Data rateIt refers to the amount of information (bits) transmitted on the channel per unit time.The greater the data rate, the greater the amount of information transmitted per unit time.The size of data rate will affect the speed of information transmission, thus affecting the quality of services.
Chinese name
Data rate
Foreign name
Data rate
Impact
Quality of video clips
Interpretation
Amount of information transmitted on the channel per unit time
Features
Limit the number of viewers who can download files
The data rate will affect the quality of video clips and the number of viewers who can download files under a given bandwidth limit.
When you use the Internet to transfer video, you should use a lower data rate to generate files.Users with high-speed Internet connections
The file can be viewed almost without waiting, but dial-up users must wait for the file to download.If you expect the audience to be a dial-up user,
A shorter video clip should be made to keep the download time within an acceptable range.
Flash Video Encoder allows you to specify the data rates required for encoding low, medium, and high quality videos
set up.If the settings provided in the Quality pop-up menu do not produce the results required for your specific source video, select Custom
And then enter a higher data rate in the Max Data Rate text box
About Data Rates
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With some video codecs, you can specify the data rate to control the amount of video information processed per second during playback[1]。 By specifying the data rate in Adobe Premiere Elements, you can set the maximum data rate, because the actual data rate will vary according to the visual content of each frame.
The specified data rate depends on the purpose of the video.The following list describes data rate guidelines for some purposes:
The DVD production data rate should be able to fit the entire program within the available space on the DVD while achieving the highest quality.By default, Adobe Premiere Elements automatically adjusts the DVD data rate.
The data rate of non DV video tape production should be within the data transmission rate of the hard disk, because the video will be played back from the hard disk to the recording device.For information about the data transfer rate of the hard disk, please check the relevant documentation.
The hard disk playback determines the typical data transmission rate of the audience's hard disk and sets the data rate accordingly.In general, the data rate of 7200 rpm hard disk can be maintained at 20 to 35 MB per second, which is very high.In contrast, the average data rate for digital video is 3.6 MB per second.Therefore, to achieve high-quality playback, it may not be necessary to set the data rate as high as 20 to 35 MB per second.However, if you are exporting videos to be used in other editing systems or composite applications (such as Adobe After Effects), export them with the highest quality.Use a lossless codec (that is, a codec that does not discard information during compression), and specify the data rate at which the editing system supports video capture and editing.
The CD-ROM playback data rate depends on the speed of the CD drive.For example, if you are preparing final video files for a two speed CD-ROM drive (300 kilobytes per second), you can specify speeds of 150 kilobytes per second and 200 kilobytes per second to meet the data rate of the drive and the system overhead required to move data.
The intranet playback data rate can be 100 kilobytes/second or faster, depending on the speed of the intranet.An intranet is an internal or private network that uses Internet network protocols.Because of their limited range, intranets usually use communication lines with higher quality than standard telephone lines, so they are usually faster than the Internet.
Although there are fewer users using dial-up connection for streaming video on the Web than in previous years, you should still consider customizing the data rate for users who still use this method to access the Internet (if you want your files to be viewable by more users).Streaming video on the Web is popular with most consumersModemLimited bandwidth (56 KB or less) constraints.If you know that your audience has broadband Internet access devices (such as DSL or cable modem services), please use a higherBit rate。
Playback from handheld devices Due to the relatively small size, capacity and low speed of handheld devices, data rate is very important.Data rates can range from 8 to 90 kilobits per second, depending on the device.You can select the preset QuickTime export option in Adobe Premiere Elements to export files optimized for playback on handheld devices.
Since the main problem of downloading video files through the Web is the time required to download the files, the data rate is not important compared with the size of the video files.However, it is still necessary to reduce the data rate of the downloaded video, because this can reduce the size of the video file, so that it can be downloaded more quickly.
Dual data rate
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Dual data rate(GDR, also:doublepumped）Select a method of computer engineering, which is consistent with the datadata busWith dual data rate is the transfer of cans.
A similar procedure isFour times data rate(QDR) and quadruple sumEight data rates(ODR) at eight data rates.
catalog1 Technology and GDR2 Application3 Designation4. Promotion: DDR2 and DDR35Nebenentwicklungen: GDDR2 and GDDR36 Semi new development: QDR and QDR II
Technology and GDR
Data bits become associated with ascending and sloping sidesClock pulseOnly transfer, rather than climb high and follow the routineUnique data ratePractice.Therefore, the incoming frequency in the storage unit does not have to be doubled, and the designated mode‘Extract first'- Returning technology: to get the equal data from the memory field very twice, when the outward direction can be specified with the mark.The other half of the buffer only spends on the falling side, and the data half spends on the rising side.As a result of the acceleration, the number must be consistently greater than the total request data of the double bus width (='brush length').Since then, that's not the case, it'sGDR SDRAMSOUTHERN GERMAN BROADCASTING CORPORATIONSDRAMUsing the same clock is inaccurate twice as fast.A further reason is that the given address and control signal are opposite to the data signal and clock side only.
Symptoms of clock frequency connection with dual data rate The clock frequency of the bus frequently confuses with the data rate, that is.Become a processor bus with 100MegahertzClock frequency and dual data rate are selected as „ 200 MHz bus ". This is made by those who becomeMarketing designationFSB200 promotes.
Also specify the start pointpersonal computerAnd the bus rate is given three numbers after megahertz (i.e. PC-133 or PC133=133 MHz).However, four numbers select the data transmission rate in MByte/s, and then clickPC-2700The GDR SDRAM memory module is 166 MHz.Calculation: 166 MHz * 2 (where GDR) * 64 bits (bus width)=21248 MBit/s/8 bits=2656 MByte/s, surrounded by 2700 MByte/s.thosepersonal computerTherefore - the data is only limited and meaningful to the GDR technology related to the bus and the signs specified by the technology (and then the bus transport clearly fixed width and factors).
Advancing: DDR2 and DDR3
DDR2alsoDDR3The promotion of this concept is special for personal computer main memory, which is different from those extracted by double first, and quadruple and/or.Eight times first extract that you operate near a higher timing input/output,bufferMake possible.With DDR2, the actual storage unit only becomes half of the buffering operation of the input/output clock.Here, on the one hand, marketing technology is often referred to as "four times first extraction and development", so that on the other hand, GDR practice (× 2) and clock fragmentation (× 2) - a total of four times first extraction.This is obviously different from DDR3 by increasing the number of clocks in the I/O buffer, and the difference between the actual memory unit's clocks is four times the height, and one will exist with the GDR method - eight times first.Although the part of the memory chip provided by the memory unit is clearly larger than 90%, the input/output clock applies to the pulse specification of DDR2/DDR3 SpeichernbufferAs a formal „ ".
DDR2 becomesDDR2-SDRAMWith the trend motherboard used by many manufacturers and systems, DDR3 came in the middle in 2007 on the market.Because it suggests names, GDDR3 Speicher technology, which is often blocked by maps, is developed on DDR2 and not on DDR3.
Nebenentwicklungen: GDDR2 and GDDR3
GDDR2alsoGDDR3It is the memory place exclusive to the map that will be blocked.On the contrary, GDDR2 in DDR2-SDRAM is recommended in GDR SDRAM and GDDR3.This connects that with the factGDDR2alsoGDDR3The formal specification is not, but in a certain sense, the name of the marketing map chip developer is only representative.
Semi new development: QDR and QDR II
Square font data rate-RAM indicates a component, which benefitsGDR SDRAMalsoDual haven RAMunite.It has a separate reading and writing haven, so it can read and write independently without collision.However, a common address line divides the data.Therefore, the QDR SRAM may transfer to the safe harbor for the rising and falling side data at the same time, resulting in a data rate of four times below the line.There are two types of QDR SRAMs. On the one hand, two words are broken Variante, and four words are broken Variante.That is, by reading or writing 2 become like and/or.Read 4 words and/or.Write.QDR is.Discovery.Use system busPentium 4Purpose, ODR andAGP-Bus (AGP-8X) andXDR trace.
QDR II-RAM is the improved deformation of QDR RAM and the outlet of the regenerated clock, the echo clock. Therefore, it is mentioned that it is used synchronously.Therefore, 35% of the legal data window will be widened at the same frequency.However, compared with QDR SRAMs, the potential factors are around one and a half clocks for a long time. The total clock frequency is higher and the driving data rate is higher.
