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From: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
To: "Pali Rohár" <pali.rohar@gmail.com>
Cc: "linux-bluetooth@vger.kernel.org" <linux-bluetooth@vger.kernel.org>
Subject: Re: [PATCH v2] a2dp-codecs: Fix SBC_MAX_BITPOOL and add SBC quality modes
Date: Tue, 29 Jan 2019 13:46:56 +0200
Message-ID: <CABBYNZJCKhfX8jdYPqQvXDrtGQvMVT-htqE8WoyGYPLh1E78zA@mail.gmail.com> (raw)
In-Reply-To: <20190128231021.22363-1-pali.rohar@gmail.com>

Hi Pali,
On Tue, Jan 29, 2019 at 1:12 AM Pali Rohár <pali.rohar@gmail.com> wrote:
>
> According to A2DP specification; section SBC; Codec Specific Information
> Elements; Minimum / Maximum Bitpool Value, range for Bitpool value is from
> 2 to 250.
>
> A2DP specification also defines bitpool values for two SBC modes: Middle
> Quality and High Quality. They depends on channel mode and frequency. So
> add definitions for them into a2dp-codecs file too.
>
> File android/hal-audio-sbc.c was updated to use High Quality mode for
> chosen frequency.
> ---
>  android/hal-audio-sbc.c      |  6 +++---
>  profiles/audio/a2dp-codecs.h | 12 +++++++++++-
>  2 files changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/android/hal-audio-sbc.c b/android/hal-audio-sbc.c
> index 80e271ed6..f11f40108 100644
> --- a/android/hal-audio-sbc.c
> +++ b/android/hal-audio-sbc.c
> @@ -92,7 +92,7 @@ static const a2dp_sbc_t sbc_presets[] = {
>                 .block_length = SBC_BLOCK_LENGTH_4 | SBC_BLOCK_LENGTH_8 |
>                                 SBC_BLOCK_LENGTH_12 | SBC_BLOCK_LENGTH_16,
>                 .min_bitpool = SBC_MIN_BITPOOL,
> -               .max_bitpool = SBC_MAX_BITPOOL
> +               .max_bitpool = SBC_BITPOOL_HIGH_QUALITY_JOINT_STEREO_44100,
>         },
>         {
>                 .frequency = SBC_SAMPLING_FREQ_44100,
> @@ -101,7 +101,7 @@ static const a2dp_sbc_t sbc_presets[] = {
>                 .allocation_method = SBC_ALLOCATION_LOUDNESS,
>                 .block_length = SBC_BLOCK_LENGTH_16,
>                 .min_bitpool = SBC_MIN_BITPOOL,
> -               .max_bitpool = SBC_MAX_BITPOOL
> +               .max_bitpool = SBC_BITPOOL_HIGH_QUALITY_JOINT_STEREO_44100,
>         },
>         {
>                 .frequency = SBC_SAMPLING_FREQ_48000,
> @@ -110,7 +110,7 @@ static const a2dp_sbc_t sbc_presets[] = {
>                 .allocation_method = SBC_ALLOCATION_LOUDNESS,
>                 .block_length = SBC_BLOCK_LENGTH_16,
>                 .min_bitpool = SBC_MIN_BITPOOL,
> -               .max_bitpool = SBC_MAX_BITPOOL
> +               .max_bitpool = SBC_BITPOOL_HIGH_QUALITY_JOINT_STEREO_48000,
>         },
>  };
>
> diff --git a/profiles/audio/a2dp-codecs.h b/profiles/audio/a2dp-codecs.h
> index 16088dc26..9bdd0f0b8 100644
> --- a/profiles/audio/a2dp-codecs.h
> +++ b/profiles/audio/a2dp-codecs.h
> @@ -53,8 +53,18 @@
>  #define SBC_ALLOCATION_SNR             (1 << 1)
>  #define SBC_ALLOCATION_LOUDNESS                1
>
> -#define SBC_MAX_BITPOOL                        64
>  #define SBC_MIN_BITPOOL                        2
> +#define SBC_MAX_BITPOOL                        250
> +
> +/* Other settings: Block length = 16, Allocation method = Loudness, Subbands = 8 */
> +#define SBC_BITPOOL_MIDDLE_QUALITY_MONO_44100          19
> +#define SBC_BITPOOL_MIDDLE_QUALITY_MONO_48000          18
> +#define SBC_BITPOOL_MIDDLE_QUALITY_JOINT_STEREO_44100  35
> +#define SBC_BITPOOL_MIDDLE_QUALITY_JOINT_STEREO_48000  33
> +#define SBC_BITPOOL_HIGH_QUALITY_MONO_44100            31
> +#define SBC_BITPOOL_HIGH_QUALITY_MONO_48000            29
> +#define SBC_BITPOOL_HIGH_QUALITY_JOINT_STEREO_44100    53
> +#define SBC_BITPOOL_HIGH_QUALITY_JOINT_STEREO_48000    51

Im quite fine with the new defines just their names could be a bit
shorter, perhaps use MQ and HQ for middle and high quality.

>  #define MPEG_CHANNEL_MODE_MONO         (1 << 3)
>  #define MPEG_CHANNEL_MODE_DUAL_CHANNEL (1 << 2)
> --
> 2.11.0
>


-- 
Luiz Augusto von Dentz

  reply index

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-26 10:45 [PATCH] a2dp-codecs: Remove wrong definition of SBC_MAX_BITPOOL Pali Rohár
2019-01-26 15:25 ` Luiz Augusto von Dentz
2019-01-27 10:07   ` Pali Rohár
2019-01-28 23:10 ` [PATCH v2] a2dp-codecs: Fix SBC_MAX_BITPOOL and add SBC quality modes Pali Rohár
2019-01-29 11:46   ` Luiz Augusto von Dentz [this message]
2019-01-29 17:12     ` [PATCH v3] " Pali Rohár
2019-01-31 10:52       ` Luiz Augusto von Dentz
2019-01-31 11:13         ` Pali Rohár

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