Analysis of video format and Encoding Problems

1. What is the video format?

Video FormatIt is an encapsulation format that encapsulates the encoded bit stream. Different video formats have different encapsulation methods. Currently, videos are composed of audio streams and video streams. The format is only encapsulation container, such as rmvb, MKV, MP4, mpg, ts, etc. Common video streams include MPEG2, MPEG4, h264, and vc1. MPEG2 is a relatively old-Fashioned Video Encoding with a low compression rate. MPEG4 is a relatively new encoding, which is commonly used in DVD films. The compression ratio is average. The latest MPEG4 video encoding is Xvid, and the older DivX. h264 (x264 is a type of h264) is a new video encoding. It is common in HD videos and has a high compression ratio. However, it requires a high computing capability and high requirements on computer configuration. Vc1 is a new generation of video encoding launched by Microsoft, which is similar to h264.

Let's talk about several common packaging containers (that is, the format) 1. rmvb and rmvb are easy to use because they are small in size and cannot be modified with built-in Subtitles (it is also a hard injury to rmvb. We often see advertisements on rmvb and some undesirable subtitles ). But the size and rmvb video encoding (real9.0) determine that rmvb will not be too clear, the resolution is only (640-800) * (272-500 ), the bit rate is only 4-5 MB/minute. Someone may have said that rmvb is clear on my computer. Of course, it is possible that the resolution of a 17-inch flat screen display is usually 1024*768. If rmvb reaches 720*300, it looks clear. However, rmvb can only achieve the quality of the DVD. For details about the DVD, HDTV, Blu-ray, and hddvd, see below. 2. MP4 and MP4 are a video format released by Microsoft. Because video encoding is updated, MP4 can encapsulate the updated video encoding to achieve high definition. Previously, all dvds were MP4 in MPEG2 encapsulation, which was very large. The size of a high-quality DVD movie is generally 4-5 GB, but the size after DivX or Xvid encoding is only 650-700 mb, which is only 1/8 of the original DVD capacity, the image quality is equivalent to that of the DVD, making the MP4 format one of the preferred formats for movie enthusiasts. 3. MKV and MKV are popular video formats. They are compatible with many video encoding formats, such as DivX, Xvid, realvideo, h264, MPEG2, and vc1. Because it is a folk format, there is no copyright restriction, and it is easy to play, so the official release of video films do not use MKV, online production and download are common. 4. mpg, that is, MPEG. Video Encoding is generally in the mpeg family, such as 1, 2, and 4. 5. Ts is a dedicated HD encapsulation container. Most common in the original Blu-ray, hddvd conversion video, usually using h264, vc1 and other latest video encoding.

2. What is the video encoding format?

Video EncodingIt is a compression technology that compresses the original video stream into a specific bit stream (depending on the encoding scheme ). I will first show you the video format information, and then let's think about what it means? As follows:

 

First, do you think about many video formats, such: MP4/FLV/3GP/mov/MP4/MKV/TS/m2ts/MTS/m4v/MPEG/WMV/ASF/MKV/RM/rmvb and other video formats. Currently, you can refer to the video format with the suffix of a video, but this statement is not very accurate. Why? Because the suffix of a video only indicates the container used for encapsulation. In fact, a video is precisely composed of video encoding and audio encoding.

Secondly, if you have some knowledge about this video format, you will find that it is a habit to call this video format.

Finally, the following figure shows the video parameters supported by the device:

Video Encoding: H.263

Video resolution: 720x480

Video Frame Rate: 60fps

Audio Encoding: MP2, MP3, AC-3, AAC, AMR-NB

Container: MP4, FLV, 3GP, mov, MP4

Iii. video encoding format Classification

Video encoding formatA total of the following types: MPEG-1, MPEG-2, MPEG-4 ASP, MJPEG, DivX 3, DivX 4, DivX 5, Xvid, H.263, AVC/h. 264, Sorenson spark, VC-1, wmv3, RV 8/9/10 and so on.

The following is a brief introduction to each video encoding format:

1. MPEG-1

MPEG-1 is the first video and audio lossy compression standard developed by MPEG organization, and is also the earliest release and Application of MPEG Technology in the market, its original main goal is to record images on CD, later, it was widely used in VCD. The video compression algorithm was defined in 1990. By the end of 1992, MPEG-1 was officially approved as an international standard.

2. MPEG-2

MPEG-2 is an international standard for video and audio compression released by the mpeg Working Group in 1994. MPEG-2 is usually used to provide video and audio encoding for broadcast signals, including satellite TV, cable TV, etc. MPEG-2 after a small number of modifications, also become the core technology of DVD products. MPEG-2 for broadband transmission of images, image quality to television broadcasting and even HDTV Standards. Compared to MPEG-1, MPEG-2 supports a wider range of resolutions and bit rates and will become a compression method for digital image disks (DVDs) and digital broadcast TVs.

3. MPEG-4 ASP

MPEG-4 is a set of compression encoding standards for audio and video information, by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) under the "dynamic image expert group" (Moving Picture Experts Group, (mPEG) developed, MPEG-4 announced in November 1998, is expected to be put into use of the international standard MPEG-4 is for a certain bit rate of video, audio encoding, more emphasis on multimedia system interaction and flexibility. To this end, the MPEG-4 introduces the AV object (audio/visual objects), making more interactive operations possible

4. MJPEG

The full name of MJPEG is "motion joint photographic Experts Group", which is a video encoding format. The Chinese name is translated as "technology: Motion static image (or frame-by-frame) compression technology ".

5. DivX 3, DivX 4, divx5

DivX is a digital multimedia compression technology invented by divxnetworks, similar to MP3. Based on MPEG-4 standards, DivX can compress multimedia files in the MPEG-2 format to the original 10%, but also the VHS format of video files to the original 1%. Through DSL, cable moden, and other broadband devices, you can enjoy full-screen high-quality digital movies.

6. XviD,

Xvid (formerly known as Xvid) is an open-source MPEG-4 video codecs written based on opendivx. Xvid is developed by a group of original opendivx volunteer developers after opendivx stops development in July 2001. Xvid supports multiple encoding modes, quantization, range control, motion search, and curve.

7. H.263

H.263 is a low-Bit Rate video coding standard developed by ITU-T for video conferencing. H.263 was originally designed for H.324-based transmission (that is, video conferencing and video calls based on public switched telephone networks and other circuit switched networks ). Later, we found that H.263 can also be successfully applied to Video Conferencing Systems Based on RTP/IP networks and H.320 (Video Conferencing Systems Based on Integrated Business digital networks ), RTSP (Stream Media Transmission System) and SIP (Internet-based video conferencing ).

8. AVC/H.264

H. 264, also Part 10 of MPEG-4, is a joint video group (JVT, Joint Video Team) composed of ITU-T video coding Expert Group (VCEG) and ISO/IEC dynamic image Expert Group (mPEG) the proposed high compression digital video codecs standard.

9. Sorenson spark

Sorenson spark is a built-in motion video decoder for Flash MX. It allows us to add video content to Flash MX. Spark is a high-quality video encoding/decoder that can significantly reduce bandwidth requirements while improving video quality.

VC-1

VC-1, full name VC-1 video codec 1, is a video codec system developed by Microsoft. The VC-1 is based on the Microsoft Windows Media video 9 (wmv9) format, and the wmv9 format has now become the actual execution part of the VC-1 standard.

11. wmv3

Wmv3 is Microsoft's latest WMV Format, sometimes also called wmv9 or VC-1, Windows Media video 9 (wmv9) format, and wmv9 format has now become the actual part of the VC-1 standard.

 

12. RV 8/9/10

The audio and video compression specification developed by RealNetworks is called RealMedia. The video encoding formats include rv8, 9, and 10. The Player version with a high decoder can be decoded at a low level, you can use RealPlayer or realoneplayer To Live Broadcast Network Audio/Video Resources that comply with RealMedia technical specifications. RealMedia can develop different compression ratios based on different network transmission rates, in this way, image data can be transmitted and played in real time on a low-speed network.

Analysis of video format and Encoding Problems