[FFmpeg-cvslog] lavfi/dnn: Async Support for TensorFlow Backend
Shubhanshu Saxena
git at videolan.org
Tue Aug 10 17:43:28 EEST 2021
ffmpeg | branch: master | Shubhanshu Saxena <shubhanshu.e01 at gmail.com> | Sun Aug 8 16:43:34 2021 +0530| [0985e9283ca2fe85dd0744f97c869bf24fbf14b5] | committer: Guo Yejun
lavfi/dnn: Async Support for TensorFlow Backend
This commit enables async execution in the TensorFlow backend
and adds function to flush extra frames.
The async execution mechanism executes the TFInferRequests on
a separate thread which is joined before the next execution of
same TFRequestItem/while freeing the model.
The following is the comparison of this mechanism with the existing
sync mechanism on TensorFlow C API 2.5 CPU variant.
Async Mode: 4m32.846s
Sync Mode: 5m17.582s
The above was performed on super resolution filter using SRCNN model.
Signed-off-by: Shubhanshu Saxena <shubhanshu.e01 at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0985e9283ca2fe85dd0744f97c869bf24fbf14b5
---
libavfilter/dnn/dnn_backend_tf.c | 121 +++++++++++++++++++++++++++++++++------
libavfilter/dnn/dnn_backend_tf.h | 3 +
libavfilter/dnn/dnn_interface.c | 3 +
3 files changed, 109 insertions(+), 18 deletions(-)
diff --git a/libavfilter/dnn/dnn_backend_tf.c b/libavfilter/dnn/dnn_backend_tf.c
index 939afec41d..3089ce8194 100644
--- a/libavfilter/dnn/dnn_backend_tf.c
+++ b/libavfilter/dnn/dnn_backend_tf.c
@@ -38,7 +38,6 @@
#include "dnn_io_proc.h"
#include "dnn_backend_common.h"
#include "safe_queue.h"
-#include "queue.h"
#include <tensorflow/c/c_api.h>
typedef struct TFOptions{
@@ -59,6 +58,7 @@ typedef struct TFModel{
TF_Status *status;
SafeQueue *request_queue;
Queue *inference_queue;
+ Queue *task_queue;
} TFModel;
/**
@@ -75,7 +75,7 @@ typedef struct TFInferRequest {
typedef struct TFRequestItem {
TFInferRequest *infer_request;
InferenceItem *inference;
- // further properties will be added later for async
+ DNNAsyncExecModule exec_module;
} TFRequestItem;
#define OFFSET(x) offsetof(TFContext, x)
@@ -89,6 +89,7 @@ static const AVOption dnn_tensorflow_options[] = {
AVFILTER_DEFINE_CLASS(dnn_tensorflow);
static DNNReturnType execute_model_tf(TFRequestItem *request, Queue *inference_queue);
+static void infer_completion_callback(void *args);
static void free_buffer(void *data, size_t length)
{
@@ -886,6 +887,9 @@ DNNModel *ff_dnn_load_model_tf(const char *model_filename, DNNFunctionType func_
av_freep(&item);
goto err;
}
+ item->exec_module.start_inference = &tf_start_inference;
+ item->exec_module.callback = &infer_completion_callback;
+ item->exec_module.args = item;
if (ff_safe_queue_push_back(tf_model->request_queue, item) < 0) {
av_freep(&item->infer_request);
@@ -899,6 +903,11 @@ DNNModel *ff_dnn_load_model_tf(const char *model_filename, DNNFunctionType func_
goto err;
}
+ tf_model->task_queue = ff_queue_create();
+ if (!tf_model->task_queue) {
+ goto err;
+ }
+
model->model = tf_model;
model->get_input = &get_input_tf;
model->get_output = &get_output_tf;
@@ -1061,7 +1070,6 @@ static DNNReturnType execute_model_tf(TFRequestItem *request, Queue *inference_q
{
TFModel *tf_model;
TFContext *ctx;
- TFInferRequest *infer_request;
InferenceItem *inference;
TaskItem *task;
@@ -1074,23 +1082,14 @@ static DNNReturnType execute_model_tf(TFRequestItem *request, Queue *inference_q
tf_model = task->model;
ctx = &tf_model->ctx;
- if (task->async) {
- avpriv_report_missing_feature(ctx, "Async execution not supported");
+ if (fill_model_input_tf(tf_model, request) != DNN_SUCCESS) {
return DNN_ERROR;
- } else {
- if (fill_model_input_tf(tf_model, request) != DNN_SUCCESS) {
- return DNN_ERROR;
- }
+ }
- infer_request = request->infer_request;
- TF_SessionRun(tf_model->session, NULL,
- infer_request->tf_input, &infer_request->input_tensor, 1,
- infer_request->tf_outputs, infer_request->output_tensors,
- task->nb_output, NULL, 0, NULL,
- tf_model->status);
- if (TF_GetCode(tf_model->status) != TF_OK) {
- tf_free_request(infer_request);
- av_log(ctx, AV_LOG_ERROR, "Failed to run session when executing model\n");
+ if (task->async) {
+ return ff_dnn_start_inference_async(ctx, &request->exec_module);
+ } else {
+ if (tf_start_inference(request) != DNN_SUCCESS) {
return DNN_ERROR;
}
infer_completion_callback(request);
@@ -1127,6 +1126,83 @@ DNNReturnType ff_dnn_execute_model_tf(const DNNModel *model, DNNExecBaseParams *
return execute_model_tf(request, tf_model->inference_queue);
}
+DNNReturnType ff_dnn_execute_model_async_tf(const DNNModel *model, DNNExecBaseParams *exec_params) {
+ TFModel *tf_model = model->model;
+ TFContext *ctx = &tf_model->ctx;
+ TaskItem *task;
+ TFRequestItem *request;
+
+ if (ff_check_exec_params(ctx, DNN_TF, model->func_type, exec_params) != 0) {
+ return DNN_ERROR;
+ }
+
+ task = av_malloc(sizeof(*task));
+ if (!task) {
+ av_log(ctx, AV_LOG_ERROR, "unable to alloc memory for task item.\n");
+ return DNN_ERROR;
+ }
+
+ if (ff_dnn_fill_task(task, exec_params, tf_model, 1, 1) != DNN_SUCCESS) {
+ av_freep(&task);
+ return DNN_ERROR;
+ }
+
+ if (ff_queue_push_back(tf_model->task_queue, task) < 0) {
+ av_freep(&task);
+ av_log(ctx, AV_LOG_ERROR, "unable to push back task_queue.\n");
+ return DNN_ERROR;
+ }
+
+ if (extract_inference_from_task(task, tf_model->inference_queue) != DNN_SUCCESS) {
+ av_log(ctx, AV_LOG_ERROR, "unable to extract inference from task.\n");
+ return DNN_ERROR;
+ }
+
+ request = ff_safe_queue_pop_front(tf_model->request_queue);
+ if (!request) {
+ av_log(ctx, AV_LOG_ERROR, "unable to get infer request.\n");
+ return DNN_ERROR;
+ }
+ return execute_model_tf(request, tf_model->inference_queue);
+}
+
+DNNAsyncStatusType ff_dnn_get_async_result_tf(const DNNModel *model, AVFrame **in, AVFrame **out)
+{
+ TFModel *tf_model = model->model;
+ return ff_dnn_get_async_result_common(tf_model->task_queue, in, out);
+}
+
+DNNReturnType ff_dnn_flush_tf(const DNNModel *model)
+{
+ TFModel *tf_model = model->model;
+ TFContext *ctx = &tf_model->ctx;
+ TFRequestItem *request;
+ DNNReturnType ret;
+
+ if (ff_queue_size(tf_model->inference_queue) == 0) {
+ // no pending task need to flush
+ return DNN_SUCCESS;
+ }
+
+ request = ff_safe_queue_pop_front(tf_model->request_queue);
+ if (!request) {
+ av_log(ctx, AV_LOG_ERROR, "unable to get infer request.\n");
+ return DNN_ERROR;
+ }
+
+ ret = fill_model_input_tf(tf_model, request);
+ if (ret != DNN_SUCCESS) {
+ av_log(ctx, AV_LOG_ERROR, "Failed to fill model input.\n");
+ if (ff_safe_queue_push_back(tf_model->request_queue, request) < 0) {
+ av_freep(&request->infer_request);
+ av_freep(&request);
+ }
+ return ret;
+ }
+
+ return ff_dnn_start_inference_async(ctx, &request->exec_module);
+}
+
void ff_dnn_free_model_tf(DNNModel **model)
{
TFModel *tf_model;
@@ -1135,6 +1211,7 @@ void ff_dnn_free_model_tf(DNNModel **model)
tf_model = (*model)->model;
while (ff_safe_queue_size(tf_model->request_queue) != 0) {
TFRequestItem *item = ff_safe_queue_pop_front(tf_model->request_queue);
+ ff_dnn_async_module_cleanup(&item->exec_module);
tf_free_request(item->infer_request);
av_freep(&item->infer_request);
av_freep(&item);
@@ -1147,6 +1224,14 @@ void ff_dnn_free_model_tf(DNNModel **model)
}
ff_queue_destroy(tf_model->inference_queue);
+ while (ff_queue_size(tf_model->task_queue) != 0) {
+ TaskItem *item = ff_queue_pop_front(tf_model->task_queue);
+ av_frame_free(&item->in_frame);
+ av_frame_free(&item->out_frame);
+ av_freep(&item);
+ }
+ ff_queue_destroy(tf_model->task_queue);
+
if (tf_model->graph){
TF_DeleteGraph(tf_model->graph);
}
diff --git a/libavfilter/dnn/dnn_backend_tf.h b/libavfilter/dnn/dnn_backend_tf.h
index 3dfd6e4280..aec0fc2011 100644
--- a/libavfilter/dnn/dnn_backend_tf.h
+++ b/libavfilter/dnn/dnn_backend_tf.h
@@ -32,6 +32,9 @@
DNNModel *ff_dnn_load_model_tf(const char *model_filename, DNNFunctionType func_type, const char *options, AVFilterContext *filter_ctx);
DNNReturnType ff_dnn_execute_model_tf(const DNNModel *model, DNNExecBaseParams *exec_params);
+DNNReturnType ff_dnn_execute_model_async_tf(const DNNModel *model, DNNExecBaseParams *exec_params);
+DNNAsyncStatusType ff_dnn_get_async_result_tf(const DNNModel *model, AVFrame **in, AVFrame **out);
+DNNReturnType ff_dnn_flush_tf(const DNNModel *model);
void ff_dnn_free_model_tf(DNNModel **model);
diff --git a/libavfilter/dnn/dnn_interface.c b/libavfilter/dnn/dnn_interface.c
index 02e532fc1b..81af934dd5 100644
--- a/libavfilter/dnn/dnn_interface.c
+++ b/libavfilter/dnn/dnn_interface.c
@@ -48,6 +48,9 @@ DNNModule *ff_get_dnn_module(DNNBackendType backend_type)
#if (CONFIG_LIBTENSORFLOW == 1)
dnn_module->load_model = &ff_dnn_load_model_tf;
dnn_module->execute_model = &ff_dnn_execute_model_tf;
+ dnn_module->execute_model_async = &ff_dnn_execute_model_async_tf;
+ dnn_module->get_async_result = &ff_dnn_get_async_result_tf;
+ dnn_module->flush = &ff_dnn_flush_tf;
dnn_module->free_model = &ff_dnn_free_model_tf;
#else
av_freep(&dnn_module);
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