[PATCH 2/3] quartz/dsoundrender: Don't let writepos advance past playpos.

[Zebediah Figura (she/her)]

On 4/27/21 2:20 AM, Anton Baskanov wrote:
> On вторник, 27 апреля 2021 г. 06:23:58 +07 you wrote:
>> On 4/25/21 9:51 PM, Anton Baskanov wrote:
>>> Fixes audio stuttering during video playback in multiple games (e.g.
>>> Commandos 2, Alien Nations, Dino Crisis Demo).
>>
>> Can you please provide a +quartz,+strmbase,+gstreamer log that
>> demonstrates the problem?
> 
> I've attached the log of the Commandos 2 (GOG version) first intro video
> playback. The relevant part is:
> 
> 0154:trace:quartz:DSoundRender_SendSampleData Wrote 75500 bytes at 17108, next
> at 4408 - (75500/88200)
> 0154:trace:quartz:SystemClockImpl_GetTime clock 002D8440, time 03FBFC20,
> returning 1569156.542.
> 0154:trace:quartz:DSoundRender_SendSampleData Wrote 12700 bytes at 4408, next
> at 17108 - (88196/12700)
> 
> First, DSoundRender_GetWritePos reports 75500 free bytes, so we write 75500
> bytes to the buffer. At this point, DSoundRender_GetWritePos must report 0 free
> bytes, since the buffer is full, but it reports 88196 instead, so we write
> another 12700 bytes, overrunning playpos.
> 
> Some time after that an underrun happens when dsound write cursor advances
> past our write position:
> 
> 0154:fixme:quartz:DSoundRender_UpdatePositions Underrun of data occurred!
> 
> To reproduce this issue there has to be enough data to fill the buffer, i.e. the
> samples must be at least 1s in length.

Thanks, I see the step I was missing.

It took me way too long to make sense of dsoundrender, but I'm finally 
convinced this patch is an improvement, if just barely...

> 
>>
>>> Signed-off-by: Anton Baskanov <baskanov at gmail.com>
>>> ---
>>>
>>>    dlls/quartz/dsoundrender.c       | 5 +----
>>>    dlls/quartz/tests/dsoundrender.c | 2 +-
>>>    2 files changed, 2 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/dlls/quartz/dsoundrender.c b/dlls/quartz/dsoundrender.c
>>> index 6c6732e468a..f7f0255d4ab 100644
>>> --- a/dlls/quartz/dsoundrender.c
>>> +++ b/dlls/quartz/dsoundrender.c
>>> @@ -149,7 +149,6 @@ static void DSoundRender_UpdatePositions(struct
>>> dsound_render *This, DWORD *seqw>
>>>    static HRESULT DSoundRender_GetWritePos(struct dsound_render *This,
>>>    
>>>            DWORD *ret_writepos, REFERENCE_TIME write_at, DWORD *pfree,
>>>            DWORD *skip)
>>>    
>>>    {
>>>
>>> -    WAVEFORMATEX *wfx = (WAVEFORMATEX *)This->sink.pin.mt.pbFormat;
>>>
>>>        DWORD writepos, min_writepos, playpos;
>>>        REFERENCE_TIME max_lag = 50 * 10000;
>>>        REFERENCE_TIME cur, writepos_t, delta_t;
>>>
>>> @@ -212,10 +211,8 @@ static HRESULT DSoundRender_GetWritePos(struct
>>> dsound_render *This,>
>>>            *ret_writepos = (min_writepos + aheadbytes) % This->buf_size;
>>>        
>>>        }
>>>    
>>>    end:
>>> -    if (playpos > *ret_writepos)
>>> +    if (playpos >= *ret_writepos)
>>>
>>>            *pfree = playpos - *ret_writepos;
>>>
>>> -    else if (playpos == *ret_writepos)
>>> -        *pfree = This->buf_size - wfx->nBlockAlign;
>>>
>>>        else
>>>        
>>>            *pfree = This->buf_size + playpos - *ret_writepos;
>>>        
>>>        if (time_from_pos(This, This->buf_size - *pfree) >=
>>>        DSoundRenderer_Max_Fill) {>
>>> diff --git a/dlls/quartz/tests/dsoundrender.c
>>> b/dlls/quartz/tests/dsoundrender.c index c33c074d93d..e591e1832d5 100644
>>> --- a/dlls/quartz/tests/dsoundrender.c
>>> +++ b/dlls/quartz/tests/dsoundrender.c
>>> @@ -737,7 +737,7 @@ static HRESULT send_frame(IMemInputPin *sink)
>>>
>>>        params->sink = sink;
>>>        params->sample = sample;
>>>        thread = CreateThread(NULL, 0, frame_thread, params, 0, NULL);
>>>
>>> -    ret = WaitForSingleObject(thread, 500);
>>> +    ret = WaitForSingleObject(thread, 2000);
>>>
>>>        todo_wine_if (ret) ok(!ret, "Wait failed.\n");
>>>        GetExitCodeThread(thread, &ret);
>>>        CloseHandle(thread);
>