I'd like to dump YUV data from OMXCodec decoding output.
It's MediaBuffer type. It's impossible to access data() pointer.
If I try to access data, crash happens due to the check code below.
frameworks/av/media/libstagefright/MediaBuffer.cpp:119 CHECK(mGraphicBuffer == NULL) failed.
Please let me know the solution to extract YUV data from this MediaBuffer.
From the MediaBuffer, I feel that the following should be functional. I haven't tried the same yet and have worked with rg2's solution i.e. directly based on gralloc handle, but feel that the following should also be functional.
sp<GraphicBuffer> mCurrGraphicBuffer;
void *vaddr;
err = source->read(&buffer, &options); // Where buffer is of MediaBuffer type
mCurrGraphicBuffer = buffer->graphicBuffer();
width = mCurrGraphicBuffer->getWidth();
height = mCurrGraphicBuffer->getWidth();
format = mCurrGraphicBuffer->getFormat();
mCurrGraphicBuffer->lock(GRALLOC_USAGE_SW_READ_OFTEN, &vaddr);
//Dump the YUV file based on the vaddr, width, height, format
mCurrGraphicBuffer->unlock();
EDIT:
In order for the aforementioned solution to work, the actual GraphicBuffer should be created or allocated with appropriate usage flags i.e. the buffer should be created with a hint that CPU would be accessing the same. Else, -EINVAL would be returned as per the documentation in gralloc.
What platform are you using?
1) Usually the easiest way to get output buffer dump is to do it in vendor OMX IL (in every vendor impl which I worked there were ready functions/macros to do it)
2) If not you should try to dump buffer in ACodec onFillBufferDone (you need to differentiate between audio/video) or onOutputBufferDrained, you must get mGraphicBuffer and get from it raw buffer - encapsulation is platform dependent eg for qc it would be
void const *buf = (void const*)((private_handle_t*)(info->mGraphicBuffer->handle))->base;
Assuming that info is (in ACodec::onOutputBufferDrained)
BufferInfo *info =
mCodec->findBufferByID(kPortIndexOutput, bufferID, &index);
In OMXCodec case you can make the same at the end of OMXCodec::read Returned buf just save into the file, size to be written will be WxHxPixelRatio.
On some platforms, the hardware decoder does not create user-space YUV by default. You may try
OMXCodec::Create(…,
flags | OMXCodec::kClientNeedsFramebuffer);
