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| 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| 2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
| 3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
| 4 | 4 |
| 5 #ifndef MEDIA_BASE_SINC_RESAMPLER_H_ | 5 #ifndef MEDIA_BASE_SINC_RESAMPLER_H_ |
| 6 #define MEDIA_BASE_SINC_RESAMPLER_H_ | 6 #define MEDIA_BASE_SINC_RESAMPLER_H_ |
| 7 | 7 |
| 8 #include "base/callback.h" | 8 #include "base/callback.h" |
| 9 #include "base/gtest_prod_util.h" | 9 #include "base/gtest_prod_util.h" |
| 10 #include "base/memory/aligned_memory.h" | 10 #include "base/memory/aligned_memory.h" |
| 11 #include "base/memory/scoped_ptr.h" | 11 #include "base/memory/scoped_ptr.h" |
| 12 #include "build/build_config.h" |
| 12 #include "media/base/media_export.h" | 13 #include "media/base/media_export.h" |
| 13 | 14 |
| 14 namespace media { | 15 namespace media { |
| 15 | 16 |
| 16 // SincResampler is a high-quality single-channel sample-rate converter. | 17 // SincResampler is a high-quality single-channel sample-rate converter. |
| 17 class MEDIA_EXPORT SincResampler { | 18 class MEDIA_EXPORT SincResampler { |
| 18 public: | 19 public: |
| 19 // The maximum number of samples that may be requested from the callback ahead | 20 enum { |
| 20 // of the current position in the stream. | 21 // The kernel size can be adjusted for quality (higher is better) at the |
| 21 static const int kMaximumLookAheadSize; | 22 // expense of performance. Must be a multiple of 32. |
| 23 // TODO(dalecurtis): Test performance to see if we can jack this up to 64+. |
| 24 kKernelSize = 32, |
| 25 |
| 26 // The number of destination frames generated per processing pass. Affects |
| 27 // how often and for how much SincResampler calls back for input. Must be |
| 28 // greater than kKernelSize. |
| 29 kBlockSize = 512, |
| 30 |
| 31 // The kernel offset count is used for interpolation and is the number of |
| 32 // sub-sample kernel shifts. Can be adjusted for quality (higher is better) |
| 33 // at the expense of allocating more memory. |
| 34 kKernelOffsetCount = 32, |
| 35 kKernelStorageSize = kKernelSize * (kKernelOffsetCount + 1), |
| 36 |
| 37 // The size (in samples) of the internal buffer used by the resampler. |
| 38 kBufferSize = kBlockSize + kKernelSize, |
| 39 |
| 40 // The maximum number of samples that may be requested from the callback |
| 41 // ahead of the current position in the stream. |
| 42 kMaximumLookAheadSize = kBufferSize |
| 43 }; |
| 22 | 44 |
| 23 // Callback type for providing more data into the resampler. Expects |frames| | 45 // Callback type for providing more data into the resampler. Expects |frames| |
| 24 // of data to be rendered into |destination|; zero padded if not enough frames | 46 // of data to be rendered into |destination|; zero padded if not enough frames |
| 25 // are available to satisfy the request. | 47 // are available to satisfy the request. |
| 26 typedef base::Callback<void(float* destination, int frames)> ReadCB; | 48 typedef base::Callback<void(float* destination, int frames)> ReadCB; |
| 27 | 49 |
| 28 // Constructs a SincResampler with the specified |read_cb|, which is used to | 50 // Constructs a SincResampler with the specified |read_cb|, which is used to |
| 29 // acquire audio data for resampling. |io_sample_rate_ratio| is the ratio of | 51 // acquire audio data for resampling. |io_sample_rate_ratio| is the ratio of |
| 30 // input / output sample rates. | 52 // input / output sample rates. |
| 31 SincResampler(double io_sample_rate_ratio, const ReadCB& read_cb); | 53 SincResampler(double io_sample_rate_ratio, const ReadCB& read_cb); |
| 32 virtual ~SincResampler(); | 54 virtual ~SincResampler(); |
| 33 | 55 |
| 34 // Resample |frames| of data from |read_cb_| into |destination|. | 56 // Resample |frames| of data from |read_cb_| into |destination|. |
| 35 void Resample(float* destination, int frames); | 57 void Resample(float* destination, int frames); |
| 36 | 58 |
| 37 // The maximum size in frames that guarantees Resample() will only make a | 59 // The maximum size in frames that guarantees Resample() will only make a |
| 38 // single call to |read_cb_| for more data. | 60 // single call to |read_cb_| for more data. |
| 39 int ChunkSize(); | 61 int ChunkSize() const; |
| 40 | 62 |
| 41 // Flush all buffered data and reset internal indices. | 63 // Flush all buffered data and reset internal indices. |
| 42 void Flush(); | 64 void Flush(); |
| 43 | 65 |
| 44 private: | 66 private: |
| 45 FRIEND_TEST_ALL_PREFIXES(SincResamplerTest, Convolve); | 67 FRIEND_TEST_ALL_PREFIXES(SincResamplerTest, Convolve); |
| 46 FRIEND_TEST_ALL_PREFIXES(SincResamplerTest, ConvolveBenchmark); | 68 FRIEND_TEST_ALL_PREFIXES(SincResamplerTest, ConvolveBenchmark); |
| 47 | 69 |
| 48 void InitializeKernel(); | 70 void InitializeKernel(); |
| 49 | 71 |
| 50 // Compute convolution of |k1| and |k2| over |input_ptr|, resultant sums are | 72 // Compute convolution of |k1| and |k2| over |input_ptr|, resultant sums are |
| 51 // linearly interpolated using |kernel_interpolation_factor|. On x86, the | 73 // linearly interpolated using |kernel_interpolation_factor|. On x86, the |
| 52 // underlying implementation is chosen at run time based on SSE support. On | 74 // underlying implementation is chosen at run time based on SSE support. On |
| 53 // ARM, NEON support is chosen at compile time based on compilation flags. | 75 // ARM, NEON support is chosen at compile time based on compilation flags. |
| 54 static float Convolve(const float* input_ptr, const float* k1, | 76 static float Convolve(const float* input_ptr, const float* k1, |
| 55 const float* k2, double kernel_interpolation_factor); | 77 const float* k2, double kernel_interpolation_factor); |
| 56 static float Convolve_C(const float* input_ptr, const float* k1, | 78 static float Convolve_C(const float* input_ptr, const float* k1, |
| 57 const float* k2, double kernel_interpolation_factor); | 79 const float* k2, double kernel_interpolation_factor); |
| 80 #if defined(ARCH_CPU_X86_FAMILY) |
| 58 static float Convolve_SSE(const float* input_ptr, const float* k1, | 81 static float Convolve_SSE(const float* input_ptr, const float* k1, |
| 59 const float* k2, | 82 const float* k2, |
| 60 double kernel_interpolation_factor); | 83 double kernel_interpolation_factor); |
| 84 #elif defined(ARCH_CPU_ARM_FAMILY) && defined(USE_NEON) |
| 61 static float Convolve_NEON(const float* input_ptr, const float* k1, | 85 static float Convolve_NEON(const float* input_ptr, const float* k1, |
| 62 const float* k2, | 86 const float* k2, |
| 63 double kernel_interpolation_factor); | 87 double kernel_interpolation_factor); |
| 88 #endif |
| 64 | 89 |
| 65 // The ratio of input / output sample rates. | 90 // The ratio of input / output sample rates. |
| 66 double io_sample_rate_ratio_; | 91 const double io_sample_rate_ratio_; |
| 67 | 92 |
| 68 // An index on the source input buffer with sub-sample precision. It must be | 93 // An index on the source input buffer with sub-sample precision. It must be |
| 69 // double precision to avoid drift. | 94 // double precision to avoid drift. |
| 70 double virtual_source_idx_; | 95 double virtual_source_idx_; |
| 71 | 96 |
| 72 // The buffer is primed once at the very beginning of processing. | 97 // The buffer is primed once at the very beginning of processing. |
| 73 bool buffer_primed_; | 98 bool buffer_primed_; |
| 74 | 99 |
| 75 // Source of data for resampling. | 100 // Source of data for resampling. |
| 76 ReadCB read_cb_; | 101 ReadCB read_cb_; |
| (...skipping 14 matching lines...) Expand all Loading... |
| 91 float* const r3_; | 116 float* const r3_; |
| 92 float* const r4_; | 117 float* const r4_; |
| 93 float* const r5_; | 118 float* const r5_; |
| 94 | 119 |
| 95 DISALLOW_COPY_AND_ASSIGN(SincResampler); | 120 DISALLOW_COPY_AND_ASSIGN(SincResampler); |
| 96 }; | 121 }; |
| 97 | 122 |
| 98 } // namespace media | 123 } // namespace media |
| 99 | 124 |
| 100 #endif // MEDIA_BASE_SINC_RESAMPLER_H_ | 125 #endif // MEDIA_BASE_SINC_RESAMPLER_H_ |
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