From 4fae51edcbb28f540cd686e04b4ce1382e3f6cd5 Mon Sep 17 00:00:00 2001
From: Brad Parker <cbparker@gmail.com>
Date: Wed, 25 Jan 2017 01:28:48 -0500
Subject: [PATCH 1/6] initial resampling wav loader

---
 Makefile.common                           |   3 +-
 libretro-common/audio/audio_mix.c         | 218 ++++++++++++++++++++++
 libretro-common/include/audio/audio_mix.h |  41 ++++
 3 files changed, 261 insertions(+), 1 deletion(-)

diff --git a/Makefile.common b/Makefile.common
index 65db082a1c..f4b1682aac 100644
--- a/Makefile.common
+++ b/Makefile.common
@@ -454,7 +454,8 @@ endif
 
 OBJ += $(LIBRETRO_COMM_DIR)/audio/conversion/s16_to_float.o \
        $(LIBRETRO_COMM_DIR)/audio/conversion/float_to_s16.o \
-		 $(LIBRETRO_COMM_DIR)/audio/audio_mix.o
+		   $(LIBRETRO_COMM_DIR)/audio/audio_mix.o \
+		   $(LIBRETRO_COMM_DIR)/formats/wav/rwav.o
 
 ifeq ($(HAVE_NEON),1)
    OBJ += $(LIBRETRO_COMM_DIR)/audio/conversion/s16_to_float_neon.o \
diff --git a/libretro-common/audio/audio_mix.c b/libretro-common/audio/audio_mix.c
index 601409f6e0..6aecd0b9b1 100644
--- a/libretro-common/audio/audio_mix.c
+++ b/libretro-common/audio/audio_mix.c
@@ -28,6 +28,14 @@
 #include <altivec.h>
 #endif
 
+#include <stdio.h>
+
+#include <retro_miscellaneous.h>
+#include <audio/audio_mix.h>
+#include <streams/file_stream.h>
+#include <audio/conversion/float_to_s16.h>
+#include <audio/conversion/s16_to_float.h>
+
 void audio_mix_volume_C(float *out, const float *in, float vol, size_t samples)
 {
    size_t i;
@@ -65,3 +73,213 @@ void audio_mix_volume_SSE2(float *out, const float *in, float vol, size_t sample
 }
 #endif
 
+void audio_mix_free_chunk(audio_chunk_t *chunk)
+{
+   if (!chunk)
+      return;
+
+   if (chunk->rwav && chunk->rwav->samples)
+   {
+      /* rwav_free only frees the samples */
+      rwav_free(chunk->rwav);
+      free(chunk->rwav);
+   }
+
+   if (chunk->buf)
+      free(chunk->buf);
+
+   if (chunk->upsample_buf)
+      free(chunk->upsample_buf);
+
+   if (chunk->float_buf)
+      free(chunk->float_buf);
+
+   if (chunk->float_resample_buf)
+      free(chunk->float_resample_buf);
+
+   if (chunk->resample_buf)
+      free(chunk->resample_buf);
+
+   if (chunk->resampler && chunk->resampler_data)
+      chunk->resampler->free(chunk->resampler_data);
+
+   free(chunk);
+}
+
+audio_chunk_t* audio_mix_load_wav_file(const char *path, int sample_rate)
+{
+   audio_chunk_t *chunk = (audio_chunk_t*)calloc(1, sizeof(*chunk));
+
+   chunk->sample_rate = sample_rate;
+
+   if (!filestream_read_file(path, &chunk->buf, &chunk->len))
+   {
+      printf("Could not open WAV file for reading.\n");
+      return NULL;
+   }
+
+   chunk->rwav = (rwav_t*)malloc(sizeof(rwav_t));
+
+   if (rwav_load(chunk->rwav, chunk->buf, chunk->len) == RWAV_ITERATE_ERROR)
+   {
+      printf("error: could not load WAV file\n");
+      audio_mix_free_chunk(chunk);
+      return NULL;
+   }
+
+   if (sample_rate != chunk->rwav->samplerate)
+   {
+      int sample_size = chunk->rwav->bitspersample / 8;
+
+      if (sample_size == 1)
+      {
+         unsigned i;
+         chunk->upsample_buf = (int16_t*)malloc(chunk->rwav->numsamples * chunk->rwav->numchannels * sizeof(int16_t));
+
+        for (i = 0; i < chunk->rwav->numsamples; i++)
+        {
+           unsigned channel;
+           uint8_t *sample = ((uint8_t*)chunk->rwav->samples) +
+                 (sample_size * i * chunk->rwav->numchannels);
+
+           for (channel = 0; channel < chunk->rwav->numchannels; channel++)
+           {
+              chunk->upsample_buf[i] = (int16_t)((sample[channel] - 128) << 8);
+           }
+        }
+      }
+      else if (sample_size != 2)
+      {
+         /* we don't support any other sample size besides 8 and 16-bit yet */
+         printf("error: we don't support a sample size of %d\n", sample_size);
+         audio_mix_free_chunk(chunk);
+         return NULL;
+      }
+
+      chunk->resample = true;
+      chunk->ratio = (double)sample_rate / chunk->rwav->samplerate;
+
+      retro_resampler_realloc(&chunk->resampler_data,
+            &chunk->resampler,
+            NULL,
+            chunk->ratio);
+
+      if (chunk->resampler && chunk->resampler_data)
+      {
+         struct resampler_data info = {0};
+
+         chunk->float_buf = (float*)malloc(chunk->rwav->numsamples * chunk->rwav->numchannels * sizeof(float));
+         chunk->float_resample_buf = (float*)malloc((chunk->rwav->numsamples * chunk->ratio + 16) * chunk->rwav->numsamples * chunk->rwav->numchannels * sizeof(float));
+
+         if (sample_size == 1)
+            convert_s16_to_float(chunk->float_buf, chunk->upsample_buf, chunk->rwav->numsamples * chunk->rwav->numchannels, 1.0);
+         else
+            convert_s16_to_float(chunk->float_buf, chunk->buf, chunk->rwav->numsamples * chunk->rwav->numchannels, 1.0);
+
+         info.data_in = (const float*)chunk->float_buf;
+         info.data_out = chunk->float_resample_buf;
+         info.input_frames = chunk->rwav->numsamples;
+         info.ratio = chunk->ratio;
+
+         chunk->resampler->process(chunk->resampler_data, &info);
+
+         chunk->resample_buf = (int16_t*)malloc(info.output_frames * chunk->rwav->numchannels * sizeof(int16_t));
+         chunk->resample_len = info.output_frames;
+
+         convert_float_to_s16(chunk->resample_buf, chunk->float_resample_buf, info.output_frames * chunk->rwav->numchannels);
+      }
+   }
+
+   return chunk;
+}
+
+size_t audio_mix_get_chunk_num_samples(audio_chunk_t *chunk)
+{
+   if (!chunk)
+      return 0;
+
+   if (chunk->rwav)
+   {
+      if (chunk->resample)
+         return chunk->resample_len;
+      else
+         return chunk->rwav->numsamples;
+   }
+   else
+   {
+      /* no other filetypes supported yet */
+      return 0;
+   }
+}
+
+/**
+ * audio_mix_get_chunk_sample:
+ * @chunk              : audio chunk instance
+ * @channel            : channel of the sample (0=left, 1=right)
+ * @index              : index of the sample
+ *
+ * Get a sample from an audio chunk.
+ *
+ * Returns: A signed 16-bit audio sample, (if necessary) resampled into the desired output rate.
+ **/
+int16_t audio_mix_get_chunk_sample(audio_chunk_t *chunk, unsigned channel, size_t index)
+{
+   if (!chunk)
+      return 0;
+
+   if (chunk->rwav)
+   {
+      int sample_size = chunk->rwav->bitspersample / 8;
+      int16_t sample_out = 0;
+
+      /* 0 is the first/left channel */
+      uint8_t *sample = ((uint8_t*)chunk->rwav->samples) +
+            (sample_size * index * chunk->rwav->numchannels) + (channel * sample_size);
+
+      if (sample_size == 1)
+      {
+         if (chunk->resample)
+            sample_out = chunk->resample_buf[index];
+         else
+         {
+            /* convert unsigned 8-bit to signed 16-bit */
+            sample_out = (*sample - 128) << 8;
+         }
+      }
+      else if (sample_size == 2)
+      {
+         if (chunk->resample)
+            return chunk->resample_buf[index];
+         else
+         {
+            /* signed 16-bit is native, pass it through */
+            sample_out = (uint16_t)*sample;
+         }
+      }
+      else
+      {
+         return 0;
+      }
+
+      return sample_out;
+   }
+   else
+   {
+      /* no other filetypes supported yet */
+      return 0;
+   }
+}
+
+int audio_mix_get_chunk_num_channels(audio_chunk_t *chunk)
+{
+   if (!chunk)
+      return 0;
+
+   if (chunk->rwav)
+      return chunk->rwav->numchannels;
+   else
+   {
+      /* don't support other formats yet */
+      return 0;
+   }
+}
diff --git a/libretro-common/include/audio/audio_mix.h b/libretro-common/include/audio/audio_mix.h
index 045e5e0d9d..e31c5ed0ba 100644
--- a/libretro-common/include/audio/audio_mix.h
+++ b/libretro-common/include/audio/audio_mix.h
@@ -27,9 +27,30 @@
 
 #include <stdint.h>
 #include <stddef.h>
+#include <unistd.h>
+
+#include <formats/rwav.h>
+#include <audio/audio_resampler.h>
 
 RETRO_BEGIN_DECLS
 
+typedef struct
+{
+   void *buf;
+   int16_t *upsample_buf;
+   float *float_buf;
+   float *float_resample_buf;
+   int16_t *resample_buf;
+   ssize_t len;
+   size_t resample_len;
+   rwav_t *rwav;
+   int sample_rate;
+   bool resample;
+   const retro_resampler_t *resampler;
+   void *resampler_data;
+   double ratio;
+} audio_chunk_t;
+
 #if defined(__SSE2__)
 #define audio_mix_volume           audio_mix_volume_SSE2
 
@@ -41,6 +62,26 @@ void audio_mix_volume_SSE2(float *out,
 
 void audio_mix_volume_C(float *dst, const float *src, float vol, size_t samples);
 
+void audio_mix_free_chunk(audio_chunk_t *chunk);
+
+audio_chunk_t* audio_mix_load_wav_file(const char *path, int sample_rate);
+
+size_t audio_mix_get_chunk_num_samples(audio_chunk_t *chunk);
+
+/**
+ * audio_mix_get_chunk_sample:
+ * @chunk              : audio chunk instance
+ * @channel            : channel of the sample (0=left, 1=right)
+ * @index              : index of the sample
+ *
+ * Get a sample from an audio chunk.
+ *
+ * Returns: A signed 16-bit audio sample, (if necessary) resampled into the desired output rate.
+ **/
+int16_t audio_mix_get_chunk_sample(audio_chunk_t *chunk, unsigned channel, size_t sample);
+
+int audio_mix_get_chunk_num_channels(audio_chunk_t *chunk);
+
 RETRO_END_DECLS
 
 #endif

From f8ad1c6622c1aabf1941eea430d3bac66800c6e0 Mon Sep 17 00:00:00 2001
From: Brad Parker <cbparker@gmail.com>
Date: Wed, 25 Jan 2017 17:30:15 -0500
Subject: [PATCH 2/6] use aligned memory buffers

---
 libretro-common/audio/audio_mix.c | 113 +++++++++++++-----------------
 1 file changed, 49 insertions(+), 64 deletions(-)

diff --git a/libretro-common/audio/audio_mix.c b/libretro-common/audio/audio_mix.c
index 6aecd0b9b1..f0b467b923 100644
--- a/libretro-common/audio/audio_mix.c
+++ b/libretro-common/audio/audio_mix.c
@@ -29,7 +29,8 @@
 #endif
 
 #include <stdio.h>
-
+#include <string.h>
+#include <memalign.h>
 #include <retro_miscellaneous.h>
 #include <audio/audio_mix.h>
 #include <streams/file_stream.h>
@@ -89,16 +90,16 @@ void audio_mix_free_chunk(audio_chunk_t *chunk)
       free(chunk->buf);
 
    if (chunk->upsample_buf)
-      free(chunk->upsample_buf);
+      memalign_free(chunk->upsample_buf);
 
    if (chunk->float_buf)
-      free(chunk->float_buf);
+      memalign_free(chunk->float_buf);
 
    if (chunk->float_resample_buf)
-      free(chunk->float_resample_buf);
+      memalign_free(chunk->float_resample_buf);
 
    if (chunk->resample_buf)
-      free(chunk->resample_buf);
+      memalign_free(chunk->resample_buf);
 
    if (chunk->resampler && chunk->resampler_data)
       chunk->resampler->free(chunk->resampler_data);
@@ -109,6 +110,7 @@ void audio_mix_free_chunk(audio_chunk_t *chunk)
 audio_chunk_t* audio_mix_load_wav_file(const char *path, int sample_rate)
 {
    audio_chunk_t *chunk = (audio_chunk_t*)calloc(1, sizeof(*chunk));
+   int sample_size;
 
    chunk->sample_rate = sample_rate;
 
@@ -127,35 +129,38 @@ audio_chunk_t* audio_mix_load_wav_file(const char *path, int sample_rate)
       return NULL;
    }
 
+   chunk->upsample_buf = (int16_t*)memalign_alloc_aligned(chunk->rwav->numsamples * chunk->rwav->numchannels * sizeof(int16_t));
+
+   sample_size = chunk->rwav->bitspersample / 8;
+
+   if (sample_size == 1)
+   {
+      unsigned i;
+
+     for (i = 0; i < chunk->rwav->numsamples; i++)
+     {
+        unsigned channel;
+        uint8_t *sample = ((uint8_t*)chunk->rwav->samples) +
+              (sample_size * i * chunk->rwav->numchannels);
+
+        for (channel = 0; channel < chunk->rwav->numchannels; channel++)
+        {
+           chunk->upsample_buf[i] = (int16_t)((sample[channel] - 128) << 8);
+        }
+     }
+   }
+   else if (sample_size == 2)
+      memcpy(chunk->upsample_buf, chunk->rwav->samples, chunk->rwav->subchunk2size);
+   else if (sample_size != 2)
+   {
+      /* we don't support any other sample size besides 8 and 16-bit yet */
+      printf("error: we don't support a sample size of %d\n", sample_size);
+      audio_mix_free_chunk(chunk);
+      return NULL;
+   }
+
    if (sample_rate != chunk->rwav->samplerate)
    {
-      int sample_size = chunk->rwav->bitspersample / 8;
-
-      if (sample_size == 1)
-      {
-         unsigned i;
-         chunk->upsample_buf = (int16_t*)malloc(chunk->rwav->numsamples * chunk->rwav->numchannels * sizeof(int16_t));
-
-        for (i = 0; i < chunk->rwav->numsamples; i++)
-        {
-           unsigned channel;
-           uint8_t *sample = ((uint8_t*)chunk->rwav->samples) +
-                 (sample_size * i * chunk->rwav->numchannels);
-
-           for (channel = 0; channel < chunk->rwav->numchannels; channel++)
-           {
-              chunk->upsample_buf[i] = (int16_t)((sample[channel] - 128) << 8);
-           }
-        }
-      }
-      else if (sample_size != 2)
-      {
-         /* we don't support any other sample size besides 8 and 16-bit yet */
-         printf("error: we don't support a sample size of %d\n", sample_size);
-         audio_mix_free_chunk(chunk);
-         return NULL;
-      }
-
       chunk->resample = true;
       chunk->ratio = (double)sample_rate / chunk->rwav->samplerate;
 
@@ -168,13 +173,10 @@ audio_chunk_t* audio_mix_load_wav_file(const char *path, int sample_rate)
       {
          struct resampler_data info = {0};
 
-         chunk->float_buf = (float*)malloc(chunk->rwav->numsamples * chunk->rwav->numchannels * sizeof(float));
-         chunk->float_resample_buf = (float*)malloc((chunk->rwav->numsamples * chunk->ratio + 16) * chunk->rwav->numsamples * chunk->rwav->numchannels * sizeof(float));
+         chunk->float_buf = (float*)memalign_alloc_aligned(chunk->rwav->numsamples * chunk->rwav->numchannels * sizeof(float));
+         chunk->float_resample_buf = (float*)memalign_alloc_aligned(chunk->rwav->numsamples * 2 * chunk->ratio * chunk->rwav->numchannels * sizeof(float));
 
-         if (sample_size == 1)
-            convert_s16_to_float(chunk->float_buf, chunk->upsample_buf, chunk->rwav->numsamples * chunk->rwav->numchannels, 1.0);
-         else
-            convert_s16_to_float(chunk->float_buf, chunk->buf, chunk->rwav->numsamples * chunk->rwav->numchannels, 1.0);
+         convert_s16_to_float(chunk->float_buf, chunk->upsample_buf, chunk->rwav->numsamples * chunk->rwav->numchannels, 1.0);
 
          info.data_in = (const float*)chunk->float_buf;
          info.data_out = chunk->float_resample_buf;
@@ -183,7 +185,7 @@ audio_chunk_t* audio_mix_load_wav_file(const char *path, int sample_rate)
 
          chunk->resampler->process(chunk->resampler_data, &info);
 
-         chunk->resample_buf = (int16_t*)malloc(info.output_frames * chunk->rwav->numchannels * sizeof(int16_t));
+         chunk->resample_buf = (int16_t*)memalign_alloc_aligned(info.output_frames * chunk->rwav->numchannels * sizeof(int16_t));
          chunk->resample_len = info.output_frames;
 
          convert_float_to_s16(chunk->resample_buf, chunk->float_resample_buf, info.output_frames * chunk->rwav->numchannels);
@@ -233,33 +235,16 @@ int16_t audio_mix_get_chunk_sample(audio_chunk_t *chunk, unsigned channel, size_
       int16_t sample_out = 0;
 
       /* 0 is the first/left channel */
-      uint8_t *sample = ((uint8_t*)chunk->rwav->samples) +
+      uint8_t *sample;
+
+      if (chunk->resample)
+         sample = (uint8_t*)chunk->resample_buf +
+            (sample_size * index * chunk->rwav->numchannels) + (channel * sample_size);
+      else
+         sample = (uint8_t*)chunk->upsample_buf +
             (sample_size * index * chunk->rwav->numchannels) + (channel * sample_size);
 
-      if (sample_size == 1)
-      {
-         if (chunk->resample)
-            sample_out = chunk->resample_buf[index];
-         else
-         {
-            /* convert unsigned 8-bit to signed 16-bit */
-            sample_out = (*sample - 128) << 8;
-         }
-      }
-      else if (sample_size == 2)
-      {
-         if (chunk->resample)
-            return chunk->resample_buf[index];
-         else
-         {
-            /* signed 16-bit is native, pass it through */
-            sample_out = (uint16_t)*sample;
-         }
-      }
-      else
-      {
-         return 0;
-      }
+      sample_out = *sample;
 
       return sample_out;
    }

From 6a79a81e4d2c22b6cf08a47a695355b788285284 Mon Sep 17 00:00:00 2001
From: Brad Parker <cbparker@gmail.com>
Date: Thu, 26 Jan 2017 00:59:53 -0500
Subject: [PATCH 3/6] allocate enough memory for resampler, always put two
 channels into buffers

---
 libretro-common/audio/audio_mix.c         | 56 +++++++++++++++++++----
 libretro-common/include/audio/audio_mix.h |  2 +
 2 files changed, 48 insertions(+), 10 deletions(-)

diff --git a/libretro-common/audio/audio_mix.c b/libretro-common/audio/audio_mix.c
index f0b467b923..1abcb27a57 100644
--- a/libretro-common/audio/audio_mix.c
+++ b/libretro-common/audio/audio_mix.c
@@ -129,7 +129,7 @@ audio_chunk_t* audio_mix_load_wav_file(const char *path, int sample_rate)
       return NULL;
    }
 
-   chunk->upsample_buf = (int16_t*)memalign_alloc_aligned(chunk->rwav->numsamples * chunk->rwav->numchannels * sizeof(int16_t));
+   chunk->upsample_buf = (int16_t*)memalign_alloc_aligned(chunk->rwav->numsamples * 2 * sizeof(int16_t));
 
    sample_size = chunk->rwav->bitspersample / 8;
 
@@ -139,18 +139,34 @@ audio_chunk_t* audio_mix_load_wav_file(const char *path, int sample_rate)
 
      for (i = 0; i < chunk->rwav->numsamples; i++)
      {
-        unsigned channel;
         uint8_t *sample = ((uint8_t*)chunk->rwav->samples) +
-              (sample_size * i * chunk->rwav->numchannels);
+              (i * chunk->rwav->numchannels);
 
-        for (channel = 0; channel < chunk->rwav->numchannels; channel++)
-        {
-           chunk->upsample_buf[i] = (int16_t)((sample[channel] - 128) << 8);
-        }
+        chunk->upsample_buf[i * 2] = (int16_t)((sample[0] - 128) << 8);
+
+        if (chunk->rwav->numchannels == 1)
+           chunk->upsample_buf[(i * 2) + 1] = (int16_t)((sample[0] - 128) << 8);
+        else if (chunk->rwav->numchannels == 2)
+           chunk->upsample_buf[(i * 2) + 1] = (int16_t)((sample[1] - 128) << 8);
      }
    }
    else if (sample_size == 2)
-      memcpy(chunk->upsample_buf, chunk->rwav->samples, chunk->rwav->subchunk2size);
+   {
+      if (chunk->rwav->numchannels == 1)
+      {
+         unsigned i;
+
+         for (i = 0; i < chunk->rwav->numsamples; i++)
+         {
+            uint16_t *sample = ((uint16_t*)chunk->rwav->samples) + i;
+
+            chunk->upsample_buf[i * 2] = (int16_t)((sample[0] - 128) << 8);
+            chunk->upsample_buf[(i * 2) + 1] = (int16_t)((sample[0] - 128) << 8);
+         }
+      }
+      else if (chunk->rwav->numchannels == 2)
+         memcpy(chunk->upsample_buf, chunk->rwav->samples, chunk->rwav->subchunk2size);
+   }
    else if (sample_size != 2)
    {
       /* we don't support any other sample size besides 8 and 16-bit yet */
@@ -173,8 +189,8 @@ audio_chunk_t* audio_mix_load_wav_file(const char *path, int sample_rate)
       {
          struct resampler_data info = {0};
 
-         chunk->float_buf = (float*)memalign_alloc_aligned(chunk->rwav->numsamples * chunk->rwav->numchannels * sizeof(float));
-         chunk->float_resample_buf = (float*)memalign_alloc_aligned(chunk->rwav->numsamples * 2 * chunk->ratio * chunk->rwav->numchannels * sizeof(float));
+         chunk->float_buf = (float*)memalign_alloc_aligned(chunk->rwav->numsamples * 2 * chunk->ratio * chunk->rwav->numchannels * sizeof(float));
+         chunk->float_resample_buf = (float*)memalign_alloc_aligned(chunk->rwav->numsamples * 3 * chunk->ratio * chunk->rwav->numchannels * sizeof(float));
 
          convert_s16_to_float(chunk->float_buf, chunk->upsample_buf, chunk->rwav->numsamples * chunk->rwav->numchannels, 1.0);
 
@@ -255,6 +271,26 @@ int16_t audio_mix_get_chunk_sample(audio_chunk_t *chunk, unsigned channel, size_
    }
 }
 
+int16_t* audio_mix_get_chunk_samples(audio_chunk_t *chunk)
+{
+   if (!chunk)
+      return 0;
+
+   if (chunk->rwav)
+   {
+      int16_t *sample;
+
+      if (chunk->resample)
+         sample = chunk->resample_buf;
+      else
+         sample = chunk->upsample_buf;
+
+      return sample;
+   }
+
+   return NULL;
+}
+
 int audio_mix_get_chunk_num_channels(audio_chunk_t *chunk)
 {
    if (!chunk)
diff --git a/libretro-common/include/audio/audio_mix.h b/libretro-common/include/audio/audio_mix.h
index e31c5ed0ba..1b66065d70 100644
--- a/libretro-common/include/audio/audio_mix.h
+++ b/libretro-common/include/audio/audio_mix.h
@@ -80,6 +80,8 @@ size_t audio_mix_get_chunk_num_samples(audio_chunk_t *chunk);
  **/
 int16_t audio_mix_get_chunk_sample(audio_chunk_t *chunk, unsigned channel, size_t sample);
 
+int16_t* audio_mix_get_chunk_samples(audio_chunk_t *chunk);
+
 int audio_mix_get_chunk_num_channels(audio_chunk_t *chunk);
 
 RETRO_END_DECLS

From 9cf4562f26add5c9a65077eb870cd0e69705375b Mon Sep 17 00:00:00 2001
From: Brad Parker <cbparker@gmail.com>
Date: Thu, 26 Jan 2017 18:46:50 -0500
Subject: [PATCH 4/6] fix memory allocation

---
 libretro-common/audio/audio_mix.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/libretro-common/audio/audio_mix.c b/libretro-common/audio/audio_mix.c
index 1abcb27a57..ca6f955d94 100644
--- a/libretro-common/audio/audio_mix.c
+++ b/libretro-common/audio/audio_mix.c
@@ -129,7 +129,7 @@ audio_chunk_t* audio_mix_load_wav_file(const char *path, int sample_rate)
       return NULL;
    }
 
-   chunk->upsample_buf = (int16_t*)memalign_alloc_aligned(chunk->rwav->numsamples * 2 * sizeof(int16_t));
+   chunk->upsample_buf = (int16_t*)memalign_alloc(128, chunk->rwav->numsamples * 2 * sizeof(int16_t));
 
    sample_size = chunk->rwav->bitspersample / 8;
 
@@ -189,10 +189,10 @@ audio_chunk_t* audio_mix_load_wav_file(const char *path, int sample_rate)
       {
          struct resampler_data info = {0};
 
-         chunk->float_buf = (float*)memalign_alloc_aligned(chunk->rwav->numsamples * 2 * chunk->ratio * chunk->rwav->numchannels * sizeof(float));
-         chunk->float_resample_buf = (float*)memalign_alloc_aligned(chunk->rwav->numsamples * 3 * chunk->ratio * chunk->rwav->numchannels * sizeof(float));
+         chunk->float_buf = (float*)memalign_alloc(128, chunk->rwav->numsamples * 2 * chunk->ratio * sizeof(float));
+         chunk->float_resample_buf = (float*)memalign_alloc(128, chunk->rwav->numsamples * 3 * chunk->ratio * sizeof(float));
 
-         convert_s16_to_float(chunk->float_buf, chunk->upsample_buf, chunk->rwav->numsamples * chunk->rwav->numchannels, 1.0);
+         convert_s16_to_float(chunk->float_buf, chunk->upsample_buf, chunk->rwav->numsamples * 2, 1.0);
 
          info.data_in = (const float*)chunk->float_buf;
          info.data_out = chunk->float_resample_buf;
@@ -201,10 +201,10 @@ audio_chunk_t* audio_mix_load_wav_file(const char *path, int sample_rate)
 
          chunk->resampler->process(chunk->resampler_data, &info);
 
-         chunk->resample_buf = (int16_t*)memalign_alloc_aligned(info.output_frames * chunk->rwav->numchannels * sizeof(int16_t));
+         chunk->resample_buf = (int16_t*)memalign_alloc(128, info.output_frames * sizeof(int16_t));
          chunk->resample_len = info.output_frames;
 
-         convert_float_to_s16(chunk->resample_buf, chunk->float_resample_buf, info.output_frames * chunk->rwav->numchannels);
+         convert_float_to_s16(chunk->resample_buf, chunk->float_resample_buf, info.output_frames);
       }
    }
 

From d7aaab7a33de712e80198552367866d2d916e50c Mon Sep 17 00:00:00 2001
From: Brad Parker <cbparker@gmail.com>
Date: Thu, 26 Jan 2017 21:20:59 -0500
Subject: [PATCH 5/6] fixes

---
 libretro-common/audio/audio_mix.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/libretro-common/audio/audio_mix.c b/libretro-common/audio/audio_mix.c
index ca6f955d94..381884bda5 100644
--- a/libretro-common/audio/audio_mix.c
+++ b/libretro-common/audio/audio_mix.c
@@ -129,6 +129,7 @@ audio_chunk_t* audio_mix_load_wav_file(const char *path, int sample_rate)
       return NULL;
    }
 
+   /* numsamples does not know or care about multiple channels, but we need space for 2 */
    chunk->upsample_buf = (int16_t*)memalign_alloc(128, chunk->rwav->numsamples * 2 * sizeof(int16_t));
 
    sample_size = chunk->rwav->bitspersample / 8;
@@ -190,21 +191,24 @@ audio_chunk_t* audio_mix_load_wav_file(const char *path, int sample_rate)
          struct resampler_data info = {0};
 
          chunk->float_buf = (float*)memalign_alloc(128, chunk->rwav->numsamples * 2 * chunk->ratio * sizeof(float));
+
+         /* why is *3 needed instead of just *2? does the sinc driver require more space than we know about? */
          chunk->float_resample_buf = (float*)memalign_alloc(128, chunk->rwav->numsamples * 3 * chunk->ratio * sizeof(float));
 
          convert_s16_to_float(chunk->float_buf, chunk->upsample_buf, chunk->rwav->numsamples * 2, 1.0);
 
          info.data_in = (const float*)chunk->float_buf;
          info.data_out = chunk->float_resample_buf;
+         /* a 'frame' consists of two channels, so we set this to the number of samples irrespective of channel count */
          info.input_frames = chunk->rwav->numsamples;
          info.ratio = chunk->ratio;
 
          chunk->resampler->process(chunk->resampler_data, &info);
 
-         chunk->resample_buf = (int16_t*)memalign_alloc(128, info.output_frames * sizeof(int16_t));
+         /* number of output_frames does not increase with multiple channels, but assume we need space for 2 */
+         chunk->resample_buf = (int16_t*)memalign_alloc(128, info.output_frames * 2 * sizeof(int16_t));
          chunk->resample_len = info.output_frames;
-
-         convert_float_to_s16(chunk->resample_buf, chunk->float_resample_buf, info.output_frames);
+         convert_float_to_s16(chunk->resample_buf, chunk->float_resample_buf, info.output_frames * 2);
       }
    }
 
@@ -238,7 +242,7 @@ size_t audio_mix_get_chunk_num_samples(audio_chunk_t *chunk)
  *
  * Get a sample from an audio chunk.
  *
- * Returns: A signed 16-bit audio sample, (if necessary) resampled into the desired output rate.
+ * Returns: A signed 16-bit audio sample.
  **/
 int16_t audio_mix_get_chunk_sample(audio_chunk_t *chunk, unsigned channel, size_t index)
 {
@@ -260,7 +264,7 @@ int16_t audio_mix_get_chunk_sample(audio_chunk_t *chunk, unsigned channel, size_
          sample = (uint8_t*)chunk->upsample_buf +
             (sample_size * index * chunk->rwav->numchannels) + (channel * sample_size);
 
-      sample_out = *sample;
+      sample_out = (int16_t)*sample;
 
       return sample_out;
    }

From 9c9fc5b76579aed10922ca6b6810a2228e9ea380 Mon Sep 17 00:00:00 2001
From: Brad Parker <cbparker@gmail.com>
Date: Fri, 27 Jan 2017 11:12:45 -0500
Subject: [PATCH 6/6] 16-bit samples don't need conversion from 8-bit

---
 libretro-common/audio/audio_mix.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/libretro-common/audio/audio_mix.c b/libretro-common/audio/audio_mix.c
index 381884bda5..43ee51902c 100644
--- a/libretro-common/audio/audio_mix.c
+++ b/libretro-common/audio/audio_mix.c
@@ -159,10 +159,10 @@ audio_chunk_t* audio_mix_load_wav_file(const char *path, int sample_rate)
 
          for (i = 0; i < chunk->rwav->numsamples; i++)
          {
-            uint16_t *sample = ((uint16_t*)chunk->rwav->samples) + i;
+            int16_t sample = ((int16_t*)chunk->rwav->samples)[i];
 
-            chunk->upsample_buf[i * 2] = (int16_t)((sample[0] - 128) << 8);
-            chunk->upsample_buf[(i * 2) + 1] = (int16_t)((sample[0] - 128) << 8);
+            chunk->upsample_buf[i * 2] = sample;
+            chunk->upsample_buf[(i * 2) + 1] = sample;
          }
       }
       else if (chunk->rwav->numchannels == 2)