Possible Bug: VLC opens both videos tracks in an mp4

[caalip]

Hi all,

I am going to submit this as a bug, if no one has an answer. I am not very sure it is a bug, as this is a somewhat unusual thing.

Here is the problem, if you have two video tracks in an mp4 file, it tries to play both. Further, if you go to the tkhd box with a hex editor and set the flag from 0x1 to 0x0, it still plays. It was my understanding that only playing material was set to 0x1.

I am using 0.8.6e Janus, on Ubuntu. I have the apt-get version, I didn't compile it, or update it in anyway.

Thanks for any help you ca give,
Grae Cullen

[Jean-Baptiste Kempf]

This is normal that it tries to play both.

About the 0x0, please fix our mp4 demuxer.

[caalip]

This is normal that it tries to play both.

About the 0x0, please fix our mp4 demuxer.

We are actually doing a project this summer, and we are basing it off of the vlc code. No promises, but I maybe I will be able to do that. For this project, We are probably going to be extensively changing the mp4 demuxer. If you have any advice or information up front, that would be great. Maybe, if I am allowed, I will submit it as a module or something. If i figure out what is wrong with the current demuxer, I will at least let you know.

Apparently, while I was babbling on in this forum, my group-mate fixed the problem. You add:

Code: Select all

&& tk->b_enable

to the if statement on line 563, in /modules/demux/mp4/mp4.c.

The demuxer looks fixed, but we only tested it with a few files. This is really first guess fix, if we find a better one, we will let you know.

I have never done a patch or anything like that. However, if you want I will try to submit it. I think i have to be a developer to have write access to VLC's SVN, right?

However, that aside, I would still like any information you think are important for working on the mp4 demuxer in VLC.

Grae

[Jean-Baptiste Kempf]

Please provide a patch on the vlc-devel@ mailing list.

Git if you don't know how to send one.

SVN is deprecated here