a2play/rtc and sbc/decode

Bluez-devel Brad Midgley 1 participant 1 message Sep 7, 2005 Bluetooth drivers

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Brad Midgley

author

2005-09-07 04:19 UTC #0 lore raw

Hey

I found out how to use the rtc value that read() provides... no docs
anywhere covered it so I had to dig into the source. Now we at least use
this properly in a2play but the timing was always wrong... using the frame timing info from libsbc may not be the right way to go about it.

I also was simplifying and preparing to unroll the decoder. Unfortunately, the decoder state array is getting walked on, apparently outside the decoder function (whether it's in libsbc or sbcdec isn't clear)

The patch attached tries to run both the 8 subband decoder that does massive copies along with the no-copy version but the no-copy version quickly goes out of sync.

Brad

? .deps
? Makefile
? Makefile.in
? a2play
? a2recv
? aclocal.m4
? autom4te.cache
? btsco
? btsco2
? charm.sbc
? config.h
? config.h.in
? config.log
? config.status
? configure
? go
? install-sh
? missing
? mkinstalldirs
? soon.sbc
? stamp-h1
? avdtp/Makefile
? avdtp/Makefile.in
? avdtp/avtest
? bt/.deps
? bt/.libs
? bt/libasound_module_pcm_a2dp.la
? bt/out
? bt/pcm_a2dp.lo
? kernel/.btsco.o.cmd
? kernel/.snd-bt-sco.ko.cmd
? kernel/.snd-bt-sco.mod.o.cmd
? kernel/.snd-bt-sco.o.cmd
? kernel/.tmp_versions
? kernel/snd-bt-sco.ko
? kernel/snd-bt-sco.mod.c
? sbc/Makefile
? sbc/Makefile.in
? sbc/a.out
? sbc/gen_fixed
? sbc/rcplay
? sbc/sbcdec
? sbc/sbcenc
? sbc/sbcinfo
? sbc/t1.au
? sbc/t1.sbc
? sbc/unroll.c
Index: sbc/sbc.c
===================================================================
RCS file: /cvsroot/bluetooth-alsa/btsco/sbc/sbc.c,v retrieving revision 1.59

sbc.c +67 -3

diff -u -b -B -w -p -r1.59 sbc.c
@@ -97,6 +97,9 @@ struct sbc_decoder_state {
 	int subbands;
 	float X[2][8];				/* Audio samples */
 	float V[2][160];	/* Vectors */
+	float X2[2][8];
+	float V2[2][160];
+	int offset;
 };
 
 struct sbc_encoder_state {

@@ -567,6 +570,9 @@ static void sbc_decoder_init(struct sbc_
 	memset(&state->X, 0, sizeof(state->X));
 	memset(&state->V, 0, sizeof(state->V));
 	state->subbands = frame->subbands;
+	state->offset = 0;
+	memset(&state->X2, 0, sizeof(state->X2));
+	memset(&state->V2, 0, sizeof(state->V2));
 }
 
 static inline void sbc_synthesize_four(struct sbc_decoder_state *state,

@@ -612,18 +618,50 @@ static inline void sbc_synthesize_eight(
 				struct sbc_frame *frame, int ch, int blk)
 {
 	int i, j, k, idx;
+	float delta;
+
+	// now compare
+	for(k = 0; k < 160; k++) 
+		if(state->V[ch][k] != state->V2[ch][(k + state->offset)%160]) {
+			printf("v[] mismatch ON RETURN!! v(%2.2f) v2(%2.2f) %d (v2 %d with offset=%d)\n[", state->V[ch][k], state->V2[ch][(k + state->offset)%160], k, (k + state->offset)%160, state->offset);
+			for(i = 0; i < 160; i++) printf("%2.2f%c", state->V[ch][i], i%16==15?'\n':',');
+			printf("]\n[");
+			for(i = 0; i < 160; i++) printf("%2.2f%c", state->V2[ch][(i + state->offset)%160], i%16==15?'\n':',');
+			printf("]\n");
+			exit(0);
+		}
 
 	/* Shifting */
 	for (i = 159; i >= 16; i--) {
 		state->V[ch][i] = state->V[ch][i - 16];
 	}
 
+	/* Shifting (virtual) */
+
+	state->offset = (state->offset + 144) % 160;
+
 	/* Matrixing */
 	for (k = 0; k < 16; k++) {
 		state->V[ch][k] = 0;
+		state->V2[ch][k + state->offset] = 0;
 		for (i = 0; i < 8; i++) {
-			state->V[ch][k] += synmatrix8[k][i] * frame->sb_sample[blk][ch][i];
-		}
+			delta = synmatrix8[k][i] * frame->sb_sample[blk][ch][i];
+			state->V[ch][k] += delta;
+			state->V2[ch][k + state->offset] += delta;
+		}
+		if(k==0) printf("v1[%d] = %2.2f\nv2[%d] = %2.2f\n", k, state->V[ch][k], 
+				k+state->offset, state->V2[ch][k + state->offset]);
+	}
+
+	// now compare
+	for(k = 0; k < 160; k++) 
+		if(state->V[ch][k] != state->V2[ch][(k + state->offset)%160]) {
+			printf("v[] mismatch after matrixing  v(%2.2f) v2(%2.2f) %d (v2 %d with offset=%d)\n[", state->V[ch][k], state->V2[ch][(k + state->offset)%160], k, (k + state->offset)%160, state->offset);
+			for(i = 0; i < 160; i++) printf("%2.2f%c", state->V[ch][i], i%16==15?'\n':',');
+			printf("]\n[");
+			for(i = 0; i < 160; i++) printf("%2.2f%c", state->V2[ch][(i + state->offset)%160], i%16==15?'\n':',');
+			printf("]\n");
+			exit(0);
 	}
 
 	/* Calculate 8 audio samples */

@@ -632,6 +670,10 @@ static inline void sbc_synthesize_eight(
 		state->X[ch][j] = 0;
 	}
 
+	for (j = 0; j < 8; j++) {
+		state->X2[ch][j] = 0;
+	}
+
 	for (i = 0; i <= 4; i++) {
 		idx = i*16;
 		for (j = 0; j < 8; j++, idx++) {

@@ -641,10 +683,30 @@ static inline void sbc_synthesize_eight(
 		}
 	}
 
+	for (i = 0; i <= 4; i++) {
+		idx = i*16;
+		for (j = 0; j < 8; j++, idx++) {
+			state->X2[ch][j] += 
+				state->V2[ch][(i * 32 + j + state->offset)%160] * sbc_proto_8_80m[idx] +
+				state->V2[ch][(i * 32 + j + 24 + state->offset)%160] * sbc_proto_8_80m[idx + 8];
+		}
+	}
+
 	/* Ouput 8 reconstructed Audio Samples */
 	for (i = 0; i < 8; i++) {
 		frame->pcm_sample[ch][blk * 8 + i] = (int16_t)state->X[ch][i];
 	}
+
+	// now compare
+	for(k = 0; k < 160; k++) 
+		if(state->V[ch][k] != state->V2[ch][(k + state->offset)%160]) {
+			printf("v[] mismatch  v(%2.2f) v2(%2.2f) %d (v2 %d with offset=%d)\n[", state->V[ch][k], state->V2[ch][(k + state->offset)%160], k, (k + state->offset)%160, state->offset);
+			for(i = 0; i < 160; i++) printf("%2.2f%c", state->V[ch][i], i%16==15?'\n':',');
+			printf("]\n[");
+			for(i = 0; i < 160; i++) printf("%2.2f%c", state->V2[ch][(i + state->offset)%160], i%16==15?'\n':',');
+			printf("]\n");
+			exit(0);
+		}
 }
 
 static int sbc_synthesize_audio(struct sbc_decoder_state *state, struct sbc_frame *frame)

@@ -665,9 +727,11 @@ static int sbc_synthesize_audio(struct s
 
 	case 8:
 		for (ch = 0; ch < frame->channels; ch++) {
+#if 0
+			// can't we skip this? everything will be reinitialized in decoder
 			memset(frame->pcm_sample[ch], 0,
 				sizeof(frame->pcm_sample[ch]));
-
+#endif
 			for (blk = 0; blk < frame->blocks; blk++)
 				sbc_synthesize_eight(state, frame, ch, blk);
 		}