Fluid if real-time video - Discontinuity if recorded (even reading directly the .ts file)

[Fulvio Spelta]

Hi all,

I'm experiencing a strange problems. Long story short:

 

Case ok: if i view a channel (hd) streaming it by media server to a pc in lan in "direct video" (vlc as renderer on the pc) i can see the audio/video perfectly.

Caso ko: if i record using timer of the same channel, then i stream the recording again using "direct video" to the same pc and vls i have a lot of discontinuities.

 

I have the same discontinuities even if i read the recorded .ts file both via lan or copied locally on the pc.

 

The .ts file is recorded with the "TS, MPEG2 video as mpg" but i have the same problem (worse) using "Always TS" too.

 

Any hint about how to troubleshoot ?

Thanks a lot

[Griga]

vor 1 Stunde schrieb Fulvio Spelta:

if i record using timer of the same channel, then i stream the recording again using "direct video" to the same pc and vls i have a lot of discontinuities.

 

For further diagnosis, activate Media Server Options (SvcOptions.exe) -> Recordings -> Wrile log file and perform another recording. The recording  log file (same name as the recording, but .log extension) will indicate all discontinuities in the arriving data before they are written to disk. It should clarify if the discontinuities occur before or after recording (on streaming).

 

[Fulvio Spelta]

Hi sorry for late answer, I've been busy. I've done the test suggested, this way (all steps in sequence with no pause):

 

1) watched for 10 min a tv channel HD using vlc on client and the "direct stream" option: fluid video and audio

2) closed vlc

3) started the same channel recording (10 min) with "!!Always TS" and audio in MP3

4) Stop the recording

5) watched the recording using vls and "direct stream": problems on video

5) watched the .ts file using vlc: problems on video

 

Media Server Version: 3.2.4.0

 

Attached the log and txt files. In the log file errors are logged but i can't understand the cause.

Thanks

 

2023-05-01_01-10-17_Rai 2 HD (AC3,ita)_Check Up - RUBRICA - L eccellenza della Medicina italiana dai.txt 2023-05-01_01-10-17_Rai 2 HD (AC3,ita)_Check Up - RUBRICA - L eccellenza della Medicina italiana dai.log

Edited April 30, 2023 by Fulvio Spelta
recording stream test + version added

[Griga]

7 hours ago, Fulvio Spelta said:

In the log file errors are logged but i can't understand the cause.

 

The errors are already present in the stream received by the Media Server, so there is nothing that can be done about it in the Media Server.

 

A frequent cause for such drop-outs (missing data packets) are "aggressive" energy saving measures, that for example let the CPU cores often change to deeper sleep states (C-states) if the CPU load is low. Since recording only needs very little CPU power and waking up from deeper CPU sleep states takes some time, the tight timing requirements for live stream processing are not fulfilled anymore. Particularly USB DVB devices are affected by it. Such errors typically vanish, if the CPU is kept busier.

 

We already had a long discussion about his topic here. Maybe it gives you some hints what you can try. Here you can read how additional CPU power settings can be made visible in the Windows advanced power settings. Please ask, if there are still questions.

 

[Fulvio Spelta]

Thanks Griga, i'll read the discussions (I've seen that they need a bit of attention 🙂 ).

 

Just a quick curiosity: why the problem doesn't arise when i watch real time tv stream and coherently is present even in watching when the recording f the same channel is active?

 

I can't figure out why the real time watching without recording is ok but is ko when recording is running. I suppose that the CPU suspension will occour in both cases.

Thanks again

f

[Griga]

On 5/4/2023 at 12:29 PM, Fulvio Spelta said:

why the problem doesn't arise when i watch real time tv stream and coherently is present even in watching when the recording f the same channel is active?

 

Who knows? I would first use this little Microsoft tool (read more about the usage here) to create a certain amount of additional CPU activity on the server PC for finding out if this avoids the errors. If yes, they are caused by energy saving measures.

 

[Fulvio Spelta]

I've setup the tool to have 60% cpu load with load on all the 4 cores but nothing changed:

 

Device: ASTROMETA DTV Filter

EventID: 160

Timer Name: Paradise La finestra sullo showbiz - INTRATTENIMENTO - Dall'Auditorium della Conciliazi

Timer Start: 06/05/2023 06:55:00

Timer Duration: 01:45:00 (105 min. incl. 5 min. lead time, 10 min. follow-up time)

Timer Options: Teletext=0, Subtitles=0, All Audio Tracks=0, Adjust PAT/PMT=1, EIT EPG Data=0, Transponder Dump=0

Timer Source: Web

 

08:30:21 / 00:00:00 (~ 0,00 MB) Start Recording

08:30:22 / 00:00:00 (~ 0,00 MB) Gli imperdibili running | EventID: 161 PDC: 0x00000

08:30:23 / 00:00:01 (~ 0,38 MB) PID 302: AC3 Audio Stereo, 48 khz, 384 kbps

08:30:23 / 00:00:01 (~ 0,38 MB) Meglio di Radio2 Social Club not running | EventID: 167 PDC: 0x00000

08:30:24 / 00:00:02 (~ 1,12 MB) PID 202: H.264 Video, 16:9, 1920x1080, 25 fps

08:30:28 / 00:00:06 (~ 3,60 MB) Errors: 2

08:30:29 / 00:00:07 (~ 4,20 MB) Errors: 1

08:30:31 / 00:00:09 (~ 5,49 MB) Errors: 1

08:30:32 / 00:00:10 (~ 6,14 MB) Errors: 1

08:30:34 / 00:00:12 (~ 7,42 MB) Errors: 1

08:30:37 / 00:00:15 (~ 9,51 MB) Errors: 1

08:30:44 / 00:00:22 (~ 13,81 MB) Errors: 1

08:30:49 / 00:00:27 (~ 17,01 MB) Errors: 1

08:30:54 / 00:00:32 (~ 20,15 MB) Errors: 1

08:31:07 / 00:00:46 (~ 28,37 MB) Errors: 1

08:31:11 / 00:00:50 (~ 30,79 MB) Errors: 1

08:31:42 / 00:01:20 (~ 48,72 MB) Errors: 1

08:31:43 / 00:01:21 (~ 49,30 MB) Errors: 1

08:31:46 / 00:01:24 (~ 50,97 MB) Errors: 3

08:31:47 / 00:01:25 (~ 51,59 MB) Errors: 1

08:31:58 / 00:01:36 (~ 56,57 MB) Errors: 2

08:31:59 / 00:01:37 (~ 57,09 MB) Errors: 1

08:32:03 / 00:01:41 (~ 59,58 MB) Errors: 1

08:32:06 / 00:01:44 (~ 61,49 MB) Errors: 1

08:32:09 / 00:01:47 (~ 63,11 MB) Errors: 1

08:32:10 / 00:01:48 (~ 63,60 MB) Errors: 1

08:32:13 / 00:01:51 (~ 65,38 MB) Stop

 

[Griga]

On 5/6/2023 at 8:39 AM, Fulvio Spelta said:

I've setup the tool to have 60% cpu load with load on all the 4 cores but nothing changed

 

Proves that energy saving is not the cause (or not the only cause).

 

What happens if you record a channel and stream it simultaneously? This does not require two tuners. The Media Server will use the same data source for both.

 

[Fulvio Spelta]

Hi Griga, after reading the posts about the problems due to energy management I've done some tests and, long story short, the solution is: use a usb hub with a dedicated power supply and to use a non-usb storage for the recorded stream. Using this configuration it seems that no errors occur.

 

Hope to have more time to better understand the root cause; if I'll have more info I'll post here to share.

 

Really thanks for your support.

f

 

 

[Fulvio Spelta]

Hi all, after further test i can share that the main cause of errors seems to be some kind of "collision" on usb bus. Avoiding to use the usb disk solve the errors.

To extract the knowledge from this case i suggest anyone with same problem to:

• Provide power supply to dvb-t stick
• Use a non usb disk as target storage

Thanks again for support.