Add support for partial processing to nodes.

This includes a leading trimming node to act as a test.
2026-04-22 00:06:59 +02:00 · 2021-12-10 16:13:16 +10:00
parent b8d04bdd87
commit ba3080d07d
4 changed files with 385 additions and 124 deletions
@@ -0,0 +1,102 @@
+
+#include "ma_ltrim_node.h"
+
+MA_API ma_ltrim_node_config ma_ltrim_node_config_init(ma_uint32 channels, float threshold)
+{
+    ma_ltrim_node_config config;
+
+    MA_ZERO_OBJECT(&config);
+    config.nodeConfig = ma_node_config_init();  /* Input and output channels will be set in ma_ltrim_node_init(). */
+    config.channels   = channels;
+    config.threshold  = threshold;
+
+    return config;
+}
+
+
+static void ma_ltrim_node_process_pcm_frames(ma_node* pNode, const float** ppFramesIn, ma_uint32* pFrameCountIn, float** ppFramesOut, ma_uint32* pFrameCountOut)
+{
+    ma_ltrim_node* pTrimNode = (ma_ltrim_node*)pNode;
+    ma_uint32 framesProcessedIn  = 0;
+    ma_uint32 framesProcessedOut = 0;
+    ma_uint32 channelCount       = ma_node_get_input_channels(pNode, 0);
+    
+    /*
+    If we haven't yet found the start, skip over every input sample until we find a frame outside
+    of the threshold.
+    */
+    if (pTrimNode->foundStart == MA_FALSE) {
+        while (framesProcessedIn < *pFrameCountIn) {
+            ma_uint32 iChannel = 0;
+            for (iChannel = 0; iChannel < channelCount; iChannel += 1) {
+                float sample = ppFramesIn[0][framesProcessedIn*channelCount + iChannel];
+                if (sample < -pTrimNode->threshold || sample > pTrimNode->threshold) {
+                    pTrimNode->foundStart = MA_TRUE;
+                    break;
+                }
+            }
+
+            if (pTrimNode->foundStart) {
+                break;  /* The start has been found. Get out of this loop and finish off processing. */
+            } else {
+                framesProcessedIn += 1;
+            }
+        }
+    }
+
+    /* If there's anything left, just copy it over. */
+    framesProcessedOut = ma_min(*pFrameCountOut, *pFrameCountIn - framesProcessedIn);
+    ma_copy_pcm_frames(ppFramesOut[0], &ppFramesIn[0][framesProcessedIn], framesProcessedOut, ma_format_f32, channelCount);
+
+    framesProcessedIn += framesProcessedOut;
+
+    /* We always "process" every input frame, but we may only done a partial output. */
+    *pFrameCountIn  = framesProcessedIn;
+    *pFrameCountOut = framesProcessedOut;
+}
+
+static ma_node_vtable g_ma_ltrim_node_vtable =
+{
+    ma_ltrim_node_process_pcm_frames,
+    NULL,
+    1,  /* 1 input channel. */
+    1,  /* 1 output channel. */
+    MA_NODE_FLAG_DIFFERENT_PROCESSING_RATES
+};
+
+MA_API ma_result ma_ltrim_node_init(ma_node_graph* pNodeGraph, const ma_ltrim_node_config* pConfig, const ma_allocation_callbacks* pAllocationCallbacks, ma_ltrim_node* pTrimNode)
+{
+    ma_result result;
+    ma_node_config baseConfig;
+
+    if (pTrimNode == NULL) {
+        return MA_INVALID_ARGS;
+    }
+
+    MA_ZERO_OBJECT(pTrimNode);
+
+    if (pConfig == NULL) {
+        return MA_INVALID_ARGS;
+    }
+
+    pTrimNode->threshold  = pConfig->threshold;
+    pTrimNode->foundStart = MA_FALSE;
+
+    baseConfig = pConfig->nodeConfig;
+    baseConfig.vtable          = &g_ma_ltrim_node_vtable;
+    baseConfig.pInputChannels  = &pConfig->channels;
+    baseConfig.pOutputChannels = &pConfig->channels;
+
+    result = ma_node_init(pNodeGraph, &baseConfig, pAllocationCallbacks, &pTrimNode->baseNode);
+    if (result != MA_SUCCESS) {
+        return result;
+    }
+
+    return MA_SUCCESS;
+}
+
+MA_API void ma_ltrim_node_uninit(ma_ltrim_node* pTrimNode, const ma_allocation_callbacks* pAllocationCallbacks)
+{
+    /* The base node is always uninitialized first. */
+    ma_node_uninit(pTrimNode, pAllocationCallbacks);
+}