Charles Simonson
Forum Replies Created
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Yes, saying half was mighty generous of me, but I didn’t really want to get into too much detail in that aspect. BTW, most of the digital cable streams that I have seen and ripped were 528×480 at 1.5 to 3.5mbps. As always, thanks for calling me out on it Ben. 😉
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AC3 encoding is built-in to Compressor 2 only. If you have Compressor 2, then A.Pack is no longer needed. If you still only have Compressor 1, then A.Pack is the solution.
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The only other apps I would recommend are Compression Master 3.1 and Canopus ProCoder 2, although I don’t think they will be much different in this situation.
Per the bitrate, while the specs of the broadcast require 10000kbps minimum, quality really does reach its saturation point with SD MPEG-2 encoding at about 8 or 9mbps and a good two-pass software encoder. I understand your need though to generate files at that high of a bitrate, but unfortunately, you will not be able to effectively test on most DVD players your encodes burned to a disc. That is because the DVD spec only guarantees playback of full mulitplexed streams at under 9 – 9.5mbps. And when you are you using DVD-/+R media, that number is more like 8 – 8.5mbps to be on the safe side. So, it is entirely possible that your encodes are fine, but that your playback device (DVD STB) can not handle the bitrate they are encoded at because it is taxing the decoder chip too much.
The sad thing is, that while you have to deliver these spots at these high bitrates, in reality, when they are broadcast you will be lucky if they are transmitted at even half the encoded bitrate.
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Please do not go by QuickBench or any other disk bench utility to determine the actual speed throughput of the drive. Ask Walter Biscardi about this, as he has run many tests regarding benchmarks to real-world use. Just today in fact, I ran a benchmarking test with AJA’s utility on a FW800 LaCie Bigger Disk 1TB drive, a 73GB 10K Ultra320 SCSI drive, a 1TB 14x73GB 15K Ultra320 RAID, and a 1.6TB 4x400GB 7200 SATA RAID. With the utility, it was reported that the FW800 and the single 73GB SCSI drives could not handle playback or capture of Uncompressed HD 8bit video. That was to be expected. The utility also reported that the two RAID configurations could handle HD Uncompressed playback and capture “with plenty of speed to spare”. Well, when I played back a 720p60 Uncompressed 8bit movie, the SCSI RAID handled it with ease and the SATA RAID choked, maxing out at about 7fps. Numbers were similar with playback of 1080p24 content. Both RAIDs were about equally full with content (~60%).
So, it really is best to not go by what some benchmarking utility tells you what you should be getting in real performance. The only way to test this out is by actually using the type of movies and files you expect to be working with on those drives. And I can tell you through my experience that the throughput of just 2 drives striped in the real world is not that great of an advantage over single drives. Yes, you should notice some speed increases, but it will not be dramatic. Drama starts with three drives striped, and four is getting an Emmy nomination.
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Walter is correct here; and to clarify, WMVs will only play in QT with the F4M QT decoder plugin installed for Mac OS X, something that certainly cannot be guaranteed. Also, about MPEG-1s, with the proper encoder, quality can actually look quite good (though never as good as the best WMV encodes). Gen at Digigami is producing some amazing stuff with MPEG-1 and his encoder, although I suspect his encoding times are astronomical to achieve that quality level.
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Were they “jerky” when they were transfered to 29.97 and edited? Are you using the telecined transfers for the compression? If so, and the telecined clips weren’t jerky, then the initial 3:2 pulldown does not sound like the issue (and I don’t see much benefit doing a reverse pulldown and then another pulldown when encoding). Just make sure when you are encoding that you are selecting the same framerate as the source.
As far as your bitrate, there really is no reason that you should encode to 15000kbps, especially if using 2-pass. I doubt that the quality is any better for 15 compared to 7, 8, or 9 for MPEG-2 SD. At 15000kbps, you may even be taxing your hardware too much to play back the MPEG-2 files at full framerate, hence the “jerkiness”.
Basically, if you are getting errors with all of the apps you mentioned, then there is something wrong on your end. Because I would expect MainConcept (are you using the mac version?) to be able to compensate in most cases where the others you named would not.
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MPEG-2 Program Streams (where the audio and video are muxed) are good for when you don’t need to build and burn a complete DVD, and sending just the MPEG-2 movie (for instance, for QCing) where it can easily be played back is more beneficial.
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Its not the single card that is causing problems. It is just a basic rule of thumb that there isn’t much benefit to just striping two drives. If you need to buy two SATA cards to support a quad-drive striped array, then I would say go ahead and do it. Although, I would look more closely at other solutions such as the cards from Sonnet so only one PCI slot needed to be used. They sell a card for the mac that offers 4 internal and 4 external ports.
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The gamma corrections controls are built in to the MPEG-4 encoder/decompressor. When the movie is opened on a PC, QT makes the automatic adjustments, as well on a mac.
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My personal tests have shown that there is not too much benefit to striping two SATA drives. In order to start seeing some performance improvements, you need to use at least three drives striped, while four is obviously better. Not saying that you couldn’t do uncompressed 8bit with just two drives, only that there is not much point to striping them beyond expanding the single partition size.