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https://github.com/Divested-Mobile/DivestOS-Build.git
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58 lines
2.1 KiB
Diff
58 lines
2.1 KiB
Diff
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: ValdikSS <iam@valdikss.org.ru>
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Date: Sun, 9 Sep 2018 01:50:42 +0300
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Subject: [PATCH] Increase maximum Bluetooth SBC codec bitrate for SBC HD
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This commit increases maximum possible bitrate to 452 kbit/s for 44.1 kHz,
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492 kbit/s for 48 kHz, which is optimal for both
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EDR 2 mbit/s (4 audio frames, 11.7 ms, 6 wasted bytes) and
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EDR 3 mbit/s (6 audio frames, 17.5 ms, 20 wasted bytes).
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It does not increase bitpool value and won't introduce higher bitrates for
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modes other than SBC Dual Channel.
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Change-Id: I43f0b48f8b99bfb296c6b5a0b7fdb4d0592f5f82
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---
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stack/a2dp/a2dp_sbc_encoder.cc | 16 ++++++++++++----
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1 file changed, 12 insertions(+), 4 deletions(-)
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diff --git a/stack/a2dp/a2dp_sbc_encoder.cc b/stack/a2dp/a2dp_sbc_encoder.cc
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index aac7e6d18..16d28e808 100644
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--- a/stack/a2dp/a2dp_sbc_encoder.cc
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+++ b/stack/a2dp/a2dp_sbc_encoder.cc
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@@ -39,15 +39,19 @@
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// A2DP SBC encoder interval in milliseconds.
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#define A2DP_SBC_ENCODER_INTERVAL_MS 20
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-/* High quality quality setting @ 44.1 khz */
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-#define A2DP_SBC_DEFAULT_BITRATE 328
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+/*
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+ * Higher quality setting. 492 kbps @ 48 khz, 452 kbps @ 44.1 khz.
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+ * Up to 4 frames for 2DH5, 6 frames for 3DH5.
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+ */
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+#define A2DP_SBC_DEFAULT_BITRATE 454
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+#define A2DP_SBC_48KHZ_BITRATE 494
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#define A2DP_SBC_NON_EDR_MAX_RATE 229
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#define A2DP_SBC_MAX_PCM_ITER_NUM_PER_TICK 3
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-#define A2DP_SBC_MAX_HQ_FRAME_SIZE_44_1 119
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-#define A2DP_SBC_MAX_HQ_FRAME_SIZE_48 115
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+#define A2DP_SBC_MAX_HQ_FRAME_SIZE_44_1 165
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+#define A2DP_SBC_MAX_HQ_FRAME_SIZE_48 165
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/* Define the bitrate step when trying to match bitpool value */
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#define A2DP_SBC_BITRATE_STEP 5
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@@ -832,6 +836,10 @@ static uint8_t calculate_max_frames_per_packet(void) {
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static uint16_t a2dp_sbc_source_rate() {
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uint16_t rate = A2DP_SBC_DEFAULT_BITRATE;
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+ if (a2dp_sbc_encoder_cb.sbc_encoder_params.s16SamplingFreq == SBC_sf48000) {
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+ rate = A2DP_SBC_48KHZ_BITRATE;
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+ }
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+
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/* restrict bitrate if a2dp link is non-edr */
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if (!a2dp_sbc_encoder_cb.is_peer_edr) {
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rate = A2DP_SBC_NON_EDR_MAX_RATE;
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