diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/media/AudioResamplerPublic.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/include/media/AudioResamplerPublic.h b/include/media/AudioResamplerPublic.h index 97847a0..b705efa 100644 --- a/include/media/AudioResamplerPublic.h +++ b/include/media/AudioResamplerPublic.h @@ -26,4 +26,17 @@ // TODO: replace with an API #define AUDIO_RESAMPLER_DOWN_RATIO_MAX 256 +// Returns the source frames needed to resample to destination frames. This is not a precise +// value and depends on the resampler (and possibly how it handles rounding internally). +// Nevertheless, this should be an upper bound on the requirements of the resampler. +// If srcSampleRate and dstSampleRate are equal, then it returns destination frames, which +// may not be true if the resampler is asynchronous. +static inline size_t sourceFramesNeeded( + uint32_t srcSampleRate, size_t dstFramesRequired, uint32_t dstSampleRate) { + // +1 for rounding - always do this even if matched ratio (resampler may use phases not ratio) + // +1 for additional sample needed for interpolation + return srcSampleRate == dstSampleRate ? dstFramesRequired : + size_t((uint64_t)dstFramesRequired * srcSampleRate / dstSampleRate + 1 + 1); +} + #endif // ANDROID_AUDIO_RESAMPLER_PUBLIC_H |