Ogg had been discussed a lot lately. Having messed a bit with it and having felt the pain about dabbling with it and with vorbis and theora probably I could chip in.
I said “a pain”, quite subjective and I think the term summarizes my overall experience with it. If that’s because it is “different”, “undocumented” or just “bad” is left to you readers to decide. Even messing with NUT hadn’t been this painful and NUT is anything but mature. Now let’s go back digressing about Ogg. Mans stated what he dislikes and why, Monty defended his format stated that his next container format will address some of shortcomings he agrees are present in Ogg. Both defense and criticism are quite technical, I’ll try to say why I think Ogg, as is, should not considered a savior using more down to earth arguments.
Tin cans, class jars, plastic bottles… Containers!
Lets think about something solid and real. If you consider a container format and a real life storage you might see some similarities:
- Usually you’d like the container to be robust so it won’t break if it falls
- You’d like to be able to know which is its content w/out having to open it
- You’d prefer if weight as less as possible if you are going to bring it around
- You’d like to be able to open and close it with minor hassle.
- If it has compartments you’d like that those won’t break and that picking and telling apart what it contains as easier as possible.
There could be other points but I think those are enough. Now let’s see why there are people that dislike Ogg using those 5 points: robustness, transparency, overhead, accessibility and seekability
I think Ogg is doing fine about robustness, the other containers are fine as well in my opinion.
In this case the heading is a bit strange so let me explain what I mean. If you think about a tin can or a glass jar usually you can figure out better what’s in a transparent container than in an opaque one, obviously you can have labels with useful information. Usually you feel better if you can figure out some details about the content of a can even if you don’t know how to cook it.
In Ogg in order to get lots of data that the other containers provide as is you need to know some intimate details about the codec muxed in. “What’s the point of knowing them if I’m not able to decode it?” is an objection I saw raised on Slashdot comments. Well, what if you do not want to DECODE it but just give information or serve it in different way, you know actual streaming ー not solutions based on HTTP ー? (e.g Feng and DSS to name a couple).
People likes plastic bottles over glass ones since the latter are heavier. When you move and store them that’s an actual concern.
Monty states that Ogg with a recent implementation of the muxer (libogg 1.2) the overhead in Ogg is about 0.6-0.7%, Mans states that it ranges between 0.4% and 1% usually nearer to the 1% than the 0.4%. So in my opinion they agree. How does that value fares with other containers? Mans states that the ISO mp4 container can easily archive about a tenth of the Ogg overhead. Monty went rambling about lots of different container stating some depressing numbers and discussing about random access on remote storage over HTTP and other protocols that are not meant for that.
I think that’s a large degree for improvement, or at least some benchmarking are required to see how that is true or false.
As in “which tool I need to use them?”. Ogg has some implementations, some even in hardware, Mans states that in some situations (e.g. embedded/minimalistic platform) isn’t the best choice. Monty states that similar problems would be there also for the other containers.
As I stated before in order to be able to process an Ogg you need to be able to decode or at least have a knowledge of the codec that nears the ability to fully decode. That means that you cannot do some kind of processing that in other containers doesn’t require such quantity of code and, to a degree, such CPU resources. Being able to do a streamcopy or to pick just a range among a content shouldn’t require decoding ability, those features are quite nice when you do actual streaming.
Mans thinks the Ogg ability to move to a random offset within the media has a great degree of issues some related to the mentioned before requirement to know a lot about the codec inside the container other due the strategy in use to actually find the requested offset within the file. Monty goes again rambling about access remote files using HTTP and on how the other containers aren’t that better. The Slashdot article is already full of people stating that they DO feel seeking in Ogg SLOW, no matter the player and kills Monty arguments alone.
In the end
Obviously nothing is perfect and everything is perfectible. I do not like Ogg, I’m not afraid to state it.
Quite often you get labeled as “evil” if you state that or, god forbid, say that Theora isn’t good enough and maybe if you are that concerned about patents mpeg1 is the way to go since the patents are expired.
I’m quite happy with mkv and mov, probably I’ll use NUT more if/once it will get more spin and community. I’ll watch with curiosity how transOgg will evolve.
PS: I liked a lot this comment, Monty do your homework better =P