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Fix possible audio corruption.
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Under some circumstances, audio already played could be heard again. This was the result of an incorrect audio circular buffer pointer calculation
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@jyavenard
jyavenard committed Oct 6, 2011
1 parent 19b31f3 commit 35468d7
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Showing 2 changed files with 22 additions and 20 deletions.
33 changes: 17 additions & 16 deletions mythtv/libs/libmyth/audiooutputbase.cpp
View file
Expand Up @@ -959,7 +959,7 @@ int AudioOutputBase::CheckFreeSpace(int &frames)
* Returns the number of frames written, which may be less than requested
* if the upmixer buffered some (or all) of them
*/
int AudioOutputBase::CopyWithUpmix(char *buffer, int frames, int &org_waud)
int AudioOutputBase::CopyWithUpmix(char *buffer, int frames, uint &org_waud)
{
int len = CheckFreeSpace(frames);
int bdiff = kAudioRingBufferSize - org_waud;
Expand All @@ -978,7 +978,7 @@ int AudioOutputBase::CopyWithUpmix(char *buffer, int frames, int &org_waud)
}
if (num > 0)
memcpy(WPOS, buffer + off, num);
org_waud += num;
org_waud = (org_waud + num) % kAudioRingBufferSize;
return len;
}

Expand All @@ -996,7 +996,7 @@ int AudioOutputBase::CopyWithUpmix(char *buffer, int frames, int &org_waud)
if (frames > 0)
AudioOutputUtil::MonoToStereo(WPOS, buffer + off, frames);

org_waud += frames * bpf;
org_waud = (org_waud + frames * bpf) % kAudioRingBufferSize;
return len;
}

Expand Down Expand Up @@ -1031,7 +1031,7 @@ int AudioOutputBase::CopyWithUpmix(char *buffer, int frames, int &org_waud)
if (nFrames > 0)
upmixer->receiveFrames((float *)(WPOS), nFrames);

org_waud += nFrames * bpf;
org_waud = (org_waud + nFrames * bpf) % kAudioRingBufferSize;
}
return len;
}
Expand All @@ -1044,12 +1044,13 @@ int AudioOutputBase::CopyWithUpmix(char *buffer, int frames, int &org_waud)
bool AudioOutputBase::AddFrames(void *in_buffer, int in_frames,
int64_t timecode)
{
int org_waud = waud, afree = audiofree();
int frames = in_frames;
void *buffer = in_buffer;
int bpf = bytes_per_frame, len = frames * source_bytes_per_frame;
int used = kAudioRingBufferSize - afree;
bool music = false;
uint org_waud = waud;
int afree = audiofree();
int frames = in_frames;
void *buffer = in_buffer;
int bpf = bytes_per_frame, len = frames * source_bytes_per_frame;
int used = kAudioRingBufferSize - afree;
bool music = false;
int bdiff;

VBAUDIOTS(QString("AddFrames frames=%1, bytes=%2, used=%3, free=%4, "
Expand Down Expand Up @@ -1202,7 +1203,7 @@ bool AudioOutputBase::AddFrames(void *in_buffer, int in_frames,
nFrames = pSoundStretch->receiveSamples((STST *)(WPOS),
nFrames);

org_waud += nFrames * bpf;
org_waud = (org_waud + nFrames * bpf) % kAudioRingBufferSize;
}

if (internal_vol && SWVolume())
Expand All @@ -1220,7 +1221,7 @@ bool AudioOutputBase::AddFrames(void *in_buffer, int in_frames,
if (num > 0)
AudioOutputUtil::AdjustVolume(WPOS, num, volume,
music, needs_upmix && upmixer);
org_waud += num;
org_waud = (org_waud + num) % kAudioRingBufferSize;
}

if (encoder)
Expand Down Expand Up @@ -1253,7 +1254,7 @@ bool AudioOutputBase::AddFrames(void *in_buffer, int in_frames,
else
{
to_get = encoder->Encode(WPOS, len, processing);
org_waud += len;
org_waud = (org_waud + len) % kAudioRingBufferSize;
}

bdiff = kAudioRingBufferSize - org_waud2;
Expand All @@ -1266,7 +1267,7 @@ bool AudioOutputBase::AddFrames(void *in_buffer, int in_frames,
if (to_get > 0)
encoder->GetFrames(audiobuffer + org_waud2, to_get);

org_waud2 += to_get;
org_waud2 = (org_waud2 + to_get) % kAudioRingBufferSize;
}
while (remaining > 0);
org_waud = org_waud2;
Expand Down Expand Up @@ -1387,7 +1388,7 @@ void AudioOutputBase::OutputAudioLoop(void)
// delay setting raud until after phys buffer is filled
// so GetAudiotime will be accurate without locking
reset_active.TestAndDeref();
int next_raud = raud;
volatile uint next_raud = raud;
if (GetAudioData(fragment, fragment_size, true, &next_raud))
{
if (!reset_active.TestAndDeref())
Expand Down Expand Up @@ -1419,7 +1420,7 @@ void AudioOutputBase::OutputAudioLoop(void)
* available. Returns the number of bytes copied.
*/
int AudioOutputBase::GetAudioData(uchar *buffer, int size, bool full_buffer,
int *local_raud)
volatile uint *local_raud)
{

#define LRPOS audiobuffer + *local_raud
Expand Down
9 changes: 5 additions & 4 deletions mythtv/libs/libmyth/audiooutputbase.h
View file
Expand Up @@ -99,7 +99,7 @@ class AudioOutputBase : public AudioOutput, public QThread
static const uint kAudioSRCInputSize = 32768;

/// Audio Buffer Size -- should be divisible by 32,24,16,12,10,8,6,4,2..
static const uint kAudioRingBufferSize = 3072000;
static const uint kAudioRingBufferSize = 3072000u;

protected:
// Following function must be called from subclass constructor
Expand All @@ -120,7 +120,8 @@ class AudioOutputBase : public AudioOutput, public QThread
virtual bool StartOutputThread(void);
virtual void StopOutputThread(void);

int GetAudioData(uchar *buffer, int buf_size, bool fill_buffer, int *local_raud = NULL);
int GetAudioData(uchar *buffer, int buf_size, bool fill_buffer,
volatile uint *local_raud = NULL);

void OutputAudioLoop(void);

Expand Down Expand Up @@ -169,7 +170,7 @@ class AudioOutputBase : public AudioOutput, public QThread
int src_quality;

private:
int CopyWithUpmix(char *buffer, int frames, int &org_waud);
int CopyWithUpmix(char *buffer, int frames, uint &org_waud);
void SetAudiotime(int frames, int64_t timecode);
AudioOutputSettings *output_settingsraw;
AudioOutputSettings *output_settings;
Expand Down Expand Up @@ -208,7 +209,7 @@ class AudioOutputBase : public AudioOutput, public QThread
int64_t audiotime;

/* Audio circular buffer */
int raud, waud; /* read and write positions */
volatile uint raud, waud; /* read and write positions */
// timecode of audio most recently placed into buffer
int64_t audbuf_timecode;
AsyncLooseLock reset_active;
Expand Down

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