Bug #715
tvheadend not recording audio with DiBcom 8000 ISDB-T
| Status: | Rejected | Start date: | 09/21/2011 | |
|---|---|---|---|---|
| Priority: | High | Due date: | ||
| Assignee: |  John Törnblom | % Done: | 0% | |
| Category: | Streaming | |||
| Target version: | - | |||
| Found in version: | git rev c88a6469 | Affected Versions: |
Description
I'm trying to record 1seg video (320x240 for mobile devices) of Brazilian DTV with a DiBcom 8000 ISDB-T.
It works perfectly for the video stream, but it seem to miss the audio stream completely.
The audio stream is AAC, and from the log bellow, it say the AAC stream has 0 channels. Could that be the issue? some weirdness on reading the amount of audio channels from the stream information?
I tried to look in the code to find were it reads the number of channels, but couldn't find it.
so, this is the log output on the webui log, with debug enable:
Sep 20 22:22:02 Service: DiBcom 8000 ISDB-T/497,142 kHz: Status changed to [Hardware input]
Sep 20 22:22:02 Service: DiBcom 8000 ISDB-T/497,142 kHz: Status changed to [Hardware input] [Input on service]
Sep 20 22:22:02 Service: DiBcom 8000 ISDB-T/497,142 kHz: Status changed to [Hardware input] [Input on service] [Demuxed packets]
Sep 20 22:22:02 TS: DiBcom 8000 ISDB-T/497,142 kHz: H264 #529: Continuity counter error #530: Continuity counter error
Sep 20 22:22:02 TS: DiBcom 8000 ISDB-T/497,142 kHz: AAC
Sep 20 22:22:03 Service: DiBcom 8000 ISDB-T/497,142 kHz: Status changed to [Hardware input] [Input on service] [Demuxed packets] [Reassembled packets]
Sep 20 22:22:08 dvr: Overwrite protection, file "/home/hts/Globo-SD-Tapas-e-Beijos.2011-09-20.22-20.mkv" exists
Sep 20 22:22:08 dvr: File "/home/hts/Globo-SD-Tapas-e-Beijos.2011-09-20.22-20-1.mkv" -- No such file or directory -- Using for recording
Sep 20 22:22:08 dvr: Globo SD-Tapas e Beijos.2011-09-20.22-20 from adapter: "DiBcom 8000 ISDB-T", network: "", mux: "497,142 kHz", provider: "", service: ""
Sep 20 22:22:08 dvr: # type lang resolution samplerate channels
Sep 20 22:22:08 dvr: 1 H264 320 x 240
Sep 20 22:22:08 dvr: 2 AAC 96000 0
Sep 20 22:27:13 parser: transport stream AAC, DTS discontinuity. DTS = 27790442, last = 14861162
Sep 20 22:30:11 parser: transport stream AAC, DTS discontinuity. DTS = 43837802, last = 27801962
Sep 20 22:33:09 parser: transport stream AAC, DTS discontinuity. DTS = 59839082, last = 43845482
To add, I tried record some 1080p, and got the same problem!
any help would be much appreciate!!! I can't wait to start recording some stuff!! 
History
#1
Updated by Roberto Hradec over 1 year ago
I forgot to add... if someone can guide me a little bit were the problem could be, I can try work on a fix myself.
#2
Updated by Roberto Hradec over 1 year ago
I tried to apply the patch found on Bug #673, but no success!
#3
Updated by Hein Rigolo over 1 year ago
because the developers of tvheadend are based in Europe they do not have access to an ISDB-T signal for testing. Therefor the support for ISDB-T is not at the same level as DVB-T/S/C.
Also AAC support is also not as robust as the support for other audio codecs.
If you some programming experience you can start by examining the code to see how the signal is processed.
Hein
#4
Updated by Jernej Fijacko over 1 year ago
As far as I can see, the audio track is not recorded because of the DTS discontinuity.
Timings are calculated using the sampling rate (in your case 96kHz). One AAC frame contains 1024 samples.
My guess would be that the detected sampling rate (96kHz) is wrong for some reason, which concludes wrong timing calculations and therefore it's being ignored during recording.
#5
Updated by Hein Rigolo over 1 year ago
so that would be a first place to start looking at the code in order to identify of the code that is used to detect the sampling rate is working correctly with a ISDB-T datastream.
#6
Updated by Diego Porto over 1 year ago
- File correiohd-dump.ts added
same thing here... (besides the discontinuity errors)
DiBcom 8000 ISDB-T, no audio on brazilian dtv recordings/stream.
here's the .ts sample (recorded with the option "write full mux to file" enabled) so you can try to identify why tvheadend doesnt record/stream the audio.
can you guys please fix this?
tvheadend is the only dtv backend that "works" for me on xbmc.
#7
Updated by Roberto Hradec 12 months ago
Jernej Fijacko wrote:
As far as I can see, the audio track is not recorded because of the DTS discontinuity.
Timings are calculated using the sampling rate (in your case 96kHz). One AAC frame contains 1024 samples.
My guess would be that the detected sampling rate (96kHz) is wrong for some reason, which concludes wrong timing calculations and therefore it's being ignored during recording.
Thanks for the reply, Jernej. Sorry the loooong 9 months gap on the reply, but I have being pushed into other things and never had time to come back to this.
Finally I have some time, so I want to get this thing working once and for all.
One question: Do you think the problem could be related to the version of V4L2 I have installed? If I'm not mistaken, the DiBcom 8000 ISDB-T drivers are built in V4L2, so I'm wondering if an update to the latest V4L2 would help, or this problem have nothing to do with the driver?
I have updated to the latest tvheadend trunk, and although LIVE stream seems to work with sound now (although the video is pretty mangled), recording still don't have the audio track.
So I'm going to start digging this tonight and I'll shout "help" here if I get stuck!
thanks lots for now... and once more, my apologies for the long timeout...
cheers...
-H
#8
Updated by Adam Sutton 10 months ago
There are several known issues with audio muxing to MKV. John Tornblom is looking to rewrite this code, he's getting on fairly well but he's still some weeks from completion.
#9
Updated by Adam Sutton 10 months ago
- Category set to Streaming
- Status changed from New to Accepted
- Assignee set to John Törnblom
Passing to John, think this is his area.
#10
Updated by Adam Sutton 9 months ago
- Status changed from Accepted to Rejected
I'm gonna close this John,
It's ancient and you've reworked much of the code. Lets deal with new issues as and when they arrive.