Adds ESPCN super resolution filter merged with SRCNN filter.

Signed-off-by: Pedro Arthur <bygrandao@gmail.com>

1 files changed, 354 insertions, 0 deletions

diff --git a/libavfilter/vf_sr.c b/libavfilter/vf_sr.c
new file mode 100644
index 0000000000..196567afda
--- /dev/null
+++ b/libavfilter/vf_sr.c
@@ -0,0 +1,354 @@
+/*
+ * Copyright (c) 2018 Sergey Lavrushkin
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * Filter implementing image super-resolution using deep convolutional networks.
+ * https://arxiv.org/abs/1501.00092
+ * https://arxiv.org/abs/1609.05158
+ */
+
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "libavutil/opt.h"
+#include "libavformat/avio.h"
+#include "libswscale/swscale.h"
+#include "dnn_interface.h"
+
+typedef enum {SRCNN, ESPCN} SRModel;
+
+typedef struct SRContext {
+    const AVClass *class;
+
+    SRModel model_type;
+    char* model_filename;
+    DNNBackendType backend_type;
+    DNNModule* dnn_module;
+    DNNModel* model;
+    DNNData input, output;
+    int scale_factor;
+    struct SwsContext* sws_context;
+    int sws_slice_h;
+} SRContext;
+
+#define OFFSET(x) offsetof(SRContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_VIDEO_PARAM
+static const AVOption sr_options[] = {
+    { "model", "specifies what DNN model to use", OFFSET(model_type), AV_OPT_TYPE_FLAGS, { .i64 = 0 }, 0, 1, FLAGS, "model_type" },
+    { "srcnn", "Super-Resolution Convolutional Neural Network model (scale factor should be specified for custom SRCNN model)", 0, AV_OPT_TYPE_CONST, { .i64 = 0 }, 0, 0, FLAGS, "model_type" },
+    { "espcn", "Efficient Sub-Pixel Convolutional Neural Network model", 0, AV_OPT_TYPE_CONST, { .i64 = 1 }, 0, 0, FLAGS, "model_type" },
+    { "dnn_backend", "DNN backend used for model execution", OFFSET(backend_type), AV_OPT_TYPE_FLAGS, { .i64 = 0 }, 0, 1, FLAGS, "backend" },
+    { "native", "native backend flag", 0, AV_OPT_TYPE_CONST, { .i64 = 0 }, 0, 0, FLAGS, "backend" },
+#if (CONFIG_LIBTENSORFLOW == 1)
+    { "tensorflow", "tensorflow backend flag", 0, AV_OPT_TYPE_CONST, { .i64 = 1 }, 0, 0, FLAGS, "backend" },
+#endif
+    {"scale_factor", "scale factor for SRCNN model", OFFSET(scale_factor), AV_OPT_TYPE_INT, { .i64 = 2 }, 2, 4, FLAGS},
+    { "model_filename", "path to model file specifying network architecture and its parameters", OFFSET(model_filename), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(sr);
+
+static av_cold int init(AVFilterContext* context)
+{
+    SRContext* sr_context = context->priv;
+
+    sr_context->dnn_module = ff_get_dnn_module(sr_context->backend_type);
+    if (!sr_context->dnn_module){
+        av_log(context, AV_LOG_ERROR, "could not create DNN module for requested backend\n");
+        return AVERROR(ENOMEM);
+    }
+    if (!sr_context->model_filename){
+        av_log(context, AV_LOG_VERBOSE, "model file for network was not specified, using default network for x2 upsampling\n");
+        sr_context->scale_factor = 2;
+        switch (sr_context->model_type){
+        case SRCNN:
+            sr_context->model = (sr_context->dnn_module->load_default_model)(DNN_SRCNN);
+            break;
+        case ESPCN:
+            sr_context->model = (sr_context->dnn_module->load_default_model)(DNN_ESPCN);
+        }
+    }
+    else{
+        sr_context->model = (sr_context->dnn_module->load_model)(sr_context->model_filename);
+    }
+    if (!sr_context->model){
+        av_log(context, AV_LOG_ERROR, "could not load DNN model\n");
+        return AVERROR(EIO);
+    }
+
+    return 0;
+}
+
+static int query_formats(AVFilterContext* context)
+{
+    const enum AVPixelFormat pixel_formats[] = {AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV444P,
+                                                AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_GRAY8,
+                                                AV_PIX_FMT_NONE};
+    AVFilterFormats* formats_list;
+
+    formats_list = ff_make_format_list(pixel_formats);
+    if (!formats_list){
+        av_log(context, AV_LOG_ERROR, "could not create formats list\n");
+        return AVERROR(ENOMEM);
+    }
+    return ff_set_common_formats(context, formats_list);
+}
+
+static int config_props(AVFilterLink* inlink)
+{
+    AVFilterContext* context = inlink->dst;
+    SRContext* sr_context = context->priv;
+    AVFilterLink* outlink = context->outputs[0];
+    DNNReturnType result;
+    int sws_src_h, sws_src_w, sws_dst_h, sws_dst_w;
+
+    switch (sr_context->model_type){
+    case SRCNN:
+        sr_context->input.width = inlink->w * sr_context->scale_factor;
+        sr_context->input.height = inlink->h * sr_context->scale_factor;
+        break;
+    case ESPCN:
+        sr_context->input.width = inlink->w;
+        sr_context->input.height = inlink->h;
+    }
+    sr_context->input.channels = 1;
+
+    result = (sr_context->model->set_input_output)(sr_context->model->model, &sr_context->input, &sr_context->output);
+    if (result != DNN_SUCCESS){
+        av_log(context, AV_LOG_ERROR, "could not set input and output for the model\n");
+        return AVERROR(EIO);
+    }
+    else{
+        outlink->h = sr_context->output.height;
+        outlink->w = sr_context->output.width;
+        switch (sr_context->model_type){
+        case SRCNN:
+            sr_context->sws_context = sws_getContext(inlink->w, inlink->h, inlink->format,
+                                                     outlink->w, outlink->h, outlink->format, SWS_BICUBIC, NULL, NULL, NULL);
+            if (!sr_context->sws_context){
+                av_log(context, AV_LOG_ERROR, "could not create SwsContext\n");
+                return AVERROR(ENOMEM);
+            }
+            sr_context->sws_slice_h = inlink->h;
+            break;
+        case ESPCN:
+            if (inlink->format == AV_PIX_FMT_GRAY8){
+                sr_context->sws_context = NULL;
+            }
+            else{
+                sws_src_h = sr_context->input.height;
+                sws_src_w = sr_context->input.width;
+                sws_dst_h = sr_context->output.height;
+                sws_dst_w = sr_context->output.width;
+
+                switch (inlink->format){
+                case AV_PIX_FMT_YUV420P:
+                    sws_src_h = (sws_src_h >> 1) + (sws_src_h % 2 != 0 ? 1 : 0);
+                    sws_src_w = (sws_src_w >> 1) + (sws_src_w % 2 != 0 ? 1 : 0);
+                    sws_dst_h = (sws_dst_h >> 1) + (sws_dst_h % 2 != 0 ? 1 : 0);
+                    sws_dst_w = (sws_dst_w >> 1) + (sws_dst_w % 2 != 0 ? 1 : 0);
+                    break;
+                case AV_PIX_FMT_YUV422P:
+                    sws_src_w = (sws_src_w >> 1) + (sws_src_w % 2 != 0 ? 1 : 0);
+                    sws_dst_w = (sws_dst_w >> 1) + (sws_dst_w % 2 != 0 ? 1 : 0);
+                    break;
+                case AV_PIX_FMT_YUV444P:
+                    break;
+                case AV_PIX_FMT_YUV410P:
+                    sws_src_h = (sws_src_h >> 2) + (sws_src_h % 4 != 0 ? 1 : 0);
+                    sws_src_w = (sws_src_w >> 2) + (sws_src_w % 4 != 0 ? 1 : 0);
+                    sws_dst_h = (sws_dst_h >> 2) + (sws_dst_h % 4 != 0 ? 1 : 0);
+                    sws_dst_w = (sws_dst_w >> 2) + (sws_dst_w % 4 != 0 ? 1 : 0);
+                    break;
+                case AV_PIX_FMT_YUV411P:
+                    sws_src_w = (sws_src_w >> 2) + (sws_src_w % 4 != 0 ? 1 : 0);
+                    sws_dst_w = (sws_dst_w >> 2) + (sws_dst_w % 4 != 0 ? 1 : 0);
+                    break;
+                default:
+                    av_log(context, AV_LOG_ERROR, "could not create SwsContext for input pixel format");
+                    return AVERROR(EIO);
+                }
+                sr_context->sws_context = sws_getContext(sws_src_w, sws_src_h, AV_PIX_FMT_GRAY8,
+                                                         sws_dst_w, sws_dst_h, AV_PIX_FMT_GRAY8, SWS_BICUBIC, NULL, NULL, NULL);
+                if (!sr_context->sws_context){
+                    av_log(context, AV_LOG_ERROR, "could not create SwsContext\n");
+                    return AVERROR(ENOMEM);
+                }
+                sr_context->sws_slice_h = sws_src_h;
+            }
+        }
+
+        return 0;
+    }
+}
+
+typedef struct ThreadData{
+    uint8_t* data;
+    int data_linesize, height, width;
+} ThreadData;
+
+static int uint8_to_float(AVFilterContext* context, void* arg, int jobnr, int nb_jobs)
+{
+    SRContext* sr_context = context->priv;
+    const ThreadData* td = arg;
+    const int slice_start = (td->height *  jobnr     ) / nb_jobs;
+    const int slice_end   = (td->height * (jobnr + 1)) / nb_jobs;
+    const uint8_t* src = td->data + slice_start * td->data_linesize;
+    float* dst = sr_context->input.data + slice_start * td->width;
+    int y, x;
+
+    for (y = slice_start; y < slice_end; ++y){
+        for (x = 0; x < td->width; ++x){
+            dst[x] = (float)src[x] / 255.0f;
+        }
+        src += td->data_linesize;
+        dst += td->width;
+    }
+
+    return 0;
+}
+
+static int float_to_uint8(AVFilterContext* context, void* arg, int jobnr, int nb_jobs)
+{
+    SRContext* sr_context = context->priv;
+    const ThreadData* td = arg;
+    const int slice_start = (td->height *  jobnr     ) / nb_jobs;
+    const int slice_end   = (td->height * (jobnr + 1)) / nb_jobs;
+    const float* src = sr_context->output.data + slice_start * td->width;
+    uint8_t* dst = td->data + slice_start * td->data_linesize;
+    int y, x;
+
+    for (y = slice_start; y < slice_end; ++y){
+        for (x = 0; x < td->width; ++x){
+            dst[x] = (uint8_t)(255.0f * FFMIN(src[x], 1.0f));
+        }
+        src += td->width;
+        dst += td->data_linesize;
+    }
+
+    return 0;
+}
+
+static int filter_frame(AVFilterLink* inlink, AVFrame* in)
+{
+    AVFilterContext* context = inlink->dst;
+    SRContext* sr_context = context->priv;
+    AVFilterLink* outlink = context->outputs[0];
+    AVFrame* out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+    ThreadData td;
+    int nb_threads;
+    DNNReturnType dnn_result;
+
+    if (!out){
+        av_log(context, AV_LOG_ERROR, "could not allocate memory for output frame\n");
+        av_frame_free(&in);
+        return AVERROR(ENOMEM);
+    }
+    av_frame_copy_props(out, in);
+    out->height = sr_context->output.height;
+    out->width = sr_context->output.width;
+    switch (sr_context->model_type){
+    case SRCNN:
+        sws_scale(sr_context->sws_context, in->data, in->linesize,
+                  0, sr_context->sws_slice_h, out->data, out->linesize);
+        td.data = out->data[0];
+        td.data_linesize = out->linesize[0];
+        td.height = out->height;
+        td.width = out->width;
+        break;
+    case ESPCN:
+        if (sr_context->sws_context){
+            sws_scale(sr_context->sws_context, in->data + 1, in->linesize + 1,
+                      0, sr_context->sws_slice_h, out->data + 1, out->linesize + 1);
+            sws_scale(sr_context->sws_context, in->data + 2, in->linesize + 2,
+                      0, sr_context->sws_slice_h, out->data + 2, out->linesize + 2);
+        }
+        td.data = in->data[0];
+        td.data_linesize = in->linesize[0];
+        td.height = in->height;
+        td.width = in->width;
+    }
+
+    nb_threads = ff_filter_get_nb_threads(context);
+    context->internal->execute(context, uint8_to_float, &td, NULL, FFMIN(td.height, nb_threads));
+    av_frame_free(&in);
+
+    dnn_result = (sr_context->dnn_module->execute_model)(sr_context->model);
+    if (dnn_result != DNN_SUCCESS){
+        av_log(context, AV_LOG_ERROR, "failed to execute loaded model\n");
+        return AVERROR(EIO);
+    }
+
+    td.data = out->data[0];
+    td.data_linesize = out->linesize[0];
+    td.height = out->height;
+    td.width = out->width;
+    context->internal->execute(context, float_to_uint8, &td, NULL, FFMIN(td.height, nb_threads));
+
+    return ff_filter_frame(outlink, out);
+}
+
+static av_cold void uninit(AVFilterContext* context)
+{
+    SRContext* sr_context = context->priv;
+
+    if (sr_context->dnn_module){
+        (sr_context->dnn_module->free_model)(&sr_context->model);
+        av_freep(&sr_context->dnn_module);
+    }
+
+    if (sr_context->sws_context){
+        sws_freeContext(sr_context->sws_context);
+    }
+}
+
+static const AVFilterPad sr_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = config_props,
+        .filter_frame = filter_frame,
+    },
+    { NULL }
+};
+
+static const AVFilterPad sr_outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+    },
+    { NULL }
+};
+
+AVFilter ff_vf_sr = {
+    .name          = "sr",
+    .description   = NULL_IF_CONFIG_SMALL("Apply DNN-based image super resolution to the input."),
+    .priv_size     = sizeof(SRContext),
+    .init          = init,
+    .uninit        = uninit,
+    .query_formats = query_formats,
+    .inputs        = sr_inputs,
+    .outputs       = sr_outputs,
+    .priv_class    = &sr_class,
+    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
+};
+