No, I made the point I wanted to make. [LWN.net]

No, I made the point I wanted to make.

Posted Feb 7, 2010 21:21 UTC (Sun) by DonDiego (guest, #24141)
In reply to: No, I made the point I wanted to make. by gmaxwell
Parent article: Blizzard: HTML5 video and H.264 - what history tells us and why we're standing with the web

I used 'mplayer -dumpaudio' and 'mplayer -dumpvideo' to extract the audio and video streams.

> Well, what can I say? I wrote a clearly described specific comparison about YT because of an outrageous goggler quote. Now you're running around the internet calling my statements fraudulent because they weren't a comparison with something else.

Your comparison is constantly being presented to me and others as proof that Theora is as good as H.264. If that was not your intention, fine. It does not change the fact that your comparison is being misread all the time. And sorry, but you are not exactly going out of your way to prevent this.

> > Without them free software desktop market share would be orders of magnitude smaller and decreasing.

> I fail to see how advancing the state of the art in the best encumbered format encoders does much of anything to preserve free desktops by helping people "listen to music and watch movies".

Simple. People use their computers to listen to music and watch movies. There are popular formats to make music and movies available in digital form. If no free software is available to handle these formats, people will use something else to get at their movies and songs. Free software loses, badly.

> But to each his own. There are perfectly viable ways to get legally'licensed encoders for your desktop even if tools like ffmpeg didn't exist, but its existence wasn't something that I was protesting.

Fluendo is much more recent than FFmpeg or MPlayer. But if Fluendo is an alternative option for you, then you don't value free software. I'm not such a person.

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Container conundrum

Posted Mar 9, 2010 20:59 UTC (Tue) by gmaxwell (guest, #30048) [Link]

So, I'm reasonably confident that your claimed mp4 overhead is simply incorrect. I don't know why.

I measured it as 86245 using one method (segment sizes from mp4dump). A friend who has implemented the mp4 demux checked the file and also calculated 86245 using his own method. My guess was that mplayer must be including packet length data in the dump output, but I just repeated your method and got 13871183 bytes video, 3796188 bytes audio. Resulting in 86245. Exactly the same figure calculated by two other distinct methods.

Perhaps you could explain why I'm getting a different figure using exactly the same method as you? I'm using Mplayer SVN-r29800-4.4.2.

I remuxed the above Theora file we were discussing for minimum overhead using a copy of libogg with the default 4k page size target removed:

http://people.xiph.org/~greg/video/ytcompare/bbb_theora_4...

This file has 84604 bytes of container overhead.

This is somewhat lower overhead than your mp4 file. Now that I understand a bit more about the mp4 format I find it actually somewhat surprising Ogg provides a lot of properties that MP4 does not. Like being incrementally written in a complete form.

I hope this update convinces you to discontinue spreading these mistaken claims.

Cheers.