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Old 7th January 2009, 03:46   #1  |  Link
traycer
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Advice on MJP2-to-H.264 conversion?

I am using a slideshow authoring program called ProShow Gold. It can output a variety of video formats and containers. However, they all seem to be saddled with 4:2:2 or 4:2:0 chroma subsampling. The only exception is a Quicktime MOV with Motion-JPEG2000 compression.

My ultimate goal is to have these slideshows available to clients on my web site. My company logo incorporates some red on black, and as you can imagine the results are terribly blocky. The MJP2-encoded Quicktime looks good, but results in too large of a file and does not appear to be widely supported (e.g., in a Flash video player).

Here are two demonstration videos:

http://luxography.ca/tmp/subsampling_mjp2.mov (8744K)
http://luxography.ca/tmp/subsampling_h264.mov (4060K)

I would like H.264 video that looks as good as the MJP2 one. I've run into a major obstacle, namely finding one utility that can both read MJP2 in a Quicktime container, and encode to H.264 with 4:4:4 chroma subsampling.

My target playback size will be around 768x512. I've tried outputting an MPEG-4 at 1536x1024, then using a utility like Handbrake to scale down and re-encode with x264. But it appears that it defaults to at best 4:2:2, and the compression artifacts are reintroduced. I have also tried Quicktime 7.5.5 Pro's export features to no avail.

Subsampling aside, I have been getting excellent results with x264 on 1280x720 videos at less than 1 Mbps streaming.

I do not have access to any of the high-end video compression tools, and it seems I'm out of luck with the free/affordable alternatives.

Anyone have any further recommendations I can try?
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Old 7th January 2009, 03:49   #2  |  Link
Dark Shikari
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Quote:
Originally Posted by traycer View Post
I am using a slideshow authoring program called ProShow Gold. It can output a variety of video formats and containers. However, they all seem to be saddled with 4:2:2 or 4:2:0 chroma subsampling. The only exception is a Quicktime MOV with Motion-JPEG2000 compression.

My ultimate goal is to have these slideshows available to clients on my web site. My company logo incorporates some red on black, and as you can imagine the results are terribly blocky. The MJP2-encoded Quicktime looks good, but results in too large of a file and does not appear to be widely supported (e.g., in a Flash video player).

Here are two demonstration videos:

http://luxography.ca/tmp/subsampling_mjp2.mov (8744K)
http://luxography.ca/tmp/subsampling_h264.mov (4060K)

I would like H.264 video that looks as good as the MJP2 one. I've run into a major obstacle, namely finding one utility that can both read MJP2 in a Quicktime container, and encode to H.264 with 4:4:4 chroma subsampling.
x264 only supports 4:2:0, and I'm pretty sure all formats supported by Flash only support 4:2:0 (except maybe that Flash Screen Video format or something, meant for screen capture?)
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Old 7th January 2009, 05:33   #3  |  Link
traycer
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Drat! Okay, I'll either have to live with 4:2:0, or forego the use of primary colours in logos and titles. Thanks for the info!
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Old 7th January 2009, 06:51   #4  |  Link
csdesigns
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If you convert your source to YUV using a tool like XScaler, then you should have better success at transcoding to H.264 from there.
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Old 28th January 2009, 16:28   #5  |  Link
traycer
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Where can I find XScaler? A Google search does not seem to turn up anything relevant. I'm not holding out much hope, though... the problem with the chroma subsampling is on the output side of the conversion, not the input side.

I also tried Quicktime 7.6 (with it's unspecified improvements to H.264 single-pass encoding quality) to no avail. Doesn't look like 4:4:4 is all that ubiquitous for H.264, despite the format supporting it.
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