Re: [PATCH 5/9] android/hal-audio: Calculate SBC stream parameters

Hi Andrzej,

On Fri, Jan 17, 2014 at 9:17 PM, Andrzej Kaczmarek
[off-list ref] wrote:

Hi Marcel,

On 17 January 2014 19:25, Marcel Holtmann [off-list ref] wrote:

quoted

Hi Andrzej,

quoted

This patch adds necessary calculations for SBC stream parameters.

Both input and output buffers are expected to have exact amount of
data to fill single media packet (based on transport channel MTU).

Frame duration will be used to synchronize input and output streams.
---
android/hal-audio.c | 50 ++++++++++++++++++++++++++++++-----
android/rtp.h       | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 120 insertions(+), 6 deletions(-)
create mode 100644 android/rtp.h

diff --git a/android/hal-audio.c b/android/hal-audio.c
index e5c646c..3f53295 100644
--- a/android/hal-audio.c
+++ b/android/hal-audio.c

@@ -33,6 +33,7 @@

#include "hal-msg.h"
#include "../profiles/audio/a2dp-codecs.h"
#include <sbc/sbc.h>
+#include "rtp.h"

static const uint8_t a2dp_src_uuid[] = {
              0x00, 0x00, 0x11, 0x0a, 0x00, 0x00, 0x10, 0x00,

@@ -46,6 +47,12 @@ static pthread_t ipc_th = 0;

static pthread_mutex_t close_mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t sk_mutex = PTHREAD_MUTEX_INITIALIZER;

+struct media_packet {
+     struct rtp_header hdr;
+     struct rtp_payload payload;
+     uint8_t data[0];
+};
+
struct audio_input_config {
      uint32_t rate;
      uint32_t channels;

@@ -56,10 +63,19 @@ struct sbc_data {
      a2dp_sbc_t sbc;

      sbc_t enc;
+
+     size_t in_frame_len;
+     size_t in_buf_size;
+
+     size_t out_buf_size;
+     uint8_t *out_buf;
+
+     unsigned frame_duration;

};

static int sbc_get_presets(struct audio_preset *preset, size_t *len);
-static int sbc_codec_init(struct audio_preset *preset, void **codec_data);
+static int sbc_codec_init(struct audio_preset *preset, uint16_t mtu,
+                             void **codec_data);
static int sbc_cleanup(void *codec_data);
static int sbc_get_config(void *codec_data,
                                      struct audio_input_config *config);

@@ -69,7 +85,8 @@ struct audio_codec {

      int (*get_presets) (struct audio_preset *preset, size_t *len);

-     int (*init) (struct audio_preset *preset, void **codec_data);
+     int (*init) (struct audio_preset *preset, uint16_t mtu,
+                             void **codec_data);
      int (*cleanup) (void *codec_data);
      int (*get_config) (void *codec_data,
                                      struct audio_input_config *config);

@@ -251,9 +268,14 @@ static void sbc_init_encoder(struct sbc_data *sbc_data)
      }

}

-static int sbc_codec_init(struct audio_preset *preset, void **codec_data)
+static int sbc_codec_init(struct audio_preset *preset, uint16_t mtu,
+                             void **codec_data)
{
      struct sbc_data *sbc_data;
+     size_t hdr_len = sizeof(struct media_packet);
+     size_t in_frame_len;
+     size_t out_frame_len;
+     size_t num_frames;

      DBG("");

@@ -268,6 +290,18 @@ static int sbc_codec_init(struct audio_preset *preset, void **codec_data)

      sbc_init_encoder(sbc_data);

+     in_frame_len = sbc_get_codesize(&sbc_data->enc);
+     out_frame_len = sbc_get_frame_length(&sbc_data->enc);
+     num_frames = (mtu - hdr_len) / out_frame_len;
+
+     sbc_data->in_frame_len = in_frame_len;
+     sbc_data->in_buf_size = num_frames * in_frame_len;
+
+     sbc_data->out_buf_size = hdr_len + num_frames * out_frame_len;
+     sbc_data->out_buf = calloc(1, sbc_data->out_buf_size);
+
+     sbc_data->frame_duration = sbc_get_frame_duration(&sbc_data->enc);
+
      *codec_data = sbc_data;

      return AUDIO_STATUS_SUCCESS;

@@ -280,6 +314,7 @@ static int sbc_cleanup(void *codec_data)
      DBG("");

      sbc_finish(&sbc_data->enc);
+     free(sbc_data->out_buf);
      free(codec_data);

      return AUDIO_STATUS_SUCCESS;

@@ -511,7 +546,7 @@ static int ipc_close_cmd(uint8_t endpoint_id)
      return result;

}

-static int ipc_open_stream_cmd(uint8_t endpoint_id,
+static int ipc_open_stream_cmd(uint8_t endpoint_id, uint16_t *mtu,
                                      struct audio_preset **caps)
{
      char buf[BLUEZ_AUDIO_MTU];

@@ -534,6 +569,7 @@ static int ipc_open_stream_cmd(uint8_t endpoint_id,
      if (result == AUDIO_STATUS_SUCCESS) {
              size_t buf_len = sizeof(struct audio_preset) +
                                      rsp->preset[0].len;
+             *mtu = rsp->mtu;
              *caps = malloc(buf_len);
              memcpy(*caps, &rsp->preset, buf_len);
      } else {

@@ -919,6 +955,7 @@ static int audio_open_output_stream(struct audio_hw_device *dev,
      struct a2dp_stream_out *out;
      struct audio_preset *preset;
      const struct audio_codec *codec;
+     uint16_t mtu;

      out = calloc(1, sizeof(struct a2dp_stream_out));
      if (!out)

@@ -946,7 +983,8 @@ static int audio_open_output_stream(struct audio_hw_device *dev,
      /* TODO: for now we always use endpoint 0 */
      out->ep = &audio_endpoints[0];

-     if (ipc_open_stream_cmd(out->ep->id, &preset) != AUDIO_STATUS_SUCCESS)
+     if (ipc_open_stream_cmd(out->ep->id, &mtu, &preset) !=
+                     AUDIO_STATUS_SUCCESS)
              goto fail;

      if (!preset)

@@ -954,7 +992,7 @@ static int audio_open_output_stream(struct audio_hw_device *dev,

      codec = out->ep->codec;

-     codec->init(preset, &out->ep->codec_data);
+     codec->init(preset, mtu, &out->ep->codec_data);
      codec->get_config(out->ep->codec_data, &out->cfg);

      DBG("rate=%d channels=%d format=%d", out->cfg.rate,

diff --git a/android/rtp.h b/android/rtp.h
new file mode 100644
index 0000000..45fddcf
--- /dev/null
+++ b/android/rtp.h

@@ -0,0 +1,76 @@
+/*
+ *
+ *  BlueZ - Bluetooth protocol stack for Linux
+ *
+ *  Copyright (C) 2004-2010  Marcel Holtmann <marcel@holtmann.org>
+ *
+ *
+ *  This library 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.
+ *
+ *  This library 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
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */

where is this file coming from? Why do we need a copy of it?

From BlueZ but it was removed (was used in pcm_bluetooth.c) so I just
added it again since we need RTP header structures. Or should these
just be added inline to hal-audio.c?

I would just add these to hal-audio.c, nothing else should need it.


-- 
Luiz Augusto von Dentz