我正在使用Windows Azure媒体服务上传视频文件，进行编码，然后发布它们。 我使用Windows Azure媒体服务示例代码对文件进行编码，我发现当我使用代码将“.mp4”文件转换为Apple HLS时，它在iOS设备中无法正常运行。只播放音频，没有视频。然而，如果我使用Windows Azure媒体服务门户在HLS中编码和发布文件，它们在iOS设备（音频和视频播放）上工作得非常好！
我几天来一直在讨论这个问题，并且真的有必要指导我编码过程（通过代码）吗？
这就是我现在所拥有的！
static IAsset CreateEncodingJob(IAsset asset)
{
// Declare a new job.
IJob job = _context.Jobs.Create("My encoding job");
// Get a media processor reference, and pass to it the name of the
// processor to use for the specific task.
IMediaProcessor processor = GetLatestMediaProcessorByName("Windows Azure Media Encoder");
// Create a task with the encoding details, using a string preset.
ITask task = job.Tasks.AddNew("My encoding task",
processor,
"H264 Broadband SD 4x3",
TaskOptions.ProtectedConfiguration);
// Specify the input asset to be encoded.
task.InputAssets.Add(asset);
// Add an output asset to contain the results of the job.
// This output is specified as AssetCreationOptions.None, which
// means the output asset is in the clear (unencrypted).
task.OutputAssets.AddNew("Output MP4 asset",
true,
AssetCreationOptions.None);
// Launch the job.
job.Submit();
// Checks job progress and prints to the console.
CheckJobProgress(job.Id);
// Get an updated job reference, after waiting for the job
// on the thread in the CheckJobProgress method.
job = GetJob(job.Id);
// Get a reference to the output asset from the job.
IAsset outputAsset = job.OutputMediaAssets[0];
return outputAsset;
}
static IAsset CreateMp4ToSmoothJob(IAsset asset)
{
// Read the encryption configuration data into a string.
string configuration = File.ReadAllText(Path.GetFullPath(_configFilePath + @"\MediaPackager_MP4ToSmooth.xml"));
//Publish the asset.
//GetStreamingOriginLocatorformp4(asset.Id);
// Declare a new job.
IJob job = _context.Jobs.Create("My MP4 to Smooth job");
// Get a media processor reference, and pass to it the name of the
// processor to use for the specific task.
IMediaProcessor processor = GetLatestMediaProcessorByName("Windows Azure Media Packager");
// Create a task with the encoding details, using a configuration file. Specify
// the use of protected configuration, which encrypts sensitive config data.
ITask task = job.Tasks.AddNew("My Mp4 to Smooth Task",
processor,
configuration,
TaskOptions.ProtectedConfiguration);
// Specify the input asset to be encoded.
task.InputAssets.Add(asset);
// Add an output asset to contain the results of the job.
task.OutputAssets.AddNew("Output Smooth asset",
true,
AssetCreationOptions.None);
// Launch the job.
job.Submit();
// Checks job progress and prints to the console.
CheckJobProgress(job.Id);
job = GetJob(job.Id);
IAsset outputAsset = job.OutputMediaAssets[0];
// Optionally download the output to the local machine.
//DownloadAssetToLocal(job.Id, _outputIsmFolder);
return outputAsset;
}
// Shows how to encode from smooth streaming to Apple HLS format.
static IAsset CreateSmoothToHlsJob(IAsset outputSmoothAsset)
{
// Read the encryption configuration data into a string.
string configuration = File.ReadAllText(Path.GetFullPath(_configFilePath + @"\MediaPackager_SmoothToHLS.xml"));
//var getismfile = from p in outputSmoothAsset.Files
// where p.Name.EndsWith(".ism")
// select p;
//IAssetFile manifestFile = getismfile.First();
//manifestFile.IsPrimary = true;
var ismAssetFiles = outputSmoothAsset.AssetFiles.ToList().Where(f => f.Name.EndsWith(".ism", StringComparison.OrdinalIgnoreCase)).ToArray();
if (ismAssetFiles.Count() != 1)
throw new ArgumentException("The asset should have only one, .ism file");
ismAssetFiles.First().IsPrimary = true;
ismAssetFiles.First().Update();
//Use the smooth asset as input asset
IAsset asset = outputSmoothAsset;
// Declare a new job.
IJob job = _context.Jobs.Create("My Smooth Streams to Apple HLS job");
// Get a media processor reference, and pass to it the name of the
// processor to use for the specific task.
IMediaProcessor processor = GetMediaProcessor("Smooth Streams to HLS Task");
// Create a task with the encoding details, using a configuration file.
ITask task = job.Tasks.AddNew("My Smooth to HLS Task", processor, configuration, TaskOptions.ProtectedConfiguration);
// Specify the input asset to be encoded.
task.InputAssets.Add(asset);
// Add an output asset to contain the results of the job.
task.OutputAssets.AddNew("Output HLS asset", true, AssetCreationOptions.None);
// Launch the job.
job.Submit();
// Checks job progress and prints to the console.
CheckJobProgress(job.Id);
// Optionally download the output to the local machine.
//DownloadAssetToLocal(job.Id, outputFolder);
job = GetJob(job.Id);
IAsset outputAsset = job.OutputMediaAssets[0];
return outputAsset;
}
答案 0 :(得分：2)
要转换为iOS兼容的HLS，您必须使用平滑流媒体源，它将成为HLS的基础。所以你的步骤将是：
HLS与Microsoft Smooth Streaming非常相似。因此，它需要具有不同比特率的源块。通过MP4进行HLS转换将不起作用。
微软在explorative门户网站中提供此类management功能，这是令人遗憾的。这会导致用户感到困惑。它在场景下的作用正是我建议的 - 首先获得高质量的MP4，然后将其转换为Microsoft Smooth流，然后通过Smooth Streaming进行HLS。但是用户通过MP4执行HLS的事情是完全错误的。
如果我们查看online documentation here，我们会看到任务预设名为Convert Smooth Streams to Apple HTTP Live Streams。从中我们必须弄清楚HLS的正确来源是Microsoft Smooth Stream。根据我的经验，良好的平滑流只能通过良好的H.264源（MP4）生成。如果您尝试将非H.264源转换为平滑流，则结果很可能是错误。
您可以尝试使用小工具WaMediaWeb（github上的源码以及向Azure网站的持续传递），现场直播：http://wamediaweb.azurewebsites.net/ - 只需提供您的媒体帐户和密钥。请查看readme on GitHub的某些细节，例如哪些来源会产生什么结果。
顺便说一句，您可以在一个作业中堆叠任务，以避免不断寻找工作结果。方法task.OutputAssets.AddNew(...)实际上返回一个IAsset，您可以将其用作另一个任务的InputAsset，并将该任务添加到同一个作业中。如果你看一下这个例子，它会在某些时候这样做。它在创建HLS流方面也做得很好，在iOS2上使用iPad2和iPhone 4进行了测试。