Negociation wth JBL E55BT headset, resulting in Dual Channel 2x40kb bitpool :
hcidump avdtp
HCI sniffer - Bluetooth packet analyzer ver 5.50
device: hci0 snap_len: 1500 filter: 0x400
< AVDTP(s): Discover cmd: transaction 0 nsp 0x00
> AVDTP(s): Discover rsp: transaction 0 nsp 0x00
ACP SEID 1 - Audio Sink
ACP SEID 2 - Audio Sink
< AVDTP(s): Capabilities cmd: transaction 1 nsp 0x00
ACP SEID 1
> AVDTP(s): Capabilities rsp: transaction 1 nsp 0x00
Media Transport
Media Codec - SBC
16kHz 32kHz 44.1kHz 48kHz
Mono DualChannel Stereo JointStereo
4 8 12 16 Blocks
4 8 Subbands
SNR Loudness
Bitpool Range 2-40
Content Protection
02 00
< AVDTP(s): Capabilities cmd: transaction 2 nsp 0x00
ACP SEID 2
> AVDTP(s): Capabilities rsp: transaction 2 nsp 0x00
Media Transport
Media Codec - SBC
16kHz 32kHz 44.1kHz 48kHz
Mono DualChannel Stereo JointStereo
4 8 12 16 Blocks
4 8 Subbands
SNR Loudness
Bitpool Range 2-40
Content Protection
02 00
< AVDTP(s): Set config cmd: transaction 3 nsp 0x00
ACP SEID 1 - INT SEID 2
Media Transport
Media Codec - SBC
44.1kHz
DualChannel
16 Blocks
8 Subbands
Loudness
Bitpool Range 2-40
19.09.2019, 10:15, "Hyperion" <h1p8r10n@xxxxxxxxxx>:
> Negociation wth Divacore Addict headset, resulting in Dual Channel 2x47kb bitpool :
>
> HCI sniffer - Bluetooth packet analyzer ver 5.50
> device: hci0 snap_len: 1500 filter: 0x400
> < AVDTP(s): Discover cmd: transaction 7 nsp 0x00
>> AVDTP(s): Discover rsp: transaction 7 nsp 0x00
>
> ACP SEID 1 - Audio Sink
> ACP SEID 5 - Audio Sink
> ACP SEID 3 - Audio Sink
> ACP SEID 2 - Audio Sink
> < AVDTP(s): Capabilities cmd: transaction 8 nsp 0x00
> ACP SEID 1
>> AVDTP(s): Capabilities rsp: transaction 8 nsp 0x00
>
> Media Transport
> Media Codec - SBC
> 16kHz 32kHz 44.1kHz 48kHz
> Mono DualChannel Stereo JointStereo
> 4 8 12 16 Blocks
> 4 8 Subbands
> SNR Loudness
> Bitpool Range 2-53
> Content Protection
> 02 00
> < AVDTP(s): Capabilities cmd: transaction 9 nsp 0x00
> ACP SEID 5
>> AVDTP(s): Capabilities rsp: transaction 9 nsp 0x00
>
> Media Transport
> Media Codec - non-A2DP (aptX)
> 16kHz 32kHz 44.1kHz 48kHz
> Stereo
> < AVDTP(s): Capabilities cmd: transaction 10 nsp 0x00
> ACP SEID 3
>> AVDTP(s): Capabilities rsp: transaction 10 nsp 0x00
>
> Media Transport
> Media Codec - MPEG-2,4 AAC
> MPEG-2 AAC LC MPEG-4 AAC LC
> 8kHz 11.025kHz 12kHz 16kHz 22.05kHz 24kHz 32kHz 44.1kHz 48kHz
> 1 2 Channels
> 320000bps VBR
> Content Protection
> 02 00
> < AVDTP(s): Capabilities cmd: transaction 11 nsp 0x00
> ACP SEID 2
>> AVDTP(s): Capabilities rsp: transaction 11 nsp 0x00
>
> Media Transport
> Media Codec - MPEG-1,2 Audio
> Layers: 3
> CRC Protection: Yes
> Mono DualChannel Stereo JointStereo
> Media Payload Format: RFC-2250
> 16kHz 22.05kHz 24kHz 32kHz 44.1kHz 48kHz
> VBR: Yes
> Bit Rate Indexes: n/a
> Content Protection
> 02 00
> < AVDTP(s): Set config cmd: transaction 12 nsp 0x00
> ACP SEID 1 - INT SEID 2
> Media Transport
> Media Codec - SBC
> 44.1kHz
> DualChannel
> 16 Blocks
> 8 Subbands
> Loudness
> Bitpool Range 2-47
>
> 19.09.2019, 10:13, "Hyperion" <h1p8r10n@xxxxxxxxxx>:
>> Negociation wth Harman Kardon Onyx, resulting in Dual Channel 2x47kb bitpool :
>>
>> device: hci0 snap_len: 1500 filter: 0x400
>> < AVDTP(s): Discover cmd: transaction 15 nsp 0x00
>>> AVDTP(s): Discover rsp: transaction 15 nsp 0x00
>>
>> ACP SEID 1 - Audio Sink
>> ACP SEID 2 - Audio Sink
>> ACP SEID 3 - Audio Sink
>> < AVDTP(s): All Capabilities cmd: transaction 0 nsp 0x00
>> ACP SEID 1
>>> AVDTP(s): All Capabilities rsp: transaction 0 nsp 0x00
>>
>> Media Transport
>> Reporting
>> Media Codec - SBC
>> 16kHz 32kHz 44.1kHz 48kHz
>> Mono DualChannel Stereo JointStereo
>> 4 8 12 16 Blocks
>> 4 8 Subbands
>> SNR Loudness
>> Bitpool Range 2-89
>> Content Protection
>> 02 00
>> Delay Reporting
>> < AVDTP(s): All Capabilities cmd: transaction 1 nsp 0x00
>> ACP SEID 2
>>> AVDTP(s): All Capabilities rsp: transaction 1 nsp 0x00
>>
>> Media Transport
>> Reporting
>> Media Codec - SBC
>> 16kHz 32kHz 44.1kHz 48kHz
>> Mono DualChannel Stereo JointStereo
>> 4 8 12 16 Blocks
>> 4 8 Subbands
>> SNR Loudness
>> Bitpool Range 2-89
>> Content Protection
>> 02 00
>> Delay Reporting
>> < AVDTP(s): All Capabilities cmd: transaction 2 nsp 0x00
>> ACP SEID 3
>>> AVDTP(s): All Capabilities rsp: transaction 2 nsp 0x00
>>
>> Media Transport
>> Reporting
>> Media Codec - SBC
>> 16kHz 32kHz 44.1kHz 48kHz
>> Mono DualChannel Stereo JointStereo
>> 4 8 12 16 Blocks
>> 4 8 Subbands
>> SNR Loudness
>> Bitpool Range 2-89
>> Content Protection
>> 02 00
>> Delay Reporting
>> < AVDTP(s): Set config cmd: transaction 3 nsp 0x00
>> ACP SEID 1 - INT SEID 2
>> Media Transport
>> Media Codec - SBC
>> 44.1kHz
>> DualChannel
>> 16 Blocks
>> 8 Subbands
>> Loudness
>> Bitpool Range 2-47
>>
>> 18.09.2019, 13:02, "Hyperion" <h1p8r10n@xxxxxxxxxx>:
>>> Patch V2 with added DUAL_CHANNEL as preferred mode.
>>>
>>> Works without any issue on more than 10 stereo and mono devices that I have here.
>>>
>>> http://download.zenwalk.org/x86_64/testing/pulseaudio-13.0-SBC-XQ_V2.patch
>>>
>>> /***
>>> This file is part of PulseAudio.
>>>
>>> Copyright 2018-2019 Pali Rohár <pali.rohar@xxxxxxxxx>
>>>
>>> PulseAudio is free software; you can redistribute it and/or modify
>>> it under the terms of the GNU Lesser General Public License as
>>> published by the Free Software Foundation; either version 2.1 of the
>>> License, or (at your option) any later version.
>>>
>>> PulseAudio is distributed in the hope that it will be useful, but
>>> WITHOUT ANY WARRANTY; without even the implied warranty of
>>> MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
>>> General Public License for more details.
>>>
>>> You should have received a copy of the GNU Lesser General Public
>>> License along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
>>> ***/
>>>
>>> #ifdef HAVE_CONFIG_H
>>> #include <config.h>
>>> #endif
>>>
>>> #include <pulsecore/core-util.h>
>>> #include <pulsecore/log.h>
>>> #include <pulsecore/macro.h>
>>> #include <pulsecore/once.h>
>>> #include <pulse/sample.h>
>>> #include <pulse/xmalloc.h>
>>>
>>> #include <arpa/inet.h>
>>>
>>> #include <sbc/sbc.h>
>>>
>>> #include "a2dp-codecs.h"
>>> #include "a2dp-codec-api.h"
>>> #include "rtp.h"
>>>
>>> #define SBC_BITPOOL_DEC_LIMIT 32
>>> #define SBC_BITPOOL_DEC_STEP 5
>>>
>>> struct sbc_info {
>>> sbc_t sbc; /* Codec data */
>>> size_t codesize, frame_length; /* SBC Codesize, frame_length. We simply cache those values here */
>>> uint16_t seq_num; /* Cumulative packet sequence */
>>> uint8_t frequency;
>>> uint8_t blocks;
>>> uint8_t subbands;
>>> uint8_t mode;
>>> uint8_t allocation;
>>> uint8_t initial_bitpool;
>>> uint8_t min_bitpool;
>>> uint8_t max_bitpool;
>>> };
>>>
>>> static bool can_accept_capabilities(const uint8_t *capabilities_buffer, uint8_t capabilities_size, bool for_encoding) {
>>> const a2dp_sbc_t *capabilities = (const a2dp_sbc_t *) capabilities_buffer;
>>>
>>> if (capabilities_size != sizeof(*capabilities))
>>> return false;
>>>
>>> if (!(capabilities->frequency & (SBC_SAMPLING_FREQ_16000 | SBC_SAMPLING_FREQ_32000 | SBC_SAMPLING_FREQ_44100 | SBC_SAMPLING_FREQ_48000)))
>>> return false;
>>>
>>> if (!(capabilities->channel_mode & (SBC_CHANNEL_MODE_MONO | SBC_CHANNEL_MODE_DUAL_CHANNEL | SBC_CHANNEL_MODE_STEREO | SBC_CHANNEL_MODE_JOINT_STEREO)))
>>> return false;
>>>
>>> if (!(capabilities->allocation_method & (SBC_ALLOCATION_SNR | SBC_ALLOCATION_LOUDNESS)))
>>> return false;
>>>
>>> if (!(capabilities->subbands & (SBC_SUBBANDS_4 | SBC_SUBBANDS_8)))
>>> return false;
>>>
>>> if (!(capabilities->block_length & (SBC_BLOCK_LENGTH_4 | SBC_BLOCK_LENGTH_8 | SBC_BLOCK_LENGTH_12 | SBC_BLOCK_LENGTH_16)))
>>> return false;
>>>
>>> return true;
>>> }
>>>
>>> static const char *choose_remote_endpoint(const pa_hashmap *capabilities_hashmap, const pa_sample_spec *default_sample_spec, bool for_encoding) {
>>> const pa_a2dp_codec_capabilities *a2dp_capabilities;
>>> const char *key;
>>> void *state;
>>>
>>> /* There is no preference, just choose random valid entry */
>>> PA_HASHMAP_FOREACH_KV(key, a2dp_capabilities, capabilities_hashmap, state) {
>>> if (can_accept_capabilities(a2dp_capabilities->buffer, a2dp_capabilities->size, for_encoding))
>>> return key;
>>> }
>>>
>>> return NULL;
>>> }
>>>
>>> static uint8_t fill_capabilities(uint8_t capabilities_buffer[MAX_A2DP_CAPS_SIZE]) {
>>> a2dp_sbc_t *capabilities = (a2dp_sbc_t *) capabilities_buffer;
>>>
>>> pa_zero(*capabilities);
>>>
>>> capabilities->channel_mode = SBC_CHANNEL_MODE_MONO | SBC_CHANNEL_MODE_DUAL_CHANNEL | SBC_CHANNEL_MODE_STEREO |
>>> SBC_CHANNEL_MODE_JOINT_STEREO;
>>> capabilities->frequency = SBC_SAMPLING_FREQ_16000 | SBC_SAMPLING_FREQ_32000 | SBC_SAMPLING_FREQ_44100 |
>>> SBC_SAMPLING_FREQ_48000;
>>> capabilities->allocation_method = SBC_ALLOCATION_SNR | SBC_ALLOCATION_LOUDNESS;
>>> capabilities->subbands = SBC_SUBBANDS_4 | SBC_SUBBANDS_8;
>>> capabilities->block_length = SBC_BLOCK_LENGTH_4 | SBC_BLOCK_LENGTH_8 | SBC_BLOCK_LENGTH_12 | SBC_BLOCK_LENGTH_16;
>>> capabilities->min_bitpool = SBC_MIN_BITPOOL;
>>> capabilities->max_bitpool = SBC_BITPOOL_HQ_JOINT_STEREO_44100;
>>>
>>> return sizeof(*capabilities);
>>> }
>>>
>>> static bool is_configuration_valid(const uint8_t *config_buffer, uint8_t config_size) {
>>> const a2dp_sbc_t *config = (const a2dp_sbc_t *) config_buffer;
>>>
>>> if (config_size != sizeof(*config)) {
>>> pa_log_error("Invalid size of config buffer");
>>> return false;
>>> }
>>>
>>> if (config->frequency != SBC_SAMPLING_FREQ_16000 && config->frequency != SBC_SAMPLING_FREQ_32000 &&
>>> config->frequency != SBC_SAMPLING_FREQ_44100 && config->frequency != SBC_SAMPLING_FREQ_48000) {
>>> pa_log_error("Invalid sampling frequency in configuration");
>>> return false;
>>> }
>>>
>>> if (config->channel_mode != SBC_CHANNEL_MODE_MONO && config->channel_mode != SBC_CHANNEL_MODE_DUAL_CHANNEL &&
>>> config->channel_mode != SBC_CHANNEL_MODE_STEREO && config->channel_mode != SBC_CHANNEL_MODE_JOINT_STEREO) {
>>> pa_log_error("Invalid channel mode in configuration");
>>> return false;
>>> }
>>>
>>> if (config->allocation_method != SBC_ALLOCATION_SNR && config->allocation_method != SBC_ALLOCATION_LOUDNESS) {
>>> pa_log_error("Invalid allocation method in configuration");
>>> return false;
>>> }
>>>
>>> if (config->subbands != SBC_SUBBANDS_4 && config->subbands != SBC_SUBBANDS_8) {
>>> pa_log_error("Invalid SBC subbands in configuration");
>>> return false;
>>> }
>>>
>>> if (config->block_length != SBC_BLOCK_LENGTH_4 && config->block_length != SBC_BLOCK_LENGTH_8 &&
>>> config->block_length != SBC_BLOCK_LENGTH_12 && config->block_length != SBC_BLOCK_LENGTH_16) {
>>> pa_log_error("Invalid block length in configuration");
>>> return false;
>>> }
>>>
>>> if (config->min_bitpool > config->max_bitpool) {
>>> pa_log_error("Invalid bitpool in configuration");
>>> return false;
>>> }
>>>
>>> return true;
>>> }
>>>
>>> static uint8_t default_bitpool(uint8_t freq, uint8_t mode) {
>>> /* These bitpool values were chosen based on the A2DP spec recommendation */
>>> switch (freq) {
>>> case SBC_SAMPLING_FREQ_48000:
>>> switch (mode) {
>>> case SBC_CHANNEL_MODE_MONO:
>>> case SBC_CHANNEL_MODE_DUAL_CHANNEL:
>>> return SBC_BITPOOL_HQ_MONO_48000;
>>>
>>> case SBC_CHANNEL_MODE_STEREO:
>>> case SBC_CHANNEL_MODE_JOINT_STEREO:
>>> return SBC_BITPOOL_HQ_JOINT_STEREO_48000;
>>> }
>>> break;
>>> case SBC_SAMPLING_FREQ_44100:
>>> switch (mode) {
>>> case SBC_CHANNEL_MODE_MONO:
>>> case SBC_CHANNEL_MODE_DUAL_CHANNEL:
>>> return SBC_BITPOOL_HQ_MONO_44100;
>>>
>>> case SBC_CHANNEL_MODE_STEREO:
>>> case SBC_CHANNEL_MODE_JOINT_STEREO:
>>> return SBC_BITPOOL_HQ_JOINT_STEREO_44100;
>>> }
>>> break;
>>> case SBC_SAMPLING_FREQ_16000:
>>> case SBC_SAMPLING_FREQ_32000:
>>> switch (mode) {
>>> case SBC_CHANNEL_MODE_MONO:
>>> case SBC_CHANNEL_MODE_DUAL_CHANNEL:
>>> case SBC_CHANNEL_MODE_STEREO:
>>> case SBC_CHANNEL_MODE_JOINT_STEREO:
>>> return SBC_BITPOOL_HQ_JOINT_STEREO_44100;
>>> }
>>> break;
>>> }
>>>
>>> pa_assert_not_reached();
>>> }
>>>
>>> static uint8_t fill_preferred_configuration(const pa_sample_spec *default_sample_spec, const uint8_t *capabilities_buffer, uint8_t capabilities_size, uint8_t config_buffer[MAX_A2DP_CAPS_SIZE]) {
>>> a2dp_sbc_t *config = (a2dp_sbc_t *) config_buffer;
>>> const a2dp_sbc_t *capabilities = (const a2dp_sbc_t *) capabilities_buffer;
>>> int i;
>>>
>>> static const struct {
>>> uint32_t rate;
>>> uint8_t cap;
>>> } freq_table[] = {
>>> { 16000U, SBC_SAMPLING_FREQ_16000 },
>>> { 32000U, SBC_SAMPLING_FREQ_32000 },
>>> { 44100U, SBC_SAMPLING_FREQ_44100 },
>>> { 48000U, SBC_SAMPLING_FREQ_48000 }
>>> };
>>>
>>> if (capabilities_size != sizeof(*capabilities)) {
>>> pa_log_error("Invalid size of capabilities buffer");
>>> return 0;
>>> }
>>>
>>> pa_zero(*config);
>>>
>>> /* Find the lowest freq that is at least as high as the requested sampling rate */
>>> for (i = 0; (unsigned) i < PA_ELEMENTSOF(freq_table); i++)
>>> if (freq_table[i].rate >= default_sample_spec->rate && (capabilities->frequency & freq_table[i].cap)) {
>>> config->frequency = freq_table[i].cap;
>>> break;
>>> }
>>>
>>> if ((unsigned) i == PA_ELEMENTSOF(freq_table)) {
>>> for (--i; i >= 0; i--) {
>>> if (capabilities->frequency & freq_table[i].cap) {
>>> config->frequency = freq_table[i].cap;
>>> break;
>>> }
>>> }
>>>
>>> if (i < 0) {
>>> pa_log_error("Not suitable sample rate");
>>> return 0;
>>> }
>>> }
>>>
>>> pa_assert((unsigned) i < PA_ELEMENTSOF(freq_table));
>>>
>>> if (default_sample_spec->channels <= 1) {
>>> if (capabilities->channel_mode & SBC_CHANNEL_MODE_MONO)
>>> config->channel_mode = SBC_CHANNEL_MODE_MONO;
>>> else if (capabilities->channel_mode & SBC_CHANNEL_MODE_JOINT_STEREO)
>>> config->channel_mode = SBC_CHANNEL_MODE_JOINT_STEREO;
>>> else if (capabilities->channel_mode & SBC_CHANNEL_MODE_STEREO)
>>> config->channel_mode = SBC_CHANNEL_MODE_STEREO;
>>> else if (capabilities->channel_mode & SBC_CHANNEL_MODE_DUAL_CHANNEL)
>>> config->channel_mode = SBC_CHANNEL_MODE_DUAL_CHANNEL;
>>> else {
>>> pa_log_error("No supported channel modes");
>>> return 0;
>>> }
>>> } else {
>>> if (capabilities->channel_mode & SBC_CHANNEL_MODE_DUAL_CHANNEL)
>>> config->channel_mode = SBC_CHANNEL_MODE_DUAL_CHANNEL;
>>> else if (capabilities->channel_mode & SBC_CHANNEL_MODE_STEREO)
>>> config->channel_mode = SBC_CHANNEL_MODE_STEREO;
>>> else if (capabilities->channel_mode & SBC_CHANNEL_MODE_JOINT_STEREO)
>>> config->channel_mode = SBC_CHANNEL_MODE_JOINT_STEREO;
>>> else if (capabilities->channel_mode & SBC_CHANNEL_MODE_MONO)
>>> config->channel_mode = SBC_CHANNEL_MODE_MONO;
>>> else {
>>> pa_log_error("No supported channel modes");
>>> return 0;
>>> }
>>> }
>>>
>>> if (capabilities->block_length & SBC_BLOCK_LENGTH_16)
>>> config->block_length = SBC_BLOCK_LENGTH_16;
>>> else if (capabilities->block_length & SBC_BLOCK_LENGTH_12)
>>> config->block_length = SBC_BLOCK_LENGTH_12;
>>> else if (capabilities->block_length & SBC_BLOCK_LENGTH_8)
>>> config->block_length = SBC_BLOCK_LENGTH_8;
>>> else if (capabilities->block_length & SBC_BLOCK_LENGTH_4)
>>> config->block_length = SBC_BLOCK_LENGTH_4;
>>> else {
>>> pa_log_error("No supported block lengths");
>>> return 0;
>>> }
>>>
>>> if (capabilities->subbands & SBC_SUBBANDS_8)
>>> config->subbands = SBC_SUBBANDS_8;
>>> else if (capabilities->subbands & SBC_SUBBANDS_4)
>>> config->subbands = SBC_SUBBANDS_4;
>>> else {
>>> pa_log_error("No supported subbands");
>>> return 0;
>>> }
>>>
>>> if (capabilities->allocation_method & SBC_ALLOCATION_LOUDNESS)
>>> config->allocation_method = SBC_ALLOCATION_LOUDNESS;
>>> else if (capabilities->allocation_method & SBC_ALLOCATION_SNR)
>>> config->allocation_method = SBC_ALLOCATION_SNR;
>>> else {
>>> pa_log_error("No supported allocation method");
>>> return 0;
>>> }
>>>
>>> config->min_bitpool = (uint8_t) PA_MAX(SBC_MIN_BITPOOL, capabilities->min_bitpool);
>>> config->max_bitpool = (uint8_t) PA_MIN(default_bitpool(config->frequency, config->channel_mode), capabilities->max_bitpool);
>>>
>>> if (config->min_bitpool > config->max_bitpool) {
>>> pa_log_error("No supported bitpool");
>>> return 0;
>>> }
>>>
>>> return sizeof(*config);
>>> }
>>>
>>> static void set_params(struct sbc_info *sbc_info) {
>>> sbc_info->sbc.frequency = sbc_info->frequency;
>>> sbc_info->sbc.blocks = sbc_info->blocks;
>>> sbc_info->sbc.subbands = sbc_info->subbands;
>>> sbc_info->sbc.mode = sbc_info->mode;
>>> sbc_info->sbc.allocation = sbc_info->allocation;
>>> sbc_info->sbc.bitpool = sbc_info->initial_bitpool;
>>> sbc_info->sbc.endian = SBC_LE;
>>>
>>> sbc_info->codesize = sbc_get_codesize(&sbc_info->sbc);
>>> sbc_info->frame_length = sbc_get_frame_length(&sbc_info->sbc);
>>> }
>>>
>>> static void *init(bool for_encoding, bool for_backchannel, const uint8_t *config_buffer, uint8_t config_size, pa_sample_spec *sample_spec) {
>>> struct sbc_info *sbc_info;
>>> const a2dp_sbc_t *config = (const a2dp_sbc_t *) config_buffer;
>>> int ret;
>>>
>>> pa_assert(config_size == sizeof(*config));
>>> pa_assert(!for_backchannel);
>>>
>>> sbc_info = pa_xnew0(struct sbc_info, 1);
>>>
>>> ret = sbc_init(&sbc_info->sbc, 0);
>>> if (ret != 0) {
>>> pa_xfree(sbc_info);
>>> pa_log_error("SBC initialization failed: %d", ret);
>>> return NULL;
>>> }
>>>
>>> sample_spec->format = PA_SAMPLE_S16LE;
>>>
>>> switch (config->frequency) {
>>> case SBC_SAMPLING_FREQ_48000:
>>> sbc_info->frequency = SBC_FREQ_48000;
>>> sample_spec->rate = 48000U;
>>> break;
>>> case SBC_SAMPLING_FREQ_44100:
>>> sbc_info->frequency = SBC_FREQ_44100;
>>> sample_spec->rate = 44100U;
>>> break;
>>> case SBC_SAMPLING_FREQ_32000:
>>> sbc_info->frequency = SBC_FREQ_32000;
>>> sample_spec->rate = 32000U;
>>> break;
>>> case SBC_SAMPLING_FREQ_16000:
>>> sbc_info->frequency = SBC_FREQ_16000;
>>> sample_spec->rate = 16000U;
>>> break;
>>> default:
>>> pa_assert_not_reached();
>>> }
>>>
>>> switch (config->channel_mode) {
>>> case SBC_CHANNEL_MODE_DUAL_CHANNEL:
>>> sbc_info->mode = SBC_MODE_DUAL_CHANNEL;
>>> sample_spec->channels = 2;
>>> break;
>>> case SBC_CHANNEL_MODE_STEREO:
>>> sbc_info->mode = SBC_MODE_STEREO;
>>> sample_spec->channels = 2;
>>> break;
>>> case SBC_CHANNEL_MODE_JOINT_STEREO:
>>> sbc_info->mode = SBC_MODE_JOINT_STEREO;
>>> sample_spec->channels = 2;
>>> break;
>>> case SBC_CHANNEL_MODE_MONO:
>>> sbc_info->mode = SBC_MODE_MONO;
>>> sample_spec->channels = 1;
>>> break;
>>> default:
>>> pa_assert_not_reached();
>>> }
>>>
>>> switch (config->allocation_method) {
>>> case SBC_ALLOCATION_LOUDNESS:
>>> sbc_info->allocation = SBC_AM_LOUDNESS;
>>> break;
>>> case SBC_ALLOCATION_SNR:
>>> sbc_info->allocation = SBC_AM_SNR;
>>> break;
>>> default:
>>> pa_assert_not_reached();
>>> }
>>>
>>> switch (config->subbands) {
>>> case SBC_SUBBANDS_4:
>>> sbc_info->subbands = SBC_SB_4;
>>> break;
>>> case SBC_SUBBANDS_8:
>>> sbc_info->subbands = SBC_SB_8;
>>> break;
>>> default:
>>> pa_assert_not_reached();
>>> }
>>>
>>> switch (config->block_length) {
>>> case SBC_BLOCK_LENGTH_4:
>>> sbc_info->blocks = SBC_BLK_4;
>>> break;
>>> case SBC_BLOCK_LENGTH_8:
>>> sbc_info->blocks = SBC_BLK_8;
>>> break;
>>> case SBC_BLOCK_LENGTH_12:
>>> sbc_info->blocks = SBC_BLK_12;
>>> break;
>>> case SBC_BLOCK_LENGTH_16:
>>> sbc_info->blocks = SBC_BLK_16;
>>> break;
>>> default:
>>> pa_assert_not_reached();
>>> }
>>>
>>> sbc_info->min_bitpool = config->min_bitpool;
>>> sbc_info->max_bitpool = config->max_bitpool;
>>>
>>> /* Set minimum bitpool for source to get the maximum possible block_size
>>> * in get_block_size() function. This block_size is length of buffer used
>>> * for decoded audio data and so is inversely proportional to frame length
>>> * which depends on bitpool value. Bitpool is controlled by other side from
>>> * range [min_bitpool, max_bitpool]. */
>>> sbc_info->initial_bitpool = for_encoding ? sbc_info->max_bitpool : sbc_info->min_bitpool;
>>>
>>> set_params(sbc_info);
>>>
>>> pa_log_info("SBC parameters: allocation=%s, subbands=%u, blocks=%u, mode=%s bitpool=%u codesize=%u frame_length=%u",
>>> sbc_info->sbc.allocation ? "SNR" : "Loudness", sbc_info->sbc.subbands ? 8 : 4,
>>> (sbc_info->sbc.blocks+1)*4, sbc_info->sbc.mode == SBC_MODE_MONO ? "Mono" :
>>> sbc_info->sbc.mode == SBC_MODE_DUAL_CHANNEL ? "DualChannel" :
>>> sbc_info->sbc.mode == SBC_MODE_STEREO ? "Stereo" : "JointStereo",
>>> sbc_info->sbc.bitpool, (unsigned)sbc_info->codesize, (unsigned)sbc_info->frame_length);
>>>
>>> return sbc_info;
>>> }
>>>
>>> static void deinit(void *codec_info) {
>>> struct sbc_info *sbc_info = (struct sbc_info *) codec_info;
>>>
>>> sbc_finish(&sbc_info->sbc);
>>> pa_xfree(sbc_info);
>>> }
>>>
>>> static void set_bitpool(struct sbc_info *sbc_info, uint8_t bitpool) {
>>> if (bitpool > sbc_info->max_bitpool)
>>> bitpool = sbc_info->max_bitpool;
>>> else if (bitpool < sbc_info->min_bitpool)
>>> bitpool = sbc_info->min_bitpool;
>>>
>>> sbc_info->sbc.bitpool = bitpool;
>>>
>>> sbc_info->codesize = sbc_get_codesize(&sbc_info->sbc);
>>> sbc_info->frame_length = sbc_get_frame_length(&sbc_info->sbc);
>>>
>>> pa_log_debug("Bitpool has changed to %u", sbc_info->sbc.bitpool);
>>> }
>>>
>>> static int reset(void *codec_info) {
>>> struct sbc_info *sbc_info = (struct sbc_info *) codec_info;
>>> int ret;
>>>
>>> ret = sbc_reinit(&sbc_info->sbc, 0);
>>> if (ret != 0) {
>>> pa_log_error("SBC reinitialization failed: %d", ret);
>>> return -1;
>>> }
>>>
>>> /* sbc_reinit() sets also default parameters, so reset them back */
>>> set_params(sbc_info);
>>>
>>> sbc_info->seq_num = 0;
>>> return 0;
>>> }
>>>
>>> static size_t get_block_size(void *codec_info, size_t link_mtu) {
>>> struct sbc_info *sbc_info = (struct sbc_info *) codec_info;
>>> size_t rtp_size = sizeof(struct rtp_header) + sizeof(struct rtp_sbc_payload);
>>> size_t frame_count = (link_mtu - rtp_size) / sbc_info->frame_length;
>>>
>>> /* frame_count is only 4 bit number */
>>> if (frame_count > 15)
>>> frame_count = 15;
>>>
>>> return frame_count * sbc_info->codesize;
>>> }
>>>
>>> static size_t reduce_encoder_bitrate(void *codec_info, size_t write_link_mtu) {
>>> struct sbc_info *sbc_info = (struct sbc_info *) codec_info;
>>> uint8_t bitpool;
>>>
>>> /* Check if bitpool is already at its limit */
>>> if (sbc_info->sbc.bitpool <= SBC_BITPOOL_DEC_LIMIT)
>>> return 0;
>>>
>>> bitpool = sbc_info->sbc.bitpool - SBC_BITPOOL_DEC_STEP;
>>>
>>> if (bitpool < SBC_BITPOOL_DEC_LIMIT)
>>> bitpool = SBC_BITPOOL_DEC_LIMIT;
>>>
>>> if (sbc_info->sbc.bitpool == bitpool)
>>> return 0;
>>>
>>> set_bitpool(sbc_info, bitpool);
>>> return get_block_size(codec_info, write_link_mtu);
>>> }
>>>
>>> static size_t encode_buffer(void *codec_info, uint32_t timestamp, const uint8_t *input_buffer, size_t input_size, uint8_t *output_buffer, size_t output_size, size_t *processed) {
>>> struct sbc_info *sbc_info = (struct sbc_info *) codec_info;
>>> struct rtp_header *header;
>>> struct rtp_sbc_payload *payload;
>>> uint8_t *d;
>>> const uint8_t *p;
>>> size_t to_write, to_encode;
>>> uint8_t frame_count;
>>>
>>> header = (struct rtp_header*) output_buffer;
>>> payload = (struct rtp_sbc_payload*) (output_buffer + sizeof(*header));
>>>
>>> frame_count = 0;
>>>
>>> p = input_buffer;
>>> to_encode = input_size;
>>>
>>> d = output_buffer + sizeof(*header) + sizeof(*payload);
>>> to_write = output_size - sizeof(*header) - sizeof(*payload);
>>>
>>> /* frame_count is only 4 bit number */
>>> while (PA_LIKELY(to_encode > 0 && to_write > 0 && frame_count < 15)) {
>>> ssize_t written;
>>> ssize_t encoded;
>>>
>>> encoded = sbc_encode(&sbc_info->sbc,
>>> p, to_encode,
>>> d, to_write,
>>> &written);
>>>
>>> if (PA_UNLIKELY(encoded <= 0)) {
>>> pa_log_error("SBC encoding error (%li)", (long) encoded);
>>> break;
>>> }
>>>
>>> if (PA_UNLIKELY(written < 0)) {
>>> pa_log_error("SBC encoding error (%li)", (long) written);
>>> break;
>>> }
>>>
>>> pa_assert_fp((size_t) encoded <= to_encode);
>>> pa_assert_fp((size_t) encoded == sbc_info->codesize);
>>>
>>> pa_assert_fp((size_t) written <= to_write);
>>> pa_assert_fp((size_t) written == sbc_info->frame_length);
>>>
>>> p += encoded;
>>> to_encode -= encoded;
>>>
>>> d += written;
>>> to_write -= written;
>>>
>>> frame_count++;
>>> }
>>>
>>> PA_ONCE_BEGIN {
>>> pa_log_debug("Using SBC codec implementation: %s", pa_strnull(sbc_get_implementation_info(&sbc_info->sbc)));
>>> } PA_ONCE_END;
>>>
>>> if (PA_UNLIKELY(frame_count == 0)) {
>>> *processed = 0;
>>> return 0;
>>> }
>>>
>>> /* write it to the fifo */
>>> pa_memzero(output_buffer, sizeof(*header) + sizeof(*payload));
>>> header->v = 2;
>>>
>>> /* A2DP spec: "A payload type in the RTP dynamic range shall be chosen".
>>> * RFC3551 defines the dynamic range to span from 96 to 127, and 96 appears
>>> * to be the most common choice in A2DP implementations. */
>>> header->pt = 96;
>>>
>>> header->sequence_number = htons(sbc_info->seq_num++);
>>> header->timestamp = htonl(timestamp);
>>> header->ssrc = htonl(1);
>>> payload->frame_count = frame_count;
>>>
>>> *processed = p - input_buffer;
>>> return d - output_buffer;
>>> }
>>>
>>> static size_t decode_buffer(void *codec_info, const uint8_t *input_buffer, size_t input_size, uint8_t *output_buffer, size_t output_size, size_t *processed) {
>>> struct sbc_info *sbc_info = (struct sbc_info *) codec_info;
>>>
>>> struct rtp_header *header;
>>> struct rtp_sbc_payload *payload;
>>> const uint8_t *p;
>>> uint8_t *d;
>>> size_t to_write, to_decode;
>>> uint8_t frame_count;
>>>
>>> header = (struct rtp_header *) input_buffer;
>>> payload = (struct rtp_sbc_payload*) (input_buffer + sizeof(*header));
>>>
>>> frame_count = payload->frame_count;
>>>
>>> /* TODO: Add support for decoding fragmented SBC frames */
>>> if (payload->is_fragmented) {
>>> pa_log_error("Unsupported fragmented SBC frame");
>>> *processed = 0;
>>> return 0;
>>> }
>>>
>>> p = input_buffer + sizeof(*header) + sizeof(*payload);
>>> to_decode = input_size - sizeof(*header) - sizeof(*payload);
>>>
>>> d = output_buffer;
>>> to_write = output_size;
>>>
>>> while (PA_LIKELY(to_decode > 0 && to_write > 0 && frame_count > 0)) {
>>> size_t written;
>>> ssize_t decoded;
>>>
>>> decoded = sbc_decode(&sbc_info->sbc,
>>> p, to_decode,
>>> d, to_write,
>>> &written);
>>>
>>> if (PA_UNLIKELY(decoded <= 0)) {
>>> pa_log_error("SBC decoding error (%li)", (long) decoded);
>>> break;
>>> }
>>>
>>> /* Reset frame length, it can be changed due to bitpool change */
>>> sbc_info->frame_length = sbc_get_frame_length(&sbc_info->sbc);
>>>
>>> pa_assert_fp((size_t) decoded <= to_decode);
>>> pa_assert_fp((size_t) decoded == sbc_info->frame_length);
>>>
>>> pa_assert_fp((size_t) written <= to_write);
>>> pa_assert_fp((size_t) written == sbc_info->codesize);
>>>
>>> p += decoded;
>>> to_decode -= decoded;
>>>
>>> d += written;
>>> to_write -= written;
>>>
>>> frame_count--;
>>> }
>>>
>>> *processed = p - input_buffer;
>>> return d - output_buffer;
>>> }
>>>
>>> const pa_a2dp_codec pa_a2dp_codec_sbc = {
>>> .name = "sbc",
>>> .description = "SBC",
>>> .id = { A2DP_CODEC_SBC, 0, 0 },
>>> .support_backchannel = false,
>>> .can_accept_capabilities = can_accept_capabilities,
>>> .choose_remote_endpoint = choose_remote_endpoint,
>>> .fill_capabilities = fill_capabilities,
>>> .is_configuration_valid = is_configuration_valid,
>>> .fill_preferred_configuration = fill_preferred_configuration,
>>> .init = init,
>>> .deinit = deinit,
>>> .reset = reset,
>>> .get_read_block_size = get_block_size,
>>> .get_write_block_size = get_block_size,
>>> .reduce_encoder_bitrate = reduce_encoder_bitrate,
>>> .encode_buffer = encode_buffer,
>>> .decode_buffer = decode_buffer,
>>> };
>>>
>>> 17.09.2019, 09:34, "Hyperion" <h1p8r10n@xxxxxxxxxx>:
>>>> btw here's the updated V12-12 patch in Pali's latest rel95 patchset that applies to PA 13.0.
>>>>
>>>> http://download.zenwalk.org/x86_64/testing/v12-12-13-zen-bluetooth-Implement-A2DP-codec-switching-and-backchannel-support-.patch
>>>>
>>>> JP
>>>>
>>>> 16.09.2019, 09:32, "Hyperion" <h1p8r10n@xxxxxxxxxx>:
>>>>> Hi,
>>>>>
>>>>> Following what has already be done in some Android derivatives, here's a simple patch that extend SBP bitpool negociation to XQ quality.
>>>>>
>>>>> According to :
>>>>> --> http://soundexpert.org/articles/-/blogs/audio-quality-of-sbc-xq-bluetooth-audio-codec
>>>>> --> https://lineageos.org/engineering/Bluetooth-SBC-XQ/ ,
>>>>> --> and confirmed by my own experimentation on more than 10 different devices,
>>>>>
>>>>> here are the features of the (very simple and non intrusive) patch :
>>>>> - allow to use bitpool 76 on devices that support it, aka SBC XQ
>>>>> - harmless for devices limited to bitpool 53
>>>>> - deprecates the need for APTX & APTX HD support, which are not better than SBC XQ, are not Open Source, and less supported by devices
>>>>>
>>>>> This patch will be superseded by multi-profiles Pali Rohar A2DP stack implementation, when it's ready for production. Thanks to Pali for the help testing many codec parameters.
>>>>>
>>>>> Let me know if I have to clone the git to push my patch, or if a regular PA dev could do it.
>>>>>
>>>>> All the best
>>>>> JP
>>>>>
>>>>> diff -rNaud pulseaudio-13.0/src/modules/bluetooth/a2dp-codec-sbc.c pulseaudio-13.0-new/src/modules/bluetooth/a2dp-codec-sbc.c
>>>>> --- pulseaudio-13.0/src/modules/bluetooth/a2dp-codec-sbc.c 2019-09-13 15:20:03.000000000 +0200
>>>>> +++ pulseaudio-13.0-new/src/modules/bluetooth/a2dp-codec-sbc.c 2019-09-16 08:57:50.363122019 +0200
>>>>> @@ -290,10 +290,10 @@
>>>>> return 0;
>>>>> }
>>>>>
>>>>> - if (capabilities->allocation_method & SBC_ALLOCATION_LOUDNESS)
>>>>> - config->allocation_method = SBC_ALLOCATION_LOUDNESS;
>>>>> - else if (capabilities->allocation_method & SBC_ALLOCATION_SNR)
>>>>> + if (capabilities->allocation_method & SBC_ALLOCATION_SNR)
>>>>> config->allocation_method = SBC_ALLOCATION_SNR;
>>>>> + else if (capabilities->allocation_method & SBC_ALLOCATION_LOUDNESS)
>>>>> + config->allocation_method = SBC_ALLOCATION_LOUDNESS;
>>>>> else {
>>>>> pa_log_error("No supported allocation method");
>>>>> return 0;
>>>>> diff -rNaud pulseaudio-13.0/src/modules/bluetooth/a2dp-codecs.h pulseaudio-13.0-new/src/modules/bluetooth/a2dp-codecs.h
>>>>> --- pulseaudio-13.0/src/modules/bluetooth/a2dp-codecs.h 2019-09-13 15:20:03.000000000 +0200
>>>>> +++ pulseaudio-13.0-new/src/modules/bluetooth/a2dp-codecs.h 2019-09-16 08:44:20.382086305 +0200
>>>>> @@ -61,14 +61,11 @@
>>>>> * Allocation method = Loudness
>>>>> * Subbands = 8
>>>>> */
>>>>> -#define SBC_BITPOOL_MQ_MONO_44100 19
>>>>> -#define SBC_BITPOOL_MQ_MONO_48000 18
>>>>> -#define SBC_BITPOOL_MQ_JOINT_STEREO_44100 35
>>>>> -#define SBC_BITPOOL_MQ_JOINT_STEREO_48000 33
>>>>> -#define SBC_BITPOOL_HQ_MONO_44100 31
>>>>> -#define SBC_BITPOOL_HQ_MONO_48000 29
>>>>> -#define SBC_BITPOOL_HQ_JOINT_STEREO_44100 53
>>>>> -#define SBC_BITPOOL_HQ_JOINT_STEREO_48000 51
>>>>> +
>>>>> +#define SBC_BITPOOL_HQ_MONO_44100 38
>>>>> +#define SBC_BITPOOL_HQ_MONO_48000 38
>>>>> +#define SBC_BITPOOL_HQ_JOINT_STEREO_44100 76
>>>>> +#define SBC_BITPOOL_HQ_JOINT_STEREO_48000 76
>>>>>
>>>>> #define MPEG_CHANNEL_MODE_MONO (1 << 3)
>>>>> #define MPEG_CHANNEL_MODE_DUAL_CHANNEL (1 << 2)
>>>>>
>>>>> _______________________________________________
>>>>> pulseaudio-discuss mailing list
>>>>> pulseaudio-discuss@xxxxxxxxxxxxxxxxxxxxx
>>>>> https://lists.freedesktop.org/mailman/listinfo/pulseaudio-discuss
>>
>> _______________________________________________
>> pulseaudio-discuss mailing list
>> pulseaudio-discuss@xxxxxxxxxxxxxxxxxxxxx
>> https://lists.freedesktop.org/mailman/listinfo/pulseaudio-discuss
>
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