Add 24 bits PCM input/output (da3b3b7b) · Commits · e / os / android_packages_modules_Bluetooth

system/embdrv/lc3/include/lc3.h

+17 −2

Original line number	Diff line number	Diff line
		@@ -144,6 +144,19 @@ extern "C" {
		((sr) == 32000) \|\| ((sr) == 48000) )


		/**
		* PCM Sample Format
		* S16 Signed 16 bits, in 16 bits words (int16_t)
		* S24 Signed 24 bits, using low three bytes of 32 bits words (int32_t).
		* The high byte sign extends the sample value (bits 31..24 set to b23).
		*/

		enum lc3_pcm_format {
		LC3_PCM_FORMAT_S16,
		LC3_PCM_FORMAT_S24,
		};


		/**
		* Handle
		*/
		@@ -231,13 +244,14 @@ lc3_encoder_t lc3_setup_encoder(
		/**
		* Encode a frame
		* encoder Handle of the encoder
		* fmt PCM input format
		* pcm, pitch Input PCM samples, and count between two consecutives
		* nbytes Target size, in bytes, of the frame (20 to 400)
		* out Output buffer of `nbytes` size
		* return 0: On success -1: Wrong parameters
		*/
		int lc3_encode(lc3_encoder_t encoder,
		const int16_t pcm, int pitch, int nbytes, void out);
		enum lc3_pcm_format fmt, const void pcm, int pitch, int nbytes, void out);

		/**
		* Return size needed for an decoder
		@@ -271,11 +285,12 @@ lc3_decoder_t lc3_setup_decoder(
		* Decode a frame
		* decoder Handle of the decoder
		* in, nbytes Input bitstream, and size in bytes, NULL performs PLC
		* fmt PCM output format
		* pcm, pitch Output PCM samples, and count between two consecutives
		* return 0: On success 1: PLC operated -1: Wrong parameters
		*/
		int lc3_decode(lc3_decoder_t decoder,
		const void in, int nbytes, int16_t pcm, int pitch);
		const void in, int nbytes, enum lc3_pcm_format fmt, void pcm, int pitch);


		#ifdef __cplusplus

system/embdrv/lc3/src/lc3.c

+63 −6

Original line number	Diff line number	Diff line
		@@ -150,8 +150,10 @@ int lc3_delay_samples(int dt_us, int sr_hz)
		* pcm, pitch Input PCM samples, and count between two consecutives
		*/
		static void load_s16(
		struct lc3_encoder encoder, const int16_t pcm, int pitch)
		struct lc3_encoder encoder, const void _pcm, int pitch)
		{
		const int16_t *pcm = _pcm;

		enum lc3_dt dt = encoder->dt;
		enum lc3_srate sr = encoder->sr_pcm;
		float *xs = encoder->xs;
		@@ -161,6 +163,25 @@ static void load_s16(
		xs[i] = pcm[i*pitch];
		}

		/**
		* Input PCM Samples from signed 24 bits
		* encoder Encoder state
		* pcm, pitch Input PCM samples, and count between two consecutives
		*/
		static void load_s24(
		struct lc3_encoder encoder, const void _pcm, int pitch)
		{
		const int32_t *pcm = _pcm;

		enum lc3_dt dt = encoder->dt;
		enum lc3_srate sr = encoder->sr_pcm;
		float *xs = encoder->xs;
		int ns = LC3_NS(dt, sr);

		for (int i = 0; i < ns; i++)
		xs[i] = ldexpf(pcm[i*pitch], -8);
		}

		/**
		* Frame Analysis
		* encoder Encoder state
		@@ -296,8 +317,13 @@ struct lc3_encoder *lc3_setup_encoder(
		* Encode a frame
		*/
		int lc3_encode(struct lc3_encoder *encoder,
		const int16_t pcm, int pitch, int nbytes, void out)
		enum lc3_pcm_format fmt, const void pcm, int pitch, int nbytes, void out)
		{
		static void (* const load[])(struct lc3_encoder , const void , int) = {
		[LC3_PCM_FORMAT_S16] = load_s16,
		[LC3_PCM_FORMAT_S24] = load_s24,
		};

		/* --- Check parameters --- */

		if (!encoder \|\| nbytes < LC3_MIN_FRAME_BYTES
		@@ -309,7 +335,7 @@ int lc3_encode(struct lc3_encoder *encoder,
		struct side_data side;
		int16_t xq[LC3_NE(encoder->dt, encoder->sr)];

		load_s16(encoder, pcm, pitch);
		load[fmt](encoder, pcm, pitch);

		analyze(encoder, nbytes, &side, xq);

		@@ -329,8 +355,10 @@ int lc3_encode(struct lc3_encoder *encoder,
		* pcm, pitch Output PCM samples, and count between two consecutives
		*/
		static void store_s16(
		struct lc3_decoder decoder, int16_t pcm, int pitch)
		struct lc3_decoder decoder, void _pcm, int pitch)
		{
		int16_t *pcm = _pcm;

		enum lc3_dt dt = decoder->dt;
		enum lc3_srate sr = decoder->sr_pcm;
		float *xs = decoder->xs;
		@@ -342,6 +370,30 @@ static void store_s16(
		}
		}

		/**
		* Output PCM Samples to signed 24 bits
		* decoder Decoder state
		* pcm, pitch Output PCM samples, and count between two consecutives
		*/
		static void store_s24(
		struct lc3_decoder decoder, void _pcm, int pitch)
		{
		int32_t *pcm = _pcm;
		const int32_t int24_max = (1 << 23) - 1;
		const int32_t int24_min = -(1 << 23);

		enum lc3_dt dt = decoder->dt;
		enum lc3_srate sr = decoder->sr_pcm;
		float *xs = decoder->xs;
		int ns = LC3_NS(dt, sr);

		for ( ; ns > 0; ns--, xs++, pcm += pitch) {
		int32_t s = xs >= 0 ? (int32_t)(ldexpf(xs, 8) + 0.5f)
		: (int32_t)(ldexpf(*xs, 8) - 0.5f);
		*pcm = LC3_CLIP(s, int24_min, int24_max);
		}
		}

		/**
		* Decode bitstream
		* decoder Decoder state
		@@ -485,8 +537,13 @@ struct lc3_decoder *lc3_setup_decoder(
		* Decode a frame
		*/
		int lc3_decode(struct lc3_decoder *decoder,
		const void in, int nbytes, int16_t pcm, int pitch)
		const void in, int nbytes, enum lc3_pcm_format fmt, void pcm, int pitch)
		{
		static void (* const store[])(struct lc3_decoder , void , int) = {
		[LC3_PCM_FORMAT_S16] = store_s16,
		[LC3_PCM_FORMAT_S24] = store_s24,
		};

		/* --- Check parameters --- */

		if (!decoder)
		@@ -504,7 +561,7 @@ int lc3_decode(struct lc3_decoder *decoder,

		synthesize(decoder, ret ? NULL : &side, nbytes);

		store_s16(decoder, pcm, pitch);
		store[fmt](decoder, pcm, pitch);

		return ret;
		}