Only a few channels are stuttering over a 100Mbps LAN (1 Viewer)

titof

Portal Pro
March 3, 2008
2,248
63
Home Country
France France
Hi,

I've make some tests :

- recording a channel with no stuttering on live and another with stuttering on live :

When I watch record with stuttering with RTSP mode : Stuttering, freeze
When I watch record with stuttering with NO RTSP mode : No stuttering, it's perfect.

With MPTVClient (and VLC), when I watch live TV on a stuttering channel : VLC totaly freeze in 4,5 second.

I've scan recordings with MediaInfo :

Channel stuttering :

Gnral
ID : 4
Nom complet : G:\TV\Les z'amours - France 2 - 2009-03-05.ts
Format : MPEG-TS
Taille du fichier : 12,5 Mio
Dure : 29s 668ms
Dbit global moyen : 3 533 Kbps

Vido
ID : 48 (0x30)
ID de menu : 137 (0x89)
Format : MPEG Video
Version du format : Version 2
Profil du format : Main@Main
Paramtres du format, Matrice : Par dfaut
Dure : 29s 668ms
Type de dbit : Variable
Dbit : 3 199 Kbps
Dbit nominal : 15,0 Mb/s
Largeur : 720 pixels
Hauteur : 576 pixels
Format l'cran : 16/9
Images par seconde : 25,000 Im/s
Norme : PAL
Colorimtrie : 4:2:0
Bits/(Pixel*Image) : 0.309

Audio
ID : 64 (0x40)
ID de menu : 137 (0x89)
Format : MPEG Audio
Version du format : Version 1
Profil du format : Layer 2
Type de dbit : Constant
Dbit : 192 Kbps
Canaux : 2 canaux
Echantillonnage : 48,0 KHz
Rsolution : 16 bits
Delai par rapport Vido : -295ms
Langue : Franais

Texte
ID : 80 (0x50)
ID de menu : 137 (0x89)
Format : DVB Subtitles
Langue : Franais

Channel with no stuttering :

Gnral
ID : 4
Nom complet : G:\TV\Pre et maire - TF1 - 2009-03-02.ts
Format : MPEG-TS
Taille du fichier : 4,25 Gio
Dure : 1h 59mn
Dbit global moyen : 5 079 Kbps

Vido
ID : 48 (0x30)
ID de menu : 137 (0x89)
Format : MPEG Video
Version du format : Version 2
Profil du format : Main@Main
Paramtres du format, Matrice : Par dfaut
Dure : 1h 59mn
Type de dbit : Variable
Dbit : 4 108 Kbps
Dbit nominal : 15,0 Mb/s
Largeur : 720 pixels
Hauteur : 576 pixels
Format l'cran : 16/9
Images par seconde : 25,000 Im/s
Norme : PAL
Colorimtrie : 4:2:0
Type d'image : Entrelac
Ordre des images : Ligne du haut d'abord
Bits/(Pixel*Image) : 0.396

Audio #1
ID : 64 (0x40)
ID de menu : 137 (0x89)
Format : MPEG Audio
Version du format : Version 1
Profil du format : Layer 2
Type de dbit : Constant
Dbit : 192 Kbps
Canaux : 2 canaux
Echantillonnage : 48,0 KHz
Rsolution : 16 bits
Delai par rapport Vido : -176ms
Langue : Franais

Audio #2
ID : 65 (0x41)
ID de menu : 137 (0x89)
Format : MPEG Audio
Version du format : Version 1
Profil du format : Layer 2
Type de dbit : Constant
Dbit : 128 Kbps
Canaux : 2 canaux
Echantillonnage : 48,0 KHz
Rsolution : 16 bits
Delai par rapport Vido : -200ms
Langue : Anglais

Audio #3
ID : 66 (0x42)
ID de menu : 137 (0x89)
Format : AC-3
Format/Info : Audio Coding 3
Type de dbit : Constant
Dbit : 384 Kbps
Canaux : 5 canaux
Position des cannaux : Front: L C R, Surround: L R
Echantillonnage : 48,0 KHz
Delai par rapport Vido : -295ms
Langue : Franais

Audio #4
ID : 67 (0x43)
ID de menu : 137 (0x89)
Format : MPEG Audio
Version du format : Version 1
Profil du format : Layer 2
Type de dbit : Constant
Dbit : 64,0 Kbps
Canaux : 2 canaux
Echantillonnage : 48,0 KHz
Rsolution : 16 bits
Delai par rapport Vido : -95ms
Langue : Allemand

Texte #1
ID : 80 (0x50)
ID de menu : 137 (0x89)
Format : DVB Subtitles
Langue : Franais

Texte #2
ID : 120 (0x78)
ID de menu : 137 (0x89)
Format : Teletext
Langue : Franais


Thanks for help !
 

titof

Portal Pro
March 3, 2008
2,248
63
Home Country
France France
another test with live TV on VLC, see print screen.
 

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titof

Portal Pro
March 3, 2008
2,248
63
Home Country
France France
When I watch a stuttering channel, evr.log, have a lot of line :

05-03-2009 16:24:00.438 [e88]Scheduling sample from the past (48 ms, last call to NotifyWorker: 17 ms)
05-03-2009 16:24:00.438 [b28]frame is too late for 49 ms, last sleep time 20 ms.
05-03-2009 16:24:00.582 [e88]Scheduling sample from the past (93 ms, last call to NotifyWorker: 143 ms)
05-03-2009 16:24:00.582 [b28]frame is too late for 93 ms, last sleep time 20 ms.
05-03-2009 16:24:00.590 [e88]Scheduling sample from the past (50 ms, last call to NotifyWorker: 9 ms)
05-03-2009 16:24:00.590 [b28]frame is too late for 50 ms, last sleep time 20 ms.
05-03-2009 16:24:00.634 [e88]Scheduling sample from the past (29 ms, last call to NotifyWorker: 44 ms)
05-03-2009 16:24:00.634 [b28]frame is too late for 29 ms, last sleep time 20 ms.

And when I watch a channel with no stuttering, evr.log don't have this lines ...
 

erosco

MP Donator
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  • June 25, 2007
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    Don't give up tos.. I'm sure I have the same problem. I too am seeing stuttering on some channels (the progressive ones) using multiseat and rtsp.

    I suspect it's a problem with the rtsp stream. I've been running network traces using wireshark and the bandwidth is not a problem (only about 12% of the cable). Also I haven't seen the 'continuity' errors in the lan trace that are appearing in the logs. My suspicion is that it's a software bug but I am not sure...

    Another interesting thing.. I turned of the epg grabber in the server (both timeshifting and background) and the stuttering decreased dramatically..

    I'm going to continue analysing this over the coming days and try and work out what's screwing up!

    Cheers
    erosco
     

    mts

    Portal Pro
    September 2, 2007
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    I turned of the epg grabber in the server (both timeshifting and background) and the stuttering decreased dramatically.

    I can confirm this.
     

    erosco

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  • June 25, 2007
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    Small update..

    I've built a patched TSREADER.ax that dumps the TS packet when an out of sequence occurs. I can confirm that this sequence error is not a LAN issue but is the way the packet is sent from the RTSP (Tv-Server) server.. So it's not a LAN problem but equally may be just transmission errors over DVB-T.

    I am still sus (especially because the stuttering increases when EPG is on). I'll continue my tracing to see what I can find.


    Cheers
    erosco

    Further update..

    After confirming today that this is not a network problem (correctly transmitted and received packets show missing TS records), I've continued me testing.

    A key point in my analysis is that after receiving a stutter in multiseat (using RTSP). If I hit the back button (to replay the last 30 seconds) the stutter doesn't happen again (in the same spot).

    This tells me that the live.ts.buffer file on the server has correctly captured an uncorrupted tv stream. The corruption is happening between the TV-Server reading the TS stream and pushing it out using the RTSP library.

    I am hoping the MP devs are following this post, as I'm now convinced this is a software bug in the TV-Server of LIVE555 library. I would appreciate any advice the TSWriter and RTSP devs could offer on where to go next. Ideally I'd like to add debug code that logs when stream TS sequence errors happen in TSWriter and matching code in the RTSP server code. Ideally matching lost packets should appear in the TSWriter Log, RTSP stream builder log, and TSReater log on the client. I strongly suspect this will show where TS records are being dropped in the server.


    Thanks
    erosco
     

    titof

    Portal Pro
    March 3, 2008
    2,248
    63
    Home Country
    France France
    Thanks for yours tests !!

    But for me, it's different :

    If I hit the back button (to replay the last 30 seconds) : Stuttering !
    If I record the stuttering channel and I watch the record with RTSP with MP (TV recording): Stuttering !
    If I Wath this record with VLC : NO stuttering !
    If I use VLC for stream this file over the network, and I watch this stream on another PC with VLC : NO Stuttering !
     

    titof

    Portal Pro
    March 3, 2008
    2,248
    63
    Home Country
    France France
    erosco
    I make an interesting test :

    - I recording a stuttering channel (stuttering in MP) with progDVB (no stuttering) and I watch this recording with MP in RTSP mode : Stuttering, with no RTSP, no stuttering.
    - Stream with VLC : no stuttering.

    This test confirms that there is a bug in stream of MP !
     

    erosco

    MP Donator
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  • June 25, 2007
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    Am still working on it..

    I've managed to dump TS records as they are read from the .ts.buffer file.. now I'm dumping TS records as they are transmitted over the UDP socket.. I believe the two dump's won't match.. I can then hone in on the problem.

    :)
     

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