REL MP4 files with seemingly hidden Sub tracks

[Mousewarp]

Hi,

I have been encountering a number of MP4 files with Subs that can turned off via the Player, MPC/VLC etc., or via LAV Splitter, but when I load them into Yamb or MKVToolnix the Sub tracks don't show up. I know they aren't hard coded or the players and LAV could not turn them off.

My question is what software can see them, how are they encoded in the first place to make them invisible to other programs, and how do I remove them?

Addendum: Media Info has this to say about one of these files...

Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : 40
Duration : 53mn 30s
Bit rate mode : Variable
Bit rate : 126 Kbps
Maximum bit rate : 164 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Compression mode : Lossy
Stream size : 48.4 MiB (16%)
Encoded date : UTC 2013-02-01 10:51:58
Tagged date : UTC 2013-02-01 10:51:58

Text
ID : 3
Format : Timed Text
Codec ID : tx3g
Duration : 53mn 21s
Bit rate mode : Variable
Bit rate : 154 bps
Stream size : 60.1 KiB (0%)
Language : English
Encoded date : UTC 2013-02-01 10:51:58
Tagged date : UTC 2013-02-01 10:51:58

I am new to 'tx3g' Soft coded Subs and would like to understand them better, plus be able to remove the pesky tracks at will...

[netmask56]

message redundant

[Baldrick]

Have you tried play with quicktime player?

If you remux to a mkv with mkvtoolnix do the subs follow ?

[videobruger]

My understanding:

Timed Text is a xml subtitle format. The MP4 container only supports subtitles in either ttxt or idx/vobsub formats.

Both MY MP4Box GUI and YAMB recognize the .ttxt subtitle and can de-mux it. My MP4Box GUI de-mux as .srt and YAMB offers a choise. Also My MP4BoxGUI and YAMB automatically converts .srt to .ttxt when muxing.

MKVMergeGUI doesn't recognise .ttxt in a MP4 container.

PS You can create a .ttxt file from a .srt by (CLI): mp4box -ttxt Subtitle.srt

[Mousewarp]

Have you tried play with quicktime player?

If you remux to a mkv with mkvtoolnix do the subs follow ?

Yes they do, they are not standard Subtitle tracks, in fact in MKVToolnix they are invisible...

[Mousewarp]

My understanding:

Timed Text is a xml subtitle format. The MP4 container only supports subtitles in either ttxt or idx/vobsub formats.

Both MY MP4Box GUI and YAMB recognize the .ttxt subtitle and can de-mux it. My MP4Box GUI de-mux as .srt and YAMB offers a choise. Also My MP4BoxGUI and YAMB automatically converts .srt to .ttxt when muxing.

MKVMergeGUI doesn't recognise .ttxt in a MP4 container.

PS You can create a .ttxt file from a .srt by (CLI): mp4box -ttxt Subtitle.srt

These subs are in a weird format 'tx3g', neither Yamb or My MP4Box see them, nothing could see them until I tried, mp4muxer-0.9.3 which I am happy to say allowed me to delete the track altogether.

I can still find nearly zero info about these subs, but it seems likely they are some variant of XML. All I know is they are a pain in the ^&% and I am encounterering more and more of the stupid things.

Sadly mp4muxer-0.9.3 does not process files in batches, or if it does I cannot determine how...

[electronicsguy]

I tried mp4muxer-0.9.3 with a .mp4 file containing Tx3g and it doesn't even see them, so I cannot remove the unnecessary Sub tracks. Any more ideas? (neither does mkvtoolnix see them).

[netmask56]

If you can't see them but you can turn them off in a program that can see them, then why bother trying to remove them especially as you might have to recode and lose quality? Maybe there is a tag editor that can set any subs as default off. ?

[electronicsguy]

If you can't see them but you can turn them off in a program that can see them, then why bother trying to remove them especially as you might have to recode and lose quality? Maybe there is a tag editor that can set any subs as default off. ?

Yes they are soft tracks, but I want to remove unnecessary ones, mark one of them with the 'forced' tag. All this cannot be done unless I can see and edit them, which currently seems impossible.

By the way, reencoding doesn't necessarily mean lossy. There's lossless encoding too. Furthermore, for what I wan to do, (change track metadata info), there's no reencoding of video involved.

[netmask56]

So if you put the file in a MKV container using MKVMerge Gui the subs don't show up in the main window? What about in the attachment window anything there?

[electronicsguy]

So if you put the file in a MKV container using MKVMerge Gui the subs don't show up in the main window? What about in the attachment window anything there?

Already tried that. Nopes, they don't. That's the basic problem. Neither windows show any subtitle track. After converting to .mkv, the resultant file doesn't contain any subtitles.

[leghorn]

Personally I've never encountered any of this. Have you looked here? Maybe that could help....