Wrong aspect ratio for converted file MPEG2->H264 with SUPER

[ronpub]

My source is an interlaced MPEG2 file:
VIDEO_SIZE_X 352
VIDEO_SIZE_Y 576
VIDEO_PAR 2.182
VIDEO_DAR 1.333
VIDEO_SAR 0.611
My destination file is an MP4 file with H264 encoded by SUPER 2006 b19 (aspect ratio set to 4:3):
VIDEO_SIZE_X 352
VIDEO_SIZE_Y 576
VIDEO_DAR 1.333
VIDEO_SAR 0.611
VIDEO_PAR (no information from Gspot)

I've got a good 4:3 aspect ratio in both files (VIDEO_DAR 1.333) but when I watch it using QT or MPC (aspect ratio is not overridden), I've got a 352x576 image, not a 768x576 one. What is wrong. How could I have a good redered file? I would like to distribute it then people should not changes parameters in the player to watch it.

Ronan

[steveryan]

What did you select in video scale size? Select the 640x480 option and it should retain the 4:3 ratio. For AVI's 352x576 will not give you 4:3 ratio.

[ronpub]

I selected "nochange". My file is not an Avi but a mp4. The original file is 352x576 intelaced MPEG2 file that my player can render correctly why not for an MP4?
The destination file is a 352x576 file that the player should strech. I have 352x576=202,752 pixels to compress.
If I go to 640x480=307,200, I increase the number of pixel to compress by 50%. Then for the same final file size, I loose quality. Second, the high of this file is only 480, the original is 576. I loose 17% of information.
That is, I think, I bad idea. Or I missed something in how it is encoded.
I prefer to have a 352x576 file @25 fps that is streched. But unfortunatly I don't manage. It should possible to do that.
Thanx.
Ronan

[guns1inger]

mpeg2 allows for flags and playback that other formats don't support, like half-d1. Your mpeg also does not have square pixels, but your mp4 requires them. To maintain aspect ratio and a 1:1 pixel aspect ratio you need to convert to 384 x 288, which SUPER can do. Or, expand back to full-d1. You choose No Change to maintain the aspect ratio it has, but it will play back distorted in most players.

[ronpub]

But if I go to 384 x 288=110592 (66% loos), I loose so much data in the file! I'm disappointed that some flags are not allowed in the new format. I selected "nochange" for video scale size but I choose "4:3" for aspect ratio and expecting a VIDEO_PAR 2.182.
Could I do what I want with Xdiv or Divx? I think then I will have a much better quality. It is better to be close to the original file than to create interpolated pixels with no information that do Mbytes for nothing and delete others that have information.
I don't know what is a full-d1. I will investigate.
Thanx.
Ronan

[guns1inger]

Full D1 is full DVD or DV resolution. For NTSC it is 720 x 480, for PAL it is 750 x 576. These are non-square pixels. Half-D1 is what you have. The horizontal resolution has been reduced by 50%. This is part of the DVD spec, and DVD players will expand the horizontal on playback to fill the screen. The image is softer than full-D1, but it allows for a lower bitrate.

Your problem is two fold.

1. You are converting from a non-square pixel format to a square pixel format. This means resizing to adjust. In your case it means resizing to 384 x 576. This is just to display the image you have without pixel distortion.

2. You are converting from half-D1 DVD to a non-DVD format which does not recognise or know that it has to double the horizontal size for playback. This means you have to either double the width or halve the height to compensate.

Some players are smarter than others and might work this out for themselves. Most wont. If you want to distribute this and have it play back, you need to make it as standard as possible. So you can either resize it to 768 x 576, or 384 x 288.

[celtic_druid]

mp4 supports PAR info. Fact is that it is at the bitstream level so it works with whatever container, including avi.

My advice would be to remux with mp4box/yamb and make sure that the AR is set correctly.

Fact is that QuickTime is a piece of crap and won't resize anyway. At least it doesn't here. MPC (depending on the decoder) will as will mencoder, VLC, Osmo4, etc. Basically everything except QT. For QT you would probably need to remux to mov to get it to resize. mkv would probably also work, but the mkv plugin is OSX only.

[ronpub]

My decoder for mpc is ffdshow and don't respect aspect-ratio.
I just tried VLC. And it works! The only one I tried
I think the video technologie go fast but is not really mature. Perhaps because it is going too fast pushed by guys like me wanting to use the last hi-performance codec.
Thanx.
Ronan

[celtic_druid]

ffdshow does resize. You just need to have it setup properly.

[manono]

I would like to distribute it then people should not changes parameters in the player to watch it.

I thought campatibility was an issue. If you have problems getting it to play, what about your friends that are just going to double-click and expect WMP to play it properly. Make it 1.33:1 at 512x384, 576x432, or 640x480.

Perhaps because it is going too fast pushed by guys like me wanting to use the last hi-performance codec.

That's all very well and good, but what about your "normal" friends, or someone that wants to play it in a standalone?

[ronpub]

I didn't make my choice now for that application. I need to evaluate pro and cons that would be too long to expose here and without much interest.
ffdshow seems to be with default values. I can in anycase override the aspect ratio in MPC and set it to 4:3 to display the video correctly but that is not a good solution. I won't investigate much more in that direction as it won't bring me much information I need. I have not enough time.
Thanx,
Ronan