-support for stereo ima-adpcm sample compression & playback

-support for converting samples to ima-adpcm upon export

3 files changed, 77 insertions, 58 deletions

diff --git a/servers/audio/audio_mixer_sw.cpp b/servers/audio/audio_mixer_sw.cpp
index 791f31719e..033cd333d5 100644
--- a/servers/audio/audio_mixer_sw.cpp
+++ b/servers/audio/audio_mixer_sw.cpp
@@ -45,14 +45,14 @@ void AudioMixerSW::do_resample(const Depth* p_src, int32_t *p_dst, ResamplerStat
 	while (p_state->amount--) {
 
 		int32_t pos=p_state->pos >> MIX_FRAC_BITS;
-		if (is_stereo)
+		if (is_stereo && !is_ima_adpcm)
 			pos<<=1;
 
 		if (is_ima_adpcm) {
 
-			int sample_pos = pos + p_state->ima_adpcm->window_ofs;
+			int sample_pos = pos + p_state->ima_adpcm[0].window_ofs;
 
-			while(sample_pos>p_state->ima_adpcm->last_nibble) {
+			while(sample_pos>p_state->ima_adpcm[0].last_nibble) {
 
 
 				static const int16_t _ima_adpcm_step_table[89] = {
@@ -72,52 +72,64 @@ void AudioMixerSW::do_resample(const Depth* p_src, int32_t *p_dst, ResamplerStat
 					-1, -1, -1, -1, 2, 4, 6, 8
 				};
 
-				int16_t nibble,signed_nibble,diff,step;
+				for(int i=0;i<(is_stereo?2:1);i++) {
 
-				p_state->ima_adpcm->last_nibble++;
-				const uint8_t *src_ptr=p_state->ima_adpcm->ptr;
 
-				nibble = (p_state->ima_adpcm->last_nibble&1)?
-						(src_ptr[p_state->ima_adpcm->last_nibble>>1]>>4):(src_ptr[p_state->ima_adpcm->last_nibble>>1]&0xF);
-				step=_ima_adpcm_step_table[p_state->ima_adpcm->step_index];
+					int16_t nibble,signed_nibble,diff,step;
 
-				p_state->ima_adpcm->step_index += _ima_adpcm_index_table[nibble];
-				if (p_state->ima_adpcm->step_index<0)
-					p_state->ima_adpcm->step_index=0;
-				if (p_state->ima_adpcm->step_index>88)
-					p_state->ima_adpcm->step_index=88;
+					p_state->ima_adpcm[i].last_nibble++;
+					const uint8_t *src_ptr=p_state->ima_adpcm[i].ptr;
 
-				/*
-				signed_nibble = (nibble&7) * ((nibble&8)?-1:1);
-				diff = (2 * signed_nibble + 1) * step / 4; */
 
-				diff = step >> 3 ;
-				if (nibble & 1)
-					diff += step >> 2 ;
-				if (nibble & 2)
-					diff += step >> 1 ;
-				if (nibble & 4)
-					diff += step ;
-				if (nibble & 8)
-					diff = -diff ;
+					uint8_t nbb = src_ptr[ (p_state->ima_adpcm[i].last_nibble>>1) *  (is_stereo?2:1) + i ];
+					nibble = (p_state->ima_adpcm[i].last_nibble&1)?(nbb>>4):(nbb&0xF);
+					step=_ima_adpcm_step_table[p_state->ima_adpcm[i].step_index];
 
-				p_state->ima_adpcm->predictor+=diff;
-				if (p_state->ima_adpcm->predictor<-0x8000)
-					p_state->ima_adpcm->predictor=-0x8000;
-				else if (p_state->ima_adpcm->predictor>0x7FFF)
-					p_state->ima_adpcm->predictor=0x7FFF;
 
+					p_state->ima_adpcm[i].step_index += _ima_adpcm_index_table[nibble];
+					if (p_state->ima_adpcm[i].step_index<0)
+						p_state->ima_adpcm[i].step_index=0;
+					if (p_state->ima_adpcm[i].step_index>88)
+						p_state->ima_adpcm[i].step_index=88;
 
-				/* store loop if there */
-				if (p_state->ima_adpcm->last_nibble==p_state->ima_adpcm->loop_pos) {
+					/*
+					signed_nibble = (nibble&7) * ((nibble&8)?-1:1);
+					diff = (2 * signed_nibble + 1) * step / 4; */
+
+					diff = step >> 3 ;
+					if (nibble & 1)
+						diff += step >> 2 ;
+					if (nibble & 2)
+						diff += step >> 1 ;
+					if (nibble & 4)
+						diff += step ;
+					if (nibble & 8)
+						diff = -diff ;
+
+					p_state->ima_adpcm[i].predictor+=diff;
+					if (p_state->ima_adpcm[i].predictor<-0x8000)
+						p_state->ima_adpcm[i].predictor=-0x8000;
+					else if (p_state->ima_adpcm[i].predictor>0x7FFF)
+						p_state->ima_adpcm[i].predictor=0x7FFF;
+
+
+					/* store loop if there */
+					if (p_state->ima_adpcm[i].last_nibble==p_state->ima_adpcm[i].loop_pos) {
+
+						p_state->ima_adpcm[i].loop_step_index = p_state->ima_adpcm[i].step_index;
+						p_state->ima_adpcm[i].loop_predictor = p_state->ima_adpcm[i].predictor;
+					}
+
+					//printf("%i - %i - pred %i\n",int(p_state->ima_adpcm[i].last_nibble),int(nibble),int(p_state->ima_adpcm[i].predictor));
 
-					p_state->ima_adpcm->loop_step_index = p_state->ima_adpcm->step_index;
-					p_state->ima_adpcm->loop_predictor = p_state->ima_adpcm->predictor;
 				}
 
 			}
 
-			final=p_state->ima_adpcm->predictor;
+			final=p_state->ima_adpcm[0].predictor;
+			if (is_stereo) {
+				final_r=p_state->ima_adpcm[1].predictor;
+			}
 
 		} else {
 			final=p_src[pos];
@@ -399,9 +411,10 @@ void AudioMixerSW::mix_channel(Channel& c) {
 
 	if (format==AS::SAMPLE_FORMAT_IMA_ADPCM) {
 
-		rstate.ima_adpcm=&c.mix.ima_adpcm;
+		rstate.ima_adpcm=c.mix.ima_adpcm;
 		if (loop_format!=AS::SAMPLE_LOOP_NONE) {
-			c.mix.ima_adpcm.loop_pos=loop_begin_fp>>MIX_FRAC_BITS;
+			c.mix.ima_adpcm[0].loop_pos=loop_begin_fp>>MIX_FRAC_BITS;
+			c.mix.ima_adpcm[1].loop_pos=loop_begin_fp>>MIX_FRAC_BITS;
 			loop_format=AS::SAMPLE_LOOP_FORWARD;
 		}
 	}
@@ -447,9 +460,11 @@ void AudioMixerSW::mix_channel(Channel& c) {
 					/* go to loop-begin */
 
 					if (format==AS::SAMPLE_FORMAT_IMA_ADPCM) {
-						c.mix.ima_adpcm.step_index=c.mix.ima_adpcm.loop_step_index;
-						c.mix.ima_adpcm.predictor=c.mix.ima_adpcm.loop_predictor;
-						c.mix.ima_adpcm.last_nibble=loop_begin_fp>>MIX_FRAC_BITS;
+						for(int i=0;i<2;i++) {
+							c.mix.ima_adpcm[i].step_index=c.mix.ima_adpcm[i].loop_step_index;
+							c.mix.ima_adpcm[i].predictor=c.mix.ima_adpcm[i].loop_predictor;
+							c.mix.ima_adpcm[i].last_nibble=loop_begin_fp>>MIX_FRAC_BITS;
+						}
 						c.mix.offset=loop_begin_fp;
 					} else {
 						c.mix.offset=loop_begin_fp+(c.mix.offset-loop_end_fp);
@@ -549,10 +564,12 @@ void AudioMixerSW::mix_channel(Channel& c) {
 			CALL_RESAMPLE_MODE(int16_t,is_stereo,false,use_filter,use_fx,interpolation_type,mix_channels);
 
 		} else if (format==AS::SAMPLE_FORMAT_IMA_ADPCM) {
-			c.mix.ima_adpcm.window_ofs=c.mix.offset>>MIX_FRAC_BITS;
-			c.mix.ima_adpcm.ptr=(const uint8_t*)data;
-			int8_t *src_ptr =  &((int8_t*)data)[(c.mix.offset >> MIX_FRAC_BITS)<<(is_stereo?1:0) ];
-			CALL_RESAMPLE_MODE(int8_t,false,true,use_filter,use_fx,interpolation_type,mix_channels);
+			for(int i=0;i<2;i++) {
+				c.mix.ima_adpcm[i].window_ofs=c.mix.offset>>MIX_FRAC_BITS;
+				c.mix.ima_adpcm[i].ptr=(const uint8_t*)data;
+			}
+			int8_t *src_ptr =  NULL;
+			CALL_RESAMPLE_MODE(int8_t,is_stereo,true,use_filter,use_fx,interpolation_type,mix_channels);
 
 		}
 
@@ -781,14 +798,16 @@ AudioMixer::ChannelID AudioMixerSW::channel_alloc(RID p_sample) {
 
 	if (sample_manager->sample_get_format(c.sample)==AudioServer::SAMPLE_FORMAT_IMA_ADPCM) {
 
-		c.mix.ima_adpcm.step_index=0;
-		c.mix.ima_adpcm.predictor=0;
-		c.mix.ima_adpcm.loop_step_index=0;
-		c.mix.ima_adpcm.loop_predictor=0;
-		c.mix.ima_adpcm.last_nibble=-1;
-		c.mix.ima_adpcm.loop_pos=0x7FFFFFFF;
-		c.mix.ima_adpcm.window_ofs=0;
-		c.mix.ima_adpcm.ptr=NULL;
+		for(int i=0;i<2;i++) {
+			c.mix.ima_adpcm[i].step_index=0;
+			c.mix.ima_adpcm[i].predictor=0;
+			c.mix.ima_adpcm[i].loop_step_index=0;
+			c.mix.ima_adpcm[i].loop_predictor=0;
+			c.mix.ima_adpcm[i].last_nibble=-1;
+			c.mix.ima_adpcm[i].loop_pos=0x7FFFFFFF;
+			c.mix.ima_adpcm[i].window_ofs=0;
+			c.mix.ima_adpcm[i].ptr=NULL;
+		}
 	}
 
 	ChannelID ret_id = index+c.check*MAX_CHANNELS;
diff --git a/servers/audio/audio_mixer_sw.h b/servers/audio/audio_mixer_sw.h
index cb38561c27..d8d9b7bacd 100644
--- a/servers/audio/audio_mixer_sw.h
+++ b/servers/audio/audio_mixer_sw.h
@@ -105,7 +105,7 @@ private:
 				int32_t loop_pos;
 				int32_t window_ofs;
 				const uint8_t *ptr;
-			} ima_adpcm;
+			} ima_adpcm[2];
 
 		} mix;
 
diff --git a/servers/audio/sample_manager_sw.cpp b/servers/audio/sample_manager_sw.cpp
index 9195136a5d..375aa88cd2 100644
--- a/servers/audio/sample_manager_sw.cpp
+++ b/servers/audio/sample_manager_sw.cpp
@@ -38,12 +38,8 @@ SampleManagerSW::~SampleManagerSW()
 
 RID SampleManagerMallocSW::sample_create(AS::SampleFormat p_format, bool p_stereo, int p_length) {
 
-	ERR_EXPLAIN("IMA-ADPCM and STEREO are not a valid combination for sample format.");
-	ERR_FAIL_COND_V( p_format == AS::SAMPLE_FORMAT_IMA_ADPCM && p_stereo,RID());
 	Sample *s = memnew( Sample );
 	int datalen = p_length;
-	if (p_stereo)
-		datalen*=2;
 	if (p_format==AS::SAMPLE_FORMAT_PCM16)
 		datalen*=2;
 	else if (p_format==AS::SAMPLE_FORMAT_IMA_ADPCM) {
@@ -53,6 +49,10 @@ RID SampleManagerMallocSW::sample_create(AS::SampleFormat p_format, bool p_stere
 		datalen/=2;
 		datalen+=4;
 	}
+
+	if (p_stereo)
+		datalen*=2;
+
 #define SAMPLE_EXTRA 16
 
 	s->data = memalloc(datalen+SAMPLE_EXTRA); //help the interpolator by allocating a little more..