<html>
<head>
<base href="https://bugs.freedesktop.org/" />
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [bluetooth] wrong SBC configuration on big endian platforms"
href="https://bugs.freedesktop.org/show_bug.cgi?id=91359">91359</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[bluetooth] wrong SBC configuration on big endian platforms
</td>
</tr>
<tr>
<th>Product</th>
<td>PulseAudio
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>Other
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux (All)
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>medium
</td>
</tr>
<tr>
<th>Component</th>
<td>modules
</td>
</tr>
<tr>
<th>Assignee</th>
<td>pulseaudio-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>p06@o2.pl
</td>
</tr>
<tr>
<th>QA Contact</th>
<td>pulseaudio-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>CC</th>
<td>lennart@poettering.net
</td>
</tr></table>
<p>
<div>
<pre>PLATFORM:
AR9311 MIPS 24K SoC
OpenWRT Chaos Calmer 15.05
BlueZ 5.32
PulseAudio 6.0
PROBLEM:
White noise when streaming audio over A2DP from bluetooth device to PA server
running on big endian platforms.
CAUSE:
method bt_transport_config_a2dp() in
src/modules/bluetooth/module-bluez4-device.c
method transport_config() in src/modules/bluetooth/module-bluez5-device.c
The current code assumes that endianness of the data returned by SBC is always
little endian and configure the transport in this way:
module-bluez4-device.c
1707| u->sample_spec.format = PA_SAMPLE_S16LE;
module-bluez5-device.c
1159| u->sample_spec.format = PA_SAMPLE_S16LE;
However an endianness in default settings returned by SBC is set according to
endianness of target platform:
1025| sbc->blocks = SBC_BLK_16;
1026| sbc->bitpool = 32;
1027| #if __BYTE_ORDER == __LITTLE_ENDIAN
1028| sbc->endian = SBC_LE;
1029| #elif __BYTE_ORDER == __BIG_ENDIAN
1030| sbc->endian = SBC_BE;
1031| #else
1032| #error "Unknown byte order"
1033| #endif
see:
<a href="http://git.kernel.org/cgit/bluetooth/sbc.git/tree/sbc/sbc.c#n1027">http://git.kernel.org/cgit/bluetooth/sbc.git/tree/sbc/sbc.c#n1027</a>
Thus on big endian platforms SBC returns data in big endian format but PA
treats it as little endian, which results with white noise.
SOLUTION:
Explicitly set SBC configuration to produce little endian data by adding:
module-bluez4-device.c
1714| sbc_info->sbc.endian = SBC_LE;
module-bluez5-device.c
1167| sbc_info->sbc.endian = SBC_LE;
WORKAROUND:
not known.</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are the QA Contact for the bug.</li>
<li>You are the assignee for the bug.</li>
</ul>
</body>
</html>