1. 09 Jul, 2017 1 commit
  2. 14 Mar, 2017 2 commits
  3. 14 Feb, 2017 1 commit
    • Joel Cunningham's avatar
      HTTP: improve performance by reducing forward seeks · 8c8e5d52
      Joel Cunningham authored
      This commit optimizes HTTP performance by reducing forward seeks, instead
      favoring a read-ahead and discard on the current connection (referred to
      as a short seek) for seeks that are within a TCP window's worth of data.
      This improves performance because with TCP flow control, a window's worth
      of data will be in the local socket buffer already or in-flight from the
      sender once congestion control on the sender is fully utilizing the window.
      
      Note: this approach doesn't attempt to differentiate from a newly opened
      connection which may not be fully utilizing the window due to congestion
      control vs one that is. The receiver can't get at this information, so we
      assume worst case; that full window is in use (we did advertise it after all)
      and that data could be in-flight
      
      The previous behavior of closing the connection, then opening a new
      with a new HTTP range value results in a massive amounts of discarded
      and re-sent data when large TCP windows are used.  This has been observed
      on MacOS/iOS which starts with an initial window of 256KB and grows up to
      1MB depending on the bandwidth-product delay.
      
      When seeking within a window's worth of data and we close the connection,
      then open a new one within the same window's worth of data, we discard
      from the current offset till the end of the window.  Then on the new
      connection the server ends up re-sending the previous data from new
      offset till the end of old window.
      
      Example (assumes full window utilization):
      
      TCP window size: 64KB
      Position: 32KB
      Forward seek position: 40KB
      
            *                      (Next window)
      32KB |--------------| 96KB |---------------| 160KB
              *
        40KB |---------------| 104KB
      
      Re-sent amount: 96KB - 40KB = 56KB
      
      For a real world test example, I have MP4 file of ~25MB, which ffplay
      only reads ~16MB and performs 177 seeks. With current ffmpeg, this results
      in 177 HTTP GETs and ~73MB worth of TCP data communication.  With this
      patch, ffmpeg issues 4 HTTP GETs and 3 seeks for a total of ~22MB of TCP data
      communication.
      
      To support this feature, the short seek logic in avio_seek() has been
      extended to call a function to get the short seek threshold value.  This
      callback has been plumbed to the URLProtocol structure, which now has
      infrastructure in HTTP and TCP to get the underlying receiver window size
      via SO_RCVBUF.  If the underlying URL and protocol don't support returning
      a short seek threshold, the default s->short_seek_threshold is used
      
      This feature has been tested on Windows 7 and MacOS/iOS.  Windows support
      is slightly complicated by the fact that when TCP window auto-tuning is
      enabled, SO_RCVBUF doesn't report the real window size, but it does if
      SO_RCVBUF was manually set (disabling auto-tuning). So we can only use
      this optimization on Windows in the later case
      Signed-off-by: 's avatarJoel Cunningham <joel.cunningham@me.com>
      Signed-off-by: 's avatarMichael Niedermayer <michael@niedermayer.cc>
      8c8e5d52
  4. 17 May, 2016 2 commits
  5. 10 Apr, 2016 1 commit
  6. 24 Mar, 2016 3 commits
  7. 17 Mar, 2016 1 commit
  8. 04 Mar, 2016 1 commit
  9. 22 Feb, 2016 5 commits
  10. 02 Feb, 2016 1 commit
  11. 29 Jan, 2016 1 commit
  12. 20 Jan, 2016 1 commit
  13. 31 Jul, 2015 1 commit
  14. 29 Jun, 2015 1 commit
  15. 24 Jun, 2015 1 commit
  16. 22 Jun, 2015 1 commit
  17. 18 Jun, 2015 1 commit
  18. 29 May, 2015 1 commit
  19. 27 Mar, 2015 1 commit
  20. 11 Mar, 2015 1 commit
  21. 20 Oct, 2014 1 commit
  22. 15 Aug, 2014 1 commit
  23. 12 Aug, 2014 1 commit
  24. 26 Jul, 2014 1 commit
  25. 17 May, 2014 1 commit
  26. 30 Mar, 2014 1 commit
  27. 05 Mar, 2014 1 commit
  28. 16 Feb, 2014 1 commit
  29. 30 Oct, 2013 1 commit
    • Martin Storsjö's avatar
      lavf: Remove a now useless parameter to ffurl_register_protocol · 0c5f8396
      Martin Storsjö authored
      This was added in 9b07a2dc as an ABI hack to allow older
      code built with lavf 52 to register protocols even if the size
      of the URLProtocol struct was increased. Later, registering
      protocols from outside of lavf was removed and this workaround
      isn't needed any longer since lavf 53.
      
      This removes an unchecked malloc and a memory leak for the cases
      when this workaround actually was used - which it hasn't since
      lavf 53.
      Signed-off-by: 's avatarMartin Storsjö <martin@martin.st>
      0c5f8396
  30. 29 Oct, 2013 1 commit
  31. 27 Oct, 2013 2 commits