Allow to specify pre-allocated buffer in audicore.WaveFile

It lets us re-use the same buffer for playing multiple files.
This also allows us to control the size of the buffer. Half of the
buffer will be used for the fist, and half for the second internal
buffer.

1 files changed, 22 insertions, 11 deletions

diff --git a/shared-module/audiocore/WaveFile.c b/shared-module/audiocore/WaveFile.c
index 810d9c33b..df5d4b61d 100644
--- a/shared-module/audiocore/WaveFile.c
+++ b/shared-module/audiocore/WaveFile.c
@@ -46,7 +46,9 @@ struct wave_format_chunk {
 };
 
 void common_hal_audioio_wavefile_construct(audioio_wavefile_obj_t* self,
-                                           pyb_file_obj_t* file) {
+                                           pyb_file_obj_t* file,
+                                           uint8_t *buffer,
+                                           size_t buffer_size) {
     // Load the wave
     self->file = file;
     uint8_t chunk_header[16];
@@ -84,7 +86,6 @@ void common_hal_audioio_wavefile_construct(audioio_wavefile_obj_t* self,
     }
     // Get the sample_rate
     self->sample_rate = format.sample_rate;
-    self->len = 256;
     self->channel_count = format.num_channels;
     self->bits_per_sample = format.bits_per_sample;
 
@@ -111,21 +112,31 @@ void common_hal_audioio_wavefile_construct(audioio_wavefile_obj_t* self,
 
     // Try to allocate two buffers, one will be loaded from file and the other
     // DMAed to DAC.
-    self->buffer = m_malloc(self->len, false);
-    if (self->buffer == NULL) {
-        common_hal_audioio_wavefile_deinit(self);
-        mp_raise_msg(&mp_type_MemoryError, translate("Couldn't allocate first buffer"));
-    }
+    if (buffer_size) {
+        self->len = buffer_size / 2;
+        self->buffer = buffer;
+        self->second_buffer = buffer + self->len;
+    } else {
+        self->len = 256;
+        self->buffer = m_malloc(self->len, false);
+        if (self->buffer == NULL) {
+            common_hal_audioio_wavefile_deinit(self);
+            mp_raise_msg(&mp_type_MemoryError,
+                         translate("Couldn't allocate first buffer"));
+        }
 
-    self->second_buffer = m_malloc(self->len, false);
-    if (self->second_buffer == NULL) {
-        common_hal_audioio_wavefile_deinit(self);
-        mp_raise_msg(&mp_type_MemoryError, translate("Couldn't allocate second buffer"));
+        self->second_buffer = m_malloc(self->len, false);
+        if (self->second_buffer == NULL) {
+            common_hal_audioio_wavefile_deinit(self);
+            mp_raise_msg(&mp_type_MemoryError,
+                         translate("Couldn't allocate second buffer"));
+        }
     }
 }
 
 void common_hal_audioio_wavefile_deinit(audioio_wavefile_obj_t* self) {
     self->buffer = NULL;
+    self->second_buffer = NULL;
 }
 
 bool common_hal_audioio_wavefile_deinited(audioio_wavefile_obj_t* self) {