Video Encoding

[Datson]

Hello,

Please bare with me as I ask these Noob questions. I really want to get this off my chest and understand what are the meanings of these questions from the good people of VideoHelp.com Forums.

1.) For Encoding / Converting MKV to VOB(DVD) with a 4 core / 8 Thread processor, Would take how long? For example: Intel Core i7-740QM? When using ConvertXToDVD and any other program?

2.) Is Encoding the same as converting? I always thought encode was the convert to another format.

3.) What is transcoding? Is it the same as encoding?

4.) If anyone could help me with encoding or transcoding or converting a MKV with CCE. I would be happy as I bought that for no reason and don't know how to use it. Waste of money!

Thanks for answering these questions as if I have anymore I will post it on here.

[The Mariner]

Howdy,

Answers are:

1).. It takes me around 45 minutes to .mkv -> DVD (including burning the DVD) on my similar system using ConvertXtoDVD. Please note that there are variables that may increase or decrease the times you experience.

2).. & 3).. As far as I am concerned they mean the same thing... changing from one format to another.

4).. Sorry, can't help.

Regards,

Phil.

[Datson]

Howdy,

Answers are:

1).. It takes me around 45 minutes to .mkv -> DVD (including burning the DVD) on my similar system using ConvertXtoDVD. Please note that there are variables that may increase or decrease the times you experience.

2).. & 3).. As far as I am concerned they mean the same thing... changing from one format to another.

4).. Sorry, can't help.

Regards,

Phil.

Hello Phil,

As regarding question number 1. It takes 45 minutes to convert .MKV to DVD plus burning with a intel core i7, With 4 Cores and 8 Threads?

[hech54]

1.) For Encoding / Converting MKV to VOB(DVD) with a 4 core / 8 Thread processor, Would take how long? For example: Intel Core i7-740QM? When using ConvertXToDVD and any other program?

Impossible to answer.
MKV is a "container" like AVI is a "container". It can contain CRAP video or it can contain high-quality video. It can contain processor-intensive video or simple video....which will result in different encoding times.

As for "transcoding"....to ME it is simply lowering the bitrate (of a DVD/MPEG2) video like DVDShrink does. It is technically a re-encode with a loss of quality in the process....but you are staying with MPEG2.

[Cornucopia]

Even though someone could consider ANYTHING with code (digital data) in it to have been "encoded", I usually consider an encoder to be a program/app/algorithm/dll/library that takes UNCOMPRESSED media and compresses it (with a certain format or "code"). This is also known as a compressor.
A decoder does the reverse (compressed->uncompressed). This is also known as a decompressor.
A TRANSCODER first does a decode step and then, from that result, does an encode step (but NOT USUALLY encoding it back to the same type it was before). This could also be known as a converter.

Transcoders can run sometimes doing a full decode+reencode, but sometimes can do a special kind of partial decode+partial re-encode (if they DO encode it back to the same type it was before and in this mode it would NOT be considered a converter). This allows them to change little in the file (e.g. quantizer matrix) and take possibly MUCH less time to complete the process than a full decode+reencode. (This is the example cited by hech54 above). There can be quality compromises when doing this, though.

As far as how long...you don't even say how long your title is - is it 5 minutes or 5 hours? That can make a huge difference regardless of equipment.

CCE doesn't accept MKVs natively, but you could always frameserve (it specifically does accept .AVS)...

Scott

[edDV]

MKV, Mpg, Mp4, VOB, etc are containers

MPeg2, h.264, AC3, DTS, etc are codecs .

If you have a MKV file, it can contain various audio and video streams encoded with different codecs. A typical MKV file will have h.264 and AC3 streams. If you just change the container (e.g. MKV to Mp4) the conversion will be very fast. If you change MKV to DVD VOB, the h.264 video will need conversion (decode-encode) to MPeg2. This will add considerable processing time. The audio won't be changed since it is already DVD compliant.

[The Mariner]

Hello Phil,

As regarding question number 1. It takes 45 minutes to convert .MKV to DVD plus burning with a intel core i7, With 4 Cores and 8 Threads?

That's right.

To qualify my answer... that's about the time it takes for me to take a ~900Mb .mkv (h.264 video & mp3 audio) movie and turn it into a single layer (4.7Gb) DVD that will play in my stand-alone DVD player.

As I said, and lots of posts after me said, there are lots of variables.

Regards,

Phil.

[fritzi93]

One meaning of "transcoding" is that it entails a reduction in error correction data in an MPEG2 stream. Specifically, as used in programs like DVDShrink, DVD2One, and Rejig.

MPEG2 compression works in two ways: the spatial domain and temporal domain. First *intra-frame* compression, dividing the frame into macroblocks, perform Discrete Cosine Transform (DCT), then "quantization", which reduces data accuracy. The result is a set of coefficients representing the frame. Second is the computationally intensive part, calculating motion vectors for *inter-frame* compression. In addition to "I" frames (reference frames), there are "P" (predictive) and "B" (bi-directional) frames, using the I frame data with motion-vector data to represent frames after the reference or key frame.

DVDShrink requantizes (reduces) DCT data, thereby reducing error correction, but leaves motion vector data alone. That is the distinction here, it does not perform a full re-encode. When DVDShrink came out, computers were far less powerful than now, and transcoding had the advantage of being much faster. If the reduction needed is small, say a few percent, DVDShrink is still a reasonable choice. Because, obviously, a re-encode with a lossy codec entails quality loss too, and if there is enough redundancy in the DCT data to begin with, the results may be nearly indistinguishable from a re-encode.

There are other meanings as well, but I wonder if the term would not be best avoided. It's used so often now, incorrectly, when a full re-encode is clearly meant, that it's just confusing. I've even seen a no-encode container change called a transcode, so IMO it's impossible any more to know what the hell people are really talking about when they say transcode.

Rip and convert are two more terms that are often used incorrectly, no thanks to DVDFab especially. Grrr.

[jagabo]

4.) If anyone could help me with encoding or transcoding or converting a MKV with CCE.

You have to first get the video into uncompressed form and with a DVD compatible frame size and frame rate. That is best performed by using an AviSynth script. But without knowing the properties of your MKV file nobody can give you a specific script.

Generally, for a NTSC 4:3 or 16:9 source it will be something like:

ffmpegSource2("filename.mkv")
BilinearResize(720, 480)

For a 2.35:1 source:

ffmpegSource2("filename.mkv")
BilinearResize(720, 360)
AddBorders(0, 60, 0, 60)

How fast the video compresses with CCE will depend to some extent on the source and how quickly it decompresses, and on any other processing you may need to perform in AviSynth. But CCE itself will probably be able to compress at about 500 frames per second on your computer (I get over 400 fps on my quad core i5 2500K). So if the decompression and filtering are fast you will be able to compress a 2 hour movie in about 6 minutes. But if your source is a high def h.264 video it will take longer.

[Datson]

4.) If anyone could help me with encoding or transcoding or converting a MKV with CCE.

You have to first get the video into uncompressed form and with a DVD compatible frame size and frame rate. That is best performed by using an AviSynth script. But without knowing the properties of your MKV file nobody can give you a specific script.

Generally, for a NTSC 4:3 or 16:9 source it will be something like:

ffmpegSource2("filename.mkv")
BilinearResize(720, 480)

For a 2.35:1 source:

ffmpegSource2("filename.mkv")
BilinearResize(720, 360)
AddBorders(0, 60, 0, 60)

How fast the video compresses with CCE will depend to some extent on the source and how quickly it decompresses, and on any other processing you may need to perform in AviSynth. But CCE itself will probably be able to compress at about 500 frames per second on your computer (I get over 400 fps on my quad core i5 2500K). So if the decompression and filtering are fast you will be able to compress a 2 hour movie in about 6 minutes. But if your source is a high def h.264 video it will take longer.

Hey,

I should of PM you, But Instead I want to ask if you could help me out here. I been reading on the internet for CCE, But No one actually wrote a guide for MKV. If you could, Can you assist me on this task. Well be very great indeed. Also, Intel Core i5 quad core 2500k is for desktop or laptops/notebooks?

James

[jagabo]

Install AviSynth. Get the ffmpegsource plugin and put the files in AviSynth's plugins folder. Install Haali. Make a text file with the extension .AVS. Open that file with a text editor. Enter the lines indicated in the scripts I gave you. Open the script in CCE as if it was a video file. Configure CCE the way you want. Encode.

http://avisynth.org/mediawiki/Main_Page#New_to_AviSynth_-_start_here
http://code.google.com/p/ffmpegsource/

[Datson]

Install AviSynth. Get the ffmpegsource plugin and put the files in AviSynth's plugins folder. Install Haali. Make a text file with the extension .AVS. Open that file with a text editor. Enter the lines indicated in the scripts I gave you. Open the script in CCE as if it was a video file. Configure CCE the way you want. Encode.

http://avisynth.org/mediawiki/Main_Page#New_to_AviSynth_-_start_here
http://code.google.com/p/ffmpegsource/

Thanks a Million. I have finally found out how to do this! Does this work the same way as AVI and any other format?

[jagabo]

AVI files can be opened without any plugins because AviSynth has a built in parser for AVI (you may still need codecs to decode the audio and video). ffmpeg can open most popular containers and has decoders for most popular codecs. So it's a safe choice for most files. It's also possible to use DirectShowSource() which is built in. That asks Windows' DirectShow to handle the file. But that Windows knows how to handle the files (DirectShow readers, splitters, and codecs have to be installed).