At Shedworx we deal with video formats every day and sometimes forget that you, our customers, usually don't.

In this article we will cover the ins and outs of video formats, for the layman. We concentrate on video files that are created by camcorders.

Getting Started

First of all we need to cover two important terms - Codecs and Bit Rates.

What is a Codec?

The word codec is shorthand for the term coder/decoder.

A codec is the file format and compression technique used to turn a real-world video or audio signal into a digital file or stream of data.

A codec relates only to the actual video and audio streams within a video file.

Examples of popular video codecs are:

  • H.264 - the de-facto industry standard for high definition video. H.264 is a very complex set of compression techniques and corresponding file storage formats; and
  • MPEG2 - the format used in DVDs. Note that MPEG2 is both a video codec and a container format. More on that later.

Examples of popular audio codecs are:

  • LPCM - Linear Pulse Code Modulation is an older audio codec that provides simple compression
  • Dolby Digital (also known as AC3) - this is a proprietary audio codec popular with video camera makers

You can use the Worldwide Number 1 FREE App on the Mac App Store, the Shedworx Smart Converter to get a detailed look into the video and audio codecs of your video file.

You can also look into the video and audio codecs in a video file by opening the video in QuickTime and pressing Command-i.

What is a Bit Rate?

When we talk about video most people understand that the quality of the video has a lot to do with the resolution of the video. Full HD is 1920x1080 pixels, HD is 1280x720 and Standard Definition is 720x480 (NTSC) and 720x576 (PAL).

The other big contributor to video quality is the bit rate. The bit rate is the number of bits per second required to make the video play. A bit is 0 or 1 - the smallest part of a digital file or signal.

Video bit rates are measured in millions of bits per second - megabits (Mbps).

The higher the bit rate, the more 'quality' you are getting in your video. For example, a 5 Mbps video contains one quarter of the quality of a 20 Mbps video.

You can have Full HD videos recorded at low bit rates, so they look very shabby. YouTube, for example, supports 1080p video now but at a very low bit rate - 5 Mbps. YouTube's 1080p video format is a gimmick. Rather than 1080p video at 5 Mbps they should stick to 720p video at the same bit rate for a better quality video.

Low bit rate videos become obvious when there is a lot of motion in the video. When this happens you will see lots of 'artifacts' in the video - little boxes everywhere instead of a good picture. The video will also look choppy and jumpy as it struggles to draw each frame without enough information for a good picture.

The main point here is that bit rate is as important as resolution when it comes to quality. High definition video is of no value without a high bit rate to support it.

What's in a Video File?

A video file is the combination of four separate things:

  • a Container;
  • some Metadata;
  • one or more Video Streams; and
  • one or more Audio Streams.

Video Container

The Video Container (also called the wrapper) is the file format that encloses the header, video stream and audio stream.

The job of the Container is to wrap up the video and audio streams and provide synchronisation and streaming support.

A Video Container usually contains one video stream and one audio stream, however multiple streams can be included. For example, 3D video can contain two separate video streams - one for each eye.

Have you ever wondered how an iTunes movie download can play on your AppleTV, iPhone and iPod? This is because the QuickTime movie contains multiple video streams at different resolutions for the different devices.

Popular video containers include:

  • AVCHD - AVCHD has become the industry standard for high-end consumer camcorders. AVCHD supports H.264 video and LPCM or AC3 audio.
  • MPEG2 - MPEG2 is used for DVDs. The MPEG2 standard includes both a container format and a codec, so the term MPEG2 can mean both the container and video codec
  • MPEG4 - similar to MPEG2, MPEG4 is both a container format and video codec, so the name MPEG4 can mean both things. MPEG4 is an update to the older MPEG2 standard. The video codec part of the MPEG4 standard contains 28 variants. MPEG4 video Part 10 is identical to H.264. They are the same codec standard.
  • Apple QuickTime - This is a general purpose container based on the MPEG4 standard. A QuickTime movie can contain a very wide range of video and audio codecs, making the QuickTime movie format extremely broad. Just because a video is in a QuickTime format doesn't mean it will play on all Apple devices. Each device (iPhone, iPad, AppleTV, etc) will have its own subset of QuickTime-supported codecs that it can play.

Metadata

A Container also contains information (or Metadata) about the video file contents. This Metadata can be the date the video was shot, resolution and even details on the video and audio codecs inside the file.

When you load up an AVCHD video into a Shedworx AVCHD product (Cosmos, VoltaicHD, RevolverHD or HD QuickLook) the information that we display comes from the Metadata of the AVCHD file.

Video Stream

The Video Stream is the picture part of the video file and contains a stream of a particular codec.

A camcorder video file will usually only contain one Video Stream, but different video files can contain many streams.

Different containers also support different video codecs. For example, AVCHD only allows H.264 video, whereas QuickTime allows a vast array of different codecs.

Audio Stream

The Audio Stream is the audio part of the video file. Just like the Video Stream, the Audio Stream will be encoded using a particular audio codec.

A camcorder video file will usually contain one Audio Stream only. Commercial videos can contain many audio streams, for example, a stream for each language the film has been translated into.

Bringing it all together

When you watch or edit a video, you are seeing all parts of the video file working together. Your device firstly had to understand the Container, then extract out the Video and Audio Streams, then start playing them in sync with each other. We take the playback of a video for granted these days but there are a lot of things that can go wrong with this.

I hope this article has shed some light on the basics of video files, containers, codecs and streams. Feel free to ask questions in the comments!

.MOD file conversion

... so .MOD files still cannot be converted? Just tried and got the same result as Charles in August last year. Is there a timeline for MOD support as this would be STUNNING!!
Thanks

MOD support

I've added MOD support to the work list for the next major upgrade (due to be released in Q3 2012). I can't promise that it will be done but our engineers will look into it when we do the major upgrade.

Lost in the conversion jungle :-(

"Feel free to ask questions in the comments!"

So I volunteer to do that with a simple problem, which I'm not able to crack: I've got 1280x720 TV recordings from a satellite receiver, in a probably European *.TS4 file format containing some sort of Mpeg-4 video.

Your smart converter doesn't recognize/convert this, but Handbrake does. So I'm free to convert it to whatever may be necessary to support the following purpose: I want to write the video onto a DVD which can be played on a Bluray player such as a PS3.

I tried this with Toast 11, only to find after 20 (!!!) hours of conversion on a quad core MBP, that Toast had miscalculated the file size and thus couldn't write the DVD. I don't want to touch this software again, if possible...

Your RevolverHD unfortunately requires a *.mts file, which (apparently?) Handbrake cannot generate. Or can it?

Then I tried Voltaic with "Native AVCHD Conversion", but only to find out that it generates a *.mov file, and for this uses a similarly long time as Toast does.

Can you recommend a workflow with Handbrake/Voltaic/Revolver (or whatever) for getting the original Mpeg-4 video burnt onto a DVD for a Bluray player?

I beg your pardon, if this layman mumbo-jumbo should be somewhat hard to decipher... ;-)

Handling TS4 video files

I think I know what you need, so here goes...

Firstly, you need to create an AVCHD DVD which will play on Blu-ray players. As the name suggests, AVCHD DVDs can contain AVCHD video only.

AVCHD files contain H.264 video and AC3 or LPCM audio.

Your TS4 video file contains MPEG2 video, so needs to be converted.

Handbrake (i.e. FFmpeg) recognises TS4 video. It can create a generic MPEG4 video (but not a specific Quicktime video).

RevolverHD can create AVCHD videos, but only from a very specific Quicktime format (H.264, LPCM audio).

The video that RevolverHD requires can only be created from a QuickTime export (i.e. not Handbrake or FFmpeg).

So, here's the recommended workflow:

  1. Using Handbrake, convert to Regular, High Profile
  2. Change the file extension from m4v to mov
  3. Drop the file in to VoltaicHD
  4. Use a Custom conversion to convert to the required Quicktime format
  5. Drop the new file into RevolverHD and burn!

Give that a go and let us know how you get on. I haven't tried this on a TS4 video, but it should work OK.

Unfortunately there seems to be no real solution... :-(

1st: Thank you so much for caring.

2nd: Possibly a side-issue: *.TS files with standard PAL resolution are indeed MPEG2, while the *.TS4 files most probably are MPEG4.

3rd: I used Handbrake to convert the *.TS4 (3 files of PAL 1280x720 totaling 85 minutes) to *.m4v (1280x720). It took around 75 minutes, which supports the assumption of *.TS4 already being MPEG4.

Then I fed this into Voltaic exactly with the described parameters, but I didn't touch the Audio parameters, because I found no possibility to set them to LPCM. Voltaic started, but everything pointed to a duration of much more than 20 hours, so it simply wouldn't make practical sense, and I stopped it after some time.

In despair I tried to feed the output from Handbrake (the *.mov renamed *.m4v files) into Revolver. But I got the message "... Required Format, H.264 Video, 2 channel, 16 bit LPCM Audio @ 48 kHz"

I also tried it with *.m4v files, which I had set to 24 fps already in Handbrake, but I got again the same unfortunate result.

Because a conversion of much more than 20 hours for a 2 hour video doesn't make practical sense (and might still have failed in the end), I have to believe that burning AVCHD DVDs from *.TS4 files should not be done.

Thank you again for your support, even if we could not find a solution.

Falk Kuebler

Just to let you know: an unexpected solution, finally

If this hurts Shedworx' commercial interests, then please delete my post and accept my sincere apologies.

After nearly having given up, I did a final internet search and found a Windows software from Sothink called HD Movie Maker. I let this run under Parallels 6 with my old WinXP VM, et voilà: after app. 80 minutes I had a good quality Bluray DVD (even with chapter menu) from my Handbrake generated *.m4v files.

Falk Kuebler

SmartConverter Sony Bravia Setting

I tried this & then tried to stream to Sony Bravia NX700 via DNLA. Sony TV did not recognize file.
Is there something else I can try? ... or how should I use this feature. ... any updates ?

I am able to stream native AVI video file formats to the Sony Bravia NX700 via DNLA.
Is there a setting on SmartConverter that forces conversion to AVI ?

Sony Bravia

Were you able to play the video directly on the TV using a USB drive? We haven't tested DNLA streaming yet.

SmartConverter overide

Every time I double click on a flv file, it automatically opens SmartConverter, but I don't want it too. How do I stop that?

File associations

sorry about that - its a bug that we've now fixed. I'd say its more of a bug with Apple's Finder, but thats another story.

To fix this, select the FLV file and hit command-i - this brings up the info window.

Go to the Open with section and you will see the app that will open these files by default. Select your preferred app, then click Change All.

Thats it! Your FLVs should now open with the right app.

File Associations - SmartConverter overide

Thank you soooo much!

smartconverter simply does precisely nothing

I cannot even figure out how to remove the thing from my new MacBook Pro. I downlodaed SmartConverter from the App Store and when I connected my JVC Everio HDD and tried to drag and drop a .mod file, the file simply floats back to the spot in Finder I dragged it from and nothing happens. I'm so frustrated I'd just like it removed now. I'm planning to use my Camcorder for target practice because its just too much of a hassle for years now. Is there a camera with an "APPLE" on it yet?

Smart Converter

You delete Smart Converter by going to the Applications folder and dragging the app to the Trash. This is the usual way for deleteing a Mac app, but with the Mac App Store purchases, its not obvious.

Smart Converter does not support MOD files yet. We'll add it to the list.

If you want an Apple-friendly camera, go with an AVCHD camera. This covers the two dominant and leading camcorder brands out there - Panasonic and Sony. In our experience Panasonic is the best camcorder brand in terms of technical capability and Mac support.

Thanks for the tips on cameras.

Thanks for the prompt response. I'm impressed. I'll check into the new cameras suggested. Please make it easier to find your list of supported file types. The CAMERA list makes it look like my camera would be supported. It makes sense to also list the FILE types supported.

I'm definitely going to bookmark Shedworx and visit again because of your quick response and good service!