Jump to time when streaming.

[MS]

On 03/01/16 16:06, Christopher Woods wrote:
>
> I suspect this is because mplayer is simply showing the raw input being
> piped to it by rtmpdump. It doesn't understand the skip request because
> it simply lives in the 'now' - it has no contextual understanding of the
> file's duration, it just plays whatever it gets until the pipe closes.
>
> The iPlayer... player is doing the streaming, decoding and playing
> itself. You'd have to figure out how to issue a time seek directive to
> rtmpdump (which may be possible, I've not RTFM for a while) without
> killing the existing stream. IANA rtmpdump guru though, I read the docs
> every time I need to do something with it! :)

Thanks.

So since rtmpdump is piping the video to vlc and because a pipe is one 
way only there's no way for vlc to send a signal back to rtmpdump that 
says jump to this position. The only reason jumping forwards to a 
specific time works is because vlc simply waits for that position to 
arrive and then resumes playing when it does.

BUT what may be possible is to send a signal to an existing rtmpdump 
process telling it to jump to a specific time? I've looked through the 
rtmpdump man page and can't see anything that looks promising.

10 mins later...

Somewhat to my surprise I've actually found a solution - rtmpdump can 
take a --start option. Here's what I did...

1. Start get_iplayer streaming a video in the usual way but using the -v 
option (verbose). After the video has started close vnc to end the 
streaming.

2. Scoll up the terminal output to the (very long) rtmpdump command line 
which on my system begins with: INFO: Command: "/usr/bin/rtmpdump"

3. Paste the whole command line into the terminal adding "--start 
NUM_SECS | vlc -" at the end.

Hey presto the video starts at the required time.

Perhaps someone in the development team might consider adding a 
"--stream-start-at num_secs" option?

Cheers.