I'm attempting to play the audio track from an mp4 file to my speaker. I know Media Foundation is able to decode the audio stream as I can play it with the TopoEdit tool.
我正在尝试从mp4文件播放音频到我的扬声器。我知道Media Foundation可以解码音频流，因为我可以用TopoEdit工具播放它。
In the sample code below I'm not using a media session or topology. I'm attempting to manually connect the media source to the sink writer. The reason I want to do this is that I ultimately intend to be getting the source samples from the network rather than from a file.
在下面的示例代码中，我不使用媒体会话或拓扑。我正在尝试手动连接媒体源到接收器写入器。我这样做的原因是我最终打算从网络而不是文件中获取源样本。
The error I get on the pSinkWriter->WriteSample line when running the sample below is MF_E_INVALIDREQUEST (0xC00D36B2). So I suspect there's something I haven't wired up correctly.
在运行下面的示例时，我在pSinkWriter->上得到的错误是MF_E_INVALIDREQUEST (0xC00D36B2)。所以我怀疑有一些东西我没有正确连接。
#include <stdio.h>
#include <tchar.h>
#include <mfapi.h>
#include <mfplay.h>
#include <mfreadwrite.h>
#pragma comment(lib, "mf.lib")
#pragma comment(lib, "mfplat.lib")
#pragma comment(lib, "mfplay.lib")
#pragma comment(lib, "mfreadwrite.lib")
#pragma comment(lib, "mfuuid.lib")
#define CHECK_HR(hr, msg) if (hr != S_OK) { printf(msg); printf("Error: %.2X.\n", hr); goto done; }
int _tmain(int argc, _TCHAR* argv[])
{
CoInitializeEx(NULL, COINIT_APARTMENTTHREADED | COINIT_DISABLE_OLE1DDE);
MFStartup(MF_VERSION);
IMFSourceResolver *pSourceResolver = NULL;
IUnknown* uSource = NULL;
IMFMediaSource *mediaFileSource = NULL;
IMFSourceReader *pSourceReader = NULL;
IMFMediaType *pAudioOutType = NULL;
IMFMediaType *pFileAudioMediaType = NULL;
MF_OBJECT_TYPE ObjectType = MF_OBJECT_INVALID;
IMFMediaSink *pAudioSink = NULL;
IMFStreamSink *pStreamSink = NULL;
IMFMediaTypeHandler *pMediaTypeHandler = NULL;
IMFMediaType *pMediaType = NULL;
IMFMediaType *pSinkMediaType = NULL;
IMFSinkWriter *pSinkWriter = NULL;
// Set up the reader for the file.
CHECK_HR(MFCreateSourceResolver(&pSourceResolver), "MFCreateSourceResolver failed.\n");
CHECK_HR(pSourceResolver->CreateObjectFromURL(
L"big_buck_bunny.mp4", // URL of the source.
MF_RESOLUTION_MEDIASOURCE, // Create a source object.
NULL, // Optional property store.
&ObjectType, // Receives the created object type.
&uSource // Receives a pointer to the media source.
), "Failed to create media source resolver for file.\n");
CHECK_HR(uSource->QueryInterface(IID_PPV_ARGS(&mediaFileSource)),
"Failed to create media file source.\n");
CHECK_HR(MFCreateSourceReaderFromMediaSource(mediaFileSource, NULL, &pSourceReader),
"Error creating media source reader.\n");
CHECK_HR(pSourceReader->GetCurrentMediaType((DWORD)MF_SOURCE_READER_FIRST_AUDIO_STREAM, &pFileAudioMediaType),
"Error retrieving current media type from first audio stream.\n");
// printf("File Media Type:\n");
// Dump pFileAudioMediaType.
// Set the audio output type on the source reader.
CHECK_HR(MFCreateMediaType(&pAudioOutType), "Failed to create audio output media type.\n");
CHECK_HR(pAudioOutType->SetGUID(MF_MT_MAJOR_TYPE, MFMediaType_Audio), "Failed to set audio output media major type.\n");
CHECK_HR(pAudioOutType->SetGUID(MF_MT_SUBTYPE, MFAudioFormat_Float), "Failed to set audio output audio sub type (Float).\n");
CHECK_HR(pSourceReader->SetCurrentMediaType((DWORD)MF_SOURCE_READER_FIRST_AUDIO_STREAM, NULL, pAudioOutType),
"Error setting reader audio output type.\n");
// printf("Source Reader Output Type:");
// Dump pAudioOutType.
CHECK_HR(MFCreateAudioRenderer(NULL, &pAudioSink), "Failed to create audio sink.\n");
CHECK_HR(pAudioSink->GetStreamSinkByIndex(0, &pStreamSink), "Failed to get audio renderer stream by index.\n");
CHECK_HR(pStreamSink->GetMediaTypeHandler(&pMediaTypeHandler), "Failed to get media type handler.\n");
// My speaker has 3 audio types of which I got the furthesr with the third one.
CHECK_HR(pMediaTypeHandler->GetMediaTypeByIndex(2, &pSinkMediaType), "Failed to get sink media type.\n");
CHECK_HR(pMediaTypeHandler->SetCurrentMediaType(pSinkMediaType), "Failed to set current media type.\n");
// printf("Sink Media Type:\n");
// Dump pSinkMediaType.
CHECK_HR(MFCreateSinkWriterFromMediaSink(pAudioSink, NULL, &pSinkWriter), "Failed to create sink writer from audio sink.\n");
printf("Read audio samples from file and write to speaker.\n");
IMFSample *audioSample = NULL;
DWORD streamIndex, flags;
LONGLONG llAudioTimeStamp;
for (int index = 0; index < 10; index++)
//while (true)
{
// Initial read results in a null pSample??
CHECK_HR(pSourceReader->ReadSample(
MF_SOURCE_READER_FIRST_AUDIO_STREAM,
0, // Flags.
&streamIndex, // Receives the actual stream index.
&flags, // Receives status flags.
&llAudioTimeStamp, // Receives the time stamp.
&audioSample // Receives the sample or NULL.
), "Error reading audio sample.");
if (flags & MF_SOURCE_READERF_ENDOFSTREAM)
{
printf("End of stream.\n");
break;
}
if (flags & MF_SOURCE_READERF_STREAMTICK)
{
printf("Stream tick.\n");
pSinkWriter->SendStreamTick(0, llAudioTimeStamp);
}
if (!audioSample)
{
printf("Null audio sample.\n");
}
else
{
CHECK_HR(audioSample->SetSampleTime(llAudioTimeStamp), "Error setting the audio sample time.\n");
CHECK_HR(pSinkWriter->WriteSample(0, audioSample), "The stream sink writer was not happy with the sample.\n");
}
}
done:
printf("finished.\n");
getchar();
return 0;
}
I've omitted the code that dumps the media types for brevity but their output is shown below. It could well be that I haven't got the media types connected properly.
我省略了为了简洁而转储媒体类型的代码，但是它们的输出如下所示。很可能是我没有正确地连接媒体类型。
File Media Type:
Audio: MAJOR_TYPE=Audio, PREFER_WAVEFORMATEX=1, {BFBABE79-7434-4D1C-94F0-72A3B9E17188}=0, {7632F0E6-9538-4D61-ACDA-EA29C8C14456}=0, SUBTYPE={00001610-0000-0010-8000-00AA00389B71}, NUM_CHANNELS=2, SAMPLES_PER_SECOND=22050, BLOCK_ALIGNMENT=1, AVG_BYTES_PER_SECOND=8000, BITS_PER_SAMPLE=16, USER_DATA=<BLOB>, {73D1072D-1870-4174-A063-29FF4FF6C11E}={05589F81-C356-11CE-BF01-00AA0055595A}, ALL_SAMPLES_INDEPENDENT=1, FIXED_SIZE_SAMPLES=1, SAMPLE_SIZE=1, MPEG4_SAMPLE_DESCRIPTION=<BLOB>, MPEG4_CURRENT_SAMPLE_ENTRY=0, AVG_BITRATE=64000,
Source Reader Output Type:
Audio: MAJOR_TYPE=Audio, SUBTYPE=Float,
Sink Media Type:
Audio: MAJOR_TYPE=Audio, SUBTYPE=Float, NUM_CHANNELS=2, SAMPLES_PER_SECOND=48000, BLOCK_ALIGNMENT=8, AVG_BYTES_PER_SECOND=384000, BITS_PER_SAMPLE=32, ALL_SAMPLES_INDEPENDENT=1, CHANNEL_MASK=3,
Any hints as to where I could look next would be appreciated.
如果有任何关于我下一步去哪里的暗示，我将不胜感激。
2 个解决方案
#1
0
I was missing the sink writer BeginWriting call.
我错过了正在写作的作家。
CHECK_HR(pSinkWriter->BeginWriting(), "Sink writer begin writing call failed.\n");
That got some audio coming out of the speakers but it has a very bad chop to it so there's something else I'm missing.
有一些音频从扬声器中传出来但它的排印很差所以我还漏掉了一些东西。
#2
0
The Media Type you are setting to the Reader is incomplete. MF_MT_AUDIO_AVG_BYTES_PER_SECOND MF_MT_AUDIO_BLOCK_ALIGNMENT and MF_MT_AUDIO_NUM_CHANNELS are missing.
您设置给读者的媒体类型是不完整的。MF_MT_AUDIO_AVG_BYTES_PER_SECOND MF_MT_AUDIO_BLOCK_ALIGNMENT和mf_mf_mt_audio_num_channels缺失。
i would set the media type you retrieved from the sink mediatypehandler.
我将设置从sink mediatypehandler检索的媒体类型。
#1
0
I was missing the sink writer BeginWriting call.
我错过了正在写作的作家。
CHECK_HR(pSinkWriter->BeginWriting(), "Sink writer begin writing call failed.\n");
That got some audio coming out of the speakers but it has a very bad chop to it so there's something else I'm missing.
有一些音频从扬声器中传出来但它的排印很差所以我还漏掉了一些东西。
#2
0
The Media Type you are setting to the Reader is incomplete. MF_MT_AUDIO_AVG_BYTES_PER_SECOND MF_MT_AUDIO_BLOCK_ALIGNMENT and MF_MT_AUDIO_NUM_CHANNELS are missing.
您设置给读者的媒体类型是不完整的。MF_MT_AUDIO_AVG_BYTES_PER_SECOND MF_MT_AUDIO_BLOCK_ALIGNMENT和mf_mf_mt_audio_num_channels缺失。
i would set the media type you retrieved from the sink mediatypehandler.
我将设置从sink mediatypehandler检索的媒体类型。