The quantization process uses a parameter called the “quantization parameter” (QP).Ī high value of QP results in high compression. The subsequent process is called quantization. The output of this process is a block of “transform coefficients”. The transformation process uses “integer transform”, a mathematical algorithm to transform blocks of residual samples. That results in more efficient video compression. However, H.264 AVC offers a more accurate prediction. The net result is called a “residual”.Įarlier video encoding standards had the prediction process too. The video encoder subtracts the prediction from the macroblock. Alternatively, the process might use data from frames that were coded and transmitted earlier. It might use previously encoded data from the current frame for this. The encoder creates a “prediction” of the macroblock. A macroblock refers to 16×16 displayed pixels. The processes involved in encoding videosĪn H.264 codec performs the following processes to create a compressed H.264 bitstream:Īn H.264 video encoder uses a unit called “Macroblock” to process video frames. This codec encodes a raw video, subsequently, it decodes it. It’s a widely used video encoding standard and is compatible with most devices available. H.264 AVC offers a higher quality of video and lower video bitrates than the earlier standards. Manufacturers can decide that, however, they need to conform to the relevant standards. The above-mentioned standardization organizations don’t prescribe how manufacturers should implement video encoding. People often refer to H.264 as AVC (Advanced Video Coding). They published this video encoding standard in 2003 as part of a document named “Recommendation H.264: Advanced Video Coding”. ITU-T (International Telecommunication Union) and ISO/IEC (International Organisation for Standardisation / International Electrotechnical Commission), two international standards bodies Created H.264. H.264 or Advanced Video Coding is a video compression technique that is used widely to convert video to a format that takes up less space while transmitting or storing video files. The quest for better video streaming quality along with lower video bitrates led industry stakeholders to develop H.264 AVC. Various standards for video encoding existed even before the advent of H.264 AVC. While different manufactures can create their products differently, they will all need to follow the same standards. They can operate effectively only if the processes to encode and decode videos are standardized. Various manufacturers create hardware and software products to cater to the video streaming space. A decoder converts them back into a format that isn’t compressed. When streaming a video, a video encoder converts the video into a compressed format. What video codec essentially does is that its encoder part first compresses the video file, and at the time of video playback, the decoder decompresses it for viewing. An encoder compresses an analog video file, whereas a decoder decompresses the video file at the device to prepare the video for playback. This would enable your viewers to watch high-quality videos on a wide range of video platforms.Ī video codec compresses a raw video file so that it can be easily streamed online. You need a codec that offers both high video quality and a lower compressed bitrate. This is where the term “codec” enters into this discussion. What Is The Role Of Video Codec in Encoding? This process also converts such video files into formats that are compatible with different browsers and devices. The term “video encoding” refers to the process of compressing raw video files into a particular format for video streaming. You will find a smaller file much easier to transfer over the Internet and the streaming is also seamless. Video then takes up less space when you store it. This is why raw files are compressed to deal with these challenges. Giving the viewer a very bad user experience. There might be several lags and buffering while streaming video. If a video streaming platform directly streams raw video files, then it will face challenges. In the raw form, a video file takes up quite a bit of space. What Is The Role Of Video Codec in Encoding?Īn Introduction To H.264 Advanced Video Coding (AVC)īefore you understand what H.264 AVC is, you’d have to know about what is video encoding and what role video codecs play in this before we go on to describe H.264 AVC.An Introduction To H.264 Advanced Video Coding?.
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