avcodec/evc_decoder: Provided support for EVC decoder

- Added EVC decoder wrapper
- Changes in project configuration file and libavcodec Makefile
- Added documentation for xevd wrapper

Signed-off-by: Dawid Kozinski <d.kozinski@samsung.com>
Signed-off-by: James Almer <jamrial@gmail.com>

1 files changed, 538 insertions, 0 deletions

diff --git a/libavcodec/libxevd.c b/libavcodec/libxevd.c
new file mode 100644
index 0000000000..58ef90d929
--- /dev/null
+++ b/libavcodec/libxevd.c
@@ -0,0 +1,538 @@
+/*
+ * libxevd decoder
+ * EVC (MPEG-5 Essential Video Coding) decoding using XEVD MPEG-5 EVC decoder library
+ *
+ * Copyright (C) 2021 Dawid Kozinski <d.kozinski@samsung.com>
+ *
+ * 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
+ */
+
+#include <float.h>
+#include <stdlib.h>
+
+#include <xevd.h>
+
+#include "libavutil/internal.h"
+#include "libavutil/common.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+#include "libavutil/pixfmt.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/cpu.h"
+
+#include "avcodec.h"
+#include "internal.h"
+#include "packet_internal.h"
+#include "codec_internal.h"
+#include "profiles.h"
+#include "decode.h"
+
+#define XEVD_PARAM_BAD_NAME -1
+#define XEVD_PARAM_BAD_VALUE -2
+
+#define EVC_NAL_HEADER_SIZE 2 /* byte */
+
+/**
+ * The structure stores all the states associated with the instance of Xeve MPEG-5 EVC decoder
+ */
+typedef struct XevdContext {
+    const AVClass *class;
+
+    XEVD id;            // XEVD instance identifier @see xevd.h
+    XEVD_CDSC cdsc;     // decoding parameters @see xevd.h
+
+    // If end of stream occurs it is required "flushing" (aka draining) the codec,
+    // as the codec might buffer multiple frames or packets internally.
+    int draining_mode; // The flag is set if codec enters draining mode.
+
+    AVPacket *pkt;     // access unit (a set of NAL units that are consecutive in decoding order and containing exactly one encoded image)
+} XevdContext;
+
+/**
+ * The function populates the XEVD_CDSC structure.
+ * XEVD_CDSC contains all decoder parameters that should be initialized before its use.
+ *
+ * @param[in] avctx codec context
+ * @param[out] cdsc contains all decoder parameters that should be initialized before its use
+ *
+ */
+static void get_conf(AVCodecContext *avctx, XEVD_CDSC *cdsc)
+{
+    int cpu_count = av_cpu_count();
+
+    /* clear XEVS_CDSC structure */
+    memset(cdsc, 0, sizeof(XEVD_CDSC));
+
+    /* init XEVD_CDSC */
+    if (avctx->thread_count <= 0)
+        cdsc->threads = (cpu_count < XEVD_MAX_TASK_CNT) ? cpu_count : XEVD_MAX_TASK_CNT;
+    else if (avctx->thread_count > XEVD_MAX_TASK_CNT)
+        cdsc->threads = XEVD_MAX_TASK_CNT;
+    else
+        cdsc->threads = avctx->thread_count;
+}
+
+/**
+ * Read NAL unit length
+ * @param bs input data (bitstream)
+ * @return the length of NAL unit on success, 0 value on failure
+ */
+static uint32_t read_nal_unit_length(const uint8_t *bs, int bs_size, AVCodecContext *avctx)
+{
+    uint32_t len = 0;
+    XEVD_INFO info;
+    int ret;
+
+    if (bs_size == XEVD_NAL_UNIT_LENGTH_BYTE) {
+        ret = xevd_info((void *)bs, XEVD_NAL_UNIT_LENGTH_BYTE, 1, &info);
+        if (XEVD_FAILED(ret)) {
+            av_log(avctx, AV_LOG_ERROR, "Cannot get bitstream information\n");
+            return 0;
+        }
+        len = info.nalu_len;
+        if (len == 0) {
+            av_log(avctx, AV_LOG_ERROR, "Invalid bitstream size! [%d]\n", bs_size);
+            return 0;
+        }
+    }
+
+    return len;
+}
+
+/**
+ * @param[in] xectx the structure that stores all the state associated with the instance of Xeve MPEG-5 EVC decoder
+ * @param[out] avctx codec context
+ * @return 0 on success, negative value on failure
+ */
+static int export_stream_params(const XevdContext *xectx, AVCodecContext *avctx)
+{
+    int ret;
+    int size;
+    int color_space;
+
+    avctx->pix_fmt = AV_PIX_FMT_YUV420P10;
+
+    size = 4;
+    ret = xevd_config(xectx->id, XEVD_CFG_GET_CODED_WIDTH, &avctx->coded_width, &size);
+    if (XEVD_FAILED(ret)) {
+        av_log(avctx, AV_LOG_ERROR, "Failed to get coded_width\n");
+        return AVERROR_EXTERNAL;
+    }
+
+    ret = xevd_config(xectx->id, XEVD_CFG_GET_CODED_HEIGHT, &avctx->coded_height, &size);
+    if (XEVD_FAILED(ret)) {
+        av_log(avctx, AV_LOG_ERROR, "Failed to get coded_height\n");
+        return AVERROR_EXTERNAL;
+    }
+
+    ret = xevd_config(xectx->id, XEVD_CFG_GET_WIDTH, &avctx->width, &size);
+    if (XEVD_FAILED(ret)) {
+        av_log(avctx, AV_LOG_ERROR, "Failed to get width\n");
+        return AVERROR_EXTERNAL;
+    }
+
+    ret = xevd_config(xectx->id, XEVD_CFG_GET_HEIGHT, &avctx->height, &size);
+    if (XEVD_FAILED(ret)) {
+        av_log(avctx, AV_LOG_ERROR, "Failed to get height\n");
+        return AVERROR_EXTERNAL;
+    }
+
+    ret = xevd_config(xectx->id, XEVD_CFG_GET_COLOR_SPACE, &color_space, &size);
+    if (XEVD_FAILED(ret)) {
+        av_log(avctx, AV_LOG_ERROR, "Failed to get color_space\n");
+        return AVERROR_EXTERNAL;
+    }
+    switch(color_space) {
+    case XEVD_CS_YCBCR400_10LE:
+        avctx->pix_fmt = AV_PIX_FMT_GRAY10LE;
+        break;
+    case XEVD_CS_YCBCR420_10LE:
+        avctx->pix_fmt = AV_PIX_FMT_YUV420P10LE;
+        break;
+    case XEVD_CS_YCBCR422_10LE:
+        avctx->pix_fmt = AV_PIX_FMT_YUV422P10LE;
+        break;
+    case XEVD_CS_YCBCR444_10LE:
+        avctx->pix_fmt = AV_PIX_FMT_YUV444P10LE;
+        break;
+    default:
+        av_log(avctx, AV_LOG_ERROR, "Unknown color space\n");
+        avctx->pix_fmt = AV_PIX_FMT_NONE;
+        return AVERROR_INVALIDDATA;
+    }
+
+    // the function returns sps->num_reorder_pics
+    ret = xevd_config(xectx->id, XEVD_CFG_GET_MAX_CODING_DELAY, &avctx->max_b_frames, &size);
+    if (XEVD_FAILED(ret)) {
+        av_log(avctx, AV_LOG_ERROR, "Failed to get max_coding_delay\n");
+        return AVERROR_EXTERNAL;
+    }
+
+    avctx->has_b_frames = (avctx->max_b_frames) ? 1 : 0;
+
+    return 0;
+}
+
+/**
+ * @brief Copy image in imgb to frame.
+ *
+ * @param avctx codec context
+ * @param[in] imgb
+ * @param[out] frame
+ * @return 0 on success, negative value on failure
+ */
+static int libxevd_image_copy(struct AVCodecContext *avctx, XEVD_IMGB *imgb, struct AVFrame *frame)
+{
+    int ret;
+    if (imgb->cs != XEVD_CS_YCBCR420_10LE) {
+        av_log(avctx, AV_LOG_ERROR, "Not supported pixel format: %s\n", av_get_pix_fmt_name(avctx->pix_fmt));
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (imgb->w[0] != avctx->width || imgb->h[0] != avctx->height) { // stream resolution changed
+        if (ff_set_dimensions(avctx, imgb->w[0], imgb->h[0]) < 0) {
+            av_log(avctx, AV_LOG_ERROR, "Cannot set new dimension\n");
+            return AVERROR_INVALIDDATA;
+        }
+    }
+
+    if (ret = ff_get_buffer(avctx, frame, 0) < 0)
+        return ret;
+
+    av_image_copy(frame->data, frame->linesize, (const uint8_t **)imgb->a,
+                  imgb->s, avctx->pix_fmt,
+                  imgb->w[0], imgb->h[0]);
+
+    return 0;
+}
+
+/**
+ * Initialize decoder
+ * Create a decoder instance and allocate all the needed resources
+ *
+ * @param avctx codec context
+ * @return 0 on success, negative error code on failure
+ */
+static av_cold int libxevd_init(AVCodecContext *avctx)
+{
+    XevdContext *xectx = avctx->priv_data;
+    XEVD_CDSC *cdsc = &(xectx->cdsc);
+
+    /* read configurations and set values for created descriptor (XEVD_CDSC) */
+    get_conf(avctx, cdsc);
+
+    /* create decoder */
+    xectx->id = xevd_create(&(xectx->cdsc), NULL);
+    if (xectx->id == NULL) {
+        av_log(avctx, AV_LOG_ERROR, "Cannot create XEVD encoder\n");
+        return AVERROR_EXTERNAL;
+    }
+
+    xectx->draining_mode = 0;
+    xectx->pkt = av_packet_alloc();
+    if (!xectx->pkt) {
+        av_log(avctx, AV_LOG_ERROR, "Cannot allocate memory for AVPacket\n");
+        return AVERROR(ENOMEM);
+    }
+
+    return 0;
+}
+
+/**
+  * Decode frame with decoupled packet/frame dataflow
+  *
+  * @param avctx codec context
+  * @param[out] frame decoded frame
+  *
+  * @return 0 on success, negative error code on failure
+  */
+static int libxevd_receive_frame(AVCodecContext *avctx, AVFrame *frame)
+{
+    XevdContext *xectx = avctx->priv_data;
+    AVPacket *pkt = xectx->pkt;
+    XEVD_IMGB *imgb = NULL;
+
+    int xevd_ret = 0;
+    int ret = 0;
+
+    // obtain access unit (input data) - a set of NAL units that are consecutive in decoding order and containing exactly one encoded image
+    ret = ff_decode_get_packet(avctx, pkt);
+    if (ret < 0 && ret != AVERROR_EOF) {
+        av_packet_unref(pkt);
+
+        return ret;
+    } else if(ret == AVERROR_EOF && xectx->draining_mode == 0) { // End of stream situations. Enter draining mode
+
+        xectx->draining_mode = 1;
+        av_packet_unref(pkt);
+    }
+
+    if (pkt->size > 0) {
+        int bs_read_pos = 0;
+        XEVD_STAT stat;
+        XEVD_BITB bitb;
+        int nalu_size;
+        AVPacket* pkt_au;
+        imgb = NULL;
+
+        pkt_au = av_packet_clone(pkt);
+        if (!pkt_au) {
+            av_log(avctx, AV_LOG_ERROR, "Cannot clone AVPacket\n");
+            av_packet_unref(pkt);
+            return AVERROR(ENOMEM);
+        }
+
+        av_packet_unref(pkt);
+
+        // get all nal units from AU
+        while(pkt_au->size > (bs_read_pos + XEVD_NAL_UNIT_LENGTH_BYTE)) {
+            memset(&stat, 0, sizeof(XEVD_STAT));
+
+            nalu_size = read_nal_unit_length(pkt_au->data + bs_read_pos, XEVD_NAL_UNIT_LENGTH_BYTE, avctx);
+            if (nalu_size == 0) {
+                av_log(avctx, AV_LOG_ERROR, "Invalid bitstream\n");
+                av_packet_free(&pkt_au);
+                ret = AVERROR_INVALIDDATA;
+
+                return ret;
+            }
+            bs_read_pos += XEVD_NAL_UNIT_LENGTH_BYTE;
+
+            bitb.addr = pkt_au->data + bs_read_pos;
+            bitb.ssize = nalu_size;
+            bitb.pdata[0] = pkt_au;
+            bitb.ts[XEVD_TS_DTS] = pkt_au->dts;
+
+            /* main decoding block */
+            xevd_ret = xevd_decode(xectx->id, &bitb, &stat);
+            if (XEVD_FAILED(xevd_ret)) {
+                av_log(avctx, AV_LOG_ERROR, "Failed to decode bitstream\n");
+                av_packet_free(&pkt_au);
+
+                return AVERROR_EXTERNAL;
+            }
+
+            bs_read_pos += nalu_size;
+
+            if (stat.nalu_type == XEVD_NUT_SPS) { // EVC stream parameters changed
+                if ((ret = export_stream_params(xectx, avctx)) != 0) {
+                    av_log(avctx, AV_LOG_ERROR, "Failed to export stream params\n");
+                    av_packet_free(&pkt_au);
+
+                    return ret;
+                }
+            }
+
+            if (stat.read != nalu_size)
+                av_log(avctx, AV_LOG_INFO, "Different reading of bitstream (in:%d, read:%d)\n,", nalu_size, stat.read);
+
+            // stat.fnum - has negative value if the decoded data is not frame
+            if (stat.fnum >= 0) {
+
+                xevd_ret = xevd_pull(xectx->id, &imgb); // The function returns a valid image only if the return code is XEVD_OK
+
+                if (XEVD_FAILED(xevd_ret)) {
+                    av_log(avctx, AV_LOG_ERROR, "Failed to pull the decoded image (xevd error code: %d, frame#=%d)\n", xevd_ret, stat.fnum);
+
+                    av_packet_free(&pkt_au);
+
+                    return AVERROR_EXTERNAL;
+                } else if (xevd_ret == XEVD_OK_FRM_DELAYED) {
+                    if(bs_read_pos == pkt_au->size) {
+                        return AVERROR(EAGAIN);
+                    }
+                } else { // XEVD_OK
+                    if (!imgb) {
+                        if(bs_read_pos == pkt_au->size) {
+                            av_log(avctx, AV_LOG_ERROR, "Invalid decoded image data\n");
+
+                            av_packet_free(&pkt_au);
+                            return  AVERROR(EAGAIN);
+                        }
+                    } else {
+                        // got frame
+                        AVPacket* pkt_au_imgb = (AVPacket*)imgb->pdata[0];
+                        if(!pkt_au_imgb) {
+                            av_log(avctx, AV_LOG_ERROR, "Invalid data needed to fill frame properties\n");
+
+                            av_packet_free(&pkt_au);
+                            av_frame_unref(frame);
+
+                            imgb->release(imgb);
+                            imgb = NULL;
+
+                            return AVERROR_INVALIDDATA;
+                        }
+
+                        ret = libxevd_image_copy(avctx, imgb, frame);
+                        if(ret < 0) {
+                            av_log(avctx, AV_LOG_ERROR, "Image copying error\n");
+
+                            av_packet_free(&pkt_au_imgb);
+                            av_frame_unref(frame);
+
+                            imgb->release(imgb);
+                            imgb = NULL;
+
+                            return ret;
+                        }
+
+                        // use ff_decode_frame_props_from_pkt() to fill frame properties
+                        ret = ff_decode_frame_props_from_pkt(avctx, frame, pkt_au_imgb);
+                        if (ret < 0) {
+                            av_log(avctx, AV_LOG_ERROR, "ff_decode_frame_props_from_pkt error\n");
+
+                            av_packet_free(&pkt_au_imgb);
+                            av_frame_unref(frame);
+
+                            imgb->release(imgb);
+                            imgb = NULL;
+
+                            return ret;
+                        }
+
+                        frame->pkt_dts = imgb->ts[XEVD_TS_DTS];
+                        frame->pts = imgb->ts[XEVD_TS_PTS];
+
+                        av_packet_free(&pkt_au_imgb);
+
+                        // xevd_pull uses pool of objects of type XEVD_IMGB.
+                        // The pool size is equal MAX_PB_SIZE (26), so release object when it is no more needed
+                        imgb->release(imgb);
+                        imgb = NULL;
+                    }
+                }
+            }
+        }
+    } else { // decoder draining mode handling
+
+        xevd_ret = xevd_pull(xectx->id, &imgb);
+
+        if (xevd_ret == XEVD_ERR_UNEXPECTED) { // draining process completed
+            av_log(avctx, AV_LOG_DEBUG, "Draining process completed\n");
+
+            return AVERROR_EOF;
+        } else if (XEVD_FAILED(xevd_ret)) { // handle all other errors
+            av_log(avctx, AV_LOG_ERROR, "Failed to pull the decoded image (xevd error code: %d)\n", xevd_ret);
+
+            return AVERROR_EXTERNAL;
+        } else { // XEVD_OK
+            AVPacket* pkt_au_imgb;
+            if (!imgb) {
+                av_log(avctx, AV_LOG_ERROR, "Invalid decoded image data\n");
+
+                return AVERROR_EXTERNAL;
+            }
+
+            pkt_au_imgb = (AVPacket*)imgb->pdata[0];
+            if(!pkt_au_imgb) {
+                av_log(avctx, AV_LOG_ERROR, "Invalid data needed to fill frame properties\n");
+
+                imgb->release(imgb);
+                imgb = NULL;
+
+                av_frame_unref(frame);
+
+                return AVERROR_INVALIDDATA;
+            }
+
+            // got frame
+            ret = libxevd_image_copy(avctx, imgb, frame);
+            if(ret < 0) {
+                av_packet_free(&pkt_au_imgb);
+                av_frame_unref(frame);
+
+                imgb->release(imgb);
+                imgb = NULL;
+
+                return ret;
+            }
+            // use ff_decode_frame_props_from_pkt() to fill frame properties
+            ret = ff_decode_frame_props_from_pkt(avctx, frame, pkt_au_imgb);
+            if (ret < 0) {
+                av_log(avctx, AV_LOG_ERROR, "ff_decode_frame_props_from_pkt error\n");
+
+                av_packet_free(&pkt_au_imgb);
+                av_frame_unref(frame);
+
+                imgb->release(imgb);
+                imgb = NULL;
+
+                return ret;
+            }
+
+            frame->pkt_dts = imgb->ts[XEVD_TS_DTS];
+            frame->pts = imgb->ts[XEVD_TS_PTS];
+
+            av_packet_free(&pkt_au_imgb);
+
+            // xevd_pull uses pool of objects of type XEVD_IMGB.
+            // The pool size is equal MAX_PB_SIZE (26), so release object when it is no more needed
+            imgb->release(imgb);
+            imgb = NULL;
+
+            return 0;
+        }
+    }
+
+    return ret;
+}
+
+/**
+ * Destroy decoder
+ *
+ * @param avctx codec context
+ * @return 0 on success
+ */
+static av_cold int libxevd_close(AVCodecContext *avctx)
+{
+    XevdContext *xectx = avctx->priv_data;
+    if (xectx->id) {
+        xevd_delete(xectx->id);
+        xectx->id = NULL;
+    }
+
+    xectx->draining_mode = 0;
+    av_packet_free(&xectx->pkt);
+
+    return 0;
+}
+
+#define OFFSET(x) offsetof(XevdContext, x)
+#define VD AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_DECODING_PARAM
+
+static const AVClass libxevd_class = {
+    .class_name = "libxevd",
+    .item_name  = av_default_item_name,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+const FFCodec ff_libxevd_decoder = {
+    .p.name             = "evc",
+    .p.long_name        = NULL_IF_CONFIG_SMALL("EVC / MPEG-5 Essential Video Coding (EVC)"),
+    .p.type             = AVMEDIA_TYPE_VIDEO,
+    .p.id               = AV_CODEC_ID_EVC,
+    .init               = libxevd_init,
+    FF_CODEC_RECEIVE_FRAME_CB(libxevd_receive_frame),
+    .close              = libxevd_close,
+    .priv_data_size     = sizeof(XevdContext),
+    .p.priv_class       = &libxevd_class,
+    .p.capabilities     = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_OTHER_THREADS | AV_CODEC_CAP_AVOID_PROBING,
+    .p.profiles         = NULL_IF_CONFIG_SMALL(ff_evc_profiles),
+    .p.wrapper_name     = "libxevd",
+    .caps_internal      = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_NOT_INIT_THREADSAFE | FF_CODEC_CAP_SETS_PKT_DTS | FF_CODEC_CAP_SETS_FRAME_PROPS
+};