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Basic Video Options



With our basic and interlacing analysis done we can look at the basic video settings. To keep things simple we'll let HDConvertToX make some decisions for us that might be worth revisiting later if you want finer control over your encodes. And that's what we'll do in another guide, but for now we'll just look at the settings you are most likely to want to customize right from the beginning.

A Word About Square and Non-Square Pixels

Depending on your video source and intended output format you may have to understand a little about PAR (pixel aspect ratio) to understand what HDC does and the information it provides. Generally speaking the software wants to assume square pixels. This means the width of a video frame can be divided by its height to find the AR. For example, 1080P video has a horizontal resolution of 1920 pixels and a vertical resolution of 1080. That results in an AR of 1920:1080 or 16:9. On the other hand a DVD with the same AR could have a resolution of 720x480 or 720x576, which would equate to 3:2 (NTSC) or 5:4 (PAL).

When dealing with a source with non-square pixels, either from your source or in your output settings, some features won't work properly and some information won't be accurate. This wil be noted as the options in question are explained. In no case does it cause insurmountable problems, but if you don't realize what you need to do differently.

All the options we'll be looking at in this section of the guide are located in the Encoding Options section of the HDC main window. We'll start with the Crop & Resize tab.


1. Crop & Resize Options

These three options will determine HDConvertToX's automatic behavior related to cropping borders from the edge of your video and resizing. If your source has square pixels, including most high definition sources and almost none at standard definition, you should check Crop obey to AR. This will ensure the image which remains after cropping will be close to the AR (aspect ratio) reported by the source. This takes PAR into account so it works whether the source has square or non-square pixels. Follow ITU Resizing is only important when the input video is at DVD resolution. It forces the use of standard calculations related to analog TV technology. It should generally be checked. No Resize & Crop obviously stops any crop or resize operation from being done at all.

2. Anamorphic Shape

If the AR of your video output will need to stretch the pixels horizontally to achieve the right AR you need to make sure Anamorphic Shape is checked. Unchecking it will produce square pixels which, in addition to standard HD resolutions (1920x1080 or 1280x720, are generally better suited for mobile devices and files which will be played back on SDTVs or other low resolution displays.
The Stream PAR listed tells you the number of pixels displayed after anamorphic resize (like by a DVD player connected to an EDTV) compared to the original (ie 853:720) and the PAR (ie 1.1852). If the PAR is anything but one your source has non-square pixels.

2. Cropping

Your movie may have black borders added to make it conform to a format like DVD which requires all widescreen movies to be presented as images with the exact same resolution. If you aren't encoding video for use in an equally restrictive format you can improve picture quality by eliminating (cropping) those borders.




Visual Crop

The auto-crop feature works reasonably well but seems a little overzealous at times. Use the Visual Crop button to adjust the crop settings interactively using one or more video frames as a reference. If the frames selected by HDC aren't well suited to detecting borders (usually because they are similar in color) you can use the Shuffle button to select new ones. Ultimately your eyes are the best tool for finding the borders so don't be surprised if you find yourself tweaking the values manually. Make sure to click the Accept button to transfer your Visual Crop settings to HDC.


4. Resizing/Resolution

You may not need to change the resolution at all, either because your destination format has the same resolution requirements as your source video or you only want to crop borders. If you are resizing there are three important factors to consider; resolution, encoder block size, and AR error.
AR error is the difference between what the source reports for the image AR and your output crop/resize settings. At the bottom of the Cropping area is an AR Error number which might alarm you if your video has non-square pixels, such as a DVD or standard definition TV source. This error figure doesn't account for PAR, but can still be used for anamorphic encodes with a little extra work. If Anamorphic Shape is unchecked AR Error will be correct with no additional work. Also remember that in some cases the AR will be incorrect in your source video, which a little bit of error can actually correct.

Resizing For Anamorphic Encoding

In order to make use of the AR Error number you'll have to pretend to be encoding to a square pixel format. In other words uncheck Anamorphic Shape temporarily. Just make sure to check it again before you go any further. Once that's done you need to manually enter the horizontal resolution your anamorphic should be stretched to. Calculate this by multiplying your desired horizontal resolution by the right-most number listed for Stream PAR.
With the horizontal number entered HDC will set the vertical resolution automatically. This should generally be the same number HDC gives you with the actual horizontal resolution entered and Anamorphic Shape selected. The difference is that the AR Error listed will be correct.

Block Width and Height

The encoders used by HDC all divide each frames into blocks, which are then compressed individually. Traditionally these blocks are 16 pixels wide by 16 pixels high. Modern encoders have the capability of using smaller blocks, which makes it easier to get the exact resolution you want (for video with no black borders). You can adjust the block size by changing the Set MOD Block Width x Height values.
The first number (on the right) is for horizontal resolution and the one on the left is vertical resolution. The resolution values (listed above each one) must be divisible by those values. For example, if you set them both to 16 you can resize to 720x464 because 16 divides into both numbers with no fractional remainder. Resizing to 712x464 would require that the horizontal block size be set to either 8 or 4 because 16 doesn't divide evenly into 712. Likewise, 720x456 would require the vertical block size be set to either 8 or 4.
The down side to using a non-MOD16 block size is loss of compressability. If your main concern is squeezing every bit of quality out of a low bitrate you should generally stick to 16x16 blocks. If not, no less than 8x8 blocks are recommended for most situations.




Basic Video Encoder Settings


HDC doesn't require you to set a lot of encoder options manually, but there are a few settings you need to look at on the Video tab.

1. Filters

Whatever editing is done by HDConvertToX is handled by AviSynth. If you look through the advanced options you can find a number of settings for what filters and settings will be used. But even if you stick with the basic options you get two types of filter to consider; De-noise Filters and De-interlace Filters.

Denoising potentially serves two purposes. The first is the most obvious. It attempts to get rid of whatever shouldn't be in the image. If you are starting with a disc-based source like DVD or Blu-ray this shouldn't generally be a consideration, although with cheaper or poorly produced discs it still may be a good idea. Simply select the amount of noise you want to remove from the list. Only in rare cases should you select anything besides None, Super Light or Light.

The other use for denoising is improving compression. Besides getting rid of details which weren't supposed to be part of the image, it can also reduce the overall level of detail. Generally speaking, less detail means fewer bits required to encode and therefore reduced file size. You should almost never select a setting higher than Super Light for compression purposes. Higher settings are just too likely to cause quality issues.

Unless you're absolutely certain about what sort of deinterlacing is appropriate for your video you should make sure to run the included analysis tool for that purpose. You can find instructions on the previous page of this guide.

Click here for help analyzing your video before deinterlacing
Use your browser's back button to return here when you're finished.

The results of the interlacing analysis should give you everything you need to set the deinterlacing options. Select the option from the dropdown list that matches what the interlace analysis told you, generally interlaced, telecine, or some combination of the two.

2. Encode Details

The only decisions you're required to make with respect to video encoding are the format/encoder, the type of encode (multiple or single pass), a quality rating, bitrate or desired file size and whether you want the encode to favor speed over quality or vice versa.

Compression Test

If you are using a single pass (quality based) encoding mode you can use the compression test to estimate the size of your video using your current settings. Compression Analysis is explained in the previous section of this guide.

Click here to learn how to predict single pass file size
Use your browser's back button to return here when you're finished.

3. Hardware Compatibility

If you are encoding to play your video on a particular type of (non-computer) hardware HDConvertToX will use the appropriate settings if you select it here. Two of the options, Create AVCHD Structure and Create Blu-ray Structure will author those two formats after all encoding is completed.




Continued On Page 4



With our video settings squared away we can consider which audio and subtitles to keep.


Next: Audio and Subtitle Options

Encoding With HDConvertToXViewing Page 3 of NumPage -- Go To

Table of Contents

  1. 1. Introduction
  2. 2. Load Source and Analyze
  3. 3. Basic Video Options
  4. 4. Audio and Subtitle Options
  5. 5. Final Steps
Written by: Rich Fiscus