From 2eb6dec8e9f0114bdbad59cf8f11f197f8fdaaf3 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Wed, 25 Apr 2007 10:27:13 +0000
Subject: initial commit

git-svn-id: file:///home/lennart/svn/public/libsydney/trunk@3 9ba3c220-e4d3-45a2-8aa3-73fcc9aff6ce
---
 resample.c | 164 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 164 insertions(+)
 create mode 100644 resample.c

(limited to 'resample.c')

diff --git a/resample.c b/resample.c
new file mode 100644
index 0000000..f69e6d6
--- /dev/null
+++ b/resample.c
@@ -0,0 +1,164 @@
+#include "sydney.h"
+
+#define MAX_OPERATIONS 10
+
+typedef struct buffer_spec buffer_spec_t;
+
+struct buffer_spec {
+    void *data;
+    size_t size;
+    size_t max_size;
+};
+
+typedef struct operation operation_t;
+
+typedef void (*operation_execute_t)(operation_t *o, buffer_spec_t *source);
+
+struct operation {
+    operation_execute_t execute;
+
+    struct buffer_spec result;
+
+    size_t sample
+    unsigned nchannels;
+};
+
+typedef struct pipeline pipeline_t;
+
+struct pipeline {
+    operation_t operations[MAX_OPERATIONS];
+};
+
+static int native_pcm_format(pcm_format_t f) {
+
+    /* Sample formats we know to handle natively */
+    
+    return
+        f == SA_PCM_FORMAT_S16_NE ||
+        f == SA_PCM_FORMAT_S32_NE ||
+        f == SA_PCM_FORMAT_FLOAT32_NE;
+    
+}
+
+/* Steps: prefmt -> volume -> remap -> resample -> postfmt */
+
+int build_pipeline_output(
+        sa_device_t *dev,
+        sa_pipeline_t *pipeline,
+        sa_pcm_format format,
+        unsigned rate,
+        unsigned nchannels,
+        const sa_channel_t map[]) {
+
+    int *channel_map_table;
+    unsigned u, t;
+    int prefmt_required;
+    int sum_required = 0;
+    int o = 0;
+    pcm_format_t work_format;
+    operation_execute_t func;
+    
+    sa_assert(dev);
+    sa_assert(pipeline);
+
+    if (!(channel_map_table = sa_new(int, nchannels * dev->nchannels)))
+        return SA_ERROR_OOM;
+
+    for (u = 0; u < nchannels; u++) {
+        unsigned k = 0;
+        
+        for (t = 0; t < dev->nchannels; t++) {
+
+            if (map[u] == map[t])
+                channel_map_table[u * dev->nchannels + k++] += t;
+        }
+
+        if (k > 1)
+            sum_required = 1;
+        
+        channel_map_table[k] = (unsigned) -1;
+    }
+    
+    prefmt_required =
+        sum_required ||
+        dev->output_volume != 0 ||
+        dev->rate != rate ||
+        dev->dsr_enabled;
+
+    if (native_pcm_format(dev->pcm_format))
+        prefmt_required = 0;
+
+    if (prefmt_required) {
+        
+        switch (dev->pcm_format) {
+            case SA_PCM_FORMAT_U8:
+            case SA_PCM_FORMAT_ULAW:
+            case SA_PCM_FORMAT_ALAW:
+            case SA_PCM_FORMAT_S16_LE:
+            case SA_PCM_FORMAT_S16_BE:
+                work_format = SA_PCM_FORMAT_S16_NE;
+                break;
+
+            case SA_PCM_FORMAT_S24_LE:
+            case SA_PCM_FORMAT_S24_BE:
+            case SA_PCM_FORMAT_S32_LE:
+            case SA_PCM_FORMAT_S32_BE:
+                work_format = SA_PCM_FORMAT_S32_NE;
+                break;
+
+            case SA_PCM_FORMAT_FLOAT32_LE:
+            case SA_PCM_FORMAT_FLOAT32_BE:
+                work_format = SA_PCM_FORMAT_FLOAT32_NE;
+                break;
+        }
+        
+        sa_assert(native_pcm_format(work_format));
+
+        func = get_format_converter(dev->pcm_format, work_format);
+        pipeline.operations[o].execute = func;
+        pipeline.operations[o].buffer.data = NULL;
+        pipeline.operations[o].buffer.stride = dev->nchannels * get_sample_size(dev->work_format);
+        pipeline.operations[o].
+        o++;
+        
+    } else
+        work_format = dev->pcm_format;
+
+    if (dev->output_volume != 0) {
+        pipeline.operations[o].execute = get_scaler(work_format);
+        pipeline.operations[o].buffer.data = NULL;
+        o++;
+    }
+
+    if (dev->rate != rate || dev->dsr_enabled) {
+        pipeline.operations[o].execute = get_resampler(work_format);
+        pipeline.operations[o].buffer.data = NULL;
+        o++;
+    }
+    
+    if (work_format != pcm_format) {
+        pipeline.operations[o].execute = get_format_converter(work_format, pcm_format);
+        pipeline.operations[o].buffer.data = NULL;
+        o++;
+    }
+
+    pipeline.operations[o].execute = NULL;
+
+    
+    
+}
+
+void execute_pipeline(sa_device_t *dev, pipeline_t *pipeline, const buffer_spec_t *buffer, buffer_spec_t *output) {
+    sa_operation_t *o;
+    
+    sa_assert(dev);
+    sa_assert(pipeline);
+    sa_assert(buffer);
+
+    for (o = pipeline->operations; o->execute; o++) {
+        o->execute(o, buffer);
+        buffer = &o->buffer;
+    }
+
+    *output = *buffer;
+}
-- 
cgit