Subtitles from mp4 file are not displayed.

[DrZoom]

Hi

I recently encoded a DVD of my collection (Hellsing, German) into MP4 streams (with Nero Recode 8, mp4 avc codec). There were one video, two audio and one subtitle stream in each mp4 container. If I play the encoded movie with VLC (0.9.9), but the subtitles aren't displayed. In other software (Nero Showtime), the subtitles are displayed correctly. With all other DVD's I encoded, everything was fine. This is the first DVD which caused this problem.

VLC is using the "spudec" to decoding the German subtitles.

What could went wrong? How can I debug this.

best regards
Tobias

[Lotesdelere]

Please post samples of the problematic MP4 files.

[DrZoom]

Here a small sample of the file:
http://drzoom.ch/temp/Sample.mp4 (21'041'943 Bytes)

[Lotesdelere]

You file contains VobSub subtitles which are NOT a part of the MPEG-4 standard in MP4.
The only compliant format for subtitles in MP4 is MPEG-4 Timed Text (TTXT).

I know there are some softwares, like Nero, which allow you to add such non standard streams and also to play them, but for staying into the MPEG-4 specifications they get a "private track ID" so no player will be able to handle such streams in MP4, but will simply ignore them.

The subtitles of your file are not dhown in VLC, in MPlayer and even in MPC-HC which is often considerated as quite tolerant with the specifications. I guess this file only plays in Nero. This is normal according to the MPEG-4 specifications so you need to convert the subtitles to TTXT (software keywords: SubtitleWorkshop, YAMB/MP4Box).

[DrZoom]

This makes sense. Thank you very much for the help.

[Jean-Baptiste Kempf]

In fact, those subtitles are decoded by VLC, but they are completly transparent...

[Jean-Baptiste Kempf]

This is fixed in VLC 1.0.0

[DrZoom]

Very nice to hear! Good work!