mirror of
https://gitlab.freedesktop.org/pulseaudio/pulseaudio.git
synced 2025-11-06 13:29:56 -05:00
bluetooth: a2dp dual channel SBC XQ codec configurations
Desired SBC bitpool value is calculated from target bitrate limit. Part-of: <https://gitlab.freedesktop.org/pulseaudio/pulseaudio/-/merge_requests/476>
This commit is contained in:
Igor V. Kovalenko
PulseAudio Marge Bot
parent
ff2f16294f
commit
89082cbfaa
2 changed files with 329 additions and 32 deletions
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@ -51,6 +51,9 @@ struct sbc_info {
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uint8_t initial_bitpool;
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uint8_t min_bitpool;
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uint8_t max_bitpool;
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uint8_t nr_blocks;
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uint8_t nr_subbands;
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};
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static bool can_be_supported(bool for_encoding) {
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@ -81,6 +84,30 @@ static bool can_accept_capabilities(const uint8_t *capabilities_buffer, uint8_t
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return true;
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}
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static bool can_accept_capabilities_xq(const uint8_t *capabilities_buffer, uint8_t capabilities_size, bool for_encoding) {
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const a2dp_sbc_t *capabilities = (const a2dp_sbc_t *) capabilities_buffer;
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if (capabilities_size != sizeof(*capabilities))
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return false;
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if (!(capabilities->frequency & (SBC_SAMPLING_FREQ_44100 | SBC_SAMPLING_FREQ_48000)))
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return false;
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if (!(capabilities->channel_mode & (SBC_CHANNEL_MODE_DUAL_CHANNEL)))
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return false;
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if (!(capabilities->allocation_method & (SBC_ALLOCATION_LOUDNESS)))
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return false;
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if (!(capabilities->subbands & (SBC_SUBBANDS_8)))
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return false;
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if (!(capabilities->block_length & (SBC_BLOCK_LENGTH_16)))
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return false;
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return true;
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}
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static const char *choose_remote_endpoint(const pa_hashmap *capabilities_hashmap, const pa_sample_spec *default_sample_spec, bool for_encoding) {
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const pa_a2dp_codec_capabilities *a2dp_capabilities;
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const char *key;
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@ -95,6 +122,20 @@ static const char *choose_remote_endpoint(const pa_hashmap *capabilities_hashmap
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return NULL;
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}
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static const char *choose_remote_endpoint_xq(const pa_hashmap *capabilities_hashmap, const pa_sample_spec *default_sample_spec, bool for_encoding) {
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const pa_a2dp_codec_capabilities *a2dp_capabilities;
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const char *key;
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void *state;
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/* There is no preference, just choose random valid entry */
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PA_HASHMAP_FOREACH_KV(key, a2dp_capabilities, capabilities_hashmap, state) {
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if (can_accept_capabilities_xq(a2dp_capabilities->buffer, a2dp_capabilities->size, for_encoding))
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return key;
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}
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return NULL;
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}
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static uint8_t fill_capabilities(uint8_t capabilities_buffer[MAX_A2DP_CAPS_SIZE]) {
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a2dp_sbc_t *capabilities = (a2dp_sbc_t *) capabilities_buffer;
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@ -113,6 +154,29 @@ static uint8_t fill_capabilities(uint8_t capabilities_buffer[MAX_A2DP_CAPS_SIZE]
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return sizeof(*capabilities);
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}
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/* SBC XQ
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*
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* References:
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* https://habr.com/en/post/456476/
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* http://soundexpert.org/articles/-/blogs/audio-quality-of-sbc-xq-bluetooth-audio-codec
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*
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*/
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static uint8_t fill_capabilities_xq(uint8_t capabilities_buffer[MAX_A2DP_CAPS_SIZE]) {
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a2dp_sbc_t *capabilities = (a2dp_sbc_t *) capabilities_buffer;
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pa_zero(*capabilities);
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capabilities->channel_mode = SBC_CHANNEL_MODE_DUAL_CHANNEL;
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capabilities->frequency = SBC_SAMPLING_FREQ_44100 | SBC_SAMPLING_FREQ_48000;
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capabilities->allocation_method = SBC_ALLOCATION_LOUDNESS;
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capabilities->subbands = SBC_SUBBANDS_8;
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capabilities->block_length = SBC_BLOCK_LENGTH_16;
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capabilities->min_bitpool = SBC_MIN_BITPOOL;
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capabilities->max_bitpool = SBC_MAX_BITPOOL;
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return sizeof(*capabilities);
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}
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static bool is_configuration_valid(const uint8_t *config_buffer, uint8_t config_size) {
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const a2dp_sbc_t *config = (const a2dp_sbc_t *) config_buffer;
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@ -314,38 +378,7 @@ static uint8_t fill_preferred_configuration(const pa_sample_spec *default_sample
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return sizeof(*config);
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}
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static void set_params(struct sbc_info *sbc_info) {
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sbc_info->sbc.frequency = sbc_info->frequency;
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sbc_info->sbc.blocks = sbc_info->blocks;
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sbc_info->sbc.subbands = sbc_info->subbands;
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sbc_info->sbc.mode = sbc_info->mode;
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sbc_info->sbc.allocation = sbc_info->allocation;
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sbc_info->sbc.bitpool = sbc_info->initial_bitpool;
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sbc_info->sbc.endian = SBC_LE;
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sbc_info->codesize = sbc_get_codesize(&sbc_info->sbc);
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sbc_info->frame_length = sbc_get_frame_length(&sbc_info->sbc);
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}
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static void *init(bool for_encoding, bool for_backchannel, const uint8_t *config_buffer, uint8_t config_size, pa_sample_spec *sample_spec, pa_core *core) {
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struct sbc_info *sbc_info;
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const a2dp_sbc_t *config = (const a2dp_sbc_t *) config_buffer;
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int ret;
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pa_assert(config_size == sizeof(*config));
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pa_assert(!for_backchannel);
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sbc_info = pa_xnew0(struct sbc_info, 1);
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ret = sbc_init(&sbc_info->sbc, 0);
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if (ret != 0) {
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pa_xfree(sbc_info);
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pa_log_error("SBC initialization failed: %d", ret);
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return NULL;
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}
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sample_spec->format = PA_SAMPLE_S16LE;
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static void set_info_and_sample_spec_from_sbc_config(struct sbc_info *sbc_info, pa_sample_spec *sample_spec, const a2dp_sbc_t *config) {
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switch (config->frequency) {
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case SBC_SAMPLING_FREQ_16000:
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sbc_info->frequency = SBC_FREQ_16000;
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@ -402,9 +435,11 @@ static void *init(bool for_encoding, bool for_backchannel, const uint8_t *config
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switch (config->subbands) {
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case SBC_SUBBANDS_4:
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sbc_info->subbands = SBC_SB_4;
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sbc_info->nr_subbands = 4;
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break;
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case SBC_SUBBANDS_8:
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sbc_info->subbands = SBC_SB_8;
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sbc_info->nr_subbands = 8;
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break;
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default:
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pa_assert_not_reached();
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@ -413,15 +448,19 @@ static void *init(bool for_encoding, bool for_backchannel, const uint8_t *config
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switch (config->block_length) {
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case SBC_BLOCK_LENGTH_4:
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sbc_info->blocks = SBC_BLK_4;
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sbc_info->nr_blocks = 4;
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break;
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case SBC_BLOCK_LENGTH_8:
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sbc_info->blocks = SBC_BLK_8;
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sbc_info->nr_blocks = 8;
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break;
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case SBC_BLOCK_LENGTH_12:
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sbc_info->blocks = SBC_BLK_12;
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sbc_info->nr_blocks = 12;
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break;
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case SBC_BLOCK_LENGTH_16:
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sbc_info->blocks = SBC_BLK_16;
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sbc_info->nr_blocks = 16;
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break;
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default:
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pa_assert_not_reached();
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@ -429,6 +468,182 @@ static void *init(bool for_encoding, bool for_backchannel, const uint8_t *config
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sbc_info->min_bitpool = config->min_bitpool;
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sbc_info->max_bitpool = config->max_bitpool;
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}
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static void set_params(struct sbc_info *sbc_info) {
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sbc_info->sbc.frequency = sbc_info->frequency;
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sbc_info->sbc.blocks = sbc_info->blocks;
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sbc_info->sbc.subbands = sbc_info->subbands;
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sbc_info->sbc.mode = sbc_info->mode;
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sbc_info->sbc.allocation = sbc_info->allocation;
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sbc_info->sbc.bitpool = sbc_info->initial_bitpool;
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sbc_info->sbc.endian = SBC_LE;
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sbc_info->codesize = sbc_get_codesize(&sbc_info->sbc);
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sbc_info->frame_length = sbc_get_frame_length(&sbc_info->sbc);
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}
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uint8_t sbc_get_max_bitpool_below_rate(a2dp_sbc_t *config, uint8_t lower_bound, uint8_t upper_bound, uint32_t bitrate_cap) {
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pa_sample_spec sample_spec;
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struct sbc_info sbc_info;
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int ret;
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pa_assert(config);
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ret = sbc_init(&sbc_info.sbc, 0);
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if (ret != 0) {
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pa_log_error("SBC initialization failed: %d", ret);
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return lower_bound;
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}
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set_info_and_sample_spec_from_sbc_config(&sbc_info, &sample_spec, config);
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while (upper_bound - lower_bound > 1) {
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size_t midpoint = (upper_bound + lower_bound) / 2;
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sbc_info.initial_bitpool = midpoint;
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set_params(&sbc_info);
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size_t bitrate = sbc_info.frame_length * 8 * sample_spec.rate / (sbc_info.nr_subbands * sbc_info.nr_blocks);
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if (bitrate > bitrate_cap)
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upper_bound = midpoint;
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else
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lower_bound = midpoint;
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}
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sbc_finish(&sbc_info.sbc);
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pa_log_debug("SBC target bitrate %u bitpool %u sample rate %u", bitrate_cap, lower_bound, sample_spec.rate);
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return lower_bound;
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}
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static uint8_t fill_preferred_configuration_xq(const pa_sample_spec *default_sample_spec, const uint8_t *capabilities_buffer, uint8_t capabilities_size, uint8_t config_buffer[MAX_A2DP_CAPS_SIZE], uint32_t bitrate_cap) {
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a2dp_sbc_t *config = (a2dp_sbc_t *) config_buffer;
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const a2dp_sbc_t *capabilities = (const a2dp_sbc_t *) capabilities_buffer;
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int i;
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static const struct {
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uint32_t rate;
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uint8_t cap;
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} freq_table[] = {
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{ 16000U, SBC_SAMPLING_FREQ_16000 },
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{ 32000U, SBC_SAMPLING_FREQ_32000 },
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{ 44100U, SBC_SAMPLING_FREQ_44100 },
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{ 48000U, SBC_SAMPLING_FREQ_48000 }
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};
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if (capabilities_size != sizeof(*capabilities)) {
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pa_log_error("Invalid size of capabilities buffer");
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return 0;
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}
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pa_zero(*config);
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/* Find the lowest freq that is at least as high as the requested sampling rate */
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for (i = 0; (unsigned) i < PA_ELEMENTSOF(freq_table); i++)
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if (freq_table[i].rate >= default_sample_spec->rate && (capabilities->frequency & freq_table[i].cap)) {
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config->frequency = freq_table[i].cap;
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break;
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}
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if ((unsigned) i == PA_ELEMENTSOF(freq_table)) {
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for (--i; i >= 0; i--) {
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if (capabilities->frequency & freq_table[i].cap) {
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config->frequency = freq_table[i].cap;
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break;
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}
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}
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if (i < 0) {
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pa_log_error("Not suitable sample rate");
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return 0;
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}
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}
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pa_assert((unsigned) i < PA_ELEMENTSOF(freq_table));
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if (default_sample_spec->channels <= 1) {
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if (capabilities->channel_mode & SBC_CHANNEL_MODE_DUAL_CHANNEL)
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config->channel_mode = SBC_CHANNEL_MODE_DUAL_CHANNEL;
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else {
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pa_log_error("No supported channel modes");
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return 0;
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}
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} else {
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if (capabilities->channel_mode & SBC_CHANNEL_MODE_DUAL_CHANNEL)
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config->channel_mode = SBC_CHANNEL_MODE_DUAL_CHANNEL;
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else {
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pa_log_error("No supported channel modes");
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return 0;
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}
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}
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if (capabilities->block_length & SBC_BLOCK_LENGTH_16)
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config->block_length = SBC_BLOCK_LENGTH_16;
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else {
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pa_log_error("No supported block lengths");
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return 0;
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}
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if (capabilities->subbands & SBC_SUBBANDS_8)
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config->subbands = SBC_SUBBANDS_8;
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else {
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pa_log_error("No supported subbands");
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return 0;
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}
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if (capabilities->allocation_method & SBC_ALLOCATION_LOUDNESS)
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config->allocation_method = SBC_ALLOCATION_LOUDNESS;
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else {
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pa_log_error("No supported allocation method");
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return 0;
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}
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config->min_bitpool = (uint8_t) PA_MAX(SBC_MIN_BITPOOL, capabilities->min_bitpool);
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config->max_bitpool = sbc_get_max_bitpool_below_rate(config, config->min_bitpool, capabilities->max_bitpool, bitrate_cap);
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if (config->min_bitpool > config->max_bitpool) {
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pa_log_error("No supported bitpool");
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return 0;
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}
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return sizeof(*config);
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}
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static uint8_t fill_preferred_configuration_xq_453kbps(const pa_sample_spec *default_sample_spec, const uint8_t *capabilities_buffer, uint8_t capabilities_size, uint8_t config_buffer[MAX_A2DP_CAPS_SIZE]) {
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return fill_preferred_configuration_xq(default_sample_spec, capabilities_buffer, capabilities_size, config_buffer, 453000);
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}
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static uint8_t fill_preferred_configuration_xq_512kbps(const pa_sample_spec *default_sample_spec, const uint8_t *capabilities_buffer, uint8_t capabilities_size, uint8_t config_buffer[MAX_A2DP_CAPS_SIZE]) {
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return fill_preferred_configuration_xq(default_sample_spec, capabilities_buffer, capabilities_size, config_buffer, 512000);
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}
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static uint8_t fill_preferred_configuration_xq_552kbps(const pa_sample_spec *default_sample_spec, const uint8_t *capabilities_buffer, uint8_t capabilities_size, uint8_t config_buffer[MAX_A2DP_CAPS_SIZE]) {
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return fill_preferred_configuration_xq(default_sample_spec, capabilities_buffer, capabilities_size, config_buffer, 552000);
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}
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static void *init(bool for_encoding, bool for_backchannel, const uint8_t *config_buffer, uint8_t config_size, pa_sample_spec *sample_spec, pa_core *core) {
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struct sbc_info *sbc_info;
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const a2dp_sbc_t *config = (const a2dp_sbc_t *) config_buffer;
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int ret;
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pa_assert(config_size == sizeof(*config));
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pa_assert(!for_backchannel);
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sbc_info = pa_xnew0(struct sbc_info, 1);
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ret = sbc_init(&sbc_info->sbc, 0);
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if (ret != 0) {
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pa_xfree(sbc_info);
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pa_log_error("SBC initialization failed: %d", ret);
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return NULL;
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}
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sample_spec->format = PA_SAMPLE_S16LE;
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set_info_and_sample_spec_from_sbc_config(sbc_info, sample_spec, config);
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/* Set minimum bitpool for source to get the maximum possible block_size
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* in get_block_size() function. This block_size is length of buffer used
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@ -692,3 +907,79 @@ const pa_a2dp_codec pa_a2dp_codec_sbc = {
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.encode_buffer = encode_buffer,
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.decode_buffer = decode_buffer,
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};
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/* There are multiple definitions of SBC XQ, but in all cases this is
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* SBC codec in Dual Channel mode, 8 bands, block length 16, allocation method Loudness,
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* with bitpool adjusted to match target bitrates.
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*
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* Most commonly choosen bitrates and reasons are:
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* 453000 - this yields most efficient packing of frames on Android for bluetooth EDR 2mbps
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* 512000 - this looks to be old limit stated in bluetooth documents
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* 552000 - this yields most efficient packing of frames on Android for bluetooth EDR 3mbps
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*
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* Efficient packing considerations do not apply on Linux (yet?) but still
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* we can gain from increased bitrate.
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*/
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const pa_a2dp_codec pa_a2dp_codec_sbc_xq_453 = {
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.name = "sbc_xq_453",
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.description = "SBC XQ 453kbps",
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.id = { A2DP_CODEC_SBC, 0, 0 },
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.support_backchannel = false,
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.can_be_supported = can_be_supported,
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.can_accept_capabilities = can_accept_capabilities_xq,
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.choose_remote_endpoint = choose_remote_endpoint_xq,
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.fill_capabilities = fill_capabilities_xq,
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.is_configuration_valid = is_configuration_valid,
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.fill_preferred_configuration = fill_preferred_configuration_xq_453kbps,
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.init = init,
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.deinit = deinit,
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.reset = reset,
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.get_read_block_size = get_block_size,
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.get_write_block_size = get_block_size,
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.reduce_encoder_bitrate = reduce_encoder_bitrate,
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.encode_buffer = encode_buffer,
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.decode_buffer = decode_buffer,
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};
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const pa_a2dp_codec pa_a2dp_codec_sbc_xq_512 = {
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.name = "sbc_xq_512",
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.description = "SBC XQ 512kbps",
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.id = { A2DP_CODEC_SBC, 0, 0 },
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.support_backchannel = false,
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.can_be_supported = can_be_supported,
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.can_accept_capabilities = can_accept_capabilities_xq,
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.choose_remote_endpoint = choose_remote_endpoint_xq,
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.fill_capabilities = fill_capabilities_xq,
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.is_configuration_valid = is_configuration_valid,
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.fill_preferred_configuration = fill_preferred_configuration_xq_512kbps,
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.init = init,
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.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,
|
||||
};
|
||||
|
||||
const pa_a2dp_codec pa_a2dp_codec_sbc_xq_552 = {
|
||||
.name = "sbc_xq_552",
|
||||
.description = "SBC XQ 552kbps",
|
||||
.id = { A2DP_CODEC_SBC, 0, 0 },
|
||||
.support_backchannel = false,
|
||||
.can_be_supported = can_be_supported,
|
||||
.can_accept_capabilities = can_accept_capabilities_xq,
|
||||
.choose_remote_endpoint = choose_remote_endpoint_xq,
|
||||
.fill_capabilities = fill_capabilities_xq,
|
||||
.is_configuration_valid = is_configuration_valid,
|
||||
.fill_preferred_configuration = fill_preferred_configuration_xq_552kbps,
|
||||
.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,
|
||||
};
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue