Patch by Case: Fixes for resampling to lower sample rates

When downsampling, more input samples are needed than output samples are generated. Thus allocate and use a bigger input sample buffer.
maikmerten · May 19, 2024 · d581e89 · d581e89
1 parent b2a13dd
commit d581e89
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Showing 3 changed files with 21 additions and 16 deletions.
diff --git a/hmp3/src/pub/srcc.h b/hmp3/src/pub/srcc.h
@@ -1,5 +1,5 @@
 /* ***** BEGIN LICENSE BLOCK *****  
- * Source last modified: 2024-03-16, Case
+ * Source last modified: 2024-05-19, Case
  *   
  * Portions Copyright (c) 1995-2005 RealNetworks, Inc. All Rights Reserved.  
  *       
@@ -86,11 +86,8 @@ class Csrc
 {
 
   public:
-    Csrc (  );
-
-    ~Csrc (  )
-    {
-    }
+    Csrc();
+    ~Csrc();
 
     int sr_convert_init ( int source, int channels, int bits, int is_float,
                           int target, int target_channels,
@@ -103,8 +100,8 @@ class Csrc
 
     unsigned int src_bytes_out;
     int src_filter;
-    int m_channels, m_bits, m_is_float;
-    float itof_buf[1152 * 2];
+    int m_channels, m_bits, m_is_float, m_frames_to_convert;
+    float *itof_buf;
 
 //-functions------------------------------------------------
     int gen_src_filter ( int source0, int target );

diff --git a/hmp3/src/srcc.cpp b/hmp3/src/srcc.cpp
@@ -1,5 +1,5 @@
 /* ***** BEGIN LICENSE BLOCK *****  
- * Source last modified: 2024-03-16, Case
+ * Source last modified: 2024-05-19, Case
  *   
  * Portions Copyright (c) 1995-2005 RealNetworks, Inc. All Rights Reserved.  
  *       
@@ -63,10 +63,15 @@
 
 /*==================================================================*/
 Csrc::Csrc (  ):
-src_bytes_out ( 0 ), src_filter ( 0 )
+src_bytes_out ( 0 ), src_filter ( 0 ), itof_buf ( NULL )
 {
 }
 
+Csrc::~Csrc()
+{
+    delete[] itof_buf;
+}
+
 /*==================================================================*/
 
 static int common_factor ( int s, int t );
@@ -781,6 +786,9 @@ Csrc::sr_convert_init ( int source, int channels, int bits, int is_float,
     m_channels = channels;
     m_bits = bits;
     m_is_float = is_float;
+    m_frames_to_convert = 1152;
+    if (source > target) m_frames_to_convert *= ((source / target) + 1);
+    itof_buf = new float[m_frames_to_convert * 2];
 
     return min_inbuf_bytes;
 }
@@ -799,26 +807,26 @@ Csrc::sr_convert ( unsigned char xin[], float yout[] )
         if (m_bits == 32) {
             if (m_is_float) {
                 float *src = (float *)xin;
-                for ( int i = 0; i < 1152 * m_channels; ++i ) {
+                for ( int i = 0; i < m_frames_to_convert * m_channels; ++i ) {
                     *dst++ = (float)(*src++) * 32768.0f;
                 }
             } else {
                 int *src = (int *)xin;
 
-                for ( int i = 0; i < 1152 * m_channels; ++i ) {
+                for ( int i = 0; i < m_frames_to_convert * m_channels; ++i ) {
                     *dst++ = (float)( (*src++) / 65536.0f );
                 }
             }
         } else if (m_bits == 24) {
             unsigned char *src = (unsigned char *)xin;
-            for (int i = 0; i < 1152 * m_channels; ++i) {
+            for (int i = 0; i < m_frames_to_convert * m_channels; ++i) {
                 int s = ( ( src[2] << 24 ) | ( src[1] << 16 ) | ( src[0] << 8 ) ) >> 8;
                 *dst++ = (float)( (float)s / 256.0f );
                 src += 3;
             }
         } else if (m_bits == 16) {
             short *src = (short *)xin;
-            for ( int i = 0; i < 1152 * m_channels; ++i ) {
+            for ( int i = 0; i < m_frames_to_convert * m_channels; ++i ) {
                 *dst++ = (float)*src++;
             }
         }

diff --git a/hmp3/src/test/tomp3.cpp b/hmp3/src/test/tomp3.cpp
@@ -1,5 +1,5 @@
 /* ***** BEGIN LICENSE BLOCK *****  
- * Source last modified: 2024-05-13, Maik Merten
+ * Source last modified: 2024-05-19, Case
  *   
  * Portions Copyright (c) 1995-2005 RealNetworks, Inc. All Rights Reserved.  
  *       
@@ -1019,7 +1019,7 @@ ff_encode ( const fn_char *filename, const fn_char *fileout, E_CONTROL *ec0 )
 	// write zero samples into the pcm buffer
 	memset(pcm_buffer,0,bytes_in_init*4);
 
-	if(fi.rate < 32000) // adjust for MPEG2
+	if(ec.samprate < 32000) // adjust for MPEG2
 		frames_expected *= 2;
 
 	while(Encode.L3_audio_encode_get_frames() < frames_expected) {