Lossless MKV to MP4 (thanks, ffmpeg)

Update

The following all still applies and is sound advice, but you can perform a simple container switch (I think the technical term is demux and remux) or lossless conversion (no re-encode) using VLC, which is pretty common among people who want to view media. I won't re-invent the wheel, and you can google "mkv to mp4 vlc" to see videos on how to do this, but you are basically opening VLC and choosing file>convert/save, then picking the source file (mkv) and clicking convert/save, then select the 'tools' by the profile dropdown and set 'encapsulation' to mp4/mov, and audio and video to 'keep original.' Then just click save and set your destination file and do it.

Keep in mind that mp4 files are, arguably, a little more well received as apple devices can play them and they are a little more friendly for web streaming. That said, I prefer the mkv container as it allows multiple subtitle tracks and allows various codecs such as . The mp4 container, I believe, is only supposed to work with older mpeg or avc/h.264 encoded video and AAC encoded audio.

And soon enough we can re-visit with HEVC/VP9/Daala thoughts...

A long time ago, I wanted to "extract" my video and audio from a mkv and put them into a html5 video friendly .ogv file/container. I wrote about it here.

This is a little more of an update to that post than a new idea, but I was dissapointed at the search results when I googled "lossless mkv to mp4" and hope this may be of some assistance. It probably won't. Here's hope.

It really isn't bad. If you want to be thorough, install MediaInfo and verify the audio code and video codec are compatible. I'm not sure what mp4 accepts, but AVC/h.264 for video and aac for audio seem to be the most common codecs. Technically, you could copy the video and recode the audio if that was needed for your situation. The code would need little modification.

Install ffmpeg. Get the package for your OS (i'm using Windows), then extract it. It doesn't have to install, so pay attention to where you extract to.

Next, open cmd (search from the start-menu search) and browse to where you extracted ffmpeg. Try using 'tab' to auto complete from cmd. It saves tons of time. Tab multiple times to cycle through potential completions.

Type the following, using the video (full location input and output --fun, I know!) for input.mkv and the name you want as output.mp4: C:\videdit\ffmpeg\bin>ffmpeg -i c:\Users\nchapman\Videos\christianeatingwackyburger.mkv -codec copy c:\Users\nchapman\Videos\newchristianeatingwackyburger.mp4

Hope this helps! You can use -acodec mp3 -vcodec copy or something crazy if you prefer.

Also, you can encode all files in a directory by saving this to a .bat file (then, drag a .mkv file onto it):
for %%a in ("*.mkv") do ffmpeg.exe -i "%%a" -vcodec copy -acodec copy "%%~na .mp4" pause

Source (last comment)

I Replaced my Old Nikon D70 with a Used Nikon D3100

But, Why?

I had two Nikon D70 cameras which, over the past couple of years, became increasingly unusable. Both had been purchased second-hand on ebay in 2005 or 2006 at reasonable prices. One came with a 18-70mm and the other a 28-80mm and a 70-300mm. I prefer the 18mm, despite the distortion, for the wider angles it provides on my DX sensor, so rarely used the 28mm zoom. 2 years ago, I was given a 50mm 1.8 and LOVE it!

First Camera

I shot the transit of venus in late 2012 with a 70-300mm and not enough filters and, seemingly, damaged my shutter. The camera stopped working properly shortly after, so that is my best guess. It still shoots up to 1/60th of a second shutter speed, but nothing higher (just black images) and has trouble syncing with the flash (related)...etc, so very limited in use (only high aperture shooting up to 1/60th frames per second -- fine for tripod landscape shooting, I guess).

Second Camera

The other has no excuse other than the wear and tear I exposed it to for the past 8 years. I use my cameras to get shots, which means on the beach, in the ocean, whilst raining, etc. Sometimes my kids run around and use them as bludgeoning devices. All the cameras get in return is a lens/sensor cleaning occasionally and maybe a UV filter on the lenses to offer some type of safeguard (well, I use lens caps when I can). One day, half-way through shooting my son at the park, it made a chunking noise (much slower and louder than the usual mirror flip/shutter release speed) and seemed to fail mid mirror flip. Since then it flashes 'Err' on the display and won't successfully shoot at all.

Hello New Old D3100

I bought a D3100 just in time for vacation. Literally, it arrived the day before we left. I really like it. I kinda want a 18-55 VR lens that usually comes with them, but may get it separately later. I have almost all positive things to say. There is a slight learning curve which reading reviews and the guide will help alleviate, but I was able to do most everything I wanted immediately and with one less rotating dial than I was used to (for aperture/f-stop adjustments, you use the rear dial when on aperture priority or hold a button and rotate the rear dial when on other modes that allow aperture adjustments -- the D70 has a rear for the shutter and front for the aperture). The ISO can easily be adjusted during shooting, too. My only complaints are as follows:

• *No IR receiver -- doesn't work with my cheap remote
• Internal flash doesn't work as commander for my SB600 -- I don't use this feature often, but like being able to play around with it occasionally
• *Doesn't auto-focus with my 50mm/1.8 or 70-300mm -- pretty much only lenses with a m/ma selector ON THE LENS can be auto-focused by this camera. This was an oversight on my part, and was clearly documented.
• The video doesn't seem to auto-focus. It is supposed to be less than impressive auto-focusing, anyway. I'll revisit this, but it is worth a mention.
• One other thing? I think so.

I was looking for a replacement, but enjoy these new features:

• Video. It isn't great, but (like smart-phone video) nice to have in a crunch!
• Higher ISO. I used to hate shooting over 400, but this isn't bad up to 1600 and the higher modes are way better than unusable pictures, even if they aren't ideal. I was able to get no-flash shots of my dad and brother gigging which were, at least, fun for later review that I never would have been able to get with my D70.
• Distortion Control -- I've read that it works well, but haven't verified.
• ADR (Automatic Dynamic Range?) -- also reportedly good, but I'll write if I disagree.

*I didn't know about these differences when I purchased, though they were clearly documented had I looked a little harder.

Good Change

I'm thinking of getting a new old D90 or another, higher end, replacement for my second failed camera that will address my complaints above. I only need two cameras for the rare occasion when my wife and I shoot simultaneously, so won't miss the features at that point. My only complaint, then, will be juggling two types of batteries. I think both will use SD cards for storage rather than the old CF cards my D70 bodies used.

Better Reviews

http://www.kenrockwell.com/nikon/d3100.htm

Ancient A22p LCD has Almost Twice the Pixel Count Compared to most Modern Entry-Level Laptops / Notebooks

Wow -- IBM was doing it right back in the day!

I was taking a brief peak at an ancient IBM Thinkpad A22p before stripping it for parts (doubt i'll be able to salvage much, sadly) and disposing of it when I noticed how crisp the display was, albeit a little dim. Upon closer inspection, this thing has a 1600x1200 (UXGA) -- the same as the 21" Samsung SyncMaster 213T I'm writing this on. That gives it approximately a 133 ppi rating. Not bad. It puts the 95 ppi of my Samsung to shame. Similarly, new (flagship) tablets and smartphones often have higher resolutions than the same group of notebooks/laptops. Sure, I've (finally) seen some 4k monitors and notebooks arriving, but they are usually targeting the professional and their cost usually puts them out of range for normal folks. Anyway, how did we go from 1200 lines of vertical resolutions on laptops (it was targeting cad / business users) to the terrible 768? I guess we can attribute some of it to the change in prominence of the 16:9 aspect ratio, as opposed to older 4:3 or 5:4. I'm not sure why I'm surprised. It is cheaper to provide a horrible, low resolution, monitor. And people don't complain (to be fair: don't notice, sometimes) enough to make a difference.

In summary

Respect to the A22p. I'm sorry I have to put you down.

Epilogue

I'm trying ubuntu/lubuntu and puppy on it.

Site Streamer // Sometimes, you just want to stream!

Site Streamer

Sometimes...you just want to stream

The other day, I wanted to listen to the songs available for download from a band's site but downloading them, then adding to my media player seemed like to much work. Strange, because I usually prefer to download -- eventually the tracks end up on my phone and I listen to them in my car. Today, I wanted to listen to them now and the process of downloading each, naming appropriately, then listening to all seemed daunting.

I should develop a website to do this for me!

Instead of spending a few minutes to work this out myself, I decided the more time-effective solution was to spend hours developing a website to do it for me. Of course!

Luckily, I already had the building blocks: 1) [bandcamp downloader] a site that parsed bandcamp pages and made the songs available for download, naming them appropriately and 2) [jPlaylister] a site that creates jPlayer playlists from a local folder's contents.

It wasn't that bad, but spending the time to polish up the site enough for public use added another month of wait due to my busy schedule and recently rekindled gaming habit (a night or two a week for a couple of hours -- nothing serious).

Hello, World!

Meet Site Streamer. A site you can use to stream content from a place which normally just allows standard linked downloads.

You visit the site, paste in a website which has plainly linked downloadable (mp3, currently) audio content, and enjoy the stream. Hope this is convenient for someone!

Intel Compiler Degrades Performance for Non-Intel CPUs

how am i just hearing about this? this is old news, but worth a read if you don't know what i'm talking about.

why so late? why haven't others written about this?

i haven't searched thoroughly, but, reportedly, intel's ties (big advertiser) with tech blogs and publications has kept this from seeing as much exposure as it deserves.

intel does what?

i'll horribly summarize: intel makes some of the best and most widely used compiler and libraries that exist. they are used in tons of compiled installers. the catch: they unfairly optimize for genuine intel products.

they finally have a notice on their website, but it isn't incredibly obvious and isn't the fix the settlement after the court case with AMD demanded.

but they are intel!

the obvious issue is that processor shouldn't matter -- instruction set should:

if (this.processor supports SSE){use sse code} else {use non sse methods}

instead, the code looks like this:

if(this.processor is genuine intel){use best instruction set method} else {use the least optimized code}

in 2012, they did comply with some court order and offer refunds to those interested (misinformed purchasers who expected an impartial compiler/libraries). not enough.

still, this would be acceptable if the product was billed as an intel exclusive or they were making use of things competitors couldn't offer. it isn't (in this case).

Agner (see source link), who has done MUCH research on the topic, claims that we need to get glibc (a rival compiler) and it's libraries properly optimized. Since that is above my head, I thought getting this dirty practice exposed a few people at a time (the extent of my reach) would have to be my contribution.

*chuckles* ...and...you are surprised?

back when AMD took the performance crown (what, 10 years ago?), no. i've been an AMD supporter for a while since they price their products competitively. but since Intel has been the obvious performance leader for a while now...at least in per-clock work and power efficiency, i thought they'd let their products based on superior manufacturing process speak for their-selves. no, gotta pull (or, not rectify) some underhanded stuff like this? and here i was pulling for them to be competitive with ARM.

source

http://www.agner.org/optimize/blog/read.php?i=49

Steam OS and AMD's Mantle API: Almost star-crossed

I feel like this should have been written elsewhere by someone more knowledgeable than myself, but it hasn't.

And if ya don't know, now ya know

Steam OS is Valve's GNU/Linux-based OS which is supposed to be optimized for games and will likely offer/feature the "Big Picture" experience which has gotten some attention recently. Presumably, OpenGL-based engines/games will play with ease on the system, but engines/games which lean on Direct3D (Microsoft's heavily used graphics API) games will almost certainly not be available. The idea is that, since GNU/Linux has the potential to be very lean, or resource-lite, performance gains could be realized while gaming as the underlying system (as compared to Windows 8/7/Vista) would need far less resources and, arguably, be more stable.

Mantle is AMD's recently released API that seems to be in direct competition with Direct3D and OpenGL. It bears some resemblances (in performance vs peers) to a long defunct API called Glide. A new API wouldn't normally be very noteworthy or welcome if performance was supposed to only be similar to existing APIs. However, Mantle claims advantages of "9 times more draw calls per second than comparable APIs" and is said to enable "Console-like" hardware access. Don't let that scare off you PC gamers. Console-like just means lower-level access (more efficient use of hardware), not last-gen/outdated performance on release. Oh, analogy time:

• [Programmer] It's like having something coded in C instead of Java. Sure, Java may be easier and more portable, but C gets far more work done per CPU cycle. (Mantle API is C and OpenGL/Direct3D are Java in this very rough analogy)
• [Communication] I tell my kid to tell my wife that I'm sorry I crashed her car instead of telling her myself. (Mantle API is me telling her, OpenGL/Direct3D is me telling my kid to tell her -- slower and less effective assuming he tells her at all. my apologies for this analogy)

The problems

For now, Mantle only works with CGN (newer) AMD Graphics Cards. This makes sense as you can't very well back-port a low level API you've just created, realistically. Notably absent from this list is newer Nvidia cards.

Mantle is a recently developed API about which AMD has made statements implying a "open nature." Currently, it isn't known if Nvidia could eventually allow Mantle API hardware access. Unless that occurs, Mantle can only EVER be a parallel/alternative API, as opposed to the exclusive API of choice by a Game/Engine/Developer for PC since Nvidia has such high market share.

Steam OS and the pending Steam Box machines seem to be Intel/Nvidia based. Valve has said the AMD hardware will certainly be supported, but since Nvidia was pretty heavily involved in Steam OS, it may have notable advantages.

Interesting note

Both the XBox One (xbone, xb1) and PS4 are built custom developed AMD APUs (CPU and GPU in one), which feature CGN technology (potentially Mantle API compatible). It seems that neither Sony nor Microsoft plan on allowing Mantle-developed games on their machines. This is notable because, IF Mantle API worked on "Next Gen" consoles and it was used by game developers, "porting" from Console to Mantle-capable PCs (or PC to console) would be drastically less work and much faster and more seamless.

So, what you're saying is...if your lips left you...

My Wife, and 8th Grade ELA Teacher, would probably tell me I need a "Call to action" statement if this were a persuasive essay. It isn't, but one or both of the following really should be done:

1. AMD needs to release drivers or lend support or whatever is necessary to enable Mantle to work with Steam OS once it comes out. While there don't seem to be any numbers that show expected performance gains of OpenGL games on Windows 8 vs Steam OS, the intention is that it will run faster. If nothing else, Linux is more malware resistant (possibly due, in part, to security by obscurity) and resource-lite, so OS resource utilization should be minimal. With wider GNU/Linux usage, AMD may be encouraged to beef up driver support. Next, they(/we?) need to get Nvidia on board. Obviously, they are rivals, but share the common goal of preserving interest in PC gaming. If Mantle has half the performance impact is seems capable of, it'll be a HUGE deal, and Nvidia will want to jump on board or (a horrible alternative) develop their own API.
2. [more of a footnote, really] Console makers should lean on Mantle API. It'll make porting between XB1, PS4, and PC much more straightforward and, unless the performance is worse than the custom APIs used by each, shouldn't hurt anything. The exception would be Windows OS sales since many gamers claim that playing is the only thing that keeps them on Windows. Likewise, if everyone else worked well with Mantle, Nvidia would be encouraged to adopt support to stay relevant.

Sources

My sources are a few articles I've read about each (Toms Hardware, probably), a few wikipedia articles I used for general summary information, and the Steam OS website.

Read More

I have come across these resources that may be of interest.

• http://www.extremetech.com/gaming/168671-xbox-one-will-not-support-amds-mantle-and-ps4-is-also-unlikely-is-mantle-doa
• http://www.anandtech.com/show/7371/understanding-amds-mantle-a-lowlevel-graphics-api-for-gcn

Google Ignores Image Extensions

Or

Google Plays Image Extensions

Or

Google! It's a PNG, not a JPG

Or

Google Plus Summarizes Backed-Up Videos as Animated GIF

I noticed the other day while working on my Photo Feed Display project that PNG files in my Picasa Web Albums RSS Feed were not being processed correctly. I had JUST added PNG support, so I thought the error was probably in my code. As I dug deeper, I noticed that the images referenced in the RSS Feed had .jpg extensions, not .png extension. I thought this was probably intentional since .jpg (for photo) often provide better results for a given file size. I thought that Google was doing me a favor, making .jpg thumbnails of my .png files for ease of use. I'll take it. But, I was mistaken. Even though the RSS Feed explicitely listed the media with a .jpg extention, they were still PNG files.

Here's what I've found -- Google ignores image extensions. Presumably, they do this because web browsers also ignore image extensions (for widely supported image formats)*. For example, my Picasa Web Album RSS Feed lists the following image source:

https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhOVLZF7VkKst4rpB4E-NlcNHicnRIccdr4JPCUZFJbAITNU6BZbW9XnfQ4n_kY6RzGVuW7i_loHu0dNKZ_jpfa0Re51RxFrgohXcZ3n6wK6zxgBv_ixQeAwaZNlQNxUGixaTRpUFVqCsN8/s288/tourniquet%252520news%252520page.jpg

But wait! I get the same image in my browser if I remove the file at all:

https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhOVLZF7VkKst4rpB4E-NlcNHicnRIccdr4JPCUZFJbAITNU6BZbW9XnfQ4n_kY6RzGVuW7i_loHu0dNKZ_jpfa0Re51RxFrgohXcZ3n6wK6zxgBv_ixQeAwaZNlQNxUGixaTRpUFVqCsN8/s288/

Or, I can see a larger variant by removing the last bit:

https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhOVLZF7VkKst4rpB4E-NlcNHicnRIccdr4JPCUZFJbAITNU6BZbW9XnfQ4n_kY6RzGVuW7i_loHu0dNKZ_jpfa0Re51RxFrgohXcZ3n6wK6zxgBv_ixQeAwaZNlQNxUGixaTRpUFVqCsN8/

...it must default to the original size or a larger variant or something.

It is Still a PNG

This is all good and dandy, but, while not stated (or incorrectly stated), the file is still a PNG. My Photo Feed Display generates thumbs of photos using a PHP function imagecreatefromjpeg() and fails when referencing any of the links above as the source image. Further, it works when I use the (similar) function, imagecreatefrompng().

Why This Matters

If you are just viewing files in a browser, it shouldn't (since the extensions are ignored -- see my proof below, by the asterisk -- by web browsers). If you are processing the files, it very well may.

I Thought this post Concerned GIF files, Too...

Oh yeah! It does. A week after discovering the previous information, I was viewing my Google Automatic Backup files on Google Plus and noticed it had converted a video into (what I assumed was) an animated GIF file. Awesome! I love those. This time, when I right-clicked to copy the image URL, I noticed that it didn't have an extension. I thought it may be some fancy code that uses multiple JPG files, changing the displayed JPG a few times per second using javascript, which would be fine but wouldn't allow me to link to a summary of the video as an animated GIF would. Nope, true animated GIF file, despite the lack of extension. The same logic as above, as far as a scaled down version, applies. For example:

https://lh3.googleusercontent.com/krJiBTc-61AznapjS1u4nON7BC6crcwtStAHTYYE7_8=w369-h207-p-no

...shows a animated GIF summarizing the video clip. Similarly, but somewhat less intuitively, removing the "=w369-h207-p-no" (width, height, progressive[?], interlaced[?]) shows a larger version:

https://lh3.googleusercontent.com/krJiBTc-61AznapjS1u4nON7BC6crcwtStAHTYYE7_8

Lastly, when I 'inspect element' for a (presumed) animated GIF on my Google Plus page, I get the following source image:

https://lh4.googleusercontent.com/-xS4TzDbCnIU/UgPbWW5PUpI/AAAAAAAAEcE/iUV1gyNyJlY/s122-c/VID_20130806_174425.m4v

...but, it is clearly not a .m4v (even though it probably links to one). When I remove the last part, I still get the animated GIF (this time, with 'play' overlay):

https://lh4.googleusercontent.com/-xS4TzDbCnIU/UgPbWW5PUpI/AAAAAAAAEcE/iUV1gyNyJlY/s122-c/

Or, I can take more off the end to get a larger version:

https://lh4.googleusercontent.com/-xS4TzDbCnIU/UgPbWW5PUpI/AAAAAAAAEcE/iUV1gyNyJlY/

In Conclusion

Hope this helps someone!

-

References

* I haven't researched this, but I'm pretty sure it is true.