Live feed, buffring? why?

Archive mAirList 4.x (English)
1

When I use the live feeds will be a delay of 11 seconds.
And I wonder why?

I made a playlist of three players and all three are allowed to play
sounds in automation mode.
when I play a file that is approximately 54 minutes long and then
going to play the live feeds, it will be a delay of 11 seconds.

But if I play a file that is about 10 seconds and then plays the live
feeds, there will be no delay.

How come?

I am using a Lynx AES16 soundcard and a new and very fast computer with a lot of memory and space.

2

How long has the item been prebuffered (loaded into the other player, or prebuffered outsite the player with a green checkmark in the icon) when the delay occurs?

When the item is prebuffered, the recording is started in the background, but no audio is passed to the playback sound card yet. I suspect that the recording soundcard delivers the audio a bit too fast, so that a delay is slowly building up while the long previous item plays.

You could verify this by putting the live feed item into the playlist only shortly before the 54-minute item ends. Or just set the “no prebuffering” flag on the live feed item. (If it’s already prebuffered at the time you set the flag, cut it from the playlist and paste it back in.)

3

Hi!

It has been charged in 54 minutes in the player.

What I want is for it to take care of automatically.

I will try “Do not prebuffring”

Here’s my playlist:

HARD - 18:03:00 - LINE ON
SOFT - 18:03:00 - ENCODER CONNECT to file RADIO SPORT
SOFT - 18:03:00 - BREAK
HARD - 18:06:00 - OFF LINE
SOFT - 18:06:00 - ENCODER DISCONNECT save file RADIO SPORT
SOFT - 18:06:00 - BREAK
HARD - 18:45:00 - PLAYLIST 1 NEXT
SOFT - 18:45:00 - mingle SOUND
HARD - 18:59:48 - PLAYLIST 1 NEXT
SOFT - 18:59:48 - P4 jingle
HARD - 19:00:00 - PLAYLIST 1 NEXT
SOFT - 19:00:00 - LIVE STREAM IP encoder EKONÄT
HARD - 19:03:00 - PLAYLIST 1 NEXT
SOFT - 19:03:00 - RADIO SPORT
HARD - 19:06:00 - PLAYLIST 1 NEXT
SOFT - 19:06:00 - P4 PREMIERE Hour 1 54:00:00 min
HARD - 20:00:00 - PLAYLIST 1 NEXT
SOFT - 20:00:00 - LIVE STREAM IP EKONÄT encoder / nets
HARD - 20:06:00 - PLAYLIST 1 NEXT
SOFT - 20:06:00 - P4 PREMIERE hour 2 53:30:00 min
SOFT - 20:59:30 - TRAILER
HARD - 21:00:00 - PLAYLIST 1 NEXT
SOFT - 21:00:00 - LIVE STREAM IP encoder
HARD - 21:03:00 - DISCONNECT

Should I write the playlist in any other way?

4

Now I have tried checking the “Do not prebuffering” box, and let the live feed be in the player for about 15 minutes.
And there is a delay of about 1 second.
But perhaps it is inevitable?

5

There will always be a slight delay; it actually depends on the sound cards used and their buffer/latency settings.

Can you please post your devices.ini and bass.ini files?

6

I understand that.

I’ll send the files here.

bass.ini (5.89 KB)

devices.ini (401 Bytes)

7

Thanks.

Another question, what recorded device did you use for the Live Feed item? And was it DirectSound, WASAPI or ASIO?

8

The name of the audio input is 03-04, on the sound card anyway.
It is the same as the encoder.

I use DirectSound.

9

I have just uploaded Build 1422 of v4.1.

There was a bug in the config processing, which made the recording take place in 44100 regardless of what you set up in the config. (Actually the config was set back to 44100 after a restart.)

This issue could be responsible for the effect you described. Some soundcards or drivers are known to deliver a signal that is slightly too slow or too fast when using a different sample rate than the “native” one. (Sound Blaster Audigy cards are a prominent example. The Lynx card might have a similar issue.)

I noticed that you use 48000 for playout, so you should download that snapshot, go to mAirListConfig -> Audio Settings -> DirectSound -> Record Devices, and set the sample rate to 48000 for all inputs of that cards.

Will the 10s delay go away then even if you prebuffer the item for a long time?

10

The delay has now almost disappeared, now it’s just two hundredths
But a new problem has arisen.

When I play the Live Feeds, so will a stuttering sound heard.
Very small sound, though frequent, and annoying.

And when I would play the last Live Feed so chopped it and got stuck.
Then it had been loaded in 54 minutes.

11

Both playback and recording are DirectSound, right?

I think we need to add an extra buffer setting, similar to the ExtraSleep setting in v4.0.

http://forum.mairlist.com/index.php/topic,5511.msg39477.html#msg39477

12

Before I change the code, can you please try to put up the Mixer Buffer Size in the DirectSound for all devices? (For the first two devices, it is set to 0. But also try to increase it for the other devices.)

13

Yes, both in and out is Direct Sound.

Have you any suggestions on how large Buffer Size to be?

14

No, because it heavily depends on the specific hardware.

Start with a very large buffer size, say 1000ms, to see if the problem goes away. If it does, decrease the size slowly until you find a value that gives you minimum latency without any crackles.

15

I tested a little now.
And it seems to work.

I have set the following:
Hardware Buffer size = 256 ms
Mixer Buffer size = 50 ms

But I will make a major test tomorrow night.

16

I have tested, and I got mixed results.

Everything works fine with timer and jingles starts properly.

Before the Live Feed started I looked at the meters and everything looked good.

But when the Live Feed started, there was a crackling noise.
I started the Live feed again, and then it worked.

I’ve attached the audio file so you hear what I mean.

Then when the next Live Feed started, an hour later, so it worked perfectly.

It seems that this error comes and goes.

Any ideas?

Live Feed problem.mp3 (96 KB)

17

Does this also happen with a slightly higher buffer setting? Perhaps your current setting is very close to what the soundcard can handle.

By the way, if you’re using Windows 7, try WASAPI instead of DirectSound. It should give you much lower latency. (You have to put down the default buffer settings though, they are set to a very high and safe value in the default configuration.)

On Vista and 7, there is no “true” DirectSound anymore, but it’s only a wrapper for the new WASAPI standard. With the new WASAPI features in v4.1, you can use the WASAPI layer directly and benefit from the better performance.

18

Now I tried to run WASAPI for the Live Feed.
But I still get crackling noise.
Although there is a latency 1000 ms.

And I get the same problem with the encoder with WASAPI.

Some ideas?

19

First of all, we should make sure that the problem is not caused by any old or buggy third-party library.

There were a couple of minor updates to the BASS related DLLs available. I have just updated the installation packages for the v4.1 alpha release - can you reinstall mAirList (just run the setup on top of the existing installation) and try again with the new DLLs? Just in case…

If the problem is still there, we will start to dissect it :slight_smile:

20

Torben, it works now!

Now that I tested, I have not heard any problems at all.
However, I shall run a bigger test, but right now it works perfectly!

Thank you!