Ogg files smaller once extracted

[LordIntruder]

Hi.


I can't find any post on that subject and have just discovered that by chance. I encoded 2 Ogg files from AC3, both differents languages, muxed them into an Ogm and MKV with AVI_MUX latest version and VirtualDubmod. Whatever the container is, when I extract audio streams I got smaller Ogg files than the originals???

So whatever I use AVI_Mux or Virtualdubmod, whatever the container I use, OGM or MKV, when I demux the audio streams they are smaller.

I also tried the good OGMDemuxer: same result. They are smaller by around 4Mb. The smaller Ogg files play fine and I can't make any differences with the original.

This bug occurs on a particular movie I encoded and I immediately tried with 2 others movies with ogg that I still had the temp files: no problem.

If you have any explication?? :confused:

Thanks a lot. :)

[echo]

Are you sure they have the same length? If they do this is weird... I'm going to do some tests to see for myself...

regards
echo

[alexnoe]

Lord-Introder:

Please check the MKV files using mkvverify -summary.
It will show the exact RAW stream size, so you will know if the streams are reduced in their size already when muxed into the MKV file, or when extracted from it.

[Suiryc]

I guess your video stream end before the original audio.
Most programs will strip the audio to match the video length, so of course when you demux the audio the file will be smaller.

[echo]

Try to use mkvmerge or mmg for muxing into mkv or Suiryc's command line ogmuxer app for muxing into ogm and you will get the whole audio file. As Suiryc said the audio is stripped to match the video length with avi_mux and vdubmod.

regards
echo