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MC2 Build
Date: 28/8/2015 Tags: mc2	So the other day I was at rehearsal and the MC1 that built started to have some issues with the External control knobs (along the top). They were jumping all over the place and making it annoying to use. I did get around to pulling all the circuitry around those pots off and doing it properly later. But it occurred to me that I'm using gear that I have no backup for. There is no 2nd controller to swap out if this one dies at a gig. And because I'd rather custom build one out of parts I [mostly] have lying around that means building the MC2. For starters the MC1 uses a tiny micro-controller with no USB or network or any modern connectivity at all. I have an old XP computer JUST to reflash the damn thing (needs a REAL parallel port). For any new system I wanted an easy way to do software development and ethernet/USB connectivity. And because I had a Raspberry Pi already I settled on that as a platform to run everything. I already had a little touchscreen to go with it and some RGB led rings with encoders that I built for a different project that I never got around to. So with all those parts just lying around I got to making some bits to glue it all together. Here's a family photo: 1) The Raspberry Pi. This is the "old" B rev 2 version... which has the slower processor. 2) The touchscreen. This interfaces with the SDL api using the Linux framebuffer. Touch events show up as mouse clicks. It's all quite straight forward to be honest. The only gotcha is you HAVE to set the video mode back to text if you crash... otherwise you're stuck in video mode without a working console. 3) LED rings + encoders: These I built for someone else but was too slack to finish that project. They basically are an extension of the Mayhew LED ring except that I'm running Red/Green/Blue LEDs instead of just one colour. It also is designed to fit in a 1U rack box, so they are nice and compact. I'll have 3 pairs of these across the top of the box, giving me 6 independent continuous controllers. Just like the old MC1 box, but importantly I'll be able to update their "position" using software when the preset changes. 4) Neopixel chain: Each foot switch on the controller will have an associated LED. I settled on the Neopixels because they wouldn't require a lot of support circuitry and there is now a software library to make them work on the Raspberry Pi. Which I've used successfully on a bread board. 5) MIDI in and out ports. This is a direct implementation of the circuit used in the MC1. All I really have to do is connect it up to the Raspberry Pi's UART pins and then program the right frequency. fingers crossed 6) This is a bunch of extra GPIO (general purpose input/output) for connecting the foot switches and encoders up to. It runs on the I2C bus from the Pi so it's easy to chain lots of things and address them in software. (I love software solutions). 7) Some analog inputs for the expression pedals. I'll be able to have up to 4 connected at once. 8) This is the break out board for the expression pedals. It connects to (7) via a 4 wire bus and basically sets up the right voltages for the 3 pins on the socket. It allows me to detect when the pedal is connected and disconnected by limiting the valid ranges of input voltage when the pedal is connected to less than 0-3.3v... That's an overview of the hardware side. But what about the software? Well I already have a lot of cross platform C++ code that will come in handy. Firstly I have written a library called LGI that allows the same code to run on Windows, Mac and Linux without much changes. So why not extend that to SDL on the Raspberry Pi? So that's what I did this month. Which gives me access to a whole bunch of little controls like, edit boxes, check boxes, labels, buttons, table layout controls, graphical design tools etc. Stuff I've already written. But I still needed to work out the general look and feel of the user interface. Check it out: Basically I'm drafting up the flow of buttons and the layout of the controls to get a feel for what I need to write in the software. I have this control that does layout for me, kinda like a HTML table in that it works out the spacing of everything based on the size of the content. And I can style all the controls with CSS which will make for a nice consistent look over the product. I expect though it'll be some months before I get this all working. Only a few parts of this are tested and none of it has been integrated into a working system. I'll try and post updates when I can.
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It's been a fantastic week at Memecode headquarters...
Date: 12/6/2015 Tags: windows	I bought a cheap new Win8.1 tablet. Which was amazing for about 24 hours until I decided that I didn't want the 5gb restore partition and tried to remove it and resize the C: to fill the available space. Yeah that didn't go so well and I think I've bricked it. Said restore partition doesn't have any trouble shooting or repair tools (I did copy it to USB first). I found the BIOS but it won't read an external OS on USB if I set that to the first boot device. The partitioning software crashes at boot on the main C: partition install of Windows. To add insult to injury my main Windows 7 install on the desktop PC died tonight. It boots to a blank black screen. Safe mode hangs with lots of disk activity. It got stuck on the Paragon HFS+ driver, so I booted into Mac and removed that (copied elsewhere). And I'm trying to fix the disks one at a time with Disk Manager. Currently it's in some sort of infinite loop verifying my Win7 NTFS partition. Sigh. Seems like all my PCs hate me at the moment. One thing to be happy about is the fixes to HTML table layout I implemented today. There were some bugs related to table layout for spanned cells that have non-dynamic width specifications that are larger than the available space. And also an off by one error in the block element flow code. Slowly that HTML control is getting quite solid.
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SourceForge to Github Migration
Date: 4/6/2015 Tags: open-source	You may or may not already be aware of this but SourceForge has started taking control of popular apps that have abandoned their SourceForge project and moved elsewhere for the purpose of injecting adware into the installer for said products. The Gimp and nmap are some high profile examples. This of course goes directly against my principles. And I can't in good conscience continue to use SourceForge to host any of my Open Source apps or libraries. So as of today Lgi, i.Ftp, i.Mage and i.Hex are all hosted on Github. I need some experience using git anyway. My main concern is that I can't actually delete the projects on SourceForge, and they may decide to take them over and zombify them in the same manner as the Gimp. There is very little I can do about that unfortunately. Personally I will consider SourceForge as a point of last resort when getting software.
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Supporting Work
Date: 1/6/2015 Tags: scribe	It seems that a few things have gradually become a problem. Firstly customers with accents in their name are getting bad key's generated off the InScribe purchase page that they land on after buying the software. This is caused by less than stella coding on my part. But something that I'm trying to fix. The issue is that the data coming from PayPal is URL encoded and is in an unknown Charset. I've implemented some PHP in the purchase page to find the charset in the headers and do all the conversion for the $name. However in trying to test it I ran into a fairly annoying PayPal sand box bug. The PayPal Sand Box Bug If you go to create a new test user with an accent in their name you'll get a field validation error along the lines of "Only use letters". Which makes it hard to test purchase scripts with non-latin characters in the buyers name. I did however find a way around this, and that is to use the bulk upload tool to create the users. You can download a .tsv template direct from the PayPal sand box site on the "Create New User" page. From that fill out the details, and supply whatever name you want. Because the file is saved in unicode it bypasses the broken field validation stuff. Then upload that and you got a test user with accents. (Haven't tried Asian characters yet, but I will at some point). My new problem is that even after doing that and putting a sandbox button on my site the purchase script gets an empty response from PayPal when it checks the transaction. Fun times. The Installer/Uninstaller Everyone knows that the official way to uninstall a Windows application is to use the Control Panel uninstall page. It had completely escaped my attention until now that Scribe provides no such uninstaller entry in that list (Thank you dear user for reminding me). So I've gone and added the right registry entries to list the uninstaller, with help / support links, and the current version. The version is read straight from the .exe during installer compile time so it's always correct. Also the installer has been refactored to have a Desktop/Portable switch baked right in. Huzzah. The Help Also the help files shipping with Scribe have drifted from reality. So I'm in the process of reading through everything and updated all the parts that aren't correct anymore. Some areas might need fleshing out as well. OAUTH2 Support An initial draft implementation of OAUTH2 support for Gmail IMAP was shipped in the most recent build of Scribe. I'm quite keen to get feedback about it. So if you have tried to get it working and either succeeded or failed. Let me know.
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Supporting Work

Date: 1/6/2015
Tags: scribe

It seems that a few things have gradually become a problem. Firstly customers with accents in their name are getting bad key's generated off the InScribe purchase page that they land on after buying the software. This is caused by less than stella coding on my part. But something that I'm trying to fix. The issue is that the data coming from PayPal is URL encoded and is in an unknown Charset. I've implemented some PHP in the purchase page to find the charset in the headers and do all the conversion for the $name. However in trying to test it I ran into a fairly annoying PayPal sand box bug.

The PayPal Sand Box Bug

If you go to create a new test user with an accent in their name you'll get a field validation error along the lines of "Only use letters". Which makes it hard to test purchase scripts with non-latin characters in the buyers name. I did however find a way around this, and that is to use the bulk upload tool to create the users. You can download a .tsv template direct from the PayPal sand box site on the "Create New User" page. From that fill out the details, and supply whatever name you want. Because the file is saved in unicode it bypasses the broken field validation stuff. Then upload that and you got a test user with accents. (Haven't tried Asian characters yet, but I will at some point). My new problem is that even after doing that and putting a sandbox button on my site the purchase script gets an empty response from PayPal when it checks the transaction. Fun times.

The Installer/Uninstaller

Everyone knows that the official way to uninstall a Windows application is to use the Control Panel uninstall page. It had completely escaped my attention until now that Scribe provides no such uninstaller entry in that list (Thank you dear user for reminding me). So I've gone and added the right registry entries to list the uninstaller, with help / support links, and the current version. The version is read straight from the .exe during installer compile time so it's always correct. Also the installer has been refactored to have a Desktop/Portable switch baked right in. Huzzah.

The Help

Also the help files shipping with Scribe have drifted from reality. So I'm in the process of reading through everything and updated all the parts that aren't correct anymore. Some areas might need fleshing out as well.

OAUTH2 Support

An initial draft implementation of OAUTH2 support for Gmail IMAP was shipped in the most recent build of Scribe. I'm quite keen to get feedback about it. So if you have tried to get it working and either succeeded or failed. Let me know.

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Stabilizing GH3 Video For Sony Vegas
Date: 19/5/2015 Tags: video	I have a GH3 camera that takes pretty nice video. Because I cheaped out and got a non-Panasonic prime for the lens, I don't have in lens stabilization. What I do have is a bunch of footage that needs stabilization so I've been looking around for software based solutions. The first (free) one I heard about was Blender and it's point tracking. After downloading that and playing around with it I found it very limited in what footage it can work with. As soon as you pan or zoom it becomes very difficult to keep the footage zooming and panned correctly. There are scripts to help but because it's not core functionality it just gets complicated fast. Then I heard about Deshaker, which primarily runs as a plugin for VirtualDub. A tool which I haven't used in a very long time. So I downloaded both of those and got to work testing it on my footage. Immediately it was obvious that it was vastly better and more powerful that Blender. The first issue I faced when using VirtualDub was that the input video was .MOV files off the camera. This is the format from ffmpeg: Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'bec+tanner 038.MOV': Duration: 00:09:03.36, start: 0.000000, bitrate: 49552 kb/s Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuvj420p(pc, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 48004 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc (default) Stream #0:1(und): Audio: pcm_s16be (twos / 0x736F7774), 48000 Hz, 2 channels, s16, 1536 kb/s (default) Stream #0:2(und): Data: none (tmcd / 0x64636D74), 0 kb/s (default) And VirtualDub uses .AVI files. Next step is converting the video to an AVI without re-encoding it. And that is best accomplished by my old friend ffmpeg. Which has the ability to convert between compatible containers without loss of quality and time caused by re-encoding the video. My initial attempt failed because the AVI container doesn't support big endian audio (the default off the camera). So I converted that to little endian using this command: ffmpeg -i "input.mov" -vcodec copy -codec:a pcm_s16le "output.avi" Now I could load my files into VirtualDub and stabilize them. The process basically involved adding 2 instances of the Deshaker plugin to the filter pipeline. The first one is set to "pass 1" and enabled. Disable the 2nd instance. Then go to the start of the video and runing the Output Playback mode. This generates all the motion vectors. Disable the first pass instance of Deshaker and enable the 2nd pass instance. Now you can export the video using your desired compression. I don't like any of the built in compressors so I downloaded the x264 codec and used that. But the output had a problem. When the camera panned to track people walking, they appeared to jump back and forth in the stabilized output. Very odd looking. So I went frame by frame and noticed that in the source video each pair of frames coming through was the same. Deshaker then would get confused by this and shift the intermediate copy of the frame by more than the new frame. I thought the best way to get around this was to delete these redundant frames from the GH3. Fortunately VirtualDub comes with just such a filter: interpolate By putting it in front of the Deshaker instances I got nice clean output, free of stuttering. At least as far as it would play in VLC. However when I loaded that into Sony Vegas there was big problems playing the AVI files back. Basically it would drop to a slide show, and on top of that there was corruption in the rendered output. Mulling my options I started looking for a way of getting the video out of VirtualDub without using the AVI container format. Fortunately there is a way. By installing an external encoder, which in my case was more just redirecting output to ffmpeg. I found that by adding the right external encoder you can call ffmpeg to encoder the video straight from VirtualDub. The process involves writing out a "ffmpeg-1.vdprof" text file with the content from that link. Then importing that into VirtualDub and editing the details a bit. I decided to lower the -crf parameter to 16 to make it pretty much visually lossless. I don't want the stabilization to drop the quality at all. Now I can bring that footage into Vegas and it plays smooth as butter. But it might have sent a few hairs grey.
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Stabilizing GH3 Video For Sony Vegas

Date: 19/5/2015
Tags: video

I have a GH3 camera that takes pretty nice video. Because I cheaped out and got a non-Panasonic prime for the lens, I don't have in lens stabilization. What I do have is a bunch of footage that needs stabilization so I've been looking around for software based solutions.

The first (free) one I heard about was Blender and it's point tracking. After downloading that and playing around with it I found it very limited in what footage it can work with. As soon as you pan or zoom it becomes very difficult to keep the footage zooming and panned correctly. There are scripts to help but because it's not core functionality it just gets complicated fast.

Then I heard about Deshaker, which primarily runs as a plugin for VirtualDub. A tool which I haven't used in a very long time. So I downloaded both of those and got to work testing it on my footage. Immediately it was obvious that it was vastly better and more powerful that Blender.

The first issue I faced when using VirtualDub was that the input video was .MOV files off the camera. This is the format from ffmpeg:

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'bec+tanner 038.MOV':
  Duration: 00:09:03.36, start: 0.000000, bitrate: 49552 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuvj420p(pc, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 48004 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc (default)
    Stream #0:1(und): Audio: pcm_s16be (twos / 0x736F7774), 48000 Hz, 2 channels, s16, 1536 kb/s (default)
    Stream #0:2(und): Data: none (tmcd / 0x64636D74), 0 kb/s (default)

And VirtualDub uses .AVI files. Next step is converting the video to an AVI without re-encoding it. And that is best accomplished by my old friend ffmpeg. Which has the ability to convert between compatible containers without loss of quality and time caused by re-encoding the video. My initial attempt failed because the AVI container doesn't support big endian audio (the default off the camera). So I converted that to little endian using this command:

ffmpeg -i "input.mov" -vcodec copy -codec:a pcm_s16le "output.avi"

Now I could load my files into VirtualDub and stabilize them. The process basically involved adding 2 instances of the Deshaker plugin to the filter pipeline. The first one is set to "pass 1" and enabled. Disable the 2nd instance. Then go to the start of the video and runing the Output Playback mode. This generates all the motion vectors. Disable the first pass instance of Deshaker and enable the 2nd pass instance. Now you can export the video using your desired compression. I don't like any of the built in compressors so I downloaded the x264 codec and used that.

But the output had a problem. When the camera panned to track people walking, they appeared to jump back and forth in the stabilized output. Very odd looking. So I went frame by frame and noticed that in the source video each pair of frames coming through was the same. Deshaker then would get confused by this and shift the intermediate copy of the frame by more than the new frame. I thought the best way to get around this was to delete these redundant frames from the GH3. Fortunately VirtualDub comes with just such a filter: interpolate

By putting it in front of the Deshaker instances I got nice clean output, free of stuttering. At least as far as it would play in VLC. However when I loaded that into Sony Vegas there was big problems playing the AVI files back. Basically it would drop to a slide show, and on top of that there was corruption in the rendered output. Mulling my options I started looking for a way of getting the video out of VirtualDub without using the AVI container format. Fortunately there is a way. By installing an external encoder, which in my case was more just redirecting output to ffmpeg.

I found that by adding the right external encoder you can call ffmpeg to encoder the video straight from VirtualDub. The process involves writing out a "ffmpeg-1.vdprof" text file with the content from that link. Then importing that into VirtualDub and editing the details a bit. I decided to lower the -crf parameter to 16 to make it pretty much visually lossless. I don't want the stabilization to drop the quality at all.

Now I can bring that footage into Vegas and it plays smooth as butter. But it might have sent a few hairs grey.

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Scribe Gmail Support Update
Date: 4/5/2015 Tags: scribe oauth2	Google has switched off so called "insecure" authentication methods, including "PLAIN", which Scribe relied on. Today I got that draft implementation working enough to be able to login to the Gmail IMAP server using OAuth2. It does take you via a detour into your default browser but in the end it works. It's also quite the hack job at this point so I want to clean up the code and make the error handling at least very verbose. I will be making a release in the next few days off the stable branch that includes functional OAuth2 support. It has been argued that Google's motivation in doing this is to force people onto the web and out of installed desktop / mobile clients, for the purpose of making Gmail's web UI more palatable. I remain unconvinced about this argument in that there seems to be another reason that makes more sense to me. OAuth2 doesn't require the client to store the plain text password. Thus reducing the possible points of failure for security. Most installed clients are bad at storing persistent account credentials in a fully secure fashion. So by removing that attack vector it could be argued that Google is doing App authors a favour. Maybe. I still find OAuth2 quite needlessly complicated. And it's very dependent on the client having lots of pre-configured knowledge about the server it's authenticating with. I mean for every service that Scribe will support OAuth2 authentication I have to have a unique ClientID and ClientSecret, as well as the token URI and access URI... none of which are "discoverable" on the fly, but hard coded in. So you can't connect Scribe to some arbitrary new service that supports OAuth2. I have to manually create support each new service. I don't yet understand how that is a reasonable state of affairs.
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Sitemap

The PayPal Sand Box Bug

The Installer/Uninstaller

The Help

OAUTH2 Support