What are the Best Digital Video Formats to Use?

The video format is essentially a video encoding method, which can be divided into two categories: local image video suitable for local playback and network streaming media video suitable for playing on the network. Although the latter may not be as good as the former in terms of playback stability and playback picture quality, the widespread dissemination of network streaming images and videos has made it widely used in Internet information such as video-on-demand, network presentations, distance education, and online video advertising. Service areas.

The video encoding format is derived from the video encoding standards formulated by relevant international organizations, civil organizations and enterprises. the study

The video packaging format is the encoding process

MPEG Video format MPEG format

The English name of MPEG is called Moving Picture Experts Group, which is the format of Moving Picture Experts Group. VCD, SVCD, and DVD often used at home are such formats. The MPEG file format is an international standard for moving image compression algorithms. It uses a lossy compression method to reduce redundant information in moving images. MPEG's compression method goes a little deeper by retaining most of the same parts of two adjacent pictures and removing redundant parts of subsequent images from the previous image to achieve the purpose of compression. Currently the main compression standards of MPEG are MPEG-1, MPEG-2, MPEG-4, MPEG-7 and MPEG-21.

MPEG-1: Established in 1992, it is an international standard designed for digital storage media moving images and audio coding with data transmission rates below 1.5Mb / s. This is the VCD production format commonly seen. MPEG-1 video uses YCbCr color space, 4: 2: 0 sampling, the code stream generally does not exceed 1.8Mb / s, and only supports progressive images. Typical resolution of MPEG-1 video: 352×240@29.97fps (NTSC) or 352 * 288 @ 25fps (PAL / SECAM). The file extensions of this video format include mpg, mlv, mpe, mpeg, and .dat files on VCD discs.

MPEG-2: Established in 1994, it is a video audio and video data coding standard for 3 ~ 10Mb / s. MPEG-2 video uses YCbCr color space, 4: 2: 0 or 4: 2: 2 or 4: 4: 4 sampling, the highest resolution is 1920 × 1080, supports 5.1 surround sound, supports interlaced or progressive scanning. This format is mainly used in the production (compression) of DVD / SVCD, and also has considerable application in some HDTV (high definition television broadcasting) and some high-demand video editing and processing. The file extensions of this video format include .mpg, .mpe, .mpeg, .m2v, and .vob files on DVD discs.

MPEG-4: Established in 1998, it is a video and audio coding standard for low transmission rates. It can use very narrow bands to compress and transmit data through frame reconstruction technology in order to obtain the best image quality with the least data . The most attractive aspect of MPEG-4 is that it can save small volume video files close to DVD quality. File extensions for this video format include .asf, .mov, Divx, AVI, and more. MPEG-4 uses Object Based Encoding technology, that is, MPEG-4 video and audio scenes are composed of multiple media objects such as still objects, moving objects and audio objects. As long as the track of a moving image is recorded, Yes, so it is better than MPEG-1 and MPEG-2 in compression and quality. MPEG-4 supports content interactivity and streaming features.

MPEG-7: MPEG-7 is not a compression coding method, but a multimedia content description interface standard (Multimedia Content Description Interface). After MPEG-4, the contradiction to be resolved is the management and rapid search of increasingly large image and sound information. MPEG-7 is a solution to this contradiction. MPEG-7 strives to be able to quickly and efficiently search for different types of multimedia materials required by users.

MPEG-21 : The MPEG-21 standard is called the Multimedia Framework, which is actually the integration of some key technologies. Through this integrated environment, global digital media resources are transparently and enhanced to manage, and realize content description, creation, distribution, and use. , Identification, charge management, property rights protection, terminal and network resource extraction, event reporting and other functions. The ultimate goal of MPEG-21 is to provide users of multimedia information with a transparent and effective electronic transaction and use environment, which will play an important role in future e-commerce activities ^[2] .

AVInAVI Video format AVI format, nAVI format

AVI (Audio Video Interleaved) is an acronym for Audio Video Interleaved. It encapsulates video and audio in a file, and allows audio to be synchronized with video playback. It was introduced by Microsoft in 1992 and shipped with Windows 3.1

Known and known together. The advantage of this video format is that the image quality is good and it can be used across multiple platforms; its disadvantages are that it is too large, and even worse, the compression standards are not uniform. The most common phenomenon is that high-level Windows media players cannot play early adopters. Encoded and edited AVI format video, and the lower version of Windows Media Player cannot play AVI formatted video edited with the latest encoding, so when playing some AVI format video playback, it often appears that the video cannot be played due to video encoding problems or even Can play, but there are some inexplicable problems such as unable to adjust the playback progress and only sound and no image during playback. If users encounter these problems when playing AVI format video playback, they can be solved by downloading the corresponding decoder, and DVD video The format is similar. AVI files support multiple video and audio streams. It uses a lossy compression method for video files, but the compression is relatively high, so although the picture quality is not very good, its application range is still very wide.

nAVI is short for NewAVl, a new video format developed by an underground organization called Shadow Realm. It is modified by the Microsoft ASF compression algorithm. The video format pursues nothing more than compression rate and image quality, so in order to pursue this goal, nAVI has improved some of the shortcomings of the original ASF format, so that nAVI can have a higher frame rate. It can be said that nAVI is an improved ASF format that removes the characteristics of video streaming ^[2] .

ASF Video format ASF format

ASF (Advanced Streaming Format) is a file compression format developed by Microsoft in order to compete with the current Real Player and can directly watch video programs on the Internet. Users can play it directly using the Windows Media Player that comes with Windows. It uses the MPEG-4 compression algorithm, and its compression rate and image quality are very good. Because ASF exists in a video stream format that can be viewed instantly on the Internet, its image quality is a little worse than VCD, but it is better than the RAM format, which is also a video stream format ^[2] .

MOV Video format MOV format

MOV is QuickTime movie format. It is an audio and video file format developed by Apple. It is used to store common digital media types. When QuickTime (w.mov) is selected as the save type, the animation will be saved as a .mov file. Quick Time was originally an image video processing software used by Apple for Mac computers.

QuickTime provides two standard image and digital video formats, namely static * .PIC and * .JPG image formats, dynamic * .MOV based on Indeo compression method and * .MPG video format based on MPEG compression method.

QuickTime video file playback program, in addition to playing MP3, also supports MIDI playback, and can listen / watch network playback, support HTTP, RTP and RTSP standards. The software supports the main image formats of JPEG, BMP, PICT, PNG and GIF. Digital video files are also supported, including MiniDV, DVCPro, DVCam, AVI, AVR, MPEG-1, OpenDML., And Macromedia Flash. The QuickTime file format supports 25-bit color, supports leading integrated compression technology, provides more than 150 video effects, and is equipped with sound devices that provide more than 200 MIDI-compatible audio and equipment. It is an excellent video encoding format whether it is played locally or transmitted as a video stream format on the Internet. Because QuickTime has the technical characteristics of cross-platform (MacOS / Windows) and small storage space requirements, it uses a MOV format file with a lossy compression method. The picture effect is slightly better than the AVI format. Now some non-editing software of this format can also handle it, including Adobe s professional-grade multimedia video processing software After Effect and Premiere, etc. ^[2] .

WMV Video format WMV format

WMV (Windows Media Video) is a streaming media format introduced by Microsoft. It is an extension and extension of the ASF format. At the same video quality, the volume of WMV format is very small, so it is very suitable for online playback and transmission.

WMV is a technology standard that is independent of the encoding method for real-time multimedia transmission on the Internet. Microsoft hopes to replace it with technical standards such as QuickTime and file extensions such as WAV and AVI. The main advantages of WMV are: scalable media types, local or network playback, scalable media types, stream prioritization, multi-language support, scalability, etc. ^[2] .

3GP Video format 3GP format

3GP is a multimedia standard developed by the "3rd Generation Partnership Project", which is a video encoding format for 3G streaming media. It is mainly developed to cope with the high transmission speed of 3G networks. It is also the most common one in mobile phones. Video formats. Its core consists of advanced audio coding, adaptive multi-rate and MPEG-4 and H.263 video codecs. Most mobile phones that support video shooting now support 3GP video playback. Real VIDEO (RA, RAM) The format was originally in the field of video streaming applications, and is also the originator of video streaming technology. It can realize uninterrupted video playback under the conditions of 56K MODEM dial-up Internet access. Of course, its image quality cannot be compared with MPEG-2, DIVX, etc. After all, to achieve uninterrupted video transmission on the Internet requires a large bandwidth Yes, it is a strong competitor to ASF in this regard ^[2] .

RMRMVB Video format RM format and RMVB format

The RM format is an audio and video compression specification developed by Real Networks, which is called Real Media. Users can use RealPlayer or RealOne Player to perform live broadcast of network audio / video resources that comply with Real Media technical specifications, and Real Media can formulate different compression ratios according to different network transmission rates, so as to achieve image on low-speed networks Data is transmitted and played in real time. Another feature of this format is that users can use Real Player or RealOne Player to play online without downloading audio / video content. In addition, RM is the mainstream network video format. It can also convert videos in other formats into RM videos through its Real Server server, and the Real Server server is responsible for publishing and playing. Generally, RM videos are softer, while ASF videos are relatively clear.

The RMVB format is a video format upgraded from the RM video format. Its advanced feature is that the RMVB video format breaks the average compression sampling method of the original RM format, and uses the bit rate resources reasonably on the basis of ensuring the average compression ratio. That is to say, the scenes with few still and motion scenes use a lower encoding rate, which can leave more bandwidth space, and these bandwidths will be used when fast-moving picture scenes appear. In this way, on the premise of ensuring the still picture quality, the picture quality of the moving image is greatly improved, so that a delicate balance is reached between the image quality and the file size. In addition, compared with the DVDrip format, RMVB video also has obvious advantages. If a DVD movie is about 700MB in size, if it is transcribed into the RMVB format with the same audiovisual quality, its maximum size is about 400MB. Not only that, this video format also has the unique advantages of built-in subtitles and no need for plug-in support ^[2] .

FLV/F4V Video format FLV / F4V format

FLV is short for Flash Video, and it is also a video streaming format. Due to the small file size and fast loading speed, it makes it possible to watch video files on the Internet. Its appearance effectively solves the problem of making the exported SWF file bulky after importing the video file into Flash, which cannot be used well on the network. And other disadvantages are widely used.

F4V is H.264 high-definition streaming media format introduced by Adobe after the FLV format. The main difference between it and FLV is that FLV format uses H.263 encoding, while F4V supports H.264 encoded high-definition video. , The bit rate is up to 50Mbps. F4V is smaller and clearer, and is more conducive to network transmission. It has gradually replaced FLV, and has been compatible with most mainstream players, without the need for complicated methods such as conversion. For example, the current mainstream video sites such as Tudou, 56, and Youku have started to use H.264 encoded F4V files. Most of the videos released by Black Bean and Cool 6 are F4V, but the download suffix is FLV, which is also one of the characteristics of F4V. With the same file size, sharpness is obviously better than MPEG-2 and H.263 encoded FLV. Due to the use of H.264 high-definition encoding, compared with traditional FLV, F4V can achieve higher resolution and support higher bit rate in the same volume. However, because FAV is an emerging format, there are many FAV standards adopted by major video websites at present, which also determines that F4V is relatively weaker in compatibility than traditional FLV. It should be noted that F4V and MP4 are compatible formats and both belong to the ISMAMP4 container, but F4V is only used to encapsulate H.264 video encoding and audio AAC. FlV is a Adobe proprietary format, but can also be used to encapsulate H.264 video encoding , AAC audio encoding or H.263 video encoding, MP3 audio encoding,

In addition, there are also many well-known companies launching high-performance video formats, such as SONY's recently launched MTS format suitable for high-definition fields, etc. ^[2] .

H.264H.265 Video format H.264, H.265

The H.264 standard is a new-generation video coding standard jointly developed by ITU-T and ISO. This new image source coding compression standard was officially approved by the ITU in July 2003. Compared with MPEG-2, under the same image quality conditions, the data rate of H.264 is only about 1/2, and the compression ratio is greatly improved. The H.264 standard is also commonly referred to as the Advanced Video Coding Standard (represented by AVC).

The predecessor of H.264, H.26L, was first proposed by the International Telecommunication Union's ITU-T Video Coding Expert Group (VCEG) in 1998. Since 2001, ITU-T's VCEG and International Standards Organization ISO / IEC MPEG (dynamic Photographic Experts Group) jointly organized the Joint Video Cooperation Group (JVT) to develop a new generation of video compression coding standard H.264 based on H.26L. At the same time, it will serve as a new part 10 of the MPEG-4 standard. Compared with the video compression coding standard in Part 2 of MPEG-4, it has better performance. Therefore, when talking about the video encoding method and performance of MPEG-4, it should be distinguished whether it refers to part 2 or part 10, and the two cannot be confused. H.264 is also a type of MPEG-4, which is called MPEG-4 Part 10 or MPEG-4 AVC (Advanced Video Coding). They are all international standards for moving picture coding ^[3] .

The ITU approved the H.265 standard in January 2013. The official name of this standard is HEVC (High Efficiency Video Coding). Although H.265 is similar to H.264 in coding architecture, H.265 introduces variable size conversion and larger size intra prediction blocks, more intra prediction modes reduce spatial redundancy, and more spatial domains. Combining with the time domain, more accurate motion compensation filters and other means, the calculation and processing of multi-core are fast and parallel, and it is suitable for high-definition real-time encoding. Its peak calculation amount reaches 500 GOPS and H.264 is only 100 GOPS, which far exceeds H in performance and function. 264 ^[4] .