Sound recording directly from DeSmuME (w/o any UI, it just does it)

desmume-wav.patch

--- desmume-0.9.10/src/sndsdl.cpp.orig	2013-11-28 01:37:18.797021001 +0100
+++ desmume-0.9.10/src/sndsdl.cpp	2015-03-14 22:24:04.184578448 +0100
@@ -16,6 +16,7 @@
 	along with the this software.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -57,6 +58,8 @@
 static u32 soundlen;
 static u32 soundbufsize;
 static SDL_AudioSpec audiofmt;
+static FILE *aofile;
+static u32 aofile_size;
 
 //////////////////////////////////////////////////////////////////////////////
 #ifdef _XBOX
@@ -137,6 +140,43 @@
 	CreateThread(0,0,SNDXBOXThread,0,0,0);
 #endif
 
+	aofile = fopen("desmume.wav", "wb");
+	if(!aofile)
+		return -1;
+	struct {
+		char magic_riff[4];
+		u32 filesize;
+		char magic_wave[4];
+		char fmt[4];
+		u32 fmt_len;
+		u16 datafmt;
+		u16 channels;
+		u32 samplerate;
+		u32 bytespersec;
+		u16 blockalign;
+		u16 bitspersample;
+		char data[4];
+		u32 data_len;
+	} wavhdr;
+#define ASSIGN_CHAR4(var, val) *((u32*) (var)) = *((u32*) (val));
+	ASSIGN_CHAR4(wavhdr.magic_riff, "RIFF");
+	wavhdr.filesize = 0xFFFFFFFF; // set in SNDSDLDeInit()
+	ASSIGN_CHAR4(wavhdr.magic_wave, "WAVE");
+	ASSIGN_CHAR4(wavhdr.fmt, "fmt ");
+	wavhdr.fmt_len = 16;
+	wavhdr.datafmt = 0x0001; // PCM
+	wavhdr.channels = 2;
+	wavhdr.samplerate = 44100;
+	wavhdr.bytespersec = 44100 * 4; // sample rate * blockalign
+	wavhdr.blockalign = 4; // channels * (int) ((bitspersample + 7) / 8)
+	wavhdr.bitspersample = 16;
+	ASSIGN_CHAR4(wavhdr.data, "data");
+	wavhdr.data_len = 0xFFFFFFFF; // set in SNDSDLDeInit()
+#undef ASSIGN_CHAR4
+	if(fwrite(&wavhdr, sizeof(wavhdr), 1, aofile) < 1)
+		return -1;
+	aofile_size = sizeof(wavhdr);
+
    return 0;
 }
 
@@ -154,6 +194,17 @@
 
    if (stereodata16)
       free(stereodata16);
+
+	fflush(aofile);
+	u32 tmp;
+	// Write correct file sizes
+	fseek(aofile, 0x04L, SEEK_SET);
+	tmp = aofile_size - 8;
+	fwrite(&tmp, 4, 1, aofile);
+	fseek(aofile, 0x28L, SEEK_SET);
+	tmp = aofile_size - 44;
+	fwrite(&tmp, 4, 1, aofile);
+	fclose(aofile);
 }
 
 //////////////////////////////////////////////////////////////////////////////
@@ -184,6 +235,9 @@
    soundoffset += copy1size + copy2size;
    soundoffset %= soundbufsize;
 
+	fwrite(buffer, num_samples * sizeof(s16) * 2, 1, aofile);
+	aofile_size += num_samples * sizeof(s16) * 2;
+
    SDL_UnlockAudio();
 }