Filesize discrepancy shrinkage when splitting AVI

[javrulez]

I tried to split a 707 MB AVI file following the tutorial using VirtualDub into 2 parts by keyframe, the first part with the intention to fill a 702 MB CD. The resultant combined filesizes (700 + 5 =705 MB) is 2 MB less than the original filesize. I can understand if the combined filesizes are larger, but in this case, there appears to be shrinkage. Is there anything that I am doing wrong?

Has anybody else encountered a similar problem?

[khp]

To check that all the video and audio is still present in the cut files, load each file into virtualdub select file->'file information' and compare the frame numbers in each file.

It is possible that your files are prefectly alright, something like this may be caused by diffrent interleaving settings in the avi file which reduce the structural overhead in the new avi files.

[javrulez]

khp, thx for your response.

I checked the file info and the # of frames did tally up fine. Incidentally, I asked the same question at another forum and the person there told me to take the precaution of moving 1 keyframe earlier than the actual keyframe breaking point for the 2nd part to compensate for possible missing film. Even after this overcompensation, the resultant combined file sizes still differred by roughly the same margin (2 MB) to the downside.

So 2 questions to you if I may:
i) Do I need to worry about the different interleaving settings, or is the # of frames check sufficient to verify against any film loss?

ii) What is your advice regarding the overcompensation of the 2nd part by advancing 1 keyframe earlier against the actual keyframe breaking point ?

[setarip]

"What is your advice regarding the overcompensation of the 2nd part by advancing 1 keyframe earlier against the actual keyframe breaking point ?"

This is totally unnecessary (but harmless)...

[khp]

Originally posted by javrulez

So 2 questions to you if I may:
i) Do I need to worry about the different interleaving settings, or is the # of frames check sufficient to verify against any film loss?

There will be no quality loss, the video and audio streams remain exactly the same. Depending on the audio format playback might in some cases become more choppy. But unless you got an ac3 audio stream virtualdubs default settings should be perfectly good.

[javrulez]

Thx all for your responses.