From e5ac60b2b230f37934384147fdee2fb6ce7b3e40 Mon Sep 17 00:00:00 2001
From: Wim Taymans <wtaymans@redhat.com>
Date: Wed, 14 Dec 2022 12:27:33 +0100
Subject: [PATCH] alsa: increase target for a52 and dca

For encoded format, we need to send bigger chunks to make the encoder
happy. Add a new min_delay variable with this info so that we never
leave less than that amount of samples in the ringbuffer.

Fixes #2650
---
 spa/plugins/alsa/alsa-pcm.c | 13 ++++++++++---
 spa/plugins/alsa/alsa-pcm.h |  1 +
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/spa/plugins/alsa/alsa-pcm.c b/spa/plugins/alsa/alsa-pcm.c
index 177a2f763..76fe433b8 100644
--- a/spa/plugins/alsa/alsa-pcm.c
+++ b/spa/plugins/alsa/alsa-pcm.c
@@ -1583,11 +1583,18 @@ int spa_alsa_set_format(struct state *state, struct spa_audio_info *fmt, uint32_
 	if (is_batch)
 		state->headroom += period_size;
 
+	if (spa_strstartswith(state->props.device, "a52") ||
+	    spa_strstartswith(state->props.device, "dca"))
+		state->min_delay = SPA_MIN(2048u, state->buffer_frames);
+	else
+		state->min_delay = 0;
+
 	state->headroom = SPA_MIN(state->headroom, state->buffer_frames);
 	state->start_delay = state->default_start_delay;
 
-	state->latency[state->port_direction].min_rate = state->headroom;
-	state->latency[state->port_direction].max_rate = state->headroom;
+	state->latency[state->port_direction].min_rate =
+		state->latency[state->port_direction].max_rate =
+			SPA_MAX(state->min_delay, state->headroom);
 
 	spa_log_info(state->log, "%s (%s): format:%s access:%s-%s rate:%d channels:%d "
 			"buffer frames %lu, period frames %lu, periods %u, frame_size %zd "
@@ -1859,7 +1866,7 @@ static int get_status(struct state *state, uint64_t current_time,
 		*delay = avail;
 		*target = SPA_MAX(*target, state->read_size);
 	}
-	*target = SPA_MIN(*target, state->buffer_frames);
+	*target = SPA_CLAMP(*target, state->min_delay, state->buffer_frames);
 	return 0;
 }
 
diff --git a/spa/plugins/alsa/alsa-pcm.h b/spa/plugins/alsa/alsa-pcm.h
index c630de3ac..9c4a86862 100644
--- a/spa/plugins/alsa/alsa-pcm.h
+++ b/spa/plugins/alsa/alsa-pcm.h
@@ -197,6 +197,7 @@ struct state {
 	uint32_t last_threshold;
 	uint32_t headroom;
 	uint32_t start_delay;
+	uint32_t min_delay;
 
 	uint32_t duration;
 	unsigned int alsa_started:1;