Multi-media works using the AVI video format
Content: AVI compression algorithm used there is no uniform standard. In other words, the same as the suffix is AVI video file, the compression algorithm used may be different, the need for corresponding software in order to identify and extract the AVI file playback. In addition to Microsoft the company, other companies also launched its own compression algorithm, as long as the driver of the algorithm (Codec) added to Windows system, you can play with the AVI file compression algorithm. The latest trends in the MPEG-4 video using AVI's name, as long as the machine its installed codecs, but also to achieve a normal player. They will be able to AVI or PowerPiont with Authorware development work among the normal screening. Codec various encoding AVI files generated by the size and quality is different from the system and hardware requirements are also different.
Therefore, when compressed AVI, computer hardware and software must be based on the situation, to consider what Codec algorithm, otherwise your work shown in the video is far from satisfactory. The following is a variety of common note Codec codec.
Common video encoding (avi to flv)
1. Cinepak Codec by Radius
When it was first released in the 386 with a computer point of view of small movies, in high-data compression rate with a high degree of playback speed. Compression scheme can be used to achieve a higher compression ratio and fast playback speed, but its relatively long compression time.
2. Microsoft Video 1
Used to compress analog video is a lossy compression program, the maximum reached only 256 colors, it can be imagined on the quality of general it is better not to use it to encode AVI.
3. Microsoft RLE (avi to swf)
An 8-bit encoding only supports 256 colors. Compression of computer animation or image, such as the synthesis of a large area of the material color can use it to code, is a lossless compression program.
4. Microsoft H.261 and H.263 Video Codec
Video conferencing for the Codec, which H.261 for ISDN, DDN lines, H.263 applies to local area network, but generally such machines Codec is used to play, can not be used for encoding.
5. Intel Indeo Video R3.2
All of the Windows version can be used to play Indeo video 3.2 encoded AVI. Its compression ratio than Cinepak, but the need for computer playback faster than Cinepak.
6. Intel Indeo Video 4 and 5
FAQ 4.5 and 5.10 of the two, quality is better than Cinepak and R3.2, you can adapt to different network bandwidth, but there must be a corresponding decoder plug-ins to work smoothly for playback will be available (usually in Windows has been ). Applicable to the company installed Intel's MMX or above CPU machines (most Pentium machines similar to the landfill into a bar), the effect of outstanding playback. If the AVI must then recommend the use of 5.10, almost the same in effect, it has faster encoding speeds and higher compression ratio. (flv to divx)
7. Intel IYUV Codec
Derived from the use of the excellent image quality, because this approach is common RGB color into a more compact model of the YUV color model. If you want to AVI compressed into MPEG-1, then use it to get more satisfactory results, but its too big block header (I am afraid you have to consider the disk space).
8. Microsoft MPEG-4 Video codec
There are three common versions 1.0,2.0,3.0, of course, is based on the MPEG-4 technology, in which 3.0 and can not be used for encoding AVI, only used to generate support for "video streaming" technology ASF file. (mkv to lash)
9. DivX-MPEG-4 Low-Motion/Fast-Motion
The actual and the Microsoft MPEG-4 Video code is quite something (said to use Microsoft MPEG-4 Video codec V3.0 change), Low-Motion is only used in a fixed rate (Constant Bitrate), Fast-Motion to adopt the dynamic Rate (Variable), the latter into the AVI compression is almost half of the former, but a number of poorer quality. Low-Motion apply to convert DVD to ensure better quality, Fast-Motion for conversion VCD to MPEG-4 embodiment of the advantages of dapper. (rm to flash)
10. DivX 4.11/4.12/5.0
In fact, DivX, original DivX is to break Microsoft's ASF specifications developed, and now the author (s) Divxnetworks into a company, it has introduced a new version of the characteristics of the largest in the encoding procedure is to add a 1-pass and 2-pass setting is equivalent to twice ,2-pass encoding, in order to maximize the network bandwidth and balance of visual effects.
The choice of encoding
Understanding of the above algorithm of AVI codec, then we in the AVI compression, it needs to integrate the hardware and software environment to play the machine, paper size, broadcast quality, encoding time, a variety of factors such as compatibility, choose the most appropriate one. I used a set of test data to compare a variety of commonly used code generated by encoding the file size and playback speed and quality for everyone in the production of compressed AVI and MPEG-4 reference. (capture youtube)
Source file size 5265kb, 30 seconds, mpg format
Output file without audio, bit-rate 650k bps (adjustable bit-rate encoding), frame rate to 29.97
Encoding codec to generate the file size (kb) encoding time (in seconds) the quality of
excellent none 226490 17
cinepak codec by radius 18596 292 difference (significant at Mosaic)
intel indeo video r3.2 9860 64 poor
intel indeo video 4.5 14402 396 good
intel indeo video 5.10 11006 135 good
intel iyuv codec 113260 12 and none quite
divx mpeg-4 low-motion 2744 17 good
divx mpeg-4 fast-motion 1972 17 slightly worse in the kinds of
good divx 4.12 2522 18
divx 5.0 pro 2482 19 good
From the test data we can see that the traditional AVI file size, broadcast quality, encoding time is dominant in both Intel Indeo Video 5.10, and it is also very good compatibility for the current mainstream hardware and software environment. MPEG-4 based on the AVI file, to use in his works to be installed in the system of its Codec, their file size, broadcast quality, the difference is not too great, if I choose, I would preferred DivX 5.0 After all, it is the latest code, as long as the CD-ROM in the inscriptions of the time, do not forget to install the program it with the Codec on engraved into it. Based on the above two types of AVI, recommended by MPEG-4 of AVI, to be used in the courseware DVD video on such a level.
