[Zero1]

Originally Posted by DarkT

As to mp4, what's better in mp4 then in mkv? I'm used to mkv... mp4 feels... "new and untried" sort of...

With regard MP4 vs MKV; it's as they say "Six of one, half a dozen of the other" (to use the term loosley). MP4's main selling points are that it's a recognised industry standard (and an MPEG one at that), so that means you get commercial companies including it in software and hardware. Unfortunately because MKV is not an industry, people are reluctant to support it (except of course in open source circles); so you have a bit of a contrast there.

With MKV, it's gained popularity in the fansub scene due to it's matured softsub formats, which as you know are very flexible. Also in contrast, MP4's softsubs are relatively simple (yet they do have features such as karaoke, displaying the subs on picture for windowed playback or in letterbox when in fullscreen, clickable web links, and of course colours, fonts and positioning/scrolling). Yet this is most likely because the 3GP Timed Text format was originally designed for portable devices with low CPU power, and so not making it as flexible as ASS means they can somewhat ensure the CPU requirements don't get crazy.

I use MP4, one because I want to try and support the industry and show that there is a call for stuff like this, and good hardware and software support, and also a lot of times I don't require subs at all (most of the encoding I do these days is for personal stuff where I don't need subs). Odd times I have encoded for groups, they have used softsubs, so MP4 also fitted my requirements. If 3GP timed text support was at the same level as ASS, I would probably suggest or use it, but a lot of groups are still uptight about having their scripts stolen (insert argument about morals and stealing what isn't legally yours ).

You basically use what fits your needs; in effect MKV is the new replacement for AVI and MP4 is the replacement for MPG (however MP4 is an open standard, so expect it to be more useful than MPG, meaning that when H.265 (or whatever it ends up being called) arrives, you will probably be storing it in MP4 rather than a new MPEG container.

Originally Posted by emptyeighty

mp4 and mkv are both pretty much on par when it comes to features. mkv has softsubs, which mp4 doesn't have (yet). mkv also supports vorbis audio by spec. There's also chapters and linked chapters in mkv. mp4 will probably have more hardware players supporting it. Other than that they both store perfectly spec compliant MPEG streams and are generally very good a/v containers.

MP4 has had softsubs since at the very latest, October 2005 (when VLC started supporting it and Gabest picked up on it). It was actually approved in 2004. However, with the supporting being poor at the moment, it might as well not have softsubs since no one uses them because of the fact that there isn't a reliable implementation (except perhaps in Osmo4, which again no one uses).

The reason being that people would rather work on the existing softsub formats than start work on another from scratch (which I can totally appreciate), it's just a little unfortunate.

Originally Posted by martino

If you don't plan on using softsubs and Vorbis audio, then I personally think that MP4 would be a better choice, since if you put in h264 video with AAC audio then the chance of people being able to play it on the XBOX360/PS3 (and some more hardware players in the future too) will be much higher. Also, I think that I myself found MP4 to seek slightly faster, but I don't have anything to base this on...

EDIT: Beat by emptyeighty...

Yeah, I don't object to using MKV, it was handy for dealing with TS dumps a while ago, but my personal preference is to use MP4 when you don't need any features that require MKV. In other words, I would rather put a simple H.264 + AAC stream in MP4, than MKV for using MKV's sake (I don't see the sense in putting it in another container when the specified industry standard one does the exact same job). To me that would make as much sense as putting MPEG-2 in AVI rather than MPG.

As you said, it can work out better for cross platform compatability, but if people want to use MKV, who am I to tell them what to do?

Originally Posted by martino

MP4 supports softsubs, in the TTXT format (read more here). Basically it can be described as XML madness. And to get a TTXT softsub you need to go from ASS/SSA (where applicable) -> SRT -> TTXT (through mp4box, or some other program if it exists...). And then you can mux it into an MP4 file, however you will only be able to see the subs if you use a splitter like Haali (AFAIK, not sure about the rest). It doesn't work with the XBOX360, as expected, and the PS3 and rest are most likely the same.

And there are no tools AFAIK for editing TTXT subs, apart from using a text editor. >_>

Ending Note: It's a rather messy format.

Yeah, the XML madness though, is only because it's easy to parse. If you wanted to you could make TTXT exactly like ASS (format wise), as long as you added support for the format in MP4Box. The actual file that gets muxed isn't like that, it's just an input format that's easy for MP4Box to read.

Again with 360 and PS3 not supporting 3GP Timed Text, that's hardly surprising when you consider the 360 supports 2.0 AAC but not 5.1 AAC, and also the PS3 supports High Profile H.264 muxed in M2TS and only Main Profile in MP4. Console MP4 support is almost as much of a mess as iTunes. Coincidentally, the KiSS 1600 supports 5.1 AAC, so at least there is one device on the right lines.

Again if software timed text support got to a good level, people might want to try it (I've had a number of people ask me about MP4 softsubs, and I've told them hardsub or MKV), and once files are out there with these subs, companies will see that there is a requirement for them and eventually implement it. It's a vicious cycle. People won't use it because the software support is poor, and the software support is poor because no one uses it.

Messy format yes, but there's nothing wrong with using SRT and converting when you are done and then just formatting the TTXT (positioning and stuff), or using a text editor like Notepad++ which makes it a little more bearable.

Originally Posted by jfs

I've added TTXT import/export to the todo-list for Aegisub, but that doesn't mean it'll be done any time soon...

Some things I can see is in ASS but not in TTXT: Specifying the border, shadows, arbitrarily rotated text, text scaling, advanced animations and yes, drawings. I'm not sure TTXT/MPEG-4 provides a method for attaching random fonts to the media, meaning you'll have to rely on the fonts installed on the playback system.

That's good to hear, this might even be the beginning for some decent support since I know Haali and CCCP must have contact with eachother. This may or may not be of use to you:
http://www.3gpp.org/ftp/Specs/archiv.../26245-600.zip

Part 17 (ISO/IEC 14496-17): Timed Text subtitle format.
Part 18 (ISO/IEC 14496-18): Font Compression and Streaming (for OpenType fonts).
Part 22 (ISO/IEC 14496-22): Open Font Format Specification (OFFS) based on OpenType (not yet finished - reached "CD" stage in July 2005)

Take that how you will. I don't know anything about part 18, but it suggests it's probably attaching fonts to MP4 and using them in playback.