[FFmpeg-user] Raspberry Pi to YouTube Live

[David Peterson]

I am trying to do kind of the same thing, except instead of grabbing what
the camera is spitting out, I am trying to grab the output from an iPad
that is sent via AirPlay to the rPi.  If I try to grab the frame buffer
using  ffmpeg -f fbdev -r 10 -i /dev/fb0 out.avi , the result "out.avi"
doesn't have anything of value in it.  I am using rPlay on the rPi to turn
the rPi into an AppleTV, basically.


On Sun, Jan 26, 2014 at 5:51 PM, Daryll Strauss <daryll.strauss at gmail.com>wrote:

>
> I've got this idea of using a raspberry pi as a cheap camera system to
> stream live events. You can get a board with a camera for $60, and $under
> $100 all in with Wifi, case, compact flash, power, etc.
>
> Streaming to YouTube works with the following command on my laptop:
>
> ffmpeg -f alsa -ar 44100 -b:a 128k -i pulse -f v4l2 -i /dev/video0
> -codec:v libx264 -s 1280x720 -r 30 -profile:v main -b:v 3000k -f flv
> -codec:a aac -strict experimental rtmp://a.rtmp.youtube.com/live2/STREAM
>
> You can tweak the parameters from there to go higher or lower resolution.
>
> That won't work for the Pi, because it doesn't have the horsepower to
> encode the video, (and they don't have audio in, but that's a different
> problem). They do have a dedicated video processor that can output h264, so
> if I can feed that to ffmpeg, then I might be able to get somewhere. That
> lead me to something like this:
>
> raspivid -t 999999 -w 1280 -h 720 -fps 30 -b 3000000 -pf main -g 30 -o -
> -ih -qp 10 -n | avconv -re -f h264 -i - -b:a 128k -f s16le -ar 44100 -ac 2
> -i /dev/zero -f flv -codec:v copy -codec:a aac -strict experimental out.flv
>
> The rapivid parameters are specifying 999999 seconds of 1280x720 video at
> 30fps with a 3Mb/s bitrate, main h264 profile, 30 frame GOP, output to std
> out, include headers (SPS, PPS which seemed like it might be useful), and
> quantization level 10 (which is fairly high quality).
>
> It spits out lines like:
>
> frame=  191 fps= 95 q=-1.0 size=       0kB time=10000000000.00 bitrate=
> 0.0kbit
> frame=  206 fps= 82 q=-1.0 size=       0kB time=10000000000.00 bitrate=
> 0.0kbit
> ...
> frame= 2845 fps= 31 q=-1.0 size=   34789kB time=0.02
> bitrate=12390920.3kbits/s
>
> That's quite odd, because the time is always 0.02 and the bitrate is
> wrong. Something gets written to out.flv, but if I ffprobe out.flv I see:
>
> Input #0, flv, from '/tmp/out.flv':
>   Metadata:
>     encoder         : Lavf53.21.1
>   Duration: 00:00:00.04, start: 0.000000, bitrate: 200 kb/s
>     Stream #0.0: Video: h264 (Main), yuv420p, 1280x720, 1k tbr, 1k tbn, 2k
> tbc
>     Stream #0.1: Audio: aac, 44100 Hz, 2 channels, 200 kb/s
>
> Clearly that's not right and doesn't play. The total bitrate is just the
> audio. The tbr, and tbc are wrong. I should be seeing something like this:
>
> Input #0, flv, from '/usr/tmp/good.flv':
>   Metadata:
>     encoder         : Lavf54.63.104
>   Duration: 00:00:11.65, start: 0.044000, bitrate: 3058 kb/s
>     Stream #0:0: Video: h264 (Main), yuv420p, 1280x720, 3000 kb/s, 30 tbr,
> 1k tbn, 60 tbc
>     Stream #0:1: Audio: aac, 44100 Hz, stereo, fltp, 128 kb/s
>
> It seems like the copy is sort of working, but the timing information
> isn't getting passed through. I'd tried a variety of options to get this
> working, but I'm stumped.
>
> Anyone have a suggestion for me?
>
>
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