audio it just crashes ... Its all very hit and miss for me sometimes if i veer away from what I know works ok.. it just annoys that so much is being devoted to audio, and that its stereo and sounding terrible for it... ogg is nice but 80k/s is poor for ogg it sounds great at 30-40k/s .. I stream audio via ICECAST at this rate..

I'll try an offline H264 encode and see what its like... is there a simple way to enable the encoder to work under VLC?

Cheers

Posted: **10 Dec 2004 01:57**

I made an offline encode with Nero recode and its AVC.. I turned off bi-directional encoding which made files VLC wouldn't play properly.. got a file that plays fine in VLC.. i then try to stream it and I just can't get it to work... if i leave it as an MPEG TS the audio part gets through ok and the client can hear it.. but the video just dont exist..

The streaming client has 3 streams

avc1 video
mp4a audio (with an incorrect reported frequency of 24khz not 48khz as its a HE AAC audio stream)
spu subtitle (which i dont seem to be able to view at all even just playing the file normally)

The recieving client gets 4 streams

h264 video
mp4a audio
mpga audio
mpgv video
mpga audio

and the afore mentioned i can hear the audio ok, but no video...

No other encapsulation methods allow the audio to get through, i've not checked everyone of those to see which streams get recieved.. its obviously confused somewhere

The VideoLAN Forums

Best settings for realtime transcoding for 30kbyte/s stream

Best settings for realtime transcoding for 30kbyte/s stream