[pulseaudio-discuss] SBC XQ for PA 13.0
Andrey Semashev
andrey.semashev at gmail.com
Thu Sep 19 08:27:32 UTC 2019
I'm not the maintainer, but it might be better to create a merge request
in GitLab project:
https://gitlab.freedesktop.org/pulseaudio/pulseaudio
and post any additional information there so it doesn't get lost.
On 2019-09-18 14:02, Hyperion wrote:
> 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 at gmail.com>
>
> 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 at yandex.com>:
>> 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 at yandex.com>:
>>> 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 at lists.freedesktop.org
>>> https://lists.freedesktop.org/mailman/listinfo/pulseaudio-discuss
> _______________________________________________
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> pulseaudio-discuss at lists.freedesktop.org
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>
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