my 5.1 downmix problems were due to either ffmpeg/pytivo or the tivo, and odds are good it was ffmpeg, and that it was my fault in misconfiguring it.
pytivo will default to something like 8mbit/sec bitrate for an hdtivo. ffmpeg won't actually use that much for dvd-sourced content, it won't need it, but it's not limited in any significant way by default.
I had only a stereo sound system, was getting stereo analog out of the tivo.
i don't know what the root cause of the problem was, whether ffmpeg was improperly downmixing it, or the tivo was. i'd bet on ffmpeg; i probably configured pytivo to do the downmix to save space on the tivo or something stupid like that.
I never really spent any time troubleshooting it so it's really hard to say what the problem was. If you configure it to just pass through 5.1 sound to your tivo (this is probably the default), odds are good it will just work.
The bitrates it transcodes to are configurable, and the default for s3 tivos is 8mbit I think. If it has a native mpeg2 stream it won't transcode at all, it will just pass it down to the tivo.
ftr dvd is 720x480 with rectangular pixels. The widescreen square-pixel display res of 480p is 854x480 or something close to that.
100Mbit is plenty fast enough to transfer hi-def streams; it's not the limiting factor. In practice the total a/v bitrate i'm transcoding to is usually less than 10Mbit.
but as i mentioned above, *something* isn't fast enough and the tivo doesn't keep up. You can have the tivo save it and watch it later though.
if pytivo thinks you have an HD Tivo, it won't change the resolution at all (it does transcode to mpeg2). The series3 will scale the video itself (and it has a pretty good scaler chip in my experience).
If it thinks you have a series2, it will change the res, presumably to 640x480 but i haven't checked. Perhaps you misconfigured it so it thought you had a series2.
pytivo tries to detect if your file uses a supported codec (includes ac3), and just copy the audio stream if so; otherwise it transcodes, but the default transcoding target is in fact AC3.
I *have* had problems with 5.1 sound not being properly mixed down to stereo (yeah, yuck, but it's what i had until recently). The center channel was always sent to one speaker or the other. not sure if it's pytivo (ffmpeg really, it does the transcoding) or the tivo that causes this. I haven't really tried to debug it.
it is under active development and the devs seem to pay attention to support requests on the forums, so i'd suggest you give it another shot.
you need to make sure you have a good ffmpeg build. this can be non-trivial; the one that comes with your linux distro may not be good/new enough. the pytivo forums have links to win32 binaries that work for most people. If you're on a mac or bsd, try the ffmpeg-devel port rather than the ffmpeg port.
pytivo recently gained the ability to stream from DVD images. I haven't tested this but i suspect it works fine.
I like pytivo a lot, the only issue i have with it is speed. I have this cpu (1.9GHz dual-core athlon) and it's not fast enough to transcode hi-def in realtime.
you xfer the program and it dribbles through and you can watch it later.
More importantly, i've tried pre-transcoding and just transferring the mpeg-2 stream (pytivo will not transcode this at all), and the tivo (presumably) can't keep up, it still is a bit slower than realtime. That's annoying; i can pre-transcode or buy a faster cpu, but if the streaming just isn't fast enough then i'm kinda stuck. I am using 100Mbit wired ethernet, it's not some crappy wireless that's the issue. I haven't really investigated this.
Use it in a dimmer, or in an unventilated enclosure, or where it's turned on and off a lot.
That's inappropriate use for pretty much any CFL, not just cheap ones.
wal-mart spec'd them and their specs say "drive every possible penny out of the production cost."
http://pbs.org/wgbh/pages/frontline/shows/walmart
Incandescent bulbs are a very mature and well-understood technology, and they are dirt cheap to start with, so there is less room/incentive to cut them to the bone.
You're probably aware that SSD's have been in the server space, at a very different price point, for a few years now, without any extraordinary reliability debacles.
I spoke to a rep from a big storage company (can't remember whether it was netapp or EMC) who claimed that the company has seen ZERO SSD failures in the field with their current tech, which has been in the field for a year and a half.
I wasn't buying SSD level stuff from them; no particular point in lying to me about it.
Of course, this kind of enterprise level SSD costs 100x what the models being discussed here, as you mention.
I'll go with "known". Certainly to me, and probably to anyone who notices that reviews don't get posted.
I won't buy DRM-protected anything from anyone.
Well, I lie. I buy DVDs and bought HD-DVDs. And I was thinking about buying some blu-rays too (the disney remasters of their classic animated films appear to be top-quality product, and i want to reward them for their good remastering job even as i want to smack them for using DRM).
I only buy such content if I knew i can get the content elsewhere if i needed to.
The typical lifetime of a CPU package is a year or 18 months.
Embedded designers want to be able to design around something that won't disappear next year right when they've got the bugs out and they're ready to ship.
it's the way of things with large companies. They can, and do, innovate. But they also know that there is a lot to be said for whipping out their checkbook.
The important thing with this is that they keep the assets & people of the acquired company. I worked at ANS Communications, which was sold by AOL to Worldcom in the mid 1990's.
ANS had a top-notch team, the best I have ever worked with. It had built the NSFNet (http://en.wikipedia.org/wiki/National_Science_Foundation_Network) more or less from scratch, and after the Internet commercialized it was one of the best tier-1 ISPs. (internal slogan: we suck less)
Worldcom let us wither on the vine. They did basically nothing to integrate us into the business, and ignored the talent we had. Folks drifted away. It's probably true that they bought us not for our staff, but because we came with a contract to run AOL's dial business; however, it was negligent of WCOM to ignore the rest of the quality asset they'd purchased.
OTOH i've heard stories of companies being acquired by cisco. cisco knows how to do it right; they pay attention to what they are buying. They integrate the staff and put them to work on something useful.
on a related note, I've got a friend who works for IBM who says that his best shot at a "promotion" (from a high to a very high level) is not to do something inside IBM, but to go to a startup, and get acquired by IBM.
it's easy to measure power usage, the US$20 kill-a-watt meter will tell you everything you need to know.
The combo of my VCR, flakey DVD/mpeg4 player, and HD-DVD player [*] draw a total of 7 watts when "off". This works out to 61 kwh/yr, which costs me about $7.50 (at $.12/kwh). A remote switch cord costs $12 from Ace Hardware. Sigh.
I buy "green" power from my local utility so in theory i'm just driving up demand and scale for renewable power by leaving it running all the time, right? Sigh.
* i bought it, cheap, after they were discontinued
Re:I stopped reading the summary
on
Best eSATA JBOD?
·
· Score: 1
When you say "adding more disks" I assume you mean raid6 vs. raid5.
You're right that consistency checking is required; but it's not good enough for important data.
I did a consistency check last week on my entire RAID. it was good.
I just lost a drive, now i want to rebuild parity. Whoops, I get a read error that crept in since my last consistency check. I am now out my data. RAID6 would have saved me.
If i didn't do a consistency check fairly regularly, i'd probably be hosed even with RAID6 since there would be enough read errors that i'd lose.
Of course, it all depends how important your data is. My MP3s and dvdrips are not so important that a lost file is a catastrophe, so they live on raid-z (like raid5 for redundancy's sake). My business runs on RAID6 and mirrors.
You paid H.264 licensing fees when you bought your Mac, AppleTV, and iPhone. you're not seeing them as line items, but you're definitely paying them.
You are probably violating patents by ripping to H.264 with handbrake. Of course if you're in the US you're already violating the DMCA probably by ripping DVDs so what the heck.
Moving forward, large video streaming services will have to start paying significant fees to stream H.264 video.
You may not see the problem in paying for this, but you are definitely paying.
LAME, as the name says, is *not* an encoder. LAME is a development project which uses the open source model to improve MP3 technology. Many people believe that compiling this code and distributing an encoder which uses this code would violate some patents (in the US, Europe and Japan). However, *only* a patent lawyer is qualified to make this determination. The LAME project tries to avoid all these legal issues by only releasing source code, much like the ISO distributes MP3 "demonstration" source code. Source code is considered as speech, which may contain descriptions of patented technology. Descriptions of patents are in the public domain.
Several companies plan on releasing encoders based on LAME, and they intend to obtain all the appropriate patent licenses. At least one company is now shipping a fully licensed version of LAME with their portable MP3 player.
Note that under German Patent Law, Â11(1) a patent doesn't cover private acts with non-industrial purposes. Probably interesting for developers is that a patent doesn't cover acts with experimental purposes, that aim at the object of the patented invention (Â11(2)).
Better yet, ask a friend who already has a system running 24/7.
beware, though - rsync will gladly delete files on the target system if you accidentally delete the originals on the local. Perhaps use --link-dest and the scheme described at http://www.mikerubel.org/computers/rsync_snapshots/
Maybe not directly relevant to the OP's question but since I see a bunch of folks mentioning using RAID, i thought i'd chime in about RAID5 survivability.
RAID5 protects you against one failure in a stripe. if you lose a drive, that's a failure. If you have a read error on a particular sector, that is another failure, and your data is gone.
the probability of a read error *somewhere* on a 1TB drive is actually quite high.
So, you lose a drive, you go to rebuild, you find you have a read error and can't get your data.
This can mean a few things.
1) lose a particular bit of data. Maybe you don't care, if you're archiving DVDs you'll probably cope just fine. If it's important data you'll be sad.
2) can't rebuild your RAID. Some RAID controllers will just give up if they get a read error during a rebuild, so then you have to back up the recoverable portion of your data (probably the vast majority), rebuild the RAID, etc.
I don't know how the various software RAIDs cope with this. I had this happen with a dell/lsilogic hardware raid card.
In my case, the read error was not something i noticed when i backed up and restored the data onto a new raid, but the parity didn't match so it wouldn't rebuild. It very well may have been on an unused portion of the filesystem.
solutions/mitigations:
1) scrub your RAID5's regularly. this process checks everything over and fixes any errors while you still have a full RAID5 set. This will reduce your chance of failure greatly.
2) use RAID6. it adds an extra drive's worth of redundancy.
You should also consider running an OS that supports ZFS (FreeBSD, OpenSolaris, Nexenta). It has additional data checksumming that can help. ZFS has software raid built in.
He talks specifically about Solaris & ZFS, but the reliability stuff is generally applicable. RAID-Z is basically equivalent to RAID5; RAID-Z2 is basically RAID6.
my experience differs - in my accord, i had basically no darkening. in my miata, with the top down, i had less than i would have liked - the windshield blocked plenty of light and i still needed my regular sunglasses.
First, they don't say 3-3000 percent (nor do they say 3-3000 times, which is what the original post above says). They say 1-3 orders of magnitude.
re: tape vs. disk:
cheaper per byte, sure.
more compatibly, possibly. i'm not sure whether you'd have an easier time reading a 1985 disk or a 1985 tape; in either case you'd need to do some digging to find the appropriate hardware to read the media.
longer? Nope. That 1985 disk might be readable by ontrack in the lab, but odds are pretty good that it won't work right once you dig up that MFM controller. The tape will probably be fine.
re: TFA:
If you RTFA they do some reasonable analysis.
They ignore the possibility that you might drop the RAID1 on your boot disk and go with a single SSD; I'm certainly considering that and if you think hardware raid controller + a pair of disks vs. 1 SSD the cost is very favorable.
They don't appear to take read latency into account; IOPS and latency are not the same thing.
Slashdot Mirror
my 5.1 downmix problems were due to either ffmpeg/pytivo or the tivo, and odds are good it was ffmpeg, and that it was my fault in misconfiguring it.
pytivo will default to something like 8mbit/sec bitrate for an hdtivo. ffmpeg won't actually use that much for dvd-sourced content, it won't need it, but it's not limited in any significant way by default.
I had only a stereo sound system, was getting stereo analog out of the tivo.
i don't know what the root cause of the problem was, whether ffmpeg was improperly downmixing it, or the tivo was. i'd bet on ffmpeg; i probably configured pytivo to do the downmix to save space on the tivo or something stupid like that.
I never really spent any time troubleshooting it so it's really hard to say what the problem was. If you configure it to just pass through 5.1 sound to your tivo (this is probably the default), odds are good it will just work.
The bitrates it transcodes to are configurable, and the default for s3 tivos is 8mbit I think. If it has a native mpeg2 stream it won't transcode at all, it will just pass it down to the tivo.
ftr dvd is 720x480 with rectangular pixels. The widescreen square-pixel display res of 480p is 854x480 or something close to that.
100Mbit is plenty fast enough to transfer hi-def streams; it's not the limiting factor. In practice the total a/v bitrate i'm transcoding to is usually less than 10Mbit.
but as i mentioned above, *something* isn't fast enough and the tivo doesn't keep up. You can have the tivo save it and watch it later though.
++ as far as tivo's actual DVR functionality.
if pytivo thinks you have an HD Tivo, it won't change the resolution at all (it does transcode to mpeg2). The series3 will scale the video itself (and it has a pretty good scaler chip in my experience).
If it thinks you have a series2, it will change the res, presumably to 640x480 but i haven't checked. Perhaps you misconfigured it so it thought you had a series2.
pytivo tries to detect if your file uses a supported codec (includes ac3), and just copy the audio stream if so; otherwise it transcodes, but the default transcoding target is in fact AC3.
I *have* had problems with 5.1 sound not being properly mixed down to stereo (yeah, yuck, but it's what i had until recently). The center channel was always sent to one speaker or the other. not sure if it's pytivo (ffmpeg really, it does the transcoding) or the tivo that causes this. I haven't really tried to debug it.
it is under active development and the devs seem to pay attention to support requests on the forums, so i'd suggest you give it another shot.
you need to make sure you have a good ffmpeg build. this can be non-trivial; the one that comes with your linux distro may not be good/new enough. the pytivo forums have links to win32 binaries that work for most people. If you're on a mac or bsd, try the ffmpeg-devel port rather than the ffmpeg port.
pytivo recently gained the ability to stream from DVD images. I haven't tested this but i suspect it works fine.
I like pytivo a lot, the only issue i have with it is speed. I have this cpu (1.9GHz dual-core athlon) and it's not fast enough to transcode hi-def in realtime.
you xfer the program and it dribbles through and you can watch it later.
More importantly, i've tried pre-transcoding and just transferring the mpeg-2 stream (pytivo will not transcode this at all), and the tivo (presumably) can't keep up, it still is a bit slower than realtime. That's annoying; i can pre-transcode or buy a faster cpu, but if the streaming just isn't fast enough then i'm kinda stuck. I am using 100Mbit wired ethernet, it's not some crappy wireless that's the issue. I haven't really investigated this.
I can imagine "why can't i own a canadian" being a joke.
Use it in a dimmer, or in an unventilated enclosure, or where it's turned on and off a lot. That's inappropriate use for pretty much any CFL, not just cheap ones.
wal-mart spec'd them and their specs say "drive every possible penny out of the production cost." http://pbs.org/wgbh/pages/frontline/shows/walmart Incandescent bulbs are a very mature and well-understood technology, and they are dirt cheap to start with, so there is less room/incentive to cut them to the bone.
You're probably aware that SSD's have been in the server space, at a very different price point, for a few years now, without any extraordinary reliability debacles.
I spoke to a rep from a big storage company (can't remember whether it was netapp or EMC) who claimed that the company has seen ZERO SSD failures in the field with their current tech, which has been in the field for a year and a half.
I wasn't buying SSD level stuff from them; no particular point in lying to me about it.
Of course, this kind of enterprise level SSD costs 100x what the models being discussed here, as you mention.
your momma wears army boots, so you're wrong.
I'll go with "known". Certainly to me, and probably to anyone who notices that reviews don't get posted.
I won't buy DRM-protected anything from anyone.
Well, I lie. I buy DVDs and bought HD-DVDs. And I was thinking about buying some blu-rays too (the disney remasters of their classic animated films appear to be top-quality product, and i want to reward them for their good remastering job even as i want to smack them for using DRM).
I only buy such content if I knew i can get the content elsewhere if i needed to.
I've had this happen at buy.com - i bought this:
http://www.buy.com/prod/ifrogz-iphone-3g-3gs-luxe-soft-touch-case-red-black/q/loc/101/208441113.html
and it was a piece of junk, finish ruined after a couple days in my pocket. It broke in pieces after 2 months.
I posted reviews to buy.com (where i bought it) and they magically never appeared.
I won't shop there anymore. Amazon rules.
It's a guarantee of availability.
The typical lifetime of a CPU package is a year or 18 months.
Embedded designers want to be able to design around something that won't disappear next year right when they've got the bugs out and they're ready to ship.
it's the way of things with large companies. They can, and do, innovate. But they also know that there is a lot to be said for whipping out their checkbook.
The important thing with this is that they keep the assets & people of the acquired company. I worked at ANS Communications, which was sold by AOL to Worldcom in the mid 1990's.
ANS had a top-notch team, the best I have ever worked with. It had built the NSFNet (http://en.wikipedia.org/wiki/National_Science_Foundation_Network) more or less from scratch, and after the Internet commercialized it was one of the best tier-1 ISPs. (internal slogan: we suck less)
Worldcom let us wither on the vine. They did basically nothing to integrate us into the business, and ignored the talent we had. Folks drifted away. It's probably true that they bought us not for our staff, but because we came with a contract to run AOL's dial business; however, it was negligent of WCOM to ignore the rest of the quality asset they'd purchased.
OTOH i've heard stories of companies being acquired by cisco. cisco knows how to do it right; they pay attention to what they are buying. They integrate the staff and put them to work on something useful.
on a related note, I've got a friend who works for IBM who says that his best shot at a "promotion" (from a high to a very high level) is not to do something inside IBM, but to go to a startup, and get acquired by IBM.
Found this, looks interesting for the DIY type.
http://www.instructables.com/id/Make-your-own-remote-power-switches/
it's easy to measure power usage, the US$20 kill-a-watt meter will tell you everything you need to know.
The combo of my VCR, flakey DVD/mpeg4 player, and HD-DVD player [*] draw a total of 7 watts when "off". This works out to 61 kwh/yr, which costs me about $7.50 (at $.12/kwh). A remote switch cord costs $12 from Ace Hardware. Sigh.
I buy "green" power from my local utility so in theory i'm just driving up demand and scale for renewable power by leaving it running all the time, right? Sigh.
* i bought it, cheap, after they were discontinued
awesome.
When you say "adding more disks" I assume you mean raid6 vs. raid5.
You're right that consistency checking is required; but it's not good enough for important data.
I did a consistency check last week on my entire RAID. it was good.
I just lost a drive, now i want to rebuild parity. Whoops, I get a read error that crept in since my last consistency check. I am now out my data. RAID6 would have saved me.
If i didn't do a consistency check fairly regularly, i'd probably be hosed even with RAID6 since there would be enough read errors that i'd lose.
Of course, it all depends how important your data is. My MP3s and dvdrips are not so important that a lost file is a catastrophe, so they live on raid-z (like raid5 for redundancy's sake). My business runs on RAID6 and mirrors.
You paid H.264 licensing fees when you bought your Mac, AppleTV, and iPhone. you're not seeing them as line items, but you're definitely paying them.
You are probably violating patents by ripping to H.264 with handbrake. Of course if you're in the US you're already violating the DMCA probably by ripping DVDs so what the heck.
Moving forward, large video streaming services will have to start paying significant fees to stream H.264 video.
You may not see the problem in paying for this, but you are definitely paying.
You may have broken the law.
http://lame.sourceforge.net/tech-FAQ.txt
6. Does LAME use any MP3 patented technology?
LAME, as the name says, is *not* an encoder. LAME is a development
project which uses the open source model to improve MP3 technology.
Many people believe that compiling this code and distributing an
encoder which uses this code would violate some patents (in the US,
Europe and Japan). However, *only* a patent lawyer is qualified to
make this determination. The LAME project tries to avoid all these
legal issues by only releasing source code, much like the ISO
distributes MP3 "demonstration" source code. Source code is
considered as speech, which may contain descriptions of patented
technology. Descriptions of patents are in the public
domain.
Several companies plan on releasing encoders based on LAME, and
they intend to obtain all the appropriate patent licenses. At least
one company is now shipping a fully licensed version of LAME with
their portable MP3 player.
Note that under German Patent Law, Â11(1) a patent doesn't cover
private acts with non-industrial purposes. Probably interesting for
developers is that a patent doesn't cover acts with experimental
purposes, that aim at the object of the patented invention (Â11(2)).
glad to hear that comcast is morally equivalent to the perpetrators of the holocaust, who killed 12 million people in concentration camps.
Better yet, ask a friend who already has a system running 24/7.
beware, though - rsync will gladly delete files on the target system if you accidentally delete the originals on the local. Perhaps use --link-dest and the scheme described at http://www.mikerubel.org/computers/rsync_snapshots/
Maybe not directly relevant to the OP's question but since I see a bunch of folks mentioning using RAID, i thought i'd chime in about RAID5 survivability.
RAID5 protects you against one failure in a stripe. if you lose a drive, that's a failure. If you have a read error on a particular sector, that is another failure, and your data is gone.
the probability of a read error *somewhere* on a 1TB drive is actually quite high.
So, you lose a drive, you go to rebuild, you find you have a read error and can't get your data.
This can mean a few things.
1) lose a particular bit of data. Maybe you don't care, if you're archiving DVDs you'll probably cope just fine. If it's important data you'll be sad.
2) can't rebuild your RAID. Some RAID controllers will just give up if they get a read error during a rebuild, so then you have to back up the recoverable portion of your data (probably the vast majority), rebuild the RAID, etc.
I don't know how the various software RAIDs cope with this. I had this happen with a dell/lsilogic hardware raid card.
In my case, the read error was not something i noticed when i backed up and restored the data onto a new raid, but the parity didn't match so it wouldn't rebuild. It very well may have been on an unused portion of the filesystem.
solutions/mitigations:
1) scrub your RAID5's regularly. this process checks everything over and fixes any errors while you still have a full RAID5 set. This will reduce your chance of failure greatly.
2) use RAID6. it adds an extra drive's worth of redundancy.
3) use http://en.wikipedia.org/wiki/Parchive or some similar additional layer of redundancy.
You should also consider running an OS that supports ZFS (FreeBSD, OpenSolaris, Nexenta). It has additional data checksumming that can help. ZFS has software raid built in.
Several good blog posts on this subject here:
http://blogs.sun.com/relling/tags/mttdl
He talks specifically about Solaris & ZFS, but the reliability stuff is generally applicable. RAID-Z is basically equivalent to RAID5; RAID-Z2 is basically RAID6.
my experience differs - in my accord, i had basically no darkening. in my miata, with the top down, i had less than i would have liked - the windshield blocked plenty of light and i still needed my regular sunglasses.
First, they don't say 3-3000 percent (nor do they say 3-3000 times, which is what the original post above says). They say 1-3 orders of magnitude.
re: tape vs. disk:
cheaper per byte, sure.
more compatibly, possibly. i'm not sure whether you'd have an easier time reading a 1985 disk or a 1985 tape; in either case you'd need to do some digging to find the appropriate hardware to read the media.
longer? Nope. That 1985 disk might be readable by ontrack in the lab, but odds are pretty good that it won't work right once you dig up that MFM controller. The tape will probably be fine.
re: TFA:
If you RTFA they do some reasonable analysis.
They ignore the possibility that you might drop the RAID1 on your boot disk and go with a single SSD; I'm certainly considering that and if you think hardware raid controller + a pair of disks vs. 1 SSD the cost is very favorable.
They don't appear to take read latency into account; IOPS and latency are not the same thing.
Also, prices have already fallen significantly since their published data. They list a 32G SSD at $739; the same one is $449 today at http://rocketdisk.com/index.php?cPath=8&gclid=CJbK8OH14ZkCFSQeDQodaikyXA
Not via e-mail.