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Diffstat (limited to 'externals/oboe/src/common/README.md')
| -rw-r--r-- | externals/oboe/src/common/README.md | 33 |
1 files changed, 0 insertions, 33 deletions
diff --git a/externals/oboe/src/common/README.md b/externals/oboe/src/common/README.md deleted file mode 100644 index d397458890..0000000000 --- a/externals/oboe/src/common/README.md +++ /dev/null @@ -1,33 +0,0 @@ -# Notes on Implementation - -## Latency from Resampling - -There are two components of the latency. The resampler itself, and a buffer that -is used to adapt the block sizes. - -1) The resampler is an FIR running at the target sample rate. So its latency is the number of taps. -From MultiChannelResampler.cpp, numTaps is - - Fastest: 2 - Low: 4 - Medium: 8 - High: 16 - Best: 32 - -For output, the device sampling rate is used, which is typically 48000.For input, the app sampling rate is used. - -2) There is a block size adapter that collects odd sized blocks into larger blocks of the correct size. - -The adapter contains one burst of frames, from getFramesPerBurst(). But if the app specifies a -particular size using setFramesPerCallback() then that size will be used. -Here is some pseudo-code to calculate the latency. - - latencyMillis = 0 - targetRate = isOutput ? deviceRate : applicationRate - // Add latency from FIR - latencyMillis += numTaps * 1000.0 / targetRate - // Add latency from block size adaptation - adapterSize = (callbackSize > 0) ? callbackSize : burstSize - if (isOutput && isCallbackUsed) latencyMillis += adapterSize * 1000.0 / deviceRate - else if (isInput && isCallbackUsed) latencyMillis += adapterSize * 1000.0 / applicationRate - else if (isInput && !isCallbackUsed) latencyMillis += adapterSize * 1000.0 / deviceRate |