[FFmpeg-user] Webcam RTMP stream - video problems

[Roger Pack]

On 6/21/16, hdt1977 at tom.com <hdt1977 at tom.com> wrote:
> Hello,
>
> I'm trying to capture audio and video from a webcam and stream it via RTMP
> to a Red5 media server, where others can then view the live stream.
> When I do it from a Flash applet (Publisher Demo from the Red5
> distribution), it works without problems.
> When I use ffmpeg, trying to stream *both* audio and video causes stuttering
> and delayed video playback.
> The video stream will be lagging behind what I do in front of the camera by
> approximately half a second, and it doesn't look "fluid".


What if you record to a local file?
Or you just mean there is an increase in latency?
If it's latency I've done a write up of what I know here:
https://trac.ffmpeg.org/wiki/StreamingGuide
Cheers/enjoy!

>
> My command line and environment:
> OS: Windows 7 x64
> FFmpeg version: N-58308-ge502783
> Command line:
> ffmpeg -f dshow -video_size 640x480 -framerate 15 -i "video=USB Video
> Device:audio=Microphone (4- USB Audio Device"^
>     -r 15/1 -s 640x480^
>     -acodec nellymoser -ac 1 -ar 22050^
>     -aq 30^
>     -q 28^
>     -threads 0^
>     -f flv rtmp://my-server-url/oflaDemo/test
>
> I'm using the Nellymoser codec because that's what the Flash applet uses - I
> also tried MP3 but then the delay is even worse.
> I've played around with the quality settings quite a bit, and some seem to
> result in a little less delay, but I couldn't find a convincing setting yet.
> If instead of streaming I write to a local flv file, it works great. If I
> disable the audio stream, it also works without problems.
> I don't think network bandwidth is an issue, as the server is connected via
> LAN.
>
> Do you have any suggestions regarding parameters/configuration, or what I
> could look into? Are other codecs more likely to work without problems?
>
> Hi,have you resolved this problem?and how to resolve it?Thanks.
>
>
>
>
>
>
>
> Best Regards,
> Niko
>
> Console output:
>
> Guessed Channel Layout for  Input Stream #0.1 : stereo
> Input #0, dshow, from 'video=USB Video Device:audio=Microphone (4- USB Audio
> Device':
>   Duration: N/A, start: 26089.932000, bitrate: 1411 kb/s
>     Stream #0:0: Video: mjpeg, yuvj422p(pc), 640x480, 15 tbr, 10000k tbn, 15
> tbc
>     Stream #0:1: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s
> [swscaler @ 0000000000301600] deprecated pixel format used, make sure you
> did set range correctly
> Output #0, flv, to 'rtmp://fb10dtools-dev/oflaDemo/test':
>   Metadata:
>     encoder         : Lavf55.21.100
>     Stream #0:0: Video: flv1 (flv) ([2][0][0][0] / 0x0002), yuv420p,
> 640x480, q=2-31, 200 kb/s, 1k tbn, 15 tbc
>     Stream #0:1: Audio: nellymoser ([6][0][0][0] / 0x0006), 22050 Hz, mono,
> flt, 128 kb/s
> Stream mapping:
>   Stream #0:0 -> #0:0 (mjpeg -> flv)
>   Stream #0:1 -> #0:1 (pcm_s16le -> nellymoser)
> Press [q] to stop, [?] for help
> [nellymoser @ 0000000000370280] Queue input is backward in time
>
>
>
>
> hdt1977 at tom.com
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