Merge "implement flow control to avoid dropping packets in btif_media_task." (044c9a16) · Commits · e / os / android_packages_modules_Bluetooth

system/btif/src/btif_media_task.c

+64 −18

Original line number	Diff line number	Diff line
		@@ -177,8 +177,11 @@ static UINT32 a2dp_media_task_stack[(A2DP_MEDIA_TASK_STACK_SIZE + 3) / 4];
		but due to link flow control or thread preemption in lower
		layers we might need to temporarily buffer up data */

		/* 24 frames is equivalent to 6.89242.9 ~= 480 ms @ 44.1 khz, 20 ms mediatick */
		#define MAX_OUTPUT_A2DP_FRAME_QUEUE_SZ 24
		/* 18 frames is equivalent to 6.89182.9 ~= 360 ms @ 44.1 khz, 20 ms mediatick */
		#define MAX_OUTPUT_A2DP_FRAME_QUEUE_SZ 18
		#define A2DP_PACKET_COUNT_LOW_WATERMARK 5
		#define MAX_PCM_FRAME_NUM_PER_TICK 40
		#define RESET_RATE_COUNTER_THRESHOLD_MS 2000

		//#define BTIF_MEDIA_VERBOSE_ENABLED

		@@ -201,6 +204,10 @@ typedef struct
		INT32 aa_feed_residue;
		UINT32 counter;
		UINT32 bytes_per_tick; /* pcm bytes read each media task tick */
		UINT32 max_counter_exit;
		UINT32 max_counter_enter;
		UINT32 overflow_count;
		BOOLEAN overflow;
		} tBTIF_AV_MEDIA_FEEDINGS_PCM_STATE;


		@@ -1775,6 +1782,11 @@ static void btif_media_task_uipc_cback(BT_HDR *p_msg)
		*******************************************************************************/
		static void btif_media_task_feeding_state_reset(void)
		{
		APPL_TRACE_WARNING3("overflow %d, enter %d, exit %d",
		btif_media_cb.media_feeding_state.pcm.overflow_count,
		btif_media_cb.media_feeding_state.pcm.max_counter_enter,
		btif_media_cb.media_feeding_state.pcm.max_counter_exit);

		/* By default, just clear the entire state */
		memset(&btif_media_cb.media_feeding_state, 0, sizeof(btif_media_cb.media_feeding_state));

		@@ -1855,7 +1867,7 @@ static void btif_media_task_aa_stop_tx(void)
		*******************************************************************************/
		static UINT8 btif_get_num_aa_frame(void)
		{
		UINT8 result=0;
		UINT32 result=0;

		switch (btif_media_cb.TxTranscoding)
		{
		@@ -1868,11 +1880,24 @@ static UINT8 btif_get_num_aa_frame(void)

		btif_media_cb.media_feeding_state.pcm.counter +=
		btif_media_cb.media_feeding_state.pcm.bytes_per_tick;
		if ((!btif_media_cb.media_feeding_state.pcm.overflow) \|\|
		(btif_media_cb.TxAaQ.count < A2DP_PACKET_COUNT_LOW_WATERMARK)) {
		if (btif_media_cb.media_feeding_state.pcm.overflow) {
		btif_media_cb.media_feeding_state.pcm.overflow = FALSE;

		if (btif_media_cb.media_feeding_state.pcm.counter >
		btif_media_cb.media_feeding_state.pcm.max_counter_exit) {
		btif_media_cb.media_feeding_state.pcm.max_counter_exit =
		btif_media_cb.media_feeding_state.pcm.counter;
		}
		}
		/* calculate nbr of frames pending for this media tick */
		result = btif_media_cb.media_feeding_state.pcm.counter/pcm_bytes_per_frame;
		if (result > MAX_PCM_FRAME_NUM_PER_TICK) result = MAX_PCM_FRAME_NUM_PER_TICK;
		btif_media_cb.media_feeding_state.pcm.counter -= result*pcm_bytes_per_frame;

		} else {
		result = 0;
		}
		VERBOSE("WRITE %d FRAMES", result);
		}
		break;
		@@ -1888,7 +1913,7 @@ static UINT8 btif_get_num_aa_frame(void)
		APPL_TRACE_DEBUG1("btif_get_num_aa_frame returns %d", result);
		#endif

		return result;
		return (UINT8)result;
		}

		/*******************************************************************************
		@@ -2185,6 +2210,32 @@ static void btif_media_aa_prep_sbc_2_send(UINT8 nb_frame)
		{
		GKI_freebuf(p_buf);
		}

		if (btif_media_cb.TxAaQ.count >= MAX_OUTPUT_A2DP_FRAME_QUEUE_SZ) {
		UINT32 reset_rate_bytes = btif_media_cb.media_feeding_state.pcm.bytes_per_tick *
		(RESET_RATE_COUNTER_THRESHOLD_MS / BTIF_MEDIA_TIME_TICK);
		btif_media_cb.media_feeding_state.pcm.overflow = TRUE;
		btif_media_cb.media_feeding_state.pcm.counter += nb_frame *
		btif_media_cb.encoder.s16NumOfSubBands *
		btif_media_cb.encoder.s16NumOfBlocks *
		btif_media_cb.media_feeding.cfg.pcm.num_channel *
		btif_media_cb.media_feeding.cfg.pcm.bit_per_sample / 8;

		btif_media_cb.media_feeding_state.pcm.overflow_count++;
		if (btif_media_cb.media_feeding_state.pcm.counter >
		btif_media_cb.media_feeding_state.pcm.max_counter_enter) {
		btif_media_cb.media_feeding_state.pcm.max_counter_enter =
		btif_media_cb.media_feeding_state.pcm.counter;
		}

		if (btif_media_cb.media_feeding_state.pcm.counter > reset_rate_bytes) {
		btif_media_cb.media_feeding_state.pcm.counter = 0;
		APPL_TRACE_WARNING0("btif_media_aa_prep_sbc_2_send:reset rate counter");
		}

		/* no more pcm to read */
		nb_frame = 0;
		}
		}
		}

		@@ -2204,13 +2255,6 @@ static void btif_media_aa_prep_2_send(UINT8 nb_frame)
		VERBOSE("btif_media_aa_prep_2_send : %d frames (queue %d)", nb_frame,
		btif_media_cb.TxAaQ.count);

		while (btif_media_cb.TxAaQ.count >= MAX_OUTPUT_A2DP_FRAME_QUEUE_SZ)
		{
		APPL_TRACE_WARNING1("btif_media_aa_prep_2_send congestion buf count %d",
		btif_media_cb.TxAaQ.count);
		GKI_freebuf(GKI_dequeue(&(btif_media_cb.TxAaQ)));
		}

		switch (btif_media_cb.TxTranscoding)
		{
		case BTIF_MEDIA_TRSCD_PCM_2_SBC:
		@@ -2240,8 +2284,10 @@ static void btif_media_send_aa_frame(void)
		/* get the number of frame to send */
		nb_frame_2_send = btif_get_num_aa_frame();

		if (nb_frame_2_send != 0) {
		/* format and Q buffer to send */
		btif_media_aa_prep_2_send(nb_frame_2_send);
		}

		/* send it */
		VERBOSE("btif_media_send_aa_frame : send %d frames", nb_frame_2_send);