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h264 encoding takes way longer than it should
I’ve exhausted a number of hours trying to resolve this to no avail, so I turn to the Cow Community once again.
I work for a university, producing short videos for live use, and editing live footage for internet viewing. I’m running a 2010 Mac Pro 5.1 with 2.8GHz quad core and HD 5770 GPU. We’re about to move to the new Mac Pro, 6 Core, Dual D700 GPU, because we turn out more footage than we ever used to, on short deadlines, and its now all HD, where it was SD until a few months ago. However, It seems the problem I’m having is more software related, or due to bad encoding settings, so I’m hoping to resolve it, or else we may have the same problem on the new MP if I don’t figure where the problem is.
Every tuesday morning, we have a chapel service which we record, and I begin editing immediately after. I have the video ready to upload to Vimeo within a few hours without much issue, but then when I try to encode to h264 to upload, everything slows to a crawl. Its about 30 minutes of Prores 422, encoding in Compressor to h264, CAVLC Entropy, High Profile, Multipass, 10000 kbit/s Data rate, keyframes set to all frames, optimization set for streaming.
This weeks video was encoding for 36 hours, and was not even halfway. I have tried using multiple instances, cluster processing, different data rates, different profiles, and nothing seems to make a difference.
If I try single pass encoding, it just stalls completely. It just sits there for an infinite amount of time until I cancel the batch, and makes no movement on the progress bar.
I can get better speed by exporting and uploading to Vimeo directly from FCPX, but it doesn’t give me any control over the encoding settings to select a more reasonable data rate, so one video takes up my entire 5GB/week upload allotment. Using compressor setting in the export window of FC gives me the same results as running through compressor directly.
As a comparison, I was able to share the 37GB file with my home desktop over the internet in about 8 hours, encode it in about 33 minutes, and upload it from there in less time than it took to encode on compressor.
what gives?
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9 Replies
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H.264 is a very processor intensive codec, to render it faster you have only two solutions:
1) get a faster computer
2) get a dedicated h.264 hardware encoder card such as a Matrox HD Compress card or an Elgato.David Roth Weiss
Director/Editor/Colorist
David Weiss ProductionsDavid is a Creative COW contributing editor and a forum host of the Apple Final Cut Pro forum.
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if it’s really that simple, then this problem will be solved soon. As I mentioned we have the new Mac Pro on the way,so that will definitely speed things up. However, 70 hours for a 30 minute video seems way beyond the realm of normal processing speed. It seems that there is something else going on, as the processor never reaches full load even with two instances of compressor running and a third instance running on a Mac Mini in a cluster.
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For the record, the dedicated hardware encoders I earlier referred to will speed your h.264 encodes by a factor of 5 to 6 times faster than software encodes. Your new Mac Pro won’t keep up with that, so you might want to consider getting one and dedicating your encodes to that machine while you edit on your new Mac.
David Roth Weiss
Director/Editor/Colorist
David Weiss ProductionsDavid is a Creative COW contributing editor and a forum host of the Apple Final Cut Pro forum.
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He’ll know soon enough if the new mac is sufficiently fast. I hope he reports back and lets us know if they decide to stay with the mac or offload the encoding to the dedicated hardware you suggest. This is a common problem for a lot of people in similar situations, like me, and I’m keeping an eye on this myself to see what seems to work out best.
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Hi Mark,
I can assure you that the single Xeon proc of the new Mac Pro, while faster than earlier Mac Pros, is still not nearly as fast as a dedicated hardware encoder. I know this because of tests I conducted at Promax using much brazier Windows machines with dual Xeon procs.
David Roth Weiss
Director/Editor/Colorist
David Weiss ProductionsDavid is a Creative COW contributing editor and a forum host of the Apple Final Cut Pro forum.
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These hardware encoders David’s talking about…won’t work on the new MacPros. As they don’t have slots in which to install them. Only if you shelled out another $1000 or so for a PCI Bridge would you be able to get them to work. Maybe
Shane
Little Frog Post
Read my blog, Little Frog in High Def -
[Shane Ross] “These hardware encoders David’s talking about…won’t work on the new MacPros. As they don’t have slots in which to install them.”
Hi Shane,
I was not advising the poster to use a card such as a Matrox HD Compress in his new Mac Pro, but rather in his current Mac. There is no real advantage to using a dedicated hardware encoder in a faster Mac, as the procs don’t affect the encoding, it’s all done onboard the hardware card. That’s why I suggested he put the card in his old Mac and use that as his dedicated encoding machine.
David Roth Weiss
Director/Editor/Colorist
David Weiss ProductionsDavid is a Creative COW contributing editor and a forum host of the Apple Final Cut Pro forum.
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I’ll definitely keep the pci accelerator option in mind. We won’t be getting rid of our current mac pro and it might not be bad to distribute the workload over both machines. I can let the old MP encode the h264 for one video and start the next video on the new machine.
I can’t help but feel there’s some underlying issue though. The fact that single pass encoding failed, and that I was able to transcode the same video in 30 minutes on a Windows machine tells me that something is wrong.
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