mp4 file conversion to DVD

[jackwolf]

Recently I converted four .mp4 files(that were originally a BDrip H264 5.1ch) into DVD using ConvertxtoDVD. These four .mp4 file are pity similar in their sizes, stating 1280x544 (i mean, when you place your cursor at it, it show) and its around 2-2.1gb, each movie is about 2hr long. However, the result is that two of the Video_TS folder is 4.1-4.2gb while the other two is only around 2.5 - 2.7gb. What would be the possible cause of the differences? I did not change any setting in the ConvertxtoDVD when converting these four files.

Also, when we convert a .mp4 file that states 1280x544 into a PAL video, does it actually reduce the video quanlity? considering that PAL's max resolution is only 720 width...

Thanks for any advise...

[yoda313]

I think you're dealing with two separate issues here - bitrate and resolution.

It would seem you are actually using different bitrates on the mp4 files when converting to dvd. If they are both the same length then using the same bitrate will get you the same size in the end. The only difference being if one has dts sound versus ac3 sound (dts being large than ac3 all things being equal) OR you have motion menus on one of them. Motion menus or other bells and whistles on a dvd will take up more space. - also you did not mention if one of the mp4 files have multiple audio tracks, that will also take up more space - though if they are commentary tracks rather than full digital surround tracks they usually have negligible impact as far as space is concerned - ie not as large.

As far as the quality yes there is reduction when going from a high def bluray (I'm assuming bluray since you said bdrip) to a standard definition. You are reducing the resolution to fit a lower quality standard. Standard dvd (pal or ntsc for that matter) is less quality than a "good" properly sourced true bluray movie (there are of course can be bluray movies that don't look as good as a dvd if the master source wasn't good or if it was a homemade job from questionable or manually upconverted sources.

[MysticE]

However, the result is that two of the Video_TS folder is 4.1-4.2gb while the other two is only around 2.5 - 2.7gb. What would be the possible cause of the differences? I did not change any setting in the ConvertxtoDVD when converting these four files.

This seems to happen with CX2D. For me I tend to see it with dark, low action sources. When it happens there is really nothing in the settings that will change it.

It would seem you are actually using different bitrates on the mp4 files when converting to dvd. If they are both the same length then using the same bitrate will get you the same size in the end.

That is not the case with CX2D. It does not work in the same fashion most are accustomed to. There is no place to set the bitrate.

To the OP, seeing as you have a high quality source try the free AVStoDVD (lock in HCenc 2 pass encoding). It should provide a better result.