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HLS Download speeds

user-585

The HLS Streams seem to download at a reasonable speed most of the time but I have noticed that if I try to download multiple programmes across 2 or 3 windows then all instances slow right down. With RTMPDump running it across a few windows didn't seem to have an impact on the speed too much so is this something to do with FFMpeg or something else?

user-30

I'm not seeing this. I tried with 5 concurrent streams and I seem to get about a constant 1.3MB/s download per stream on a 150mbps cable connection. Are you trying any particular set of programmes?

user-30

Though I did just see something I wasn't expecting. With get_iplayer --modes=hlsbest --pid=b069b0lt I noticed the following:

get_iplayer Output:

192904.447 kB / 658.00 sec (18.5%)
ERROR: RTMP_ReadPacket, failed to read RTMP packet header
192904.447 kB / 658.00 sec (18.5%)
INFO: Connection timed out, trying to resume.
Resuming download at: 192904.447 kB

Should there be RTMP errors when using an HLS stream?

user-585

No particular programmes. We are on a 60mbps connection but it should still have the power to run a few concurrently. A 1 hour programme run on its own takes about 6 minutes.

Also you seem to be getting output in percentages. I'm getting it like this:

get_iplayer Output:

frame=  151 fps= 42 q=-1.0 size=    1920kB time=00:00:06.04 bitrate=2604.5kbits/
frame=  175 fps= 42 q=-1.0 size=    2409kB time=00:00:07.00 bitrate=2819.7kbits/
frame=  191 fps= 40 q=-1.0 size=    2634kB time=00:00:07.64 bitrate=2824.2kbits/
frame=  195 fps= 34 q=-1.0 size=    2683kB time=00:00:07.80 bitrate=2818.1kbits/

user-30

I've always got a percentage reading. I was wondering why people were talking about frames per second on the mailing list. Perhaps it's because I'm using the PPA version?

get_iplayer Output:

get_iplayer 2.94-ppa23

user-2

SP: For some reason, you're not downloading HLS . That progress display is from rtmpdump, not ffmpeg.

user-30

For me the problem is --modes=hlsbest. That simply gives me the RTMP stream. I have to use --tvmode=hlsbest and then I receive the HLS stream.

Do you experience this behaviour?

Example commands...

Receive RTMP:

get_iplayer --modes=hlsbest --pid=p02z83jc --force

Receive HLS:

get_iplayer --tvmode=hlsbest --pid=p02z83jc --force

user-2

No.  Do you have tvmode set in preferences?

user-30

Oops...

get_iplayer Output:

tvmode = best
fileprefix = <nameshort><-senum><-episodeshort>
type = tv

user-585

Are you still able to run 5 concurrent HLS downloads at a good speed?

user-30

Yes. I get a lower reported frame rate per stream (around 300fps) compared to when I run a single download (around 650fps) but looking at the network I see I'm pulling down about 19MBps (megabytes per second) when running 5 streams which is maxing out my connection.

A single stream seems to max out at around 10MBps for me, though it is fairly unstable and drops down to about 600fps by the time the download is complete.

user-585

Yes the fps reading does seem to be quite unreliable compared to the actual MB/s.

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