Question

我有MediaStreamSource实现，可以打开包含多个音频流的文件。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

但是我当然要向ReportOpenMediaCompleted报告第一和第二音频流，结果是MediaElement有2个音频流。此外，我在MediaStreamSource类中发现了StreamId字段，但它没有set访问器，当使用ReportOpenMediaCompleted报告流时，所有MediaStreamDescription都有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);
}

Answer 1

使用Player framework可能是个好主意。它支持多种音频流。

具有多个音频流的Windows Phone 8 MediaStreamSource

1 个答案: