Add libavresample

This is a new library for audio sample format, channel layout, and sample rate
conversion.

1 files changed, 108 insertions, 0 deletions

diff --git a/libavresample/audio_mix.h b/libavresample/audio_mix.h
new file mode 100644
index 0000000000..ffa1b23842
--- /dev/null
+++ b/libavresample/audio_mix.h
@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com>
+ *
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVRESAMPLE_AUDIO_MIX_H
+#define AVRESAMPLE_AUDIO_MIX_H
+
+#include <stdint.h>
+
+#include "libavutil/samplefmt.h"
+#include "avresample.h"
+#include "audio_data.h"
+
+typedef void (mix_func)(uint8_t **src, void **matrix, int len, int out_ch,
+                        int in_ch);
+
+typedef struct AudioMix {
+    AVAudioResampleContext *avr;
+    enum AVSampleFormat fmt;
+    enum AVMixCoeffType coeff_type;
+    uint64_t in_layout;
+    uint64_t out_layout;
+    int in_channels;
+    int out_channels;
+
+    int ptr_align;
+    int samples_align;
+    int has_optimized_func;
+    const char *func_descr;
+    const char *func_descr_generic;
+    mix_func *mix;
+    mix_func *mix_generic;
+
+    int16_t *matrix_q6[AVRESAMPLE_MAX_CHANNELS];
+    int32_t *matrix_q15[AVRESAMPLE_MAX_CHANNELS];
+    float   *matrix_flt[AVRESAMPLE_MAX_CHANNELS];
+    void   **matrix;
+} AudioMix;
+
+/**
+ * Set mixing function if the parameters match.
+ *
+ * This compares the parameters of the mixing function to the parameters in the
+ * AudioMix context. If the parameters do not match, no changes are made to the
+ * active functions. If the parameters do match and the alignment is not
+ * constrained, the function is set as the generic mixing function. If the
+ * parameters match and the alignment is constrained, the function is set as
+ * the optimized mixing function.
+ *
+ * @param am             AudioMix context
+ * @param fmt            input/output sample format
+ * @param coeff_type     mixing coefficient type
+ * @param in_channels    number of input channels, or 0 for any number of channels
+ * @param out_channels   number of output channels, or 0 for any number of channels
+ * @param ptr_align      buffer pointer alignment, in bytes
+ * @param sample_align   buffer size alignment, in samples
+ * @param descr          function type description (e.g. "C" or "SSE")
+ * @param mix_func       mixing function pointer
+ */
+void ff_audio_mix_set_func(AudioMix *am, enum AVSampleFormat fmt,
+                           enum AVMixCoeffType coeff_type, int in_channels,
+                           int out_channels, int ptr_align, int samples_align,
+                           const char *descr, void *mix_func);
+
+/**
+ * Initialize the AudioMix context in the AVAudioResampleContext.
+ *
+ * The parameters in the AVAudioResampleContext are used to initialize the
+ * AudioMix context and set the mixing matrix.
+ *
+ * @param avr  AVAudioResampleContext
+ * @return     0 on success, negative AVERROR code on failure
+ */
+int ff_audio_mix_init(AVAudioResampleContext *avr);
+
+/**
+ * Close an AudioMix context.
+ *
+ * This clears and frees the mixing matrix arrays.
+ */
+void ff_audio_mix_close(AudioMix *am);
+
+/**
+ * Apply channel mixing to audio data using the current mixing matrix.
+ */
+int ff_audio_mix(AudioMix *am, AudioData *src);
+
+/* arch-specific initialization functions */
+
+void ff_audio_mix_init_x86(AudioMix *am);
+
+#endif /* AVRESAMPLE_AUDIO_MIX_H */