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H.264 to mpeg2 – very slow
I have two different H.264 quicktime movies that vary widely in their processing times to convert to MPEG-2 using compressor (DVD Best Quality 4:3).
Source 1 – 20-minute video (NTSC source, 29.97 fps), 640×480, 2000 kb/s – about 8 hours conversion time (video only, no audio)
Source 2 – 2-minute video (animation, 30 fps), 1280×1024, 4700 kb/s – about 6 minutes conversion time (video only)Extrapolating the 2 minute video to a 20 minute video puts it up to about 1 hour conversion time. I would have thought it would take longer to convert the 1280×1024 video. Any insights into why there’s such a huge difference in conversion times?
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18 Replies
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Hi Raven,
I think that once converted to H264 the original format (Animation or DV) it doesn’t matter.
But is really strange the difference. Should be the opposite timing.
H264 is a slow to compress codec, but I thin is really fast to de-compress.
Unless you have different setting in the Compressor’s “Frame control” I can’t understand such big difference.
You may try to export the H264-DV to an uncompress format (8b Unc) or Proress, them make the MPG2.
Rafael -
The other difference is that the 20-minute video was created by Handbrake (as an H.264 mp4 file, which I resaved as MOV) whereas the 2-minute video was created from a Combustion animation. But H.264 is H.264, no?
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H264 is NOT an editing codec, and files from Handbrake are useless, no wait, worse than useless, in FCP. That is nowhere near a professional app, files from it have to be uprezed to a codec you can edit, but will look horrible.
You need to start over.
Have a wonderful day.
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I’m not using Final Cut, nor am I doing any editting. Only transcoding using Compressor.
I’m not making the case for Handbrake as a professional worktool, it was a last ditch effort to create a backup copy of a single copy-protected DVD we were going to use for a convention. Nor am I intending to use H.264 files in an editing workflow.
All that aside, are you suggesting that the H.264 file was taking extra long to transcode to mpeg-2 because it was created by Handbrake?
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[Raven Plenty] “All that aside, are you suggesting that the H.264 file was taking extra long to transcode to mpeg-2 because it was created by Handbrake?”
Anything that has been compressed once and is being re-compressed takes longer than working with a native editing format. So taking H.264 and converting it to MPEG-2 takes much longer than if you had an 8bit Uncompressed video file and converted that to MPEG-2. That’s been our experience.
Walter Biscardi, Jr.
Biscardi Creative Media
HD and SD Production for Broadcast and Independent Productions.STOP STARING AND START GRADING WITH APPLE COLOR Apple Color Training DVD available now!
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I have a feeling that this thread isn’t being read from the beginning.
I realize that it takes longer to transcode from one compressed format to another. However, this H.264 file is taking way longer than a different (and much higher res) H.264 file to transcode to MPEG-2. Please review my earlier postings for more details.
Also, thanks very much for your help.
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Compressor is the same as FCP as far as how it handles QT files. What Walter said should explain the slowness to you, very clear. My point was that H264 is a delivery codec, highly compressed, not something to start with for further compression.
I went back and read your original post, what you need to do is start over and get your material in an editable format.
Have a wonderful day.
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[Raven Plenty] “this H.264 file is taking way longer than a different (and much higher res) H.264 file to transcode to MPEG-2”
Not ALL h264 files are compressed equally. One of your files probably has a much higher amount of compassion thus taking it much longer to convert to something else.
[Raven Plenty] “Please review my earlier postings for more details. “
I believe people are reading them, the reason they are confused is because you posted this question on a Final Cut Pro Forum, a forum where questions about the use of FCP are asked, so it is assumed unless you state otherwise that you are going to be using that video with FCP. You never told anyone that until later.
Your post probably belongs in the Compression techniques forum.
There are no “technical solutions” to your “artistic problems”.
Don’t let technology get in the way of your creativity! -
Thank you very much Zane. I did not notice that there was a forum for “Compression techniques” – I looked for Apple Compressor, and since I didn’t see that went with what I thought was the next best. I’ll repost there since I’m still interested in more information about this (i.e. if there is anything unusual happening or if this is normal).
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Huh?
Raven, I agree, those responding to this thread either haven’t read it properly, or haven’t understood your question.
Guys: Raven wants to know why one H.264 clip takes longer to compress than another H.264 clip.
Chris, why should she need to “start over and get your material in an editable format”, H.264 is not only a delivery format H.264 is capable of 10bit 4:4:4 at 4K to over 950Mb/s – andto wide spread acquisition formats like AVCHD
https://en.wikipedia.org/wiki/H.264.
P.s. I noticed that the FishEyeEdit clip on your home page is neither 1.33:1 or 1.78:1 (it’s 1.48:1) and uses a frame size that’s not very suitable for Flash (which loves dimensions divisible by 16 on both axis). Lovely content though.
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Please post back saying what solved your problem. It could help others, and saying ‘thanks’ is free!
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