What is the difference between decoding, encoding and transcoding?

Every digital medium - whether it contains image, video or audio - has something to do with encoding. When an analogue signal (light or sound) is digitised, it must be digitally encoded in order to record, transmit and play back the image, video or audio.

At the beginning of the chain there is always the creation of a digital signal, the encoding. Typical applications for this are the recording of an image or video signal with a digital camera or smartphone or also the recording of sound via microphone with a digital audio recorder or smartphone. For playback, the recorded digital signal is decoded. There is a standardised basis for encoding and decoding: the so-called codecs.

In order to be able to create and play back complex digital signals in high quality, the data in the respective codec is compressed by algorithms. Depending on the codec, the signal quality differs.

Codecs can be hardware-based or software-based. For example, a video or photo camera contains a digital processor (encoder) that generates the digital signal. In the Blu-ray player, a hardware-based decoder ensures the playback of the video codec on the Blu-ray disc.

Transcoding means converting. This process is used when converting one digital media format into another. A typical example is the conversion of audio WAV files into MP3 files. 

During the transcoding process, one has the option to make several changes. For example, the bit rate of the video, i.e. the speed at which the data is transferred, can be changed. Higher bit rates are useful for better streaming quality. Frame rates of 1080p are ideal for viewers who have the bandwidth to consume media in high definition. However, it is often useful to transcode video into multiple formats so that viewers can select a frame rate that suits them. 

Why is transcoding important? 

When videos are transcoded into different formats, users have the opportunity to watch this content in the best possible quality - regardless of which player they used or how fast their internet connection is. This enhances the customer experience!