When you open up an export menu you’re confronted with a lot of options. There’s no shame is choosing a preset and calling it a day, but if you want to gain more control over the quality of your export, there are some key settings to know about. To export for delivery, you need to specify a container file format, as well as video and audio parameters. The primary video parameters we need to define are codec, bit rate, resolution, pixel aspect ratio, frame rate, and scanning method. The audio parameters are codec, sample rate, channels, bit depth, and bitrate. It’s important to note that the container file format you choose may restrict or expand your parameter options. There is quite a bit of confusion about containers, codecs, and bitrate. To begin, let’s talk about what a container file format is. The “file” you double click on your computer is really a container or “wrapper” that “contains” all the pertinent pieces that make up your video and audio. The container file format can be identified by the character extension in a windows environment. mov, avi, flv, mp4, and mxf are some of the most common. Inside these containers are video and audio data, instructions on how to play them and potentially even timecode and subtitles. A codec, which stands for coder/decoder, is used to record and play back the video and audio data that resides inside the container file. Codecs compress video and audio in order to reduce file sizes. The codec itself is not present inside of the container. In order to play back a file, the video codec and audio codec used to create the file must be installed on the computer attempting to play it. In simple terms, the container holds the files and instructions, and codecs are used to play the files back. Let’s look closer at the MOV container as an example. screen record: media encoder, quicktime format, different codec options Regardless of what container and codec you choose, a third key component of any export is bitrate. Bitrate represents how much data is used to encode and decode the video for playback. It’s typically measured in kilobits or megabits per second. The bitrate you choose for your video determines the size of the video data in a file, and the bitrate you choose for your audio determines the size of the audio data in your file. The combined result is the main factor that determines the final size of your container. If you take a given container, and a given codec, and you keep all the other video parameters the same, using a higher bitrate will result in a larger file, but also have better compression. However, if you were to keep your bitrate exactly the same, but alter other parameters, your file size will remain the same, but the quality of the compression will be altered. Let’s take resolution as an example. At the same bitrate, lowering your resolution will improve the overall quality of the compression, while raising the resolution will diminish the overall quality of the compression. But of course this “improvement” in quality may not be worth the decrease in resolution. Altering your frame rate at a given bitrate has a similar effect. Slower frame rates will result in better compression than faster frame rates. It’s important to note that not all codecs are created equally. At a given bitrate h264 may yield a much better result than an older codec. You’ll also need to choose between a constant bitrate and a variable bitrate. These are commonly abbreviated as CBR and VBR. a constant bitrate applies the same bitrate to each frame regardless of the video content, while a variable bitrate will vary the bitrate within a range you set. The idea here is to use a lower rate on sections of your video that don’t need it, and raise it on the sections that do to maximize quality. It’s common to have options for 1pass or 2pass VBR. two-pass takes longer, but yields better results with the same file size. So, why not choose CBR and crank it up to the highest bitrate possible? Well, of course there is a catch. The higher the bitrate, the more processing power a computer or device has to have to play back the file without stuttering or outright failing to play. Also, as a general rule constant bitrates play more reliably on more devices. The most important thing is to determine the ideal container, codec, and bitrate to get good quality playback for your final destination. Okay, now that we’ve got that cleared up, let’s talk about some common video settings, including resolution, pixel aspect ratio, frame rate, and scanning method. The resolution refers to the number of horizontal pixels by by the number of vertical pixels that make up each frame. The right choice here could range from SD to 4K, depending on your output. Common choices are 640x480, 1280x720, 1920x1080, 3840x2160, and 4096x2160 The pixel aspect ratio refers to the shape of each individual pixel. Web exports typically use a 1.0 square pixel, but some other destinations may use nonsquare pixels. the frame rate refers to how many individual frames will play back each second to form motion video. typical choices here are 24p, 30p, 60i, or 60p for the U.S., and 25p, 50i, or 50p for europe. It’s important to note that if you choose a frame rate, and then select a TV standard of NTSC or PAL, it may override your choice and change the rate to one that fits the standard. Another important option is the scanning method. You’ll have two choices here. Progressive or interlaced. All video on the web is progressive. Interlaced might be appropriate for disc delivery like DVD, or for broadcast, like television commercials or programming. If you’re exporting interlaced, you’ll also need to specify the field order. If you’re exporting DVD, lower field first should be your default setting, while blu ray is typically upper field first. For more on resolution, pixel aspect ratio, frame rates, and scanning method check out our lessons from the Camera Settings and controls course. Now it’s time to tackle the audio export options, including codec choice, sample rate, bit depth, channels, and bitrate. Depending on the file format container you choose, you may see multiple codec options for your audio, or none at all if there’s only one supported option. For the most part, you can stick with the one your software selects. The sample rate, or frequency refers to how often the audio gets “sampled” each second. A higher rate increases the quality as well as the file size. Matching this to your original audio sample rate is ideal if your delivery destination supports it. Two common sample rates are 48,000 Hertz for a standard dvd, and 96,000 hertz for Blu-Ray. In addition you’ll want to define the audio channels to be exported. This will be mono, stereo, or 5.1 surround. Mono will give you half the file size of stereo, and 5.1 will result in the largest file size. The right choice here will depend on your source mix, and your final destination. Finally, you may also see an option to set the audio bit depth. The bit depth determines how many bits are used to describe each audio sample. The more bits that are used, the greater the range of detail available for each sample that is taken. This allows for greater dynamic range in your audio. Typical settings here can be 16, 24, or 32. Higher bit-depth means larger file sizes. If you’re exporting an uncompressed audio file such as wav or aiff, the bitrate is determined by the sample rate, bit depth, and number of channels you select. If you’re compressing your audio to a lossy format such as aac or mp3, the bitrate will dictates how much space can be used each second to compress your audio. A higher bitrate means better quality, but larger files sizes. Of course, the size compared to your video is fairly small, regardless of your settings. Typical settings here are 192 kilobits per second, or 320 kilobits per second. You may also see the option for constant or variable bit rate. which works in a similar fashion to video. Now for the good news. Most video editors and encoding programs come with a whole host of presets to get you close to the mark, or directly on it. In fact, one of the best ways to get an idea of what settings work for a particular export option is to select the preset and see what the setting defaults are. Let’s talk a quick walkthrough of some common presets.