版本
Wwise SDK 2023.1.3
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依据规定限值削减内存用量并不是一件容易的事。以下是帮助降低内存占用的几个技巧:
Object 内存用量直接受内存中加载的声音和 Event 数量以及游戏对象数量影响。它包含工程中用于实现声音设计的行为所必需的对象的所有属性。它还包含所有游戏对象及其相关信息(游戏同步器值、位置、朝向等)。加载的 SoundBank 越多,所需分配的内存就越多。所需的大小完全取决于在一个场景、关卡、地图、游戏区域等中可能播放的声音数量。您可以采用以下做法来减少这些内存分配:
Processing 类别中的内存用于播放声音。它包含用于解压缩、应用效果器和对音频源做混音的缓冲区。它直接受到同时播放的声音数量的影响。它还受到同时使用的效果器数量和类型的影响。为了节省内存,您需要考虑想同时听到多少声音。某些游戏中很少有超过10种声音的场景,而别的游戏的场景中则可能有数百个声音。您需要考虑最坏的情况。
作为参照指南,我们对一些游戏执行了性能分析(在Xbox One 上),并获得了以下数据:
为了降低处理所需的内存用量,您需要减少同时播放的声部数。通过以下方式可以做到这一点:
备注: 您还可以对总线也设置限制。 |
备注: 您可以在运行时以编程的方式更改音量阈值。您可以在游戏中 CPU 运算更繁重的位置使用此设置,以将更多的声部发送到“低于音量阈值”的状态。 |
SoundBank 占用的内存量几乎都取决于 SoundBank 中的声音数据。控制媒体所占用的内存量可通过以下方式来做到:
Wwise uses an internal pool of memory to manage some temporary allocations that persist for less than one audio-render tick, which are represented in the Advanced Profiler's Memory tab as "Temp Alloc". These temporary allocations exist for a specific amount of time, have very little overhead, are handled internally by the sound engine, and cannot be forwarded to developer-provided memory allocation hooks. Instead, the only allocations in this regard that are observed by the Advanced Profiler and memory allocation hooks are the larger memory blocks that the temporary allocations are made from. Therefore, it might be desirable to manually tune the management of "Temp Alloc" memory blocks, in order to better optimize memory usage in your game.
During AK::MemoryMgr::Init
, AkMemSettings::tempAllocSettings
controls the behavior of the memory blocks for each Temp Alloc category. Notably, this includes configuring the size of the memory blocks, the minimum number of blocks that the system keeps allocated at all times, and how many blocks have to be unused for a tick before the system starts freeing memory. You can use AK::GetTempAllocStats()
to see how much memory the Temp Alloc system uses in your game at runtime, and better fine tune configuration of the system.
The following are some suggestions depending on your game's requirements, or other behavior observed during profiling:
AK::TempAllocInitSettings::uMinimumBlockSize
to a lower value than the default, so that it better matches the memory usage of your game's needs at any given time.AK::TempAllocStats::uPeakMemUsed
to view the Temp Alloc system's peak memory usage, and then ensure that the AK::TempAllocInitSettings::uMinimumBlockCount
is set to a high enough value so that all of the blocks you might use are allocated when the sound engine is initialized, and never freed afterward.AK::TempAllocInitSettings::uMaximumUnusedBlocks
to a high value to ensure that the system can allocate new blocks, but not free them, even during periods of low memory load.AK::TempAllocInitSettings::uMinimumBlockSize
so that using more workers does not cause a significant increase in used memory in your game.AK::TempAllocInitSettings::uMinimumBlockSize
to a slightly reduced value than intended in order to mitigate waste in this regard.Some debugging options are available in AK::TempAllocInitSettings
. In the Debug and Profile configuration of the sound engine, AK::TempAllocInitSettings::bDebugDetailedStats
and AK::TempAllocInitSettings::bDebugEnableSentinels
are enabled by default in order to improve tracking of usage statistics, and to provide some easy detection of buffer overruns. Disable these options when the highest performance, or most accurate profiling data, is required for your application. Support for these options is removed entirely in the Release configuration of the sound engine.
If your Memory Manager integration relies on Wwise's integration of rpmalloc, it might be desirable to adjust AK::MemSettings::uVMSpanCount
and AK::MemSettings::uDeviceSpanCount
in order to reduce the amount of memory reserved by the system. There are three options available for these settings, which provide different trade-offs for CPU and Memory use: AkSpanCount_Small
, AkSpanCount_Medium
, and AkSpanCount_Huge
.
AkSpanCount_Huge
is the default value, which offers the best CPU performance by reducing the number of calls made to AkMemSettings::pfAllocVM
, but also because in supported integrations, and on some platforms, memory mappings can be made using 2MiB pages, instead of 4KiB or 16KiB pages. Utilization of 2MiB pages can reduce the number of translation lookaside buffer (TLB) misses during sound engine execution, and help improve overall CPU performance.
AkSpanCount_Small
adjusts the amount of memory requested at any given time to be as low as 64KiB. This can reduce the amount of memory reserved by Wwise, but can increase the amount of CPU usage due to an increase in calls to AkMemSettings::pfAllocVM
. Depending on your implementation of the AkMemSettings::pfAllocVM
callback, this might also prevent the usage of 2MiB pages for memory mappings.
AkSpanCount_Medium
balances memory and CPU usage, by requesting memory blocks as low as 512KiB. This can reduce the number of calls to AkMemSettings::pfAllocVM
compared to AkSpanCount_Small
, but still might prevent the usage of 2MiB pages for memory mappings.
备注: If your implementation of AkMemSettings::pfAllocVM provides blocks of pre-mapped memory, and rarely invokes a system call for a new memory mapping, we strongly recommend that you use a setting of AkSpanCount_Small because the relative cost of calls to AkMemSettings::pfAllocVM should be greatly reduced, and your pre-mapped memory might already be using 2MiB pages. |