Questions and answers about MPEG4
Movies recorded in the MPEG-4 format have already gained deserved popularity among a wide audience of PC users.
These films will generally fit on a CD, and in terms of image quality they can compete successfully with video tapes. Not the last factor that determines the popularity of MPEG-4 discs is their price. Therefore, MPEG-4 could well become a middle ground on the path of the massive transition of home users from analog VHS video recorders to the digital DVD standard.
In the Russian-language part of the Internet, you can find a large number of materials about the MPEG-4 standard, but most of them contain a description of the complexities of the process of compressing video in this format. This is, of course, a specific question that requires detailed research, but for users acting only as viewers, these articles often cannot answer the questions that arise when they want to watch movies. Another important source of information is conferences. In the “Processors”, “Video”, “Multimedia” sections, issues related to speed, quality, optimal settings and everything related to MPEG-4 are constantly raised, but the answers received often contradict each other. Someone claims that all his life he watched MPEG-4 without brakes on Pentium 200, others complain about the slideshow,
This article attempts to clarify frequently asked questions from people who have recently encountered this format, as well as to draw the attention of those who have never encountered MPEG-4 before. Hopefully, after reading this material, the reader who is not involved in video editing and compression can confidently say, “Now I know enough about this.”
What is MPEG?
MPEG is an abbreviation that stands for Moving Picture Experts Group (before writing a letter the first letter is not deciphered, so go to www.mpeg.org).
It is a fairly large organization, consisting of developers of audio, video and computer equipment, as well as programmers and specialists involved in the development and implementation of standards for algorithms for compression, transmission, storage and reproduction of audio and video data. .
Among the developments of this group in the field of digital video recording, the most famous are:
MPEG-1 standard. It was released in 1992. Users most often associate it with movies on VideoCD. The typical consumer video format for MPEG-1 in the PAL standard is 352 * 288 pixels, 25 frames per second. The audio part is stereo audio with a sampling frequency of 44.1 kHz, compressed in MPEG-1 Layer II. A feature film recorded in this format occupies two CDs in the VideoCD standard. The picture quality of VideoCDs is on par with a consumer VHS videotape.
MPEG-2 standard. Released in 1995. Users come across this video compression format primarily when purchasing DVD with movies. The typical frame size for a DVD movie in the PAL / SECAM video standard is 720 * 576 at 25 frames per second, or 640 * 480 at 30 frames per second in the NTSC standard. Compared to MPEG-1, support for multi-channel audio (Dolby Digital 5.1, DTS, etc.) has been added to the audio part. Increasing the bit rate and using an improved video compression algorithm have provided DVD movies with much better image quality than VideoCD. MPEG-2 is also used today in digital satellite television. Home DVD players in our country are gaining popularity. The relatively high price of DVD movies plays a big role in this.
MPEG-4 standard. It began to develop in the first half of the 90s of the last century. In December 1999, a launch of this format was presented, which received the official status of ISO / IEC standard. MPEG-4 was conceived as a way to transfer data from transmission media, mainly video, over low-bandwidth channels. The standard unexpectedly gained popularity among low-budget users: the use of more complex compression algorithms made it possible to put one-and-a-half-hour to two-hour feature films in acceptable quality on a single CD. With the same bit rate and certain encoding conditions, the image quality of a movie in MPEG-4 can be comparable or even better than when using MPEG-1 or MPEG-2. However, the use of new compression algorithms also led to a significant increase in the computing resources required for decompressing high-quality images from this format.
