Recently, I sent dozens of applications to iPlay official for the product, finally I am lucky enough to get one iPlayer for testing. Formerly, official claimed iPlayer supports various video formats, and among these formats AVI consideriing as the stunt because of its popularity. But actually I prefer FLV. Why FLV? As we all know the flle size of FLV is small, so I think the loading speed definitely is the best advantage. Besides, Let us look more details about it.
The format has quickly established itself as the format of choice for embedded video on the web. Notable users of the Flash Video format include YouTube, Google Video, Yahoo! Video, metacafe, Reuters.com, and many other news providers. The standards documentation for BBC Online deprecates the use of other formats previously in use on its sites such as RealVideo or WMV.
Though the Flash Video container format itself is open, the codecs used with it are patented. Flash Video files usually contain material encoded with codecs following the H.263 or VP6 standards. The most recent public releases of Flash Player also support H.264 video and HE-AAC audio.
Flash Video is viewable on most operating systems, via the widely available Adobe Flash Player and web browser plugin, or one of several third-party programs such as MPlayer, VLC media player, or any player which uses DirectShow filters (such as ALLPlayer, Media Player Classic, Windows Media Player, and Windows Media Center) when the ffdshow filter is installed.
OK, now I wander the effects of FLV playing by iPlayer. Look at the informations of some FLV videos I have prepared in advance below:
Complete name atongmu.flv (the original name is expressed by Chinese character, it is from a Japanese anime named astroboy)
Format : Flash Video
File size: 1.74 MiB
PlayTime : 48s 333ms
Bit rat : 303 Kbps
Tagged_Application : Tudou.Com
Codec: Sorenson H263
Width: 352 pixels
Height: 264 pixels
Aspect ratio: 4/3
Frame rate: 15.021 fps
Complete name :last friends.flv(also have Chinese characters)
Format : Flash Video
File size : 1.65 MiB
PlayTime : 45s 133ms
Bit rate : 306 Kbps
Tagged_Application : iku
Codec : Sorenson H263
Width : 320 pixels
Height : 214 pixels
Aspect ratio : 1.495
Frame rate : 15.022 fps
This video is not large. The resolution is 320 X 214, code rate is 306kbps, playing smoothly. From the first picture we could see the subtitles clearly, so I draw the conclusion that the standard resolution videos from common video service site(youtube and so on), is no problems with its subtitles.
Next a DS game trailer from game site GT, my favorite Dragon Quest 9. The resolution is perfect for DS screen.
Complete name :t_dragonq9_ovw_jp_v2.flv
Format : Flash Video
File size : 58.7 MiB
PlayTime : 7mn 14s
Bit rate : 1135 Kbps
Codec : On2 VP6
Width : 480 pixels
Height : 360 pixels
Aspect ratio : 4/3
Frame rate : 29.970 fps
Besides the three videos, there are more testing below:
|knights||19.6M||29.970fps||1148kbps||480 X 360||little frames dropped|
|Project Origin trailer||14.3M||29.970fps||1149kbps||640 X 360||frames droppedseriously|
|mengshoumeinv||1.35M||14.896fps||297kbps||246 X 320||smoothly|
|Rexuegaoxiao||1.17M||15.030fps||292Kbps||243 X 320||smoothly|
|The Fast and the Furious||3.87M||15.008fps||254kbps||320 X 136||smoothly|
|xiaohaizibuben||5.67M||15.003fps||250kbps||320 X 240||smoothly|
|Final Fantasy VII Advent Children trailer||12.3M||15.001fps||247Kbps||320 X 262||smoothly|
|Crayon Shin Chan||1.05M||15.023 fps||293kbps||320 X 240||smoothly|
|2009 new Japan anime trailer collection||53.8M||11.585fps||299kbps||320 X 240||little frames dropped|
|DRINK IT DOWN||8.41M||15.004fps||258Kbps||320 X 240||smoothly|
|NARUTO 334 trailer||1.40M||14.966fps||290kbps||320 X 182||smoothly|
|Ice Age trailer||2.10M||15.016fps||285kbps||352 X 264||smoothly|
The test results show us that most of FLV videos play well, except the first two video, knights and Project Origin trailer, which bit rate is too high, so frame dropped is not surprise. And the frame of 2009 new Japan anime trailer collection itself is low, so play effect by iPlay is the same.
Conclusions: FLV with 15fps/250-310Kbps is able to be played soomtly, subtitle also looks clearly, and it is the standard of Common video service site uploaded video. There are many advantages with FLV, including source is very abundance and popularity, file size is small, downloading convenience and so on.
iPlayer official site: http://dsiplayer.com/