diff options
author | VaL Doroshchuk <valentyn.doroshchuk@qt.io> | 2019-10-25 12:29:34 +0200 |
---|---|---|
committer | VaL Doroshchuk <valentyn.doroshchuk@qt.io> | 2020-03-25 11:33:30 +0000 |
commit | 61a6a09429cf8c34a356748a3bb76fc7868a54b1 (patch) | |
tree | f693ebef1103ebea29932c8aba9dc40a426a3676 | |
parent | c22f263c5d7bd602197215978d59e53d67a7dd6d (diff) |
ALSA: Calculate buffer size based on min period time
When defualt buffer size (100000us) and period time (20000us)
are out of range, currently buffer size is computed with
respect of either 2 or 4 chunks of maximum buffer time.
Which is not enough.
Fixing computing of buffer time based on minimum period time:
How many minimum periods could fit in maximum suggested buffer time.
Fixes: QTBUG-43256
Task-number: QTBUG-79526
Change-Id: I722e5145e3b6d323e306da420ec764db3575225f
Reviewed-by: Christian Strømme <christian.stromme@qt.io>
(cherry picked from commit 8b92454d6fffcee7a8cf1fb5e0c92920c77733c8)
Reviewed-by: Andy Shaw <andy.shaw@qt.io>
-rw-r--r-- | src/plugins/alsa/qalsaaudiooutput.cpp | 34 |
1 files changed, 15 insertions, 19 deletions
diff --git a/src/plugins/alsa/qalsaaudiooutput.cpp b/src/plugins/alsa/qalsaaudiooutput.cpp index ddbe04de9..5c8ae171c 100644 --- a/src/plugins/alsa/qalsaaudiooutput.cpp +++ b/src/plugins/alsa/qalsaaudiooutput.cpp @@ -53,9 +53,11 @@ #include <QtMultimedia/private/qaudiohelpers_p.h> #include "qalsaaudiooutput.h" #include "qalsaaudiodeviceinfo.h" +#include <QLoggingCategory> QT_BEGIN_NAMESPACE +Q_LOGGING_CATEGORY(lcAlsaOutput, "qt.multimedia.alsa.output") //#define DEBUG_AUDIO 1 QAlsaAudioOutput::QAlsaAudioOutput(const QByteArray &device) @@ -403,28 +405,22 @@ bool QAlsaAudioOutput::open() fatal = true; errMessage = QString::fromLatin1("QAudioOutput: buffer/period min and max: err = %1").arg(err); } else { - if (maxBufferTime < buffer_time || buffer_time < minBufferTime || maxPeriodTime < period_time || minPeriodTime > period_time) { -#ifdef DEBUG_AUDIO - qDebug()<<"defaults out of range"; - qDebug()<<"pmin="<<minPeriodTime<<", pmax="<<maxPeriodTime<<", bmin="<<minBufferTime<<", bmax="<<maxBufferTime; -#endif - period_time = minPeriodTime; - if (period_time*4 <= maxBufferTime) { - // Use 4 periods if possible - buffer_time = period_time*4; - chunks = 4; - } else if (period_time*2 <= maxBufferTime) { - // Use 2 periods if possible - buffer_time = period_time*2; - chunks = 2; + static unsigned user_buffer_time = qEnvironmentVariableIntValue("QT_ALSA_OUTPUT_BUFFER_TIME"); + static unsigned user_period_time = qEnvironmentVariableIntValue("QT_ALSA_OUTPUT_PERIOD_TIME"); + const bool outOfRange = maxBufferTime < buffer_time || buffer_time < minBufferTime || maxPeriodTime < period_time || minPeriodTime > period_time; + if (outOfRange || user_period_time || user_buffer_time) { + period_time = user_period_time ? user_period_time : minPeriodTime; + if (!user_buffer_time) { + chunks = maxBufferTime / period_time; + buffer_time = period_time * chunks; } else { - qWarning()<<"QAudioOutput: alsa only supports single period!"; - fatal = true; + buffer_time = user_buffer_time; + chunks = buffer_time / period_time; } -#ifdef DEBUG_AUDIO - qDebug()<<"used: buffer_time="<<buffer_time<<", period_time="<<period_time; -#endif } + qCDebug(lcAlsaOutput) << "buffer time: [" << minBufferTime << "-" << maxBufferTime << "] =" << buffer_time; + qCDebug(lcAlsaOutput) << "period time: [" << minPeriodTime << "-" << maxPeriodTime << "] =" << period_time; + qCDebug(lcAlsaOutput) << "chunks =" << chunks; } } if ( !fatal ) { |