[Matroska-devel] Re: Containers overhead

[ChristianHJW]

Hi Davide,

i assume these are bytes ? Pls. note that your comparison is not correct 
for such very small file sizes, because mkvmerge will by default reserve 
a few KB in the header for tags, so that these can be written into the 
file afterwards with our tag editor, without having to remux the 
complete file. In your case, this is totally wasted space.

If you create such small files, you should deactivate that with the 
right switch in mkvmerge ( −−no−tags ) . Also, it may happen that our 
file header structure will not allow very small overheads on such 
untypically small files of just 2 MB.

Retry with real video file sizes, like 50 - 1000 MB, and you'll see the 
difference.

Christian
matroska project admin
http://www.matroska.org

Davide Capodaglio schrieb:

> Sorry if maybe a little OT...
> I read an article about Matroska container having the less overhead for 
> muxing, so I tried some experiments using a small video track containing a 
> h264 video and an mp3 audio, but I found out that mp4 has an even less 
> overhead.
> 
> 
> 2333916 set 20 23:39 264.avi
> 
> avi2raw --video 264.avi 264.264
> avi2raw --audio 264.avi 264.mp3
> 
> 1847349 set 24 15:44 264.264
>  473710 set 24 15:44 264.mp3
> 
> 
> MP4Box -add 264.264 -fps 10 -add 264.mp3 264.mp4
> 
> 2325001 set 24 15:46 264.mp4
> 
> 
> MP4Box -add 264.264 -fps 10 264.mp4
> mkvmerge -o 264.mkv 264.mp4 264.mp3
> 
> 2331111 set 24 15:47 264.mkv
> 
> 
> mkvmerge -o 264_avi.mkv --engage allow_avc_in_vfw_mode 264.avi
> 
> 2331484 set 24 15:52 264_avi.mkv
> 
> 
> 264+mp3 = 2321059
> avi:  2333916-2321059 = 12857
> mp4: 2325001-2321059 = 3942
> mkv: 2331111-2321059 = 10052
> mkv (avi): 2331484-2321059 = 10425
> 
> 
> So the .mp4 seem to be the one with MUCH LESS overhead than the others, even 
> that Matroska...
> Is my test right??
> 
> Thanks & bye
> Davide
> 
>