FFMPEG streaming to Justin.tv/Twitch.tv

[SAKeeler]

Does anyone have any advice on how to make this work? I am using a modified script found using google.
Running Ubuntu 11.10 with Unity

#Streaming screen to Justin.tv
streaming() {
INRES="1920x1080" # input resolution
OUTRES="1280x720"
FPS="30" # target FPS
QUAL="medium"  # one of the many FFMPEG preset
STREAM_KEY="$1"
URL="rtmp://live.justin.tv/app/$STREAM_KEY" #flashver=FMLE/3.0\20(compatible;\20FMSc/1.0)"  

#ffmpeg -f x11grab -s "$INRES" -r "$FPS" -i :0.0 -ab 22050\
# -f alsa -ac 2 -i pulse -vcodec libx264 -s "$OUTRES" -level 30 -f mpegts \
# -acodec libmp3lame -ac 1  \
# -f flv "$URL"




ffmpeg -f x11grab -s "$INRES" -r "$FPS" -i :0.0  -ab 96k \
    -f alsa -ac 2 -i pulse -vcodec libx264 -crf 30 -vpre "$QUAL" -s "1280x720" \
    -acodec libmp3lame -ar 44100 -threads 8 \
    -f flv "$URL"
}

After modifying slighly I have it working, somewhat, it doesn't throw errors in the command line, but I don't get any video coming through when I load my channel on Juistin.tv.

Any sugestions? Pointers? and please don't say Webcamstudio, ffmpeg is far lighter weight, and all things considered easier to deal with. Aside from this little hiccup of course.

[balloons]

You want to use vlc with this:

http://apiwiki.justin.tv/mediawiki/i...oadcasting_API

[SAKeeler]

You want to use vlc with this:

http://apiwiki.justin.tv/mediawiki/i...oadcasting_API

I really was trying to avoid it, but I will be giving it a read through and testing it this weekend. Still tinkering with the ffmpeg solution though,
it's infuriating, it should work but just isn't, and I can't figure out why.
Makes me crazy.

Thanks for the link btw.

[balloons]

LOL -- ok, here's an example of ffmpeg working

#!/bin/bash
API_KEY="live_*****************"
FPS="15"

INRES='1280x1024'
OUTRES='1280x1024'

ffmpeg -f x11grab -s "$INRES" -r "$FPS" -i :0.0+1280 \
       -f alsa -i pulse -vcodec libx264  -s "$OUTRES"  \
       -acodec libmp3lame -ab 64k -ar 22050 -threads 0 \
       -f flv "rtmp://live.justin.tv/app/$API_KEY"

[vitrums]

It's actually kinda weird that this issue hasn't been resolved yet. At least I just couldn't find any solution whether googling or posting the official FFmpeg IRC channels. Any idea why I get a blank video on such RTMP resources as justin.tv, own3d and so on. Once again, there's no issue with local recordings, it works just fine.

[vitrums]

The solution came from a member of FFmpeg development group. Since the video itself is fine when it's examined locally, there must be some trouble with some of the formats. Actually it was all about pixel format.

If we capture the screen locally with the output option set as -f flv out.flv, the later examining of the video with ffprobe out.flv would show that the pixel format is 444, and it's not yet widely supported. Hence, it's necessary to add -pix_fmt yuv420p in the encoder properties to get your video playable by justin, twitch, own3d, ustream and other rtmp services

[SAKeeler]

Man, I'll have to make note and try it when i get a Ubuntu box up and running again.

thanks, wouldn't have thought of that.

The solution came from a member of FFmpeg development group. Since the video itself is fine when it's examined locally, there must be some trouble with some of the formats. Actually it was all about pixel format.

If we capture the screen locally with the output option set as -f flv out.flv, the later examining of the video with ffprobe out.flv would show that the pixel format is 444, and it's not yet widely supported. Hence, it's necessary to add -pix_fmt yuv420p in the encoder properties to get your video playable by justin, twitch, own3d, ustream and other rtmp services

[FakeOutdoorsman]

Why do you want to "save CPU power"? What's the actual question here? Why do you not want ffmpeg to take advantage of all available resources? It's a tradeoff: fewer resources = lower frame rate and/or frame size.

• Why do you use "-threads 6"? libx264 automatically determines the optimal number of threads by default so you generally do not need to declare threads unless you want to reduce them.
• "-qscale" and "-b" are mutually exclusive, but luckily libx264 ignores "-qscale".
• "-b" is ambiguous and you should use a stream specifier with this option: "-b:v" or "-b:a" (same with "-qscale").
• A better suggestion may be to base your encoding options on your upload rate if that is a limiting factor. I will expand on this later when I return from a trip. What is your max upload rate?
• There is no "lossless_ultrafast" preset unless you're using ancient or fake ffmpeg. Lossless = huge files which would probably not be good for uploading a live stream to this video service.