Android：使用 OMXCodec 作为 MediaSource 时 MPEG4Writer 无法启动

我正在尝试从字节数组缓冲区对视频进行编码，为此我正在使用MPEG4Writer来自本机代码的 API。

我已经创建了我的自定义MediaSource提供数据的类，我用它包装它OMXCodec给它MPEG4Writer:

sp<MediaSource> mVideoEncoder = OMXCodec::Create(client.interface(), omxEncMeta, true, mVideoOutSource);
mVideoEncoder->start();

mVideoOutSource是我的习惯MediaSource class, omxEncMeta如下：

int32_t colorFormat = OMX_COLOR_FormatYUV420SemiPlanar;
int32_t width = 480;
int32_t height = 360;
int32_t frameRate = 24;
int32_t bitRate = 500 * 1024;
int32_t iFrameInterval = 1;

sp<MetaData> omxEncMeta = new MetaData;
omxEncMeta->setCString(kKeyMIMEType, MEDIA_MIMETYPE_VIDEO_AVC);
omxEncMeta->setInt32(kKeyColorFormat, colorFormat);
omxEncMeta->setInt32(kKeyWidth, width);
omxEncMeta->setInt32(kKeyHeight, height);
omxEncMeta->setInt32(kKeyStride, width);
omxEncMeta->setInt32(kKeySliceHeight, height);
omxEncMeta->setInt32(kKeyFrameRate, frameRate);
omxEncMeta->setInt32(kKeySampleRate, frameRate);
omxEncMeta->setInt32(kKeyBitRate, bitRate);
omxEncMeta->setInt32(kKeyIFramesInterval, iFrameInterval);

但当我打电话时start()方法返回错误代码UNKNOWN_ERROR.

相反，如果我尝试给予MPEG4Writer直接我的定制MediaSource（不用包裹它OMXCodec它成功启动，但最终会停止记录并出现错误Missing codec specific data（大约12帧后），我认为这是因为我的习惯MediaSource仅提供有关实际帧的信息，但不提供有关编解码器格式的信息。

我确定我错过了一些东西OMXCodec，但我不知道是什么......有没有人可以为我提供一个自定义的工作示例MediaSource用于编码？或者给我一些关于为什么这根本不起作用的提示？
如果您需要更多信息，请询问，谢谢！

EDIT：我正在针对 API 14 开发这个，所以请不要建议我使用MediaCodec从 API 16 开始:)

EDIT: 我就是这样开始的MPEG4Writer:

int32_t outputFormat = OUTPUT_FORMAT_MPEG_4;
int64_t startTimeUs = systemTime() / 1000;
int32_t totalBitRate = bitRate;

sp<MetaData> meta = new MetaData;
meta->setInt64(kKeyTime, startTimeUs);
meta->setInt32(kKeyFileType, outputFormat);
meta->setInt32(kKeyBitRate, totalBitRate);

sp<MPEG4Writer> mWriter = new MPEG4Writer("/sdcard/encode_manual.mp4");
mWriter->addSource(mVideoEncoder);
status_t error = mWriter->start(meta.get());
if (error != OK) {
    LOGE("Writer NOT started! %x", error);
} else {
    LOGI("Writer started!");
}

这是 logcat 的输出（adb logcat OMXClient:V OMXCodec:V *:W):

W/ResourceType(  370): Skipping entry 0x7f04002f in package table 0 because it is not complex!
E/        ( 4127): Can't open file for reading
E/        ( 4127): Can't open file for reading
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  omx_video(): Inside Constructor()
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  omx_venc(): Inside component_init()
E/OMX-VENC-720p(  155): bool venc_dev::venc_validate_profile_level(OMX_U32*, OMX_U32*): Returning with eProfile = 1Level = 4
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  bool venc_dev::venc_open(OMX_U32)(): Init Profile/Level setting success
E/OMX-VENC-720p(  155): vidc.venc.debug.sliceinfo value is 0
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  Component_init return value = 0x0
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155): WARNING: Requested i/p bufsize[40960],Driver's updated i/p bufsize = 262144
E/OMX-VENC-720p(  155): bool venc_dev::venc_validate_profile_level(OMX_U32*, OMX_U32*): Returning with eProfile = 1Level = 256
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  bool venc_dev::venc_set_param(void*, OMX_INDEXTYPE)(): Profile/Level setting success
E/OMX-VENC-720p(  155): bool venc_dev::venc_validate_profile_level(OMX_U32*, OMX_U32*): Returning with eProfile = 1Level = 64
E/OMX-VENC-720p(  155): Calling set level (Framerate) with 15
E/OMX-VENC-720p(  155): bool venc_dev::venc_validate_profile_level(OMX_U32*, OMX_U32*): Returning with eProfile = 1Level = 64
E/OMX-VENC-720p(  155): Calling set level (Bitrate) with 15
E/OMX-VENC-720p(  155): get_parameter: OMX_IndexParamVideoProfileLevelQuerySupported for Input port returned Profile:1, Level:2048
E/OMX-VENC-720p(  155): Profile/Level set equal to 1/64
E/OMX-VENC-720p(  155): bool venc_dev::venc_validate_profile_level(OMX_U32*, OMX_U32*): Returning with eProfile = 1Level = 64
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  venc_set_intra_period: nPFrames = 25 nBFrames = 0
E/OMX-VENC-720p(  155): bool venc_dev::venc_validate_profile_level(OMX_U32*, OMX_U32*): Returning with eProfile = 1Level = 64
E/OMX-VENC-720p(  155): Calling set level (Bitrate) with 15
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  allocate_input_buffer()::
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  allocate_input_buffer()::
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  allocate_input_buffer()::
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  allocate_output_buffer()::
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  actual cnt = 5
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  allocate_output_buffer()::
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  actual cnt = 5
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  allocate_output_buffer()::
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  actual cnt = 5
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  allocate_output_buffer()::
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  actual cnt = 5
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  allocate_output_buffer()::
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  actual cnt = 5
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  unsigned int venc_dev::venc_start()(): Check Profile/Level set in driver before start
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  unsigned int venc_dev::venc_start()(): Driver Profile[3]/Level[15] successfully SET
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155): ENC_CONFIG: Codec: 2, Profile 3, level : 15
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  ENC_CONFIG: Width: 480, Height:360, Fps: 25
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155): ENC_CONFIG: Bitrate: 512000, RC: 3, I-Period: 25
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155): ENC_CONFIG: qpI: 0, qpP: 80, qpb: 0
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155): ENC_CONFIG: VOP_Resolution: 4343391, Slice-Mode: 1, Slize_Size: 0
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155): ENC_CONFIG: EntropyMode: 1, CabacModel: 0
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155): ENC_CONFIG: DB-Mode: 2, alpha: 0, Beta: 0
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155): ENC_CONFIG: IntraMB/Frame: 18, HEC: 843271745
E/OMX-VENC-720p(  155): Width 480, Height 360, w_round 480, h_round 368, yuv_size 294912 alignment 8192 count 2
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  Allocated virt:0x4432e000, FD: 145 of size 294912
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  Allocated virt:0x4432e000, FD: 145 of size 294912 at index: 0
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  Allocated virt:0x44895000, FD: 147 of size 294912
E/OMX-VENC-720p(  155):
E/OMX-VENC-720p(  155):  Allocated virt:0x44895000, FD: 147 of size 294912 at index: 1
E/TestEnc-JNI( 4127): Writer NOT started! 80000000

我刚刚弄清楚我的（dumb) 问题：我正在打电话start() on mVideoEncoder (the OMXCodec实例）调用之前start() on MPEG4Writer，这给出了UNKNOWN_ERROR.

我通过调用解决了start()仅在MPEG4Writer实例。