can't hear sound with some AC3 5.1 files on Shield

[justinrh 260]

It seems like every Disney movie on TV (or is it the local channel 31 that broadcasts them??) has AC3 5.1 but there is no sound when I play the recording.  I have to switch to the stereo track or turn on the Shield's Dolby processing (I normally leave have it off).  Any ideas as to why this would be a problem for some AC3 5.1 files?

Sent ATV app logs @ 3:52 CT, user home.

embyserver.txt

[rbjtech 5284]

Probably need an example of the file itself to determine - but I suspect they are not properly formatted AC3 or not AC3 at all, but that's what's it is being reported as - and thus need to be further processed by the Shield.

What does Mediainfo say about the Audio track ?

[ebr 16174]

Hi.  The major difference I see is the bitrate of the audio track (as well as channel content).  384k vs. 192k.

What happens with the same recording in the web app?

[justinrh 260]

MediaInfo says:

Audio #1
ID                                       : 52 (0x34)
Menu ID                                  : 1 (0x1)
Format                                   : AC-3
Format/Info                              : Audio Coding 3
Commercial name                          : Dolby Digital
Codec ID                                 : 129
Duration                                 : 31 min 58 s
Bit rate mode                            : Constant
Bit rate                                 : 384 kb/s
Channel(s)                               : 6 channels
Channel layout                           : L R C LFE Ls Rs
Sampling rate                            : 48.0 kHz
Frame rate                               : 31.250 FPS (1536 SPF)
Compression mode                         : Lossy
Delay relative to video                  : -305 ms
Stream size                              : 87.8 MiB (6%)
Language                                 : English
Service kind                             : Complete Main

 

Web app direct plays the 5.1 w/o issue in Edge (has to transcode in Fx), but the video has to transcode, of course.

If Emby would divulge how to share video files I would.

 

Edited October 31, 2023 by justinrh

[Luke 42078]

Hi.  Can you try sideloading our standard android app on the same device and see how that compares?

https://emby.media/emby-for-android.html

Thanks.

 

[rbjtech 5284]

11 hours ago, justinrh said:

MediaInfo says:

Audio #1
ID                                       : 52 (0x34)
Menu ID                                  : 1 (0x1)
Format                                   : AC-3
Format/Info                              : Audio Coding 3
Commercial name                          : Dolby Digital
Codec ID                                 : 129
Duration                                 : 31 min 58 s
Bit rate mode                            : Constant
Bit rate                                 : 384 kb/s
Channel(s)                               : 6 channels
Channel layout                           : L R C LFE Ls Rs
Sampling rate                            : 48.0 kHz
Frame rate                               : 31.250 FPS (1536 SPF)
Compression mode                         : Lossy
Delay relative to video                  : -305 ms
Stream size                              : 87.8 MiB (6%)
Language                                 : English
Service kind                             : Complete Main

 

Web app direct plays the 5.1 w/o issue in Edge (has to transcode in Fx), but the video has to transcode, of course.

If Emby would divulge how to share video files I would.

 

Looks fairly typical, so nothing obvious.

re - sharing the file, then trim a sample in mkvtoolnix (use the output tab, split mode, by parts based on timestamps - then use '00:01:00-00:02:00' (for example) to create an extractt of 60 seconds worth of video starting after 60 seconds. (format is HH:MM:SS)

 

 

[justinrh 260]

13 hours ago, rbjtech said:

re - sharing the file

??

[seanbuff 1316]

On 01/11/2023 at 08:21, justinrh said:

If Emby would divulge how to share video files I would.

 

3 minutes ago, justinrh said:

??

 

[justinrh 260]

But, how about this? 

ffmpeg.exe -i "Toy Story of Terror! 2013-10-16.ts" -t 30 -codec copy out.ts

BUT, if I trim it the problem is not seen.

@LukeI PM'd you a link to the uncut file, even though you didn't ask for it.  The std app is worser (even the trimmed file won't play audio).
The link expires in ONE WEEK!

Edited November 2, 2023 by justinrh

[rbjtech 5284]

7 hours ago, justinrh said:

But, how about this? 

ffmpeg.exe -i "Toy Story of Terror! 2013-10-16.ts" -t 30 -codec copy out.ts

 

Sure - you can use ffmpeg to trim if you like as this a transport stream (TS) - but as you've seen, there is a chance the 'timing' is corrected if you do this - which is probably the original problem.

[justinrh 260]

So maybe I just need to trim off a couple of seconds of each channel 31 recording 

[rbjtech 5284]

11 hours ago, justinrh said:

So maybe I just need to trim off a couple of seconds of each channel 31 recording 

Possible just do a post recording processing script - probably better to just write to an MKV rather than keep as a TS.  

[rbjtech 5284]

Just now, rbjtech said:

Possible just do a post recording processing script - probably better to just write to an MKV rather than keep as a TS.  

I don't know what OS Emby is running on - but some examples of a post processing script in this thread, but plenty more if you search the TV forum.

https://emby.media/community/index.php?/topic/118947-scheduled-mp4-conversion-after-recording-is-done/#comment-1293923

[justinrh 260]

Why prefer MKV?  The video track would still be MPEG, right?

[pwhodges 2012]

Because MKV has a much more flexible structure, which makes it easier to handle.

Paul

[rbjtech 5284]

9 hours ago, justinrh said:

Why prefer MKV?  The video track would still be MPEG, right?

Yes, MKV is just a container - but the key issues with some TS files is timing - by putting the mpeg2 in an MKV container, it adds timing into the stream, making ffwd/rwd, jump to a time etc possible.   With the native TS, it's likely to have sync issues.

[ebr 16174]

As others have said, the container can be very important/helpful.  TS is a Transport Stream which is something that is not indexed and not intended to be seekable.

[Luke 42078]

Do you get audio with this file in the standard app?

[justinrh 260]

Up until the freeze point.

[justinrh 260]

I've been converting all my recordings to MKV.  It does seek faster, but it doesn't fix the audio out-of-sync issue or the freeze issue.