HarmonyOS 录制生成mp4文件音画不同步；录制3-5分钟短视频音画正常，超过3-5分钟左右的视频音画会不同步。

参考修改视频时间戳：

#include <chrono>
  namespace {
  using namespace std::chrono_literals;
  constexpr int64_t MICROSECOND = 1000000;
}
if ((bufferInfo.attr.flags & AVCODEC_BUFFER_FLAGS_SYNC_FRAME) || (bufferInfo.attr.flags == AVCODEC_BUFFER_FLAGS_NONE)) {
  encVideoContext_->outputFrameCount_++;
  uint64_t systemTimeUs = time_point_cast<std::chrono::microseconds>(std::chrono::system_clock::now()).time_since_epoch().count();
  bufferInfo.attr.pts = systemTimeUs;
} else {
  bufferInfo.attr.pts = 0;
}
AVCODEC_SAMPLE_LOGW("video Out buffer count: %{public}u, size: %{public}d, pts: %{public}lu, time: %{public}.1f, frameRate: %{public}.1f fps",
  encVideoContext_->outputFrameCount_, bufferInfo.attr.size,
  bufferInfo.attr.pts, encVideoContext_->outputFrameCount_ * MICROSECOND,
  sampleInfo_.frameRate);

音频编码时默认自带时间戳，不用设置。可去掉此处代码，同时修改视频的时间戳为当前系统时间后，音画同步，问题解决。