> However, I can't seem to get my latency down to
> less than about 1 second.
>
> [...]
>
> ffmpeg <input options> -loglevel debug -f webm -vcodec libvpx
Off the top of my head, -f webm could well be the problem. You don't
say how you're streaming the format, but it's hard to get less than a
second of latency if you mux into space-oriented format like webm and
stream over (for example) http.
For realtime streaming one generally wants to use an RTP stream instead.
HTH,
-r
> ffmpeg = vp8
> skip_threshold = drop_frame
> speed = cpu_used
> quality = --rt
> -b -maxrate -minrate = --end_usage=cbr --target-bitrate=
> -bufsize -rc_init_occupancy = buf-sz, buf-initial, buf-optimal (with
> current values, these will be set to 1000)
> -qmin, -qmax = --min-q, --max-q
>
The rc buffer settings do have some impact on latency when you're
bandwidth constrained. I just merged a revised algorithm that makes
this case perform better and should be included in our next release.
Can you provide any details on how you're measuring latency? If you're
seeing 1 second on localhost, there's something else going on. There
may be buffering in the webm muxer, as mentioned by Raplh Giles.
I'm doing almost the same thing, trying VP8, coming from H264. I'm seeing this issue using the webrtc project, working off their trunk. I was hoping that group could help me figure out how to track down where the latency is coming from but it must be a question nobody their really knows where to start looking.. My link to the webrtc post is below. Eventually I'll need to figure out why the video quality is not the greatest when using webrtc for faster moving thing as well, but right now I cannot move forward until I can get rid of the latency. Can someone assist me in trying to narrow down where to start looking? I have eliminated directshow and have my thread and process set to a high priority. It just acts like a buffer n levels deep exists...piling up video frames.
On Friday, October 26, 2012 4:27:09 PM UTC-4, hca...@gmail.com wrote:Hi, Rohan! What was your conclusion, here? I'm tantalized by vp8 / webm , but also can't get less than 1.5 approx latency