// Copyright 2019 The MediaPipe Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#import <CoreVideo/CoreVideo.h>
#import <Metal/Metal.h>
#import <MetalKit/MetalKit.h>
#include <cstring>
#include <memory>
#include <string>
#include <vector>
#include "absl/log/absl_log.h"
#include "absl/memory/memory.h"
#include "absl/strings/str_format.h"
#include "mediapipe/calculators/tensor/inference_calculator.h"
#include "mediapipe/calculators/tensor/inference_io_mapper.h"
#include "mediapipe/calculators/tensor/tensor_span.h"
#include "mediapipe/framework/formats/tensor.h"
#include "mediapipe/framework/formats/tensor_mtl_buffer_view.h"
#import "mediapipe/gpu/MPPMetalHelper.h"
#include "mediapipe/gpu/MPPMetalUtil.h"
#include "mediapipe/gpu/gpu_buffer.h"
#include "mediapipe/util/tflite/config.h"
#include "tensorflow/lite/delegates/gpu/common/shape.h"
#include "tensorflow/lite/delegates/gpu/metal/buffer_convert.h"
#include "tensorflow/lite/delegates/gpu/metal_delegate.h"
#include "tensorflow/lite/delegates/gpu/metal_delegate_internal.h"
namespace {
// Round up n to next multiple of m.
template <typename T>
T RoundUp(T n, T m) {
return ((n + m - T{1}) / m) * m;
}
} // namespace
namespace mediapipe {
namespace api2 {
#if MEDIAPIPE_TFLITE_METAL_INFERENCE
namespace {
tflite::gpu::BHWC BhwcFromTensorShape(const Tensor::Shape& shape) {
tflite::gpu::BHWC result;
result.b = shape.dims[0];
switch (shape.dims.size()) {
case 1:
// result.b is already filled.
break;
case 2:
result.h = 1;
result.w = 1;
result.c = shape.dims[1];
break;
case 3:
result.h = 1;
result.w = shape.dims[1];
result.c = shape.dims[2];
break;
case 4:
result.h = shape.dims[1];
result.w = shape.dims[2];
result.c = shape.dims[3];
break;
default:
// Handles 0 and >4.
ABSL_LOG(FATAL)
<< "Dimensions size must be in range [1,4] for GPU inference, but "
<< shape.dims.size() << " is provided";
}
return result;
}
} // namespace
#endif // MEDIAPIPE_TFLITE_METAL_INFERENCE
class InferenceCalculatorMetalImpl
: public InferenceCalculatorNodeImpl<InferenceCalculatorMetal,
InferenceCalculatorMetalImpl> {
public:
static absl::Status UpdateContract(CalculatorContract* cc);
absl::Status Open(CalculatorContext* cc) override;
absl::Status Close(CalculatorContext* cc) override;
private:
absl::StatusOr<std::vector<Tensor>> Process(
CalculatorContext* cc, const TensorSpan& tensor_span) override;
absl::Status InitInterpreter(CalculatorContext* cc);
void AddDelegate(CalculatorContext* cc,
tflite::InterpreterBuilder* interpreter_builder);
absl::Status CreateConverters(CalculatorContext* cc);
// TfLite requires us to keep the model alive as long as the interpreter is.
Packet<TfLiteModelPtr> model_packet_;
std::unique_ptr<tflite::Interpreter> interpreter_;
TfLiteDelegatePtr delegate_;
bool allow_precision_loss_ = false;
#if MEDIAPIPE_TFLITE_METAL_INFERENCE
MPPMetalHelper* gpu_helper_ = nullptr;
TFLBufferConvert* converter_to_BPHWC4_ = nil;
TFLBufferConvert* converter_from_BPHWC4_ = nil;
#endif // MEDIAPIPE_TFLITE_GL_INFERENCE
#if MEDIAPIPE_TFLITE_GPU_SUPPORTED
std::vector<Tensor::Shape> output_shapes_;
std::vector<std::unique_ptr<Tensor>> gpu_buffers_in_;
std::vector<std::unique_ptr<Tensor>> gpu_buffers_out_;
#endif // MEDIAPIPE_TFLITE_GPU_SUPPORTED
};
absl::Status InferenceCalculatorMetalImpl::UpdateContract(
CalculatorContract* cc) {
MP_RETURN_IF_ERROR(TensorContractCheck(cc));
RET_CHECK(!kDelegate(cc).IsConnected())
<< "Delegate configuration through side packet is not supported.";
const auto& options = cc->Options<mediapipe::InferenceCalculatorOptions>();
RET_CHECK(!options.model_path().empty() ^ kSideInModel(cc).IsConnected())
<< "Either model as side packet or model path in options is required.";
WarnFeedbackTensorsUnsupported(cc);
MP_RETURN_IF_ERROR([MPPMetalHelper updateContract:cc]);
return absl::OkStatus();
}
absl::Status InferenceCalculatorMetalImpl::Open(CalculatorContext* cc) {
const auto& options = cc->Options<::mediapipe::InferenceCalculatorOptions>();
allow_precision_loss_ = options.delegate().gpu().allow_precision_loss();
gpu_helper_ = [[MPPMetalHelper alloc] initWithCalculatorContext:cc];
RET_CHECK(gpu_helper_);
return InitInterpreter(cc);
}
absl::StatusOr<std::vector<Tensor>> InferenceCalculatorMetalImpl::Process(
CalculatorContext* cc, const TensorSpan& tensor_span) {
std::vector<Tensor> output_tensors;
id<MTLCommandBuffer> command_buffer;
command_buffer = [gpu_helper_ commandBuffer];
command_buffer.label = @"InferenceCalculator";
// Explicit copy input with conversion float 32 bits to 16 bits.
for (int i = 0; i < tensor_span.size(); ++i) {
auto input_view =
MtlBufferView::GetReadView(tensor_span[i], command_buffer);
// Reshape tensor.
tflite::gpu::BHWC shape = BhwcFromTensorShape(tensor_span[i].shape());
auto gpu_buffer_view =
MtlBufferView::GetWriteView(*gpu_buffers_in_[i], command_buffer);
id<MTLComputeCommandEncoder> input_encoder =
[command_buffer computeCommandEncoder];
[converter_to_BPHWC4_ convertWithEncoder:input_encoder
shape:shape
sourceBuffer:input_view.buffer()
convertedBuffer:gpu_buffer_view.buffer()];
[input_encoder endEncoding];
}
// Run inference.
RET_CHECK(TFLGpuDelegateSetCommandBuffer(delegate_.get(), command_buffer));
RET_CHECK_EQ(interpreter_->Invoke(), kTfLiteOk);
output_tensors.reserve(output_shapes_.size());
for (int i = 0; i < output_shapes_.size(); ++i) {
output_tensors.emplace_back(Tensor::ElementType::kFloat32,
output_shapes_[i]);
// Reshape tensor.
tflite::gpu::BHWC shape = BhwcFromTensorShape(output_shapes_[i]);
auto read_view =
MtlBufferView::GetReadView(*gpu_buffers_out_[i], command_buffer);
auto write_view =
MtlBufferView::GetWriteView(output_tensors[i], command_buffer);
id<MTLComputeCommandEncoder> output_encoder =
[command_buffer computeCommandEncoder];
[converter_from_BPHWC4_ convertWithEncoder:output_encoder
shape:shape
sourceBuffer:read_view.buffer()
convertedBuffer:write_view.buffer()];
[output_encoder endEncoding];
}
[command_buffer commit];
// The below call is found (manual testing) to resolve flickering issues for
// some use cases where multiple Metal calculators are involved.
// TODO: investigate and ensure proper synchronization
// (e.g. fences/barriers/events).
[command_buffer waitUntilScheduled];
return output_tensors;
}
absl::Status InferenceCalculatorMetalImpl::Close(CalculatorContext* cc) {
converter_to_BPHWC4_ = nil;
converter_from_BPHWC4_ = nil;
gpu_buffers_in_.clear();
gpu_buffers_out_.clear();
interpreter_ = nullptr;
delegate_ = nullptr;
return absl::OkStatus();
}
absl::Status InferenceCalculatorMetalImpl::InitInterpreter(
CalculatorContext* cc) {
MP_ASSIGN_OR_RETURN(model_packet_, GetModelAsPacket(cc));
const auto& model = *model_packet_.Get();
MP_ASSIGN_OR_RETURN(auto op_resolver_packet, GetOpResolverAsPacket(cc));
const auto& op_resolver = op_resolver_packet.Get();
tflite::InterpreterBuilder interpreter_builder(model, op_resolver);
AddDelegate(cc, &interpreter_builder);
interpreter_builder.SetNumThreads(
cc->Options<mediapipe::InferenceCalculatorOptions>().cpu_num_thread());
RET_CHECK_EQ(interpreter_builder(&interpreter_), kTfLiteOk);
RET_CHECK(interpreter_);
MP_ASSIGN_OR_RETURN(
const auto& io_mapping,
InferenceIoMapper::GetInputOutputTensorNamesFromInterpreter(
*interpreter_));
MP_RETURN_IF_ERROR(
InferenceCalculatorNodeImpl::UpdateIoMapping(cc, io_mapping));
MP_RETURN_IF_ERROR(CreateConverters(cc));
RET_CHECK_EQ(interpreter_->AllocateTensors(), kTfLiteOk);
// TODO: Support quantized tensors.
RET_CHECK_NE(
interpreter_->tensor(interpreter_->inputs()[0])->quantization.type,
kTfLiteAffineQuantization);
return absl::OkStatus();
}
void InferenceCalculatorMetalImpl::AddDelegate(
CalculatorContext* cc, tflite::InterpreterBuilder* interpreter_builder) {
// Configure and create the delegate.
TFLGpuDelegateOptions options;
// `enable_quantization` enables the run of sparse models i.e. the models with
// DENSIFY op preceding DEQUINTIZE op. Both ops get removed from the execution
// graph after the tensor of the weights is read.
options.enable_quantization = true;
options.allow_precision_loss = allow_precision_loss_;
options.wait_type = TFLGpuDelegateWaitType::TFLGpuDelegateWaitTypeDoNotWait;
delegate_ =
TfLiteDelegatePtr(TFLGpuDelegateCreate(&options), &TFLGpuDelegateDelete);
interpreter_builder->AddDelegate(delegate_.get());
}
absl::Status InferenceCalculatorMetalImpl::CreateConverters(
CalculatorContext* cc) {
id<MTLDevice> device = gpu_helper_.mtlDevice;
// Get input image sizes.
const auto& input_indices = interpreter_->inputs();
for (int i = 0; i < input_indices.size(); ++i) {
const TfLiteTensor* tensor = interpreter_->tensor(input_indices[i]);
RET_CHECK(tensor->dims->size > 0) << absl::StrFormat(
"Input tensor at index [%d] doesn't specify dimensions.",
input_indices[i]);
// Create and bind input buffer.
std::vector<int> dims{tensor->dims->data,
tensor->dims->data + tensor->dims->size};
dims.back() = RoundUp(dims.back(), 4);
gpu_buffers_in_.emplace_back(absl::make_unique<Tensor>(
allow_precision_loss_ ? Tensor::ElementType::kFloat16
: Tensor::ElementType::kFloat32,
Tensor::Shape{dims}));
auto buffer_view =
MtlBufferView::GetWriteView(*gpu_buffers_in_[i], gpu_helper_.mtlDevice);
RET_CHECK_EQ(TFLGpuDelegateBindMetalBufferToTensor(
delegate_.get(), input_indices[i], buffer_view.buffer()),
true);
}
interpreter_->SetAllowBufferHandleOutput(true);
// Get output image sizes.
const auto& output_indices = interpreter_->outputs();
output_shapes_.resize(output_indices.size());
for (int i = 0; i < output_shapes_.size(); ++i) {
const TfLiteTensor* tensor = interpreter_->tensor(output_indices[i]);
RET_CHECK(tensor->dims->size > 0) << absl::StrFormat(
"Output tensor at index [%d] doesn't specify dimensions.",
output_indices[i]);
RET_CHECK(tensor->dims->size <= 4);
// Create and bind output buffers.
// Channels are always padded to multiple of 4.
std::vector<int> dims{tensor->dims->data,
tensor->dims->data + tensor->dims->size};
output_shapes_[i] = {dims};
dims.back() = RoundUp(dims.back(), 4);
gpu_buffers_out_.emplace_back(absl::make_unique<Tensor>(
allow_precision_loss_ ? Tensor::ElementType::kFloat16
: Tensor::ElementType::kFloat32,
Tensor::Shape{dims}));
RET_CHECK_EQ(TFLGpuDelegateBindMetalBufferToTensor(
delegate_.get(), output_indices[i],
MtlBufferView::GetWriteView(*gpu_buffers_out_[i],
gpu_helper_.mtlDevice)
.buffer()),
true);
}
// Create converter for GPU input.
converter_to_BPHWC4_ =
[[TFLBufferConvert alloc] initWithDevice:device
isFloat16:allow_precision_loss_
convertToPBHWC4:true];
if (converter_to_BPHWC4_ == nil) {
return mediapipe::InternalError(
"Error initializating input buffer converter");
}
// Create converter for GPU output.
converter_from_BPHWC4_ =
[[TFLBufferConvert alloc] initWithDevice:device
isFloat16:allow_precision_loss_
convertToPBHWC4:false];
if (converter_from_BPHWC4_ == nil) {
return absl::InternalError("Error initializating output buffer converter");
}
return absl::OkStatus();
}
} // namespace api2
} // namespace mediapipe