Fix REF-IMA ADPCM decoding/num_samples, as it's based on MS-IMA

src/coding/ima_decoder.c

@@ -331,6 +331,62 @@ void decode_ms_ima(VGMSTREAM * vgmstream,VGMSTREAMCHANNEL * stream, sample * out
     //stream->adpcm_step_index = step_index;
 }
 
+/* Reflection's MS-IMA (some layout info from XA2WAV by Deniz Oezmen) */
+void decode_ref_ima(VGMSTREAM * vgmstream, VGMSTREAMCHANNEL * stream, sample * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do, int channel) {
+    int i, samples_read = 0, samples_done = 0, max_samples;
+
+    int32_t hist1;// = stream->adpcm_history1_32;
+    int step_index;// = stream->adpcm_step_index;
+
+    /* internal interleave (configurable size), mixed channels (4 byte per ch) */
+    int block_channel_size = (vgmstream->interleave_block_size - 0x04*vgmstream->channels) / vgmstream->channels;
+    int block_samples = ((vgmstream->interleave_block_size - 0x04*vgmstream->channels) * 2 / vgmstream->channels) + 1;
+    first_sample = first_sample % block_samples;
+
+    /* normal header (hist+step+reserved per channel) */
+    {
+        off_t header_offset = stream->offset + 0x04*channel;
+
+        hist1 =   read_16bitLE(header_offset+0x00,stream->streamfile);
+        step_index = read_8bit(header_offset+0x02,stream->streamfile); /* 0x03: reserved */
+        if (step_index < 0) step_index = 0;
+        if (step_index > 88) step_index = 88;
+
+        /* write header sample */
+        if (samples_read >= first_sample && samples_done < samples_to_do) {
+            outbuf[samples_done * channelspacing] = (short)hist1;
+            samples_done++;
+        }
+        samples_read++;
+    }
+
+    max_samples = (block_samples - samples_read);
+    if (max_samples > samples_to_do + first_sample - samples_done)
+        max_samples = samples_to_do + first_sample - samples_done; /* for smaller last block */
+
+    /* decode nibbles (layout: all nibbles from one channel, then other channels) */
+    for (i = 0; i < max_samples; i++) {
+        off_t byte_offset = stream->offset + 0x04*vgmstream->channels + block_channel_size*channel + i/2;
+        int nibble_shift = (i&1?4:0); /* low nibble first */
+
+        std_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
+
+        if (samples_read >= first_sample && samples_done < samples_to_do) {
+            outbuf[samples_done * channelspacing] = (short)(hist1);
+            samples_done++;
+        }
+        samples_read++;
+    }
+
+    /* internal interleave: increment offset on complete frame */
+    if (first_sample + samples_done == block_samples)  {
+        stream->offset += vgmstream->interleave_block_size;
+    }
+
+    //stream->adpcm_history1_32 = hist1;
+    //stream->adpcm_step_index = step_index;
+}
+
 /* ************************************ */
 /* XBOX-IMA                             */
 /* ************************************ */
@@ -387,7 +443,7 @@ void decode_xbox_ima(VGMSTREAM * vgmstream,VGMSTREAMCHANNEL * stream, sample * o
     stream->adpcm_step_index = step_index;
 }
 
-/* mono XBOX ADPCM for interleave */
+/* mono XBOX-IMA ADPCM for interleave */
 void decode_xbox_ima_int(VGMSTREAMCHANNEL * stream, sample * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do, int channel) {
     int i, sample_count = 0, num_frame;
     int32_t hist1 = stream->adpcm_history1_32;
@@ -674,44 +730,6 @@ void decode_wwise_ima(VGMSTREAM * vgmstream,VGMSTREAMCHANNEL * stream, sample *
     stream->adpcm_step_index = step_index;
 }
 
-/* Reflection's MS-IMA (some layout info from XA2WAV) */
-void decode_ref_ima(VGMSTREAM * vgmstream,VGMSTREAMCHANNEL * stream, sample * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do,int channel) {
-    int i, sample_count;
-
-    int32_t hist1 = stream->adpcm_history1_32;
-    int step_index = stream->adpcm_step_index;
-
-    //internal interleave (configurable size), mixed channels (4 byte per ch)
-    int block_channel_size = (vgmstream->interleave_block_size - 4*vgmstream->channels) / vgmstream->channels;
-    int block_samples = (vgmstream->interleave_block_size - 4*vgmstream->channels) * 2 / vgmstream->channels;
-    first_sample = first_sample % block_samples;
-
-    //normal header (per channel)
-    if (first_sample == 0) {
-        off_t header_offset = stream->offset + 4*channel;
-
-        hist1 = read_16bitLE(header_offset,stream->streamfile);
-        step_index = read_8bit(header_offset+2,stream->streamfile);
-        if (step_index < 0) step_index=0;
-        if (step_index > 88) step_index=88;
-    }
-
-    //layout: all nibbles from one channel, then all nibbles from other
-    for (i=first_sample,sample_count=0; i<first_sample+samples_to_do; i++,sample_count+=channelspacing) {
-        off_t byte_offset = stream->offset + 4*vgmstream->channels + block_channel_size*channel + i/2;
-        int nibble_shift = (i&1?4:0); //low nibble first
-
-        std_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
-        outbuf[sample_count] = (short)(hist1);
-    }
-
-    //internal interleave: increment offset on complete frame
-    if (i == block_samples) stream->offset += vgmstream->interleave_block_size;
-
-    stream->adpcm_history1_32 = hist1;
-    stream->adpcm_step_index = step_index;
-}
-
 void decode_awc_ima(VGMSTREAMCHANNEL * stream, sample * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do) {
     int i, sample_count;
 

src/vgmstream.c

@@ -1076,16 +1076,16 @@ int get_vgmstream_samples_per_frame(VGMSTREAM * vgmstream) {
         case coding_APPLE_IMA4:
             return 64;
         case coding_MS_IMA:
-            return ((vgmstream->interleave_block_size-4*vgmstream->channels) * 2 / vgmstream->channels) + 1;
+        case coding_REF_IMA:
+            return ((vgmstream->interleave_block_size - 0x04*vgmstream->channels) * 2 / vgmstream->channels) + 1;
         case coding_RAD_IMA:
         case coding_WWISE_IMA:
-        case coding_REF_IMA:
+            return (vgmstream->interleave_block_size - 0x04*vgmstream->channels) * 2 / vgmstream->channels;
-            return (vgmstream->interleave_block_size-4*vgmstream->channels)*2/vgmstream->channels;
         case coding_NDS_IMA:
         case coding_DAT4_IMA:
-            return (vgmstream->interleave_block_size-4)*2;
+            return (vgmstream->interleave_block_size - 0x04) * 2;
         case coding_AWC_IMA:
-            return (0x800-4)*2;
+            return (0x800 - 0x04) * 2;
         case coding_RAD_IMA_mono:
             return 32;