我有 MediaStreamSource 实现,它可以打开具有多个音频流的文件。在 OpenMediaAsync 方法中,我为所有视频和音频流提供 MediaStreamDescription,但 MediaElement 仅检测到 1 个音频流。我还测试了下一个有效的逻辑:
检测到 2 个流
仅向 ReportOpenMediaCompleted 报告音频流的第一个或第二个 MediaStreamDescription
但是我当然想向 ReportOpenMediaCompleted 报告第一个和第二个音频流,结果是 MediaElement 有 2 个音频流。我还在 MediaStreamSource 类中发现了 StreamId 字段,但它没有设置访问器,并且当使用 ReportOpenMediaCompleted 报告流时,所有 MediaStreamDescription 的 StreamId == 0。
OpenMediaAsync 代码:
protected override void OpenMediaAsync()
{
this.streamDesc = new Dictionary<int, MediaStreamDescription>();
List<MediaStreamDescription> availableStreams = new List<MediaStreamDescription>();
for (int i = 0; i < this.parser.StreamCount; i++)
{
Dictionary<MediaStreamAttributeKeys, string> streamAttributes = new Dictionary<MediaStreamAttributeKeys, string>();
MediaStreamDescription msd = null;
var type = this.parser.GetStreamType(i);
streamAttributes[MediaStreamAttributeKeys.CodecPrivateData] = this.parser.GetCodecPrivateData(i);
if (type == ParserComponent.StreamType.Video)
{
streamAttributes[MediaStreamAttributeKeys.VideoFourCC] = this.parser.GetCodecID(i);
streamAttributes[MediaStreamAttributeKeys.Width] = this.parser.GetWidth(i).ToString();
streamAttributes[MediaStreamAttributeKeys.Height] = this.parser.GetHeight(i).ToString();
msd = new MediaStreamDescription(MediaStreamType.Video, streamAttributes);
}
else if (type == ParserComponent.StreamType.Audio)
{
msd = new MediaStreamDescription(MediaStreamType.Audio, streamAttributes);
}
if (msd != null)
{
if (i == this.parser.CurrentAudioStreamIndex || i == this.parser.CurrentVideoStreamIndex)
{
this.parser.SetStreamActive(i, true);
// quick fix for multilanguage videos to submit only 1 audio stream
// availableStreams.Add(msd);
}
this.streamDesc.Add(i, msd);
availableStreams.Add(msd);
}
}
Dictionary<MediaSourceAttributesKeys, string> sourceAttributes = new Dictionary<MediaSourceAttributesKeys, string>();
sourceAttributes[MediaSourceAttributesKeys.CanSeek] = this.parser.Seekable.ToString();
sourceAttributes[MediaSourceAttributesKeys.Duration] = this.parser.Duration.Ticks.ToString();
ReportOpenMediaCompleted(sourceAttributes, availableStreams);
}