c++ - 如何在 OpenAL 中获取具有单个缓冲区的源的长度(持续时间)？

Question

我正在从 FMOD 迁移到 OpenAL，我找不到 FSOUND_Sample_GetLength() 函数的类似物，它返回samples 中样本的长度(不考虑频率)...我从 alutLoadMemoryFromFileImage() 得到 OpenAL 缓冲区名称，所以我无法通过这种方式获取波形数据。

请帮忙!

Answer 1

您需要自己使用 alGetBufferi() 将其拼凑起来:

ALint sizeInBytes;
ALint channels;
ALint bits;

alGetBufferi(bufferID, AL_SIZE, &sizeInBytes);
alGetBufferi(bufferID, AL_CHANNELS, &channels);
alGetBufferi(bufferID, AL_BITS, &bits);

lengthInSamples = sizeInBytes * 8 / (channels * bits);

持续时间以秒为单位:

ALint frequency;

alGetBufferi(bufferID, AL_FREQUENCY, &frequency);

durationInSeconds = (float)lengthInSamples / (float)frequency;