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Bug #5177

Weird stream encoding

Added by Mathias Neuhaus over 3 years ago. Updated over 3 years ago.

Status:
New
Priority:
Normal
Assignee:
-
Category:
-
Target version:
-
Start date:
2018-08-19
Due date:
% Done:

0%

Estimated time:
Found in version:
4.3-1292~g9b9ee6859
Affected Versions:

Description

Found some really odd encoding in recorded streams - please see attached media info.

Stream is 17.something seconds long, but the media info shows a video-length of 24:49:10 h; the offset into the streem (delay) is 24:48:53, so (lenght - delay) gives the correct running length. for the (2) audio streams the values are even more garbled.
You can get all the correct information from duration, delay, and "delay relative to ovideo" but the number are weird.

In consequence some (HW) decoders stumble, when palying those streams.
The "amcodec" used in Vero 4K won't synchronize correctly when skipping (ffd / bwd) within the stream.
The stream starts to play just fine, but when skipping synchronization is lost resulting in really bad video judder.

Problem seems to only show up, when AAC - or AAC_LATM - audio stream is recorded; with EAC3 audio at least everything's OK.

The .TS was recorded from German DVB-T2 (ARD bouquet (yes, it shows the ZDF label; but indeed is ARD)).
I'm not sure, whether this is encoded by Tvheadend or coming from the received transport stream.

This garbled encoding seems to also be used in the "htsp" stream profile (live TV) - at least the judder after skipping looks the same.


Files

ZDF-Morgenmagazin.ts (7.31 MB) ZDF-Morgenmagazin.ts recorded stream Mathias Neuhaus, 2018-08-17 06:08
ZDF-Morgenmagazin.ts.info (91.1 KB) ZDF-Morgenmagazin.ts.info Mediainfo for stream Mathias Neuhaus, 2018-08-17 06:08

History

#2

Updated by saen acro over 3 years ago

Maby is connected with HW transcoding and B frames

General
ID                                       : 1 (0x1)
Complete name                            : C:\Users\Saen\Desktop\ZDF-Morgenmagazin.ts
Format                                   : MPEG-TS
File size                                : 7.31 MiB
Duration                                 : 17 s 178 ms
Overall bit rate mode                    : Variable
Overall bit rate                         : 3 503 kb/s
Original network name                    : Astra Satellite Network 19,2'E

Video
ID                                       : 341 (0x155)
Menu ID                                  : 1 (0x1)
Format                                   : HEVC
Format/Info                              : High Efficiency Video Coding
Format profile                           : [email protected]@Main
Codec ID                                 : 36
Duration                                 : 24 h 49 min
Width                                    : 1 920 pixels
Height                                   : 1 080 pixels
Display aspect ratio                     : 16:9
Frame rate                               : 50.000 FPS
Standard                                 : Component
Color space                              : YUV
Chroma subsampling                       : 4:2:0 (Type 0)
Bit depth                                : 8 bits
Color range                              : Limited
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709

Audio #1
ID                                       : 342 (0x156)
Menu ID                                  : 1 (0x1)
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format profile                           : LC
Muxing mode                              : LATM
Codec ID                                 : 17-2
Duration                                 : 17 s 152 ms
Bit rate mode                            : Variable
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 48.0 kHz
Frame rate                               : 46.875 FPS (1024 SPF)
Compression mode                         : Lossy
Delay relative to video                  : -392 ms
Language                                 : German

Audio #2
ID                                       : 343 (0x157)
Menu ID                                  : 1 (0x1)
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format profile                           : LC
Muxing mode                              : LATM
Codec ID                                 : 17-2
Duration                                 : 17 s 24 ms
Bit rate mode                            : Variable
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 48.0 kHz
Frame rate                               : 46.875 FPS (1024 SPF)
Compression mode                         : Lossy
Delay relative to video                  : -392 ms

Text
ID                                       : 344 (0x158)-150
Menu ID                                  : 1 (0x1)
Format                                   : Teletext Subtitle
Language                                 : German

Other
ID                                       : 344 (0x158)-100
Menu ID                                  : 1 (0x1)
Format                                   : Teletext
Language                                 : German

Menu
ID                                       : 340 (0x154)
Menu ID                                  : 1 (0x1)
Duration                                 : 17 s 178 ms
List                                     : 341 (0x155) (HEVC) / 342 (0x156) (AAC, German) / 343 (0x157) (AAC) / 344 (0x158)-100 (Teletext, de) / 344 (0x158)-150 (Teletext Subtitle, de)
Language                                 :  / German /  / German / German
Service name                             : Das Erste HD
Service provider                         : ARD
Service type                             : reserved for future use
UTC 2018-08-14 03:30:00                  : de:ZDF-Morgenmagazin / de:Moderation: Wolf-Christian Ulrich, Dunja Hayali und Mitri Sirin / news/current affairs /  / 03:30:00 / Running
UTC 2018-08-14 07:00:00                  : de:Tagesschau / de: / news/current affairs /  / 00:05:00 / Not running
UTC 2018-08-14 07:05:00                  : de:Live nach Neun / de:Raus ins Leben / news/current affairs /  / 00:50:00 / 

rest of EPG is CUT

#3

Updated by Mathias Neuhaus over 3 years ago

I suspect as much.

The decoder doesn't seem to find the I-frame / B-frame when skipping (or takes a B-frame for an I-frame).

Nevertheless the duration / delay encoding is garbled.

#4

Updated by saen acro over 3 years ago

Keep in mind, that operator do not offer any time-shift optimisations.
So transcoding is 100% needed!

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