MPEG2 as DVD-compliant Files

Discuss about generic usage of MediaCoder.

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MPEG2 as DVD-compliant Files

Post by meRobs » Sat Jan 09, 2010 10:15 pm

[updated 28 Nov 2010]

I have created many DVDs, but my experience is mainly limited to what is possible with a 'professional' package involving Adobe Premiere for video editing and then Adobe Encore, for what is called 'Authoring' and burning to disc. I use MediaCoder to create files that suit Premiere (see: the guide on Premiere: viewtopic.php?f=17&t=9488&p=28837#p28837), and I source material from DVDs, VHS tape, TV or downloads from the web. I rarely create DVD-compliant files directly. I have also done some experimentation with other Video Editors (viewtopic.php?f=17&t=8741&start=0) and Authoring Apps (viewtopic.php?f=17&t=8454&start=0).

However, because of the frequent requests on this Forum for information on creating DVD-compliant files, with the aim of burning them to DVD, I offer this somewhat simplified discussion on what is needed and how to do it.

To begin with: the audio/video files for a DVD should comply with certain specifications. They are detailed in a Post on this Forum by 'mixer', see: viewtopic.php?f=17&t=8151. Also, modern players will accommodate even more options and formats (some departures from the Specs).

But this is not all. The files on a DVD should have a defined structure, which is one of the tasks best left to an authoring program, as discussed below.

1. Basic DVD Requirements
The creation of DVD-compliant files, if done properly, may avoid the need to re-encode in the authoring program. So, I list here the basic parameters and their optimum or usual values. If you have good reasons for lowering the resolution or of using a different audio format, then, by all means change them. However, the following will work for a standard-definition DVD and do a good job.

I give the values for PAL and those for NTSC in brackets, if different:
Video resolution ('Resize') = 720x576 pixels (720x480)
Video frame rate = 25 fps (29.97)
Audio format = AC3
Audio Sample rate = 48,000 Hz
GOP length = 12 (15), but see: "Set a DVD-compliant GOP size", below.
With the Container set for MPEG-PS (see below).

A suitable Bitrate is required for both the Video and the Audio. For the former, I suggest a value of at least 3000 kbps for good quality (but see Note 1, below). A value of 3000 kbps results in a capacity of ~3 hours for a standard, single-layer DVD. If the source is a low quality file, such as an FLV, a video bitrate of 1000 kbps will usually do. It's up to you to experiment with a few short files and make your own judgement of quality.

For audio, a value around 128 kbps will usually do for AC3, though a smaller value is possible (multiple of 8 and your choice). Note that the DVD specs also allow PCM audio, but since this would be at 1410 kbps, it would reduce the space available for the video.

The relationship between Video and Audio bitrates and the DVD capacity in minutes is discussed in viewtopic.php?f=17&t=8740&start=0.

2. MediaCoder Settings
The MPEG-PS format is available in MediaCoder via the MPEG2 Codec ('Format') set on the Video tab and the Container should be 'MPEG2', not MPEG2-TS. Thus, I suggest:

Video tab: Format = MPEG2 at 1000 to 5000 kbps; Source = MEncoder; Encoder = FFmpeg.
Audio tab: Encoder = FFmpeg; Format = AC3; Resample = 48 kHz; Audio ID = the desired stream (select from Properties panel).
Container = MPEG2 and Multiplexer = Disabled
Picture tab: Resize = 720x576 (720x480)' frame rate = 25 fps (29.97)
Sound tab: Channels = Stereo or 5.1 channels, as required.
GOP length: see "Set a DVD-compliant GOP size", below.

The output will have the MPG extension. If this is changed to ".VOB" and the file is the only one burnt to a DVD as a 'data disc', it will most likely play on a modern standalone DVD player. This is a useful trick for testing. See also: "Set a DVD-compliant GOP size", below.

There are various ways of using MediaCoder:
(1) set the above values manually on the various tabs in MediaCoder. Once happy with the outcome, it could be kept as a Preset (see viewtopic.php?f=17&t=8131). Next time, load the Preset and make minor changes on the tabs, such as to the Crop method, Aspect Ratio, Sound channel, etc.
(2) use MediaCoder's Video Disc Player, see below. However, in some builds this may set inappropriate values on the tabs – so check!
(3) or a combination of the above: use the Video Disc Player (VDP) to set the essentials, then, check the tabs and make suitable adjustments.

Video Disc Player (VDP): This is available in MediaCoder via the Menu bar: click Features > UI Plugins > Home Players. When first selected, it opens a Popup that asks whether to revert all settings to their defaults (recommended) and, then, the VDP window opens. It offers choices for Type (PAL or NTSC for DVD, SVSC, etc), the Quality (leave as 'Standard'), Resolution ('Standard' or specific values), Audio (may leave as 'Default') and the Aspect Ratio (4:3, 16:9, etc). The resultant settings are summarised in its panel at right.

While using the VDP window, the settings are reflected on the main tabs (Video, Audio, Picture, etc) and changes may be made here as well. The tabs are still accessible while the VDP window is open. Once ready, click the 'Start' button on the VDP window.

Note 1: the video bitrates achieved for MPEG2 are limited (other settings as above). In build 4602, as the set bitrate is increased from 2000 kbps, the actual rate achieved increasingly falls behind the set value, and the maximum from this build is ~4000 kbps at a setting of 6000 kbps and above! It is a bit higher if a reasonable GOP is set (see below). For build 4606, the maximum for the above settings is 5200 kbps or so.

3. Set a DVD-compliant GOP size
The DVD specs have set a max value for the GOP length (distance between I-frames). It is 18 frames for NTSC and 15 for PAL.
To understand what is required and how to set it, read: viewtopic.php?f=17&t=8599&start=0.
By default, the FFmpeg encoder in MediaCoder will usually give a GOP of 250 frames.
This may serve your needs, although, such a file may not work well if the resultant DVD is played on a Standalone player, because the GOP length is not in accordance with the Specs.

4. Author and Burn
The next step is to use an authoring program. Without it, standalone DVD players will have difficulty playing the DVD if all it contains is one or more MPEG2 files. Some modern players will play a single MPEG2 file if its extension had been changed to .VOB.

Many DVD burners come with Authoring software and there appears to be a number of freebies around, such as those discussed in viewtopic.php?f=17&t=8454&start=0.

The commercial ones will handle MPEG-2, preferably already DVD-complaint, and not in need of a re-encode, and will accept others such as AVI files, which it would need to transcode.

5. Further Options
This Topic dealt only with the creation of standard DVDs, not SVCD or VCD, which are similar to some extent, but offer a reduced quality and limited playing time, being on a CD. In any case, with blank DVDs being so cheap, there is little need to consider a CD.

The alternatives to the conventional, standard-definition DVD are the Blu-Ray disc and the DivX (or Xvid) disc. The latter is able to deliver menus provided the Player is “ Ultra-certified” and its creation using MediaCoder is best left to another Topic.
Have you checked out the Tips & Guides for MediaCoder? Try:
Also, get older builds at: