Question

我现在正试图在Win10 pro Insider预览中使用MP3编码器mft，但未能设置输出媒体类型。

以下是我的代码：

// Fill in MPEGLAYER3WAVEFORMAT data   
MPEGLAYER3WAVEFORMAT mp3wfx;
ZeroMemory(&mp3wfx, sizeof(mp3wfx));
mp3wfx.wID = MPEGLAYER3_ID_MPEG;
mp3wfx.fdwFlags = 2; // no padding
mp3wfx.nBlockSize = int16_t(144 * (128000 / 44100)); // bitrate = 128000kbps
mp3wfx.nFramesPerBlock = 1;
mp3wfx.nCodecDelay = 0;
mp3wfx.wfx.wFormatTag = WAVE_FORMAT_MPEGLAYER3;  // MP3 
mp3wfx.wfx.nChannels = 2;
mp3wfx.wfx.nSamplesPerSec = 44100;
mp3wfx.wfx.wBitsPerSample = 16;
mp3wfx.wfx.nBlockAlign = (mp3wfx.wfx.nChannels * mp3wfx.wfx.wBitsPerSample) / 8;
mp3wfx.wfx.nAvgBytesPerSec = mp3wfx.wfx.nSamplesPerSec * mp3wfx.wfx.nBlockAlign;
mp3wfx.wfx.cbSize = sizeof(MPEGLAYER3WAVEFORMAT) - sizeof(WAVEFORMATEX); // 12

LComObject<IMFMediaType> ciOutputType;  // Output media type of the encoder
hr = fpMFCreateMediaType((IMFMediaType**)(ciOutputType.GetAssignablePtrRef()));
WAVEFORMATEX* pWave = (WAVEFORMATEX*)&mp3wfx;
MFInitMediaTypeFromWaveFormatEx(ciOutputType.get(), pWave, sizeof(MPEGLAYER3WAVEFORMAT));
hr = ciEncoder->SetOutputType(0, ciOutputType.get(), 0);

请忽略我在这些COM对象/接口上的包装器。 Mftrace输出这些

5552,500 05:05:15.03439 CMFPlatExportDetours::MFTEnumEx @ Activate 00 @034CE628, MFT_FRIENDLY_NAME_Attribute=MP3 Encoder ACM Wrapper MFT;MFT_INPUT_TYPES_Attributes=61 75 64 73 00 00 10 00 80 00 00 aa 00 38 9b 71 01 00 00 00 00 00 10 00 80 00 00 aa 00 38 9b 71 ;MFT_TRANSFORM_CLSID_Attribute={11103421-354C-4CCA-A7A3-1AFF9A5B6701};MFT_OUTPUT_TYPES_Attributes=61 75 64 73 00 00 10 00 80 00 00 aa 00 38 9b 71 55 00 00 00 00 00 10 00 80 00 00 aa 00 38 9b 71 ;MF_TRANSFORM_FLAGS_Attribute=1;MF_TRANSFORM_CATEGORY_Attribute=MFT_CATEGORY_AUDIO_ENCODER
5552,500 05:05:15.03616 COle32ExportDetours::CoCreateInstance @ New MFT @03510D20, <NULL>
5552,500 05:05:15.03618 COle32ExportDetours::CoCreateInstance @ Created {11103421-354C-4CCA-A7A3-1AFF9A5B6701} MP3 ACM Wrapper MFT (C:\Windows\System32\mfcore.dll) @03510D20 - traced interfaces: IMFTransform @03510D20, 
5552,500 05:05:15.03681 CMFTransformDetours::SetOutputType @03510D20 Failed MT: MF_MT_AUDIO_AVG_BYTES_PER_SECOND=176400;MF_MT_AUDIO_BLOCK_ALIGNMENT=4;MF_MT_AUDIO_NUM_CHANNELS=2;MF_MT_MAJOR_TYPE=MEDIATYPE_Audio;MF_MT_AUDIO_SAMPLES_PER_SECOND=44100;MF_MT_AUDIO_PREFER_WAVEFORMATEX=1;MF_MT_USER_DATA=01 00 02 00 00 00 20 01 01 00 00 00 ;MF_MT_AUDIO_BITS_PER_SAMPLE=16;MF_MT_SUBTYPE=MFAudioFormat_MP3

感谢您的帮助

Answer 1

所以它说：

SetOutputType @03510D20 Failed MT: 
MF_MT_MAJOR_TYPE=MEDIATYPE_Audio;
MF_MT_SUBTYPE=MFAudioFormat_MP3; 
MF_MT_AUDIO_PREFER_WAVEFORMATEX=1;
MF_MT_AUDIO_SAMPLES_PER_SECOND=44100;
MF_MT_AUDIO_NUM_CHANNELS=2;
MF_MT_AUDIO_BITS_PER_SAMPLE=16;
MF_MT_AUDIO_AVG_BYTES_PER_SECOND=176400;
MF_MT_AUDIO_BLOCK_ALIGNMENT=4;
MF_MT_USER_DATA=01 00 02 00 00 00 20 01 01 00 00 00 ;

这里有两件重要的事情：

MF_MT_AUDIO_AVG_BYTES_PER_SECOND需要正确的值，因为有一个可接受的比特率列表
MF_MT_USER_DATA是媒体类型的其他格式数据;大概在MPEGLAYER3WAVEFORMAT字段之后的WAVEFORMATEX值 - MFT可能会预期某些值与您提供的值不同。

您采用了正确的方法，要求MFT枚举输出媒体类型。现在你需要选择最接近的并与你所拥有的相比，你应该看到使编解码器拒绝你的格式的差异。

设置MP3编码器mft输出类型失败

1 个答案: