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MP1.16 Remote Client Unable to Play: B43534E1 error watching Recorded TV
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<blockquote data-quote="Owlsroost" data-source="post: 1223502" data-attributes="member: 83973"><p>Yes, Windows will perform 'read ahead' caching if it thinks the file read access pattern is basically sequential (and you don't open the file in 'random access' mode). Basically Windows tries to adapt the caching behaviour to the access pattern it's seeing from the software (as far as I've ever managed to find out. So after it's seen the series of sequential 64K reads (from MP) it assumes that is the access pattern, and starts to read-ahead and cache the data.</p><p></p><p>I would expect (for a static file) that the data the duration measurement is reading (the very beginning and end of the flle) would be cached and hence not cause actual disk reads most of the time - certainly for my own single-seat system that is what seems to happen (I've had debug code in TsReader to measure the duration access times and they are normally very short).</p><p></p><p>Here are some links to info about file caching behaviour in Windows:</p><p></p><p><a href="https://blogs.msdn.microsoft.com/oldnewthing/20120120-00/?p=8493" target="_blank">How do FILE_FLAG_SEQUENTIAL_SCAN and FILE_FLAG_RANDOM_ACCESS affect how the operating system treats my file?</a></p><p></p><p><a href="http://geekswithblogs.net/akraus1/archive/2014/12/14/160652.aspx" target="_blank">What Is The Difference Between FileFlags.Random (FILE_FLAG_RANDOM_ACCESS) And FileFlags.SequentialScan (FILE_FLAG_SEQUENTIAL_SCAN)?</a></p><p></p><p>(In TsReader and StreamingServer, timeshift files are opened in FILE_FLAG_RANDOM_ACCESS mode, and other files in FILE_FLAG_SEQUENTIAL_SCAN mode).</p></blockquote><p></p>
[QUOTE="Owlsroost, post: 1223502, member: 83973"] Yes, Windows will perform 'read ahead' caching if it thinks the file read access pattern is basically sequential (and you don't open the file in 'random access' mode). Basically Windows tries to adapt the caching behaviour to the access pattern it's seeing from the software (as far as I've ever managed to find out. So after it's seen the series of sequential 64K reads (from MP) it assumes that is the access pattern, and starts to read-ahead and cache the data. I would expect (for a static file) that the data the duration measurement is reading (the very beginning and end of the flle) would be cached and hence not cause actual disk reads most of the time - certainly for my own single-seat system that is what seems to happen (I've had debug code in TsReader to measure the duration access times and they are normally very short). Here are some links to info about file caching behaviour in Windows: [URL="https://blogs.msdn.microsoft.com/oldnewthing/20120120-00/?p=8493"]How do FILE_FLAG_SEQUENTIAL_SCAN and FILE_FLAG_RANDOM_ACCESS affect how the operating system treats my file?[/URL] [URL="http://geekswithblogs.net/akraus1/archive/2014/12/14/160652.aspx"]What Is The Difference Between FileFlags.Random (FILE_FLAG_RANDOM_ACCESS) And FileFlags.SequentialScan (FILE_FLAG_SEQUENTIAL_SCAN)?[/URL] (In TsReader and StreamingServer, timeshift files are opened in FILE_FLAG_RANDOM_ACCESS mode, and other files in FILE_FLAG_SEQUENTIAL_SCAN mode). [/QUOTE]
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