Difference between Normal file and PD streamable clip

Difference between Normal file and PD streamable clip:

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                   Normal video file can have the file index information at the end. ( video track audio track and its duration and all informations available @ the end. if it is so, we can play the file only after downloading the entire contents of a file.)

                 Progressive Download streamable clip will have the index information at the beginning.In case of 3gp file, moov atom will have the file index position and information .

              if the moov atom is available @ the end of the file, then the file is not streamable using PD.

     In case of rtsp streamable 3gp file also have some hint track @ the beginning to inform the file index positions @ the beginning.

                

Assumptions:
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1.Quicktime, mp4,3gp file having hint track can be transferred thru http or ftp protocols
 
2.Moov atom index must be at the beginning of the file ... so that player can play the file before downloading the entire content...

3.Self contained movie can be streamable...

 

Solutions:
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  Any Quicktime,mp4 or 3gp files can be able to do Progressive Download Streaming
if moov  atom is @ first..Moov atom index must be at the beginning of the file ... so that player can play the file before downloading the entire content.

 

 For Example

3gp file atoms are like this:
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 ftyp
 moov
  mdat

 we can stream it in PD streaming.

if the 3gp atoms are as follows:

 ftyp
 mdat
 moov

 this indicates Moov atom is at the end of the file... So it can't be streamable in Progressive Download.

 

PD Stack:
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 within PD stack,we will wait for the File Size and information about the video and audio track info...

 if it doesnt receive the video, audio track info and file information it will not proceed to download the content.