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• Adventures In NAS

  1er janvier, par Multimedia Mike — General

  In my post last year about my out-of-control single-board computer (SBC) collection which included my meager network attached storage (NAS) solution, I noted that :

  I find that a lot of my fellow nerds massively overengineer their homelab NAS setups. I’ll explore this in a future post. For my part, people tend to find my homelab NAS solution slightly underengineered.

  So here I am, exploring this is a future post. I’ve been in the home NAS game a long time, but have never had very elaborate solutions for such. For my part, I tend to take an obsessively reductionist view of what constitutes a NAS : Any small computer with a pool of storage and a network connection, running the Linux operating system and the Samba file sharing service.

  
  
  

  Many home users prefer to buy turnkey boxes, usually that allow you to install hard drives yourself, and then configure the box and its services with a friendly UI. My fellow weird computer nerds often buy cast-off enterprise hardware and set up more resilient, over-engineered solutions, as long as they have strategies to mitigate the noise and dissipate the heat, and don’t mind the electricity bills.

  If it works, awesome ! As an old hand at this, I am rather stuck in my ways, however, preferring to do my own stunts, both with the hardware and software solutions.

  My History With Home NAS Setups
  In 1998, I bought myself a new computer — beige box tower PC, as was the style as the time. This was when normal people only had one computer at most. It ran Windows, but I was curious about this new thing called “Linux” and learned to dual boot that. Later that year, it dawned on me that nothing prevented me from buying a second ugly beige box PC and running Linux exclusively on it. Further, it could be a headless Linux box, connected by ethernet, and I could consolidate files into a single place using this file sharing software named Samba.
  

  I remember it being fairly onerous to get Samba working in those days. And the internet was not quite so helpful in those days. I recall that the thing that blocked me for awhile was needing to know that I had to specify an entry for the Samba server machine in the LMHOSTS (Lanman hosts) file on the Windows 95 machine.

  However, after I cracked that code, I have pretty much always had some kind of ad-hoc home NAS setup, often combined with a headless Linux development box.

  In the early 2000s, I built a new beige box PC for a file server, with a new hard disk, and a coworker tutored me on setting up a (P)ATA UDMA 133 (or was it 150 ? anyway, it was (P)ATA’s last hurrah before SATA conquered all) expansion card and I remember profiling that the attached hard drive worked at a full 21 MBytes/s reading. It was pretty slick. Except I hadn’t really thought things through. You see, I had a hand-me-down ethernet hub cast-off from my job at the time which I wanted to use. It was a 100 Mbps repeater hub, not a switch, so the catch was that all connected machines had to be capable of 100 Mbps. So, after getting all of my machines (3 at the time) upgraded to support 10/100 ethernet (the old off-brand PowerPC running Linux was the biggest challenge), I profiled transfers and realized that the best this repeater hub could achieve was about 3.6 MBytes/s. For a long time after that, I just assumed that was the upper limit of what a 100 Mbps network could achieve. Obviously, I now know that the upper limit ought to be around 11.2 MBytes/s and if I had gamed out that fact in advance, I would have realized it didn’t make sense to care about super-fast (for the time) disk performance.

  At this time, I was doing a lot for development for MPlayer/xine/FFmpeg. I stored all of my multimedia material on this NAS. I remember being confused when I was working with Y4M data, which is raw frames, which is lots of data. xine, which employed a pre-buffering strategy, would play fine for a few seconds and then stutter. Eventually, I reasoned out that the files I was working with had a data rate about twice what my awful repeater hub supported, which is probably the first time I came to really understand and respect streaming speeds and their implications for multimedia playback.

  Smaller Solutions
  For a period, I didn’t have a NAS. Then I got an Apple AirPort Extreme, which I noticed had a USB port. So I bought a dual drive brick to plug into it and used that for a time. Later (2009), I had this thing called the MSI Wind Nettop which is the only PC I’ve ever seen that can use a CompactFlash (CF) card for a boot drive. So I did just that, and installed a large drive so it could function as a NAS, as well as a headless dev box. I’m still amazed at what a low-power I/O beast this thing is, at least when compared to all the ARM SoCs I have tried in the intervening 1.5 decades. I’ve had spinning hard drives in this thing that could read at 160 MBytes/s (‘dd’ method) and have no trouble saturating the gigabit link at 112 MBytes/s, all with its early Intel Atom CPU.

  Around 2015, I wanted a more capable headless dev box and discovered Intel’s line of NUCs. I got one of the fat models that can hold a conventional 2.5″ spinning drive in addition to the M.2 SATA SSD and I was off and running. That served me fine for a few years, until I got into the ARM SBC scene. One major limitation here is that 2.5″ drives aren’t available in nearly the capacities that make a NAS solution attractive.

  Current Solution
  My current NAS solution, chronicled in my last SBC post– the ODroid-HC2, which is a highly compact ARM SoC with an integrated USB3-SATA bridge so that a SATA drive can be connected directly to it :

  
  

  

  ODROID-HC2 NAS

  
  

  I tend to be weirdly proficient at recalling dates, so I’m surprised that I can’t recall when I ordered this and put it into service. But I’m pretty sure it was circa 2018. It’s only equipped with an 8 TB drive now, but I seem to recall that it started out with only a 4 TB drive. I think I upgraded to the 8 TB drive early in the pandemic in 2020, when ISPs were implementing temporary data cap amnesty and I was doing what a r/DataHoarder does.

  The HC2 has served me well, even though it has a number of shortcomings for a hardware set chartered for NAS :

  1. While it has a gigabit ethernet port, it’s documented that it never really exceeds about 70 MBytes/s, due to the SoC’s limitations
  2. The specific ARM chip (Samsung Exynos 5422 ; more than a decade old as of this writing) lacks cryptography instructions, slowing down encryption if that’s your thing (e.g., LUKS)
  3. While the SoC supports USB3, that block is tied up for the SATA interface ; the remaining USB port is only capable of USB2 speeds
  4. 32-bit ARM, which prevented me from running certain bits of software I wanted to try (like Minio)
  5. Only 1 drive, so no possibility for RAID (again, if that’s your thing)

  I also love to brag on the HC2’s power usage : I once profiled the unit for a month using a Kill-A-Watt and under normal usage (with the drive spinning only when in active use). The unit consumed 4.5 kWh… in an entire month.

  New Solution
  Enter the ODroid-HC4 (I purchased mine from Ameridroid but Hardkernel works with numerous distributors) :

  
  

  

  ODroid-HC4 with an SSD and a conventional drive

  
  

  I ordered this earlier in the year and after many months of procrastinating and obsessing over the best approach to take with its general usage, I finally have it in service as my new NAS. Comparing point by point with the HC2 :

  1. The gigabit ethernet runs at full speed (though a few things on my network run at 2.5 GbE now, so I guess I’ll always be behind)
  2. The ARM chip (Amlogic S905X3) has AES cryptography acceleration and handles all the LUKS stuff without breaking a sweat ; “cryptsetup benchmark” reports between 500-600 MBytes/s on all the AES variants
  3. The USB port is still only USB2, so no improvement there
  4. 64-bit ARM, which means I can run Minio to simulate block storage in a local dev environment for some larger projects I would like to undertake
  5. Supports 2 drives, if RAID is your thing

  How I Set It Up
  How to set up the drive configuration ? As should be apparent from the photo above, I elected for an SSD (500 GB) for speed, paired with a conventional spinning HDD (18 TB) for sheer capacity. I’m not particularly trusting of RAID. I’ve watched it fail too many times, on systems that I don’t even manage, not to mention that aforementioned RAID brick that I had attached to the Apple AirPort Extreme.

  I had long been planning to use bcache, the block caching interface for Linux, which can use the SSD as a speedy cache in front of the more capacious disk. There is also LVM cache, which is supposed to achieve something similar. And then I had to evaluate the trade-offs in whether I wanted write-back, write-through, or write-around configurations.

  This was all predicated on the assumption that the spinning drive would not be able to saturate the gigabit connection. When I got around to setting up the hardware and trying some basic tests, I found that the conventional HDD had no trouble keeping up with the gigabit data rate, both reading and writing, somewhat obviating the need for SSD acceleration using any elaborate caching mechanisms.

  Maybe that’s because I sprung for the WD Red Pro series this time, rather than the Red Plus ? I’m guessing that conventional drives do deteriorate over the years. I’ll find out.

  For the operating system, I stuck with my newest favorite Linux distro : DietPi. While HardKernel (parent of ODroid) makes images for the HC units, I had also used DietPi for the HC2 for the past few years, as it tends to stay more up to date.

  Then I rsync’d my data from HC2 -> HC4. It was only about 6.5 TB of total data but it took days as this WD Red Plus drive is only capable of reading at around 10 MBytes/s these days. Painful.

  For file sharing, I’m pretty sure most normal folks have nice web UIs in their NAS boxes which allow them to easily configure and monitor the shares. I know there are such applications I could set up. But I’ve been doing this so long, I just do a bare bones setup through the terminal. I installed regular Samba and then brought over my smb.conf file from the HC2. 1 by 1, I tested that each of the old shares were activated on the new NAS and deactivated on the old NAS. I also set up a new share for the SSD. I guess that will just serve as a fast I/O scratch space on the NAS.

  The conventional drive spins up and down. That’s annoying when I’m actively working on something but manage not to hit the drive for like 5 minutes and then an application blocks while the drive wakes up. I suppose I could set it up so that it is always running. However, I micro-manage this with a custom bash script I wrote a long time ago which logs into the NAS and runs the “date” command every 2 minutes, appending the output to a file. As a bonus, it also prints data rate up/down stats every 5 seconds. The spinning file (“nas-main/zz-keep-spinning/keep-spinning.txt”) has never been cleared and has nearly a quarter million lines. I suppose that implies that it has kept the drive spinning for 1/2 million minutes which works out to around 347 total days. I should compare that against the drive’s SMART stats, if I can remember how. The earliest timestamp in the file is from March 2018, so I know the HC2 NAS has been in service at least that long.

  For tasks, vintage cron still does everything I could need. In this case, that means reaching out to websites (like this one) and automatically backing up static files.

  I also have to have a special script for starting up. Fortunately, I was able to bring this over from the HC2 and tweak it. The data disks (though not boot disk) are encrypted. Those need to be unlocked and only then is it safe for the Samba and Minio services to start up. So one script does all that heavy lifting in the rare case of a reboot (this is the type of system that’s well worth having on a reliable UPS).

  Further Work
  I need to figure out how to use the OLED display on the NAS, and how to make it show something more useful than the current time and date, which is what it does in its default configuration with HardKernel’s own Linux distro. With DietPi, it does nothing by default. I’m thinking it should be able to show the percent usage of each of the 2 drives, at a minimum.

  I also need to establish a more responsible backup regimen. I’m way too lazy about this. Fortunately, I reason that I can keep the original HC2 in service, repurposed to accept backups from the main NAS. Again, I’m sort of micro-managing this since a huge amount of data isn’t worth backing up (remember the whole DataHoarder bit), but the most important stuff will be shipped off.

  The post Adventures In NAS first appeared on Breaking Eggs And Making Omelettes.

• Xuggle mp4 output (isom mp41 codec ?) issues

  19 mai 2017, par JonSides

  We’re using Xuggler to create an mp4 from pictures, with no audio at this point. The mp4 we’re getting is playable locally, but cannot be embedded in a webpage or chromecast. I suspect the issue is that we’re getting an older ISOM mp41 codec that’s not supported by HTML5 and chromecast. That’s a guess based on this snippet of header info :

  Internet media type                      : video/mp4
  
  Codec ID                                 : isom
  
  Codec ID                                 : isom (isom/iso2/mp41)
  
  Codec ID/Url                             : 
  
  http://www.apple.com/quicktime/download/standalone.html
  
  CodecID_Compatible                       : isom/iso2/mp41
  
  Codec                                    : MPEG-4
  
  Codec                                    : MPEG-4
  
  Codec/Extensions usually used            : mov mp4 m4v m4a m4b m4p 3ga 3gpa 
  
  3gpp 3gp 3gpp2 3g2 k3g jpm jpx mqv ismv isma ismt f4a f4b f4v  

  I can embed and chromecast mp42 type files. So the first part of my question is Am I on the right track in looking at isom and mp41 ? And if so, can I get Xuggler to output using a newer codec ?
  I can post the full header if that would be helpful.
  The above snippet is from mediainfo. Here’s the whole thing, which is too long for a comment :
  General
  Count : 325
  Count of stream of this kind : 1
  Kind of stream : General
  Kind of stream : General
  Stream identifier : 0
  Inform : MPEG-4 (Base Media) : 377 KiB, 12 s 301 ms
  Count of video streams : 1
  Video_Format_List : MPEG-4 Visual
  Video_Format_WithHint_List : MPEG-4 Visual
  Codecs Video : MPEG-4 Visual
  Complete name : C :\Users\Jon\Desktop\vid-1.mp4
  Folder name : C :\Users\Jon\Desktop
  File name : vid-1
  File extension : mp4
  Format : MPEG-4
  Format : MPEG-4
  Format/Extensions usually used : mov mp4 m4v m4a m4b m4p 3ga 3gpa 3gpp 3gp 3gpp2 3g2 k3g jpm jpx mqv ismv isma ismt f4a f4b f4v
  Commercial name : MPEG-4
  Format profile : Base Media
  Internet media type : video/mp4
  Codec ID : isom
  Codec ID : isom (isom/iso2/mp41)
  Codec ID/Url :
  http://www.apple.com/quicktime/download/standalone.html
  CodecID_Compatible : isom/iso2/mp41
  Codec : MPEG-4
  Codec : MPEG-4
  Codec/Extensions usually used : mov mp4 m4v m4a m4b m4p 3ga 3gpa 3gpp 3gp 3gpp2 3g2 k3g jpm jpx mqv ismv isma ismt f4a f4b f4v
  File size : 386063
  File size : 377 KiB
  File size : 377 KiB
  File size : 377 KiB
  File size : 377 KiB
  File size : 377.0 KiB
  Duration : 12301
  Duration : 12 s 301 ms
  Duration : 12 s 301 ms
  Duration : 12 s 301 ms
  Duration : 00:00:12.301
  Duration : 00:00:14:00
  Duration : 00:00:12.301 (00:00:14:00)
  Overall bit rate mode : CBR
  Overall bit rate mode : Constant
  Overall bit rate : 251077
  Overall bit rate : 251 kb/s
  Frame rate : 3.415
  Frame rate : 3.415 FPS
  Frame count : 42
  Stream size : 1368
  Stream size : 1.34 KiB (0%)
  Stream size : 1 KiB
  Stream size : 1.3 KiB
  Stream size : 1.34 KiB
  Stream size : 1.336 KiB
  Stream size : 1.34 KiB (0%)
  Proportion of this stream : 0.00354
  HeaderSize : 36
  DataSize : 384703
  FooterSize : 1324
  IsStreamable : No
  File creation date : UTC 2017-05-05 19:49:25.209
  File creation date (local) : 2017-05-05 15:49:25.209
  File last modification date : UTC 2017-01-04 19:04:53.000
  File last modification date (local) : 2017-01-04 15:04:53.000
  Writing application : Lavf54.3.100
  Writing application : Lavf54.3.100

  Video
  
  
  
  Count                                    : 338
  
  Count of stream of this kind             : 1
  
  Kind of stream                           : Video
  
  Kind of stream                           : Video
  
  Stream identifier                        : 0
  
  StreamOrder                              : 0
  
  Inform                                   : 250 kb/s, 200*200 (1.000), at 
  
  3.415 FPS, MPEG-4 Visual (Simple@L1)
  
  ID                                       : 1
  
  ID                                       : 1
  
  Format                                   : MPEG-4 Visual
  
  Commercial name                          : MPEG-4 Visual
  
  Format profile                           : Simple@L1
  
  Format settings, BVOP                    : No
  
  Format settings, BVOP                    : No
  
  Format settings, QPel                    : No
  
  Format settings, QPel                    : No
  
  Format settings, GMC                     : 0
  
  Format settings, GMC                     : No warppoints
  
  Format settings, Matrix                  : Default (H.263)
  
  Format settings, Matrix                  : Default (H.263)
  
  Internet media type                      : video/MP4V-ES
  
  Codec ID                                 : 20
  
  Codec                                    : MPEG-4V
  
  Codec                                    : MPEG-4 Visual
  
  Codec/Family                             : MPEG-4V
  
  Codec/CC                                 : 20
  
  Codec profile                            : Simple@L1
  
  Codec settings, Packet bitstream         : No
  
  Codec settings, BVOP                     : No
  
  Codec settings, QPel                     : No
  
  Codec settings, GMC                      : 0
  
  Codec settings, GMC                      : No warppoints
  
  Codec settings, Matrix                   : Default (H.263)
  
  Duration                                 : 12301
  
  Duration                                 : 12 s 301 ms
  
  Duration                                 : 12 s 301 ms
  
  Duration                                 : 12 s 301 ms
  
  Duration                                 : 00:00:12.301
  
  Duration                                 : 00:00:14:00
  
  Duration                                 : 00:00:12.301 (00:00:14:00)
  
  Bit rate mode                            : CBR
  
  Bit rate mode                            : Constant
  
  Bit rate                                 : 250207
  
  Bit rate                                 : 250 kb/s
  
  Width                                    : 200
  
  Width                                    : 200 pixels
  
  Height                                   : 200
  
  Height                                   : 200 pixels
  
  Sampled_Width                            : 200
  
  Sampled_Height                           : 200
  
  Pixel aspect ratio                       : 1.000
  
  Display aspect ratio                     : 1.000
  
  Display aspect ratio                     : 1.000
  
  Rotation                                 : 0.000
  
  Frame rate mode                          : VFR
  
  Frame rate mode                          : Variable
  
  Frame rate                               : 3.415
  
  Frame rate                               : 3.415 FPS
  
  Minimum frame rate                       : 3.333
  
  Minimum frame rate                       : 3.333 FPS
  
  Maximum frame rate                       : 65535.000
  
  Maximum frame rate                       : 65 535.000 FPS
  
  Frame count                              : 42
  
  Resolution                               : 8
  
  Resolution                               : 8 bits
  
  Colorimetry                              : 4:2:0
  
  Color space                              : YUV
  
  Chroma subsampling                       : 4:2:0
  
  Chroma subsampling                       : 4:2:0
  
  Bit depth                                : 8
  
  Bit depth                                : 8 bits
  
  Scan type                                : Progressive
  
  Scan type                                : Progressive
  
  Interlacement                            : PPF
  
  Interlacement                            : Progressive
  
  Compression mode                         : Lossy
  
  Compression mode                         : Lossy
  
  Bits/(Pixel*Frame)                       : 1.832
  
  Stream size                              : 384695
  
  Stream size                              : 376 KiB (100%)
  
  Stream size                              : 376 KiB
  
  Stream size                              : 376 KiB
  
  Stream size                              : 376 KiB
  
  Stream size                              : 375.7 KiB
  
  Stream size                              : 376 KiB (100%)
  
  Proportion of this stream                : 0.99646
  
  Writing library                          : Lavc54.14.101
  
  Writing library                          : Lavc54.14.101

• Sequencing MIDI From A Chiptune

  28 avril 2013, par Multimedia Mike — Outlandish Brainstorms

  The feature requests for my game music appreciation website project continue to pour in. Many of them take the form of “please add player support for system XYZ and the chiptune library to go with it.” Most of these requests are A) plausible, and B) in process. I have also received recommendations for UI improvements which I take under consideration. Then there are the numerous requests to port everything from Native Client to JavaScript so that it will work everywhere, even on mobile, a notion which might take a separate post to debunk entirely.

  But here’s an interesting request about which I would like to speculate : Automatically convert a chiptune into a MIDI file. I immediately wanted to dismiss it as impossible or highly implausible. But, as is my habit, I started pondering the concept a little more carefully and decided that there’s an outside chance of getting some part of the idea to work.

  Intro to MIDI
  MIDI stands for Musical Instrument Digital Interface. It’s a standard musical interchange format and allows music instruments and computers to exchange musical information. The file interchange format bears the extension .mid and contains a sequence of numbers that translate into commands separated by time deltas. E.g. : turn key on (this note, this velocity) ; wait x ticks ; turn key off ; wait y ticks ; etc. I’m vastly oversimplifying, as usual.

  MIDI fascinated me back in the days of dialup internet and discrete sound cards (see also my write-up on the Gravis Ultrasound). Typical song-length MIDI files often ranged from a few kilobytes to a few 10s of kilobytes. They were significantly smaller than the MOD et al. family of tracker music formats mostly by virtue of the fact that MIDI files aren’t burdened by transporting digital audio samples.
  
  I know I’m missing a lot of details. I haven’t dealt much with MIDI in the past… 15 years or so (ever since computer audio became a blur of MP3 and AAC audio). But I’m led to believe it’s still relevant. The individual who requested this feature expressed an interest in being able to import the sequenced data into any of the many music programs that can interpret .mid files.

  The Pitch
  To limit the scope, let’s focus on music that comes from the 8-bit Nintendo Entertainment System or the original Game Boy. The former features 2 square wave channels, a triangle wave, a noise channel, and a limited digital channel. The latter creates music via 2 square waves, a wave channel, and a noise channel. The roles that these various channels usually play typically break down as : square waves represent the primary melody, triangle wave is used to simulate a bass line, noise channel approximates a variety of percussive sounds, and the DPCM/wave channels are fairly free-form. They can have random game sound effects or, if they are to assist in the music, are often used for more authentic percussive sounds.

  The various channels are controlled via an assortment of memory-mapped hardware registers. These registers are fed values such as frequency, volume, and duty cycle. My idea is to modify the music playback engine to track when various events occur. Whenever a channel is turned on or off, that corresponds to a MIDI key on or off event. If a channel is already playing but a new frequency is written, that would likely count as a note change, so log a key off event followed by a new key on event.

  There is the major obstacle of what specific note is represented by a channel in a particular state. The MIDI standard defines 128 different notes spanning 11 octaves. Empirically, I wonder if I could create a table which maps the assorted frequencies to different MIDI notes ?

  I think this strategy would only work with the square and triangle waves. Noise and digital channels ? I’m not prepared to tackle that challenge.

  Prior Work ?
  I have to wonder if there is any existing work in this area. I’m certain that people have wanted to do this before ; I wonder if anyone has succeeded ?

  Just like reverse engineering a binary program entails trying to obtain a higher level abstraction of a program from a very low level representation, this challenge feels like reverse engineering a piece of music as it is being performed and automatically expressing it in a higher level form.