Converting MP4 to MPG/VOB (Progressive to Interlaced)

[danielmak]

I'm hoping someone more experienced than I can help with this problem. My friend has an MP4 video that he wants to convert to DVD and has asked if I can help him since his conversions are causing the final DVD to have missed or dropped frames.

The original file is and MP4
Scan type: Progressive
Frame rate: 25.000 fps

So it is PAL (SD) but usually PAL is interlaced. In this case the file is progressive. He is a Windows user so I don't know the software programs he uses. I had hoped that MPEGStreamclip could work to convert since that program handles MP4 and MPG and there is a Save As option. But there is not a Save As from MP4 to MPG.

Does anyone have a recommendation for converting from MP4 to MPG that will not result in lost or dropped frames where I can keep bitrate the same? My sense is that he'd like this to be an interlaced DVD but if we can make a PAL dvd that is progressive then that's what we will do. I am posting in the Mac forum because I'm a Mac user; however, if there isn't a Mac program that will do this but you know a good Windows program then I can share that with him. Thanks.

[manono]

So it is PAL (SD) but usually PAL is interlaced.

No, it's not. Yes, PAL DVDs are usually encoded as interlaced, but the content can be (and often is) progressive. There's a big difference. And there's no problem in encoding it as progressive to begin with.

You didn't tell us what he used to encode it for DVD (because you don't know). Just go back and tell him to use AvsToDVD instead.

Does anyone have a recommendation for converting from MP4 to MPG that will not result in lost or dropped frames where I can keep bitrate the same?

No decent conversion program will remove frames. And you don't want to keep the bitrate the same. MPEG-2 is less efficient than is MPEG-4 so to get a reasonably decent result the bitrate should be greater than that of the source. Someone else will have to give you a Mac program recommendation.

[danielmak]

Thanks for the quick reply. Since I'm not familiar with Windows stuff, I can't be certain of the order of software that was tested or used, but I know that he told me about testing with VideoReDo TVSuite V5 and TMPGEnc MPEG Editor 2.0. I will tell him about AVStoDVD.

I assume that the dropped frames are a problem with converting from progressive to interlaced so I will tell him to try converting with AVS and leaving the progressive part as is.

[jagabo]

Note that MP4 is a container that can contain video encoded with many different codecs. You haven't specified what codec was used in the MP4 file so it's not certain whether you will need more or less bitrate with MPEG 2 compression for DVD. But it's likely your MP4 file contains MPEG 4 part 2 (Divx/Xvid) or MPEG 4 part 10 (h.264, AVC) compressed video, both of which are more advanced than MPEG 2, so you will need to use more bitrate than the source.

I assume that the dropped frames are a problem with converting from progressive to interlaced

No. Encoding progressive frames as they are interlaced would not change the number of frames. So there would be no duplicates or deletions. It's more likely the program used screwed up decoding of the source. Or your friend just screwed up.

[danielmak]

Here are the details from Media Info

[jagabo]

Assuming you're going to make a PAL DVD: The video has to be scaled up to 720x576 and flagged 16:9 to keep the correct aspect ratio. Then, since the video is only 57 minutes, encode it MPEG 2 at ~9000 kbps VBR and the audio at 256 kbps (or higher) AC3.

[Case]

I read that as 1h 57mn, so 117 minutes. Then a mere 4800 kbps video with one audio track at 224 kbps would fill a DVD-5 disc. A DVD-9 disc would accommodate a more generous bitrate and/or more audio tracks.
Will you be needing to keep all 4 audio streams that Media Info reports?

[jagabo]

LOL! I missed the 1h on the line above!