Make sbc codec to write directly in application buffers and so avoiding memcpys.

4 files changed, 88 insertions, 67 deletions

diff --git a/sbc/sbc.c b/sbc/sbc.c
index c95862a0..ec1cc37d 100644
--- a/sbc/sbc.c
+++ b/sbc/sbc.c
@@ -95,6 +95,8 @@ struct sbc_frame {
 	} allocation_method;
 	uint8_t subbands;
 	uint8_t bitpool;
+	uint8_t codesize;
+	uint8_t length;
 
 	/* bit number x set means joint stereo has been used in subband x */
 	uint8_t join;
@@ -1230,23 +1232,24 @@ int sbc_init(sbc_t *sbc, unsigned long flags)
 	return 0;
 }
 
-int sbc_parse(sbc_t *sbc, void *data, int count)
+int sbc_parse(sbc_t *sbc, void *input, int input_len)
 {
-	return sbc_decode(sbc, data, count);
+	return sbc_decode(sbc, input, input_len, NULL, 0, NULL);
 }
 
-int sbc_decode(sbc_t *sbc, void *data, int count)
+int sbc_decode(sbc_t *sbc, void *input, int input_len, void *output,
+		int output_len, int *written)
 {
 	struct sbc_priv *priv;
 	char *ptr;
 	int i, ch, framelen, samples;
 
-	if (!sbc)
+	if (!sbc && !input)
 		return -EIO;
 
 	priv = sbc->priv;
 
-	framelen = sbc_unpack_frame(data, &priv->frame, count);
+	framelen = sbc_unpack_frame(input, &priv->frame, input_len);
 
 	if (!priv->init) {
 		sbc_decoder_init(&priv->dec_state, &priv->frame);
@@ -1257,26 +1260,23 @@ int sbc_decode(sbc_t *sbc, void *data, int count)
 		sbc->subbands = priv->frame.subbands;
 		sbc->blocks = priv->frame.blocks;
 		sbc->bitpool = priv->frame.bitpool;
+
+		priv->frame.codesize = sbc_get_codesize(sbc);
+		priv->frame.length = sbc_get_frame_length(sbc);
 	}
 
-	samples = sbc_synthesize_audio(&priv->dec_state, &priv->frame);
+	if (!output)
+		return framelen;
 
-	if (!sbc->data) {
-		sbc->size = samples * priv->frame.channels * 2;
-		sbc->data = malloc(sbc->size);
-	}
+	if (written)
+		*written = 0;
 
-	if (sbc->size < samples * priv->frame.channels * 2) {
-		sbc->size = samples * priv->frame.channels * 2;
-		sbc->data = realloc(sbc->data, sbc->size);
-	}
+	samples = sbc_synthesize_audio(&priv->dec_state, &priv->frame);
 
-	if (!sbc->data) {
-		sbc->size = 0;
-		return -ENOMEM;
-	}
+	ptr = output;
 
-	ptr = sbc->data;
+	if (output_len < samples * priv->frame.channels * 2)
+		samples = output_len / (priv->frame.channels * 2);
 
 	for (i = 0; i < samples; i++) {
 		for (ch = 0; ch < priv->frame.channels; ch++) {
@@ -1293,22 +1293,27 @@ int sbc_decode(sbc_t *sbc, void *data, int count)
 		}
 	}
 
-	sbc->len = samples * priv->frame.channels * 2;
+	if (written)
+		*written = samples * priv->frame.channels * 2;
 
 	return framelen;
 }
 
-int sbc_encode(sbc_t *sbc, void *data, int count)
+int sbc_encode(sbc_t *sbc, void *input, int input_len, void *output,
+		int output_len, int *written)
 {
 	struct sbc_priv *priv;
 	char *ptr;
 	int i, ch, framelen, samples;
 
-	if (!sbc)
+	if (!sbc && !input)
 		return -EIO;
 
 	priv = sbc->priv;
 
+	if (written)
+		*written = 0;
+
 	if (!priv->init) {
 		priv->frame.sampling_frequency = sbc->rate;
 		priv->frame.channels = sbc->channels;
@@ -1325,16 +1330,22 @@ int sbc_encode(sbc_t *sbc, void *data, int count)
 		priv->frame.subbands = sbc->subbands;
 		priv->frame.blocks = sbc->blocks;
 		priv->frame.bitpool = sbc->bitpool;
+		priv->frame.codesize = sbc_get_codesize(sbc);
+		priv->frame.length = sbc_get_frame_length(sbc);
 
 		sbc_encoder_init(&priv->enc_state, &priv->frame);
 		priv->init = 1;
 	}
 
 	/* input must be large enough to encode a complete frame */
-	if (count < priv->frame.subbands * priv->frame.blocks * sbc->channels * 2)
+	if (input_len < priv->frame.codesize)
 		return 0;
 
-	ptr = data;
+	/* output must be large enough to receive the encoded frame */
+	if (!output || output_len < priv->frame.length)
+		return -ENOSPC;
+
+	ptr = input;
 
 	for (i = 0; i < priv->frame.subbands * priv->frame.blocks; i++) {
 		for (ch = 0; ch < sbc->channels; ch++) {
@@ -1351,19 +1362,10 @@ int sbc_encode(sbc_t *sbc, void *data, int count)
 
 	samples = sbc_analyze_audio(&priv->enc_state, &priv->frame);
 
-	if (!sbc->data) {
-		sbc->size = 1024;
-		sbc->data = malloc(sbc->size);
-	}
-
-	if (!sbc->data) {
-		sbc->size = 0;
-		return -ENOMEM;
-	}
+	framelen = sbc_pack_frame(output, &priv->frame, output_len);
 
-	framelen = sbc_pack_frame(sbc->data, &priv->frame, sbc->size);
-
-	sbc->len = framelen;
+	if (written)
+		*written = framelen;
 
 	sbc->duration = (1000000 * priv->frame.subbands * priv->frame.blocks) / sbc->rate;
 
@@ -1375,11 +1377,29 @@ void sbc_finish(sbc_t *sbc)
 	if (!sbc)
 		return;
 
-	if (sbc->data)
-		free(sbc->data);
-
 	if (sbc->priv)
 		free(sbc->priv);
 
 	memset(sbc, 0, sizeof(sbc_t));
 }
+
+int sbc_get_frame_length(sbc_t *sbc)
+{
+	int ret;
+
+	ret = 4 + (4 * sbc->subbands * sbc->channels) / 8;
+
+	/* This term is not always evenly devide so we round it up */
+	if (sbc->channels == 1)
+		ret += ((sbc->blocks * sbc->channels * sbc->bitpool) + 7) / 8;
+	else
+		ret += ((sbc->joint * sbc->subbands + sbc->blocks * sbc->bitpool)
+			+ 7) / 8;
+
+	return ret;
+}
+
+int sbc_get_codesize(sbc_t *sbc)
+{
+	return sbc->subbands * sbc->blocks * sbc->channels * 2;
+}
diff --git a/sbc/sbc.h b/sbc/sbc.h
index 72512c02..d55587d0 100644
--- a/sbc/sbc.h
+++ b/sbc/sbc.h
@@ -42,10 +42,6 @@ struct sbc_struct {
 	int bitpool;
 	int swap;
 
-	void *data;
-	int size;
-	int len;
-
 	unsigned long duration;
 
 	void *priv;
@@ -54,9 +50,13 @@ struct sbc_struct {
 typedef struct sbc_struct sbc_t;
 
 int sbc_init(sbc_t *sbc, unsigned long flags);
-int sbc_parse(sbc_t *sbc, void *data, int count);
-int sbc_decode(sbc_t *sbc, void *data, int count);
-int sbc_encode(sbc_t *sbc, void *data, int count);
+int sbc_parse(sbc_t *sbc, void *input, int input_len);
+int sbc_decode(sbc_t *sbc, void *input, int input_len, void *output,
+		int output_len, int *len);
+int sbc_encode(sbc_t *sbc, void *input, int input_len, void *output,
+		int output_len, int *written);
+int sbc_get_frame_length(sbc_t *sbc);
+int sbc_get_codesize(sbc_t *sbc);
 void sbc_finish(sbc_t *sbc);
 
 #ifdef __cplusplus
diff --git a/sbc/sbcdec.c b/sbc/sbcdec.c
index 866b8448..09a211a1 100644
--- a/sbc/sbcdec.c
+++ b/sbc/sbcdec.c
@@ -46,7 +46,7 @@ static void decode(char *filename, char *output, int tofile)
 	struct stat st;
 	off_t filesize;
 	sbc_t sbc;
-	int fd, ad, pos, streamlen, framelen, count, written;
+	int fd, ad, pos, streamlen, framelen, count, written, len;
 	int format = AFMT_S16_BE;
 
 	if (stat(filename, &st) < 0) {
@@ -97,7 +97,7 @@ static void decode(char *filename, char *output, int tofile)
 	sbc_init(&sbc, 0L);
 	sbc.swap = 1;
 
-	framelen = sbc_decode(&sbc, stream, streamlen);
+	framelen = sbc_decode(&sbc, stream, streamlen, buf, sizeof(buf), &len);
 	printf("%d Hz, %d channels\n", sbc.rate, sbc.channels);
 	if (!tofile) {
 		if (ioctl(ad, SNDCTL_DSP_SETFMT, &format) < 0) {
@@ -125,7 +125,7 @@ static void decode(char *filename, char *output, int tofile)
 		 * length of the frame we just decoded count is the number of
 		 * decoded bytes yet to be written */
 
-		if (count + sbc.len > BUF_SIZE) {
+		if (count + len > BUF_SIZE) {
 			/* buffer is too full to stuff decoded audio in so it
 			 * must be written to the device */
 			written = write(ad, buf, count);
@@ -134,23 +134,23 @@ static void decode(char *filename, char *output, int tofile)
 		}
 
 		/* sanity check */
-		if (count + sbc.len > BUF_SIZE) {
+		if (count + len > BUF_SIZE) {
 			fprintf(stderr,
 				"buffer size of %d is too small for decoded"
-				" data (%d)\n", BUF_SIZE, sbc.len + count);
+				" data (%d)\n", BUF_SIZE, len + count);
 			exit(1);
 		}
 
-		/* move the latest decoded data into buf and increase
-		 * the count */
-		memcpy(buf + count, sbc.data, sbc.len);
-		count += sbc.len;
+		/* increase the count */
+		count += len;
 
 		/* push the pointer in the file forward to the next bit to be
 		 * decoded tell the decoder to decode up to the remaining
 		 * length of the file (!) */
 		pos += framelen;
-		framelen = sbc_decode(&sbc, stream + pos, streamlen - pos);
+		framelen = sbc_decode(&sbc, stream + pos, streamlen - pos,
+					buf + count, sizeof(buf) - count,
+					&len);
 	}
 
 	if (count > 0) {
diff --git a/sbc/sbcenc.c b/sbc/sbcenc.c
index 94b9f642..cba31c7b 100644
--- a/sbc/sbcenc.c
+++ b/sbc/sbcenc.c
@@ -104,9 +104,9 @@ static ssize_t __write(int fd, const void *buf, size_t count)
 static void encode(char *filename, int subbands, int joint)
 {
 	struct au_header *au_hdr;
-	unsigned char buf[2048];
+	unsigned char input[2048], output[2048];
 	sbc_t sbc;
-	int fd, len, size, count;
+	int fd, len, size, count, encoded;
 
 	if (strcmp(filename, "-")) {
 		fd = open(filename, O_RDONLY);
@@ -118,7 +118,7 @@ static void encode(char *filename, int subbands, int joint)
 	} else
 		fd = fileno(stdin);
 
-	len = __read(fd, buf, sizeof(buf));
+	len = __read(fd, input, sizeof(input));
 	if (len < sizeof(*au_hdr)) {
 		if (fd > fileno(stderr))
 			fprintf(stderr, "Can't read header from file %s: %s\n",
@@ -128,7 +128,7 @@ static void encode(char *filename, int subbands, int joint)
 		goto done;
 	}
 
-	au_hdr = (struct au_header *) buf;
+	au_hdr = (struct au_header *) input;
 
 	if (au_hdr->magic != AU_MAGIC ||
 			BE_INT(au_hdr->hdr_size) > 128 ||
@@ -147,11 +147,11 @@ static void encode(char *filename, int subbands, int joint)
 	sbc.swap = 1;
 	count = BE_INT(au_hdr->data_size);
 	size = len - BE_INT(au_hdr->hdr_size);
-	memmove(buf, buf + BE_INT(au_hdr->hdr_size), size);
+	memmove(input, input + BE_INT(au_hdr->hdr_size), size);
 
 	while (1) {
-		if (size < sizeof(buf)) {
-			len = __read(fd, buf + size, sizeof(buf) - size);
+		if (size < sizeof(input)) {
+			len = __read(fd, input + size, sizeof(input) - size);
 			if (len == 0)
 				break;
 
@@ -163,17 +163,18 @@ static void encode(char *filename, int subbands, int joint)
 			size += len;
 		}
 
-		len = sbc_encode(&sbc, buf, size);
+		len = sbc_encode(&sbc, input, size, output, sizeof(output),
+					&encoded);
 		if (len < size)
-			memmove(buf, buf + len, size - len);
+			memmove(input, input + len, size - len);
 
 		size -= len;
 
-		len = __write(fileno(stdout), sbc.data, sbc.len);
+		len = __write(fileno(stdout), output, encoded);
 		if (len == 0)
 			break;
 
-		if (len < 0 || len != sbc.len) {
+		if (len < 0 || len != encoded) {
 			perror("Can't write SBC output");
 			break;
 		}