Traditional transcoding solutions produce transcoded content that is only as good in quality as the source footage. However, when video is acquired outside studio settings, the quality of the source footage can be less than ideal. The Cisco® MXE 3000® Media Experience Engine supports a variety of preprocessing features that allow you to significantly improve the quality of the transcoded content relative to the source footage.
The Cisco MXE 3000 preprocessing settings not only optimize the quality of the video, but also allow you to perform video editing functions such as selecting particular sections of clips from a larger footage, or combining multiple video clips to result in a single, contiguous clip.
You can easily customize preprocessing settings and apply them to video footage during processing. To automate the workflow, you can save preprocessing settings in a profile so you can apply the same settings to different video clips without having to create preprocessing settings each time. Prior to the application of preprocessing settings, you can preview what the video would like if the settings were applied. This preview feature streamlines operations because you do not have to perform an entire transcode to assess whether or not the preprocessor settings result in the desired viewing experience.
Figure 1 is a screenshot of the Cisco MXE 3000 GUI that shows how you can easily preview video editing changes prior to preprocessing so you know what to expect in the final video content. Simply move the slider bar indicated by the red arrow across the sample picture to reveal the before-after split.
The following sections describe some of the many parameters that you can adjust during the preprocessing stage to obtain stunning, high-quality video footage. Video editing features are also described.
Video Editing
• Selecting footage to process from a larger file: You can mark the point in time, relative to the beginning of the clip, to start encoding. You can mark (express as time intervals) "in points" and "out points" on video footage and use them when only a section of a larger file will be encoded. When these parameters are specified, the Cisco MXE 3000 knows to discard the portion of the video prior to the "in point" and following the "endpoint."
• Inserting transitions between clips: You can determine the number of seconds to fade in from black to full brightness at the beginning of the video clip or fade out at the end of the clip. The specified "fade-in" time is appended to the beginning of the preprocessed file, including any bumpers that you may add, and you can append the "fade out" time to the end of a trailer.
• Cropping: Crop settings are used to trim unwanted material from the outer edges of the incoming video image.
• Bumpers and trailers: If you need to append clips before or after video footage, you can apply bumpers and trailers. You can specify the file to be used as a bumper or trailer at the introduction or conclusion of the encoded clip, respectively. You can use movie files of any Cisco MXE 3000-supported format or still files for bumpers and trailers.
Figure 2 is a screenshot of the Cisco MXE 3000 GUI that displays the video editing features that enable you to easily cut, append, and stitch video clips together to obtain studio-quality content.
Figure 2. Screenshot of Cisco MXE 3000 GUI: Video Editing Features
Color and Noise-Reduction Settings
Often the ambient conditions of the area of video taping are less than ideal. This situation could be due to the quality of the video equipment or environmental conditions, such as lighting. The Cisco MXE 3000 delivers a suite of preprocessing features that allow you to control a variety of color adjustments to improve quality relative to the video area.
The following color adjustments are supported:
• Brightness: The Cisco MXE 3000 adjusts luminance as measured against the source video.
• Contrast: It adjusts separation between the blackest black and the whitest white.
• Hue: The Cisco MXE 3000 adjusts hue of colors in the video from red (decrease) to green (increase).
• Saturation: The application adjusts the amount of color in the video image expressed as a percentage of source video color.
• Gamma: The Cisco MXE 3000 adjusts the midrange (gray) luminance values of the video, thereby adjusting the luminance of midrange colors and leaving black and white values unchanged.
Figure 3 is a screenshot of the Cisco MXE 3000 GUI that demonstrates many color and noise-reduction adjustments that you can apply during the preprocessing stage to significantly improve the quality of your video footage.
Figure 3. Screenshot of Cisco MXE 3000 GUI: Adjusting Color and Noise Reduction
Another effective tool for improving the quality of video footage during the preprocessing stage is to use noise-reduction controls to minimize and control video imperfections. The Cisco MXE 3000 supports the following noise-reduction features:
• Temporal smoothing: The Cisco MXE 3000 defines how frames are combined for interframe smoothing. This setting specifies the number of input frames to average when constructing an output frame.
• Blur: The application specifies how much to blur the source footage. Blur is generally used at lower bit rates to reduce image detail, improving the overall appearance of the finished clip at high compression rates. Blurring degrades the image but enables better compression.
• Noise reduction: With this feature you can remove small, irregular detail from the source video.
• Unsharping: With the Unsharp Mask feature you can enhance edge detail in the image without enhancing other detail. This feature reduces compression efficiency, but can improve the perceived quality of the image. It is recommended for some video formats, such as VHS, and for multigenerational images where a sharper image is desired.
Aspect Ratio Conversion
The Aspect Ratio Conversion tools provide several methods for scaling media between various formats. For example, you can convert an image with a 4:3 aspect ratio to a 16:9 aspect ratio, or conversely. The Cisco MXE 3000 uses pixel aspect-ratio information in the conversions and uses default assumptions about the pixel aspect ratio based on the pixel dimensions of an image. For example, an image size of 720 x 480 or 720 x 486 is assumed to be standard-definition National Television Standards Committee (SD NTSC), and is assigned the NTSC pixel aspect ratio of 0.9. For complete control, you can explicitly set both the input media pixel aspect ratio and the pixel aspect ratio for the preprocessor output image. The input dimensions are read from the input media. The preprocessor output dimensions are set by the encoder that receives the preprocessed video.
Watermark Settings
Most organizations have explicit corporate policy surrounding distribution restrictions of company confidential content. Visible watermarking is a method by which video content can be marked as material that must comply with corporate distribution guidelines. The Cisco MXE 3000 allows you to apply highly customizable watermarks during the preprocessing stage so the consumer of the content is aware of how the content must be handled. Figure 4 shows an example of how visible watermarks appear on the video footage. Customization parameters include adjustments to placement, text, and appearance of the watermark.
Figure 4. Visible Watermarking on Video Footage that Was Processed Using Cisco MXE 3000
The preprocessing features discussed in this paper allow you to perform an exceptional range of video editing and quality optimizations. The Cisco MXE 3000 can help you create high-quality video without incurring costly studio fees. It is important to note the ease by which you can apply these preprocessing settings to video content. You do not need to adjust these settings during each preprocessing job. Rather, you can store templates in the Cisco MXE 3000, invoke them, and then apply them automatically to numerous jobs.
