Introduction of H.264 and H.265 Codec

The new IP decoder recently released by Magewell is compatible with multiple IP streaming protocols and supports decoding video streams in H.264 or H.265 format.Speaking of which, some users might ask: what is codec standard?

In English, the codec standard is represented by the word CODEC. This word is actually a compound, which can be understood as the combination of "coder" and "decoder", or it can be considered as the synthesis of "compression" and "depression". From the composition of words, we can assume that the codec standard is actually a standard that specifies the compression and decompression process, and this process needs to be completed with the help of a codec. Of course, the codec can be based on software or hardware. The object of compression and decompression is a signal source or a data stream. In a nutshell, the so-called codec is to compress or decompress the signal (audio or video) or data stream (audio data, video data and metadata) through hardware or software. The purpose of encoding is usually for transmission, storage or encryption; the purpose of decoding is usually for preview, production or playback.

At present, the codec standards on the market are very complex. International organizations for standardizaion and Internet giants have launched their own codec standards. However, H.264 stands out as the most successful codec standard in history and it is adopted by many mainstream software and hardware products and supported by many peripheral devices. At the same time, its successor H.265 has also been placed countless hopes.

What is H.264?

H.264, also the tenth part of MPEG-4, is a highly compressed digital video codec standard proposed by the Joint Video Team (JVT), which is a combination of the ITU-T Video Coding Experts Group (VCEG) and ISO/IEC Moving Picture Experts Group (MPEG). This standard is often called H.264/AVC (or AVC/H.264 or H.264/MPEG-4AVC or MPEG-4/H.264 AVC).

The biggest advantage of H.264 is the high data compression ratio. Under the same image quality, the compression ratio of H.264 is more than 2 times that of MPEG-2, and 1.5 to 2 times that of MPEG-4. H.264 compression technology greatly saves users' download time and data traffic charges. While ensuring a high compression ratio, H.264 also has a higher video quality. Because of this, H.264 has been recognized by people and is widely used in network streaming media data, various high-definition TV and satellite TV broadcast. Apart from dedicated hardware encoders and decoders, almost all IP cameras support H.264 encoding; it is also generally supported by streaming programs on PC and mobile phones, many web-based players or streaming platforms also support H.264 decoding. H.264 has a very complete using ecology from signal encoding to decoding.

What is H.265, the successor to H.264? How is it different from H.264?

H.265 is also called HEVC (High Efficiency Video Coding), a new video coding standard formulated by ITU-TVCEG after H.264. H.265 is mainly based on the existing video coding standard H.264. In addition to retaining some of the original technologies, it adds correlations that can improve the relationship among code stream, encoding quality, latency and algorithm complexity. H.265 is designed to transmit higher-quality network video under limited bandwidth, and it only costs half the bandwidth of H.264 when playing the same quality video.The H.265 standard also supports 4K (4096x2160) and 8K (8192x4320) ultra high definition video. It can be said that the H.265 standard has allowed the network video to keep pace with the "high resolution" of the monitor. But in some respects, compared with H.264, the H.265 encoding standard still needs to create a more complete ecosystem. Many platforms that support RTMP streaming do not yet support H.265 decoding, so users who want to take the advantages of H.265 for streaming have to purchase dedicated decoding equipment.

For Magewell capture cards, we provide developers with SDK packaged with multi-platform graphics card, which enables them to capture high-quality AV data with lower latency, and make use of GPU performance to achieve H.264 encoding more efficiently and reduce the difficulty of studying the encoding features of different platforms during development. For users who want to use a dedicated codec, Magewell's Ultra Stream products support H.264 or H.265 encoding. Users can implement H.264 encoded network streaming, and can also complete H.264 or H. 265 encoding and recording; Magewell Pro Convert decoders help users to stably and smoothly decode H.264 or H.265 compressed streams sent by hardware or software encoders.