[FFmpeg-devel] [PATCH v26 5/9] avcodec/evc_decoder: Provided support for EVC decoder

James Almer jamrial at gmail.com
Wed Jul 26 18:45:59 EEST 2023


On 6/15/2023 8:48 AM, Dawid Kozinski wrote:
> - Added EVC decoder wrapper
> - Changes in project configuration file and libavcodec Makefile
> - Added documentation for xevd wrapper
> 
> Signed-off-by: Dawid Kozinski <d.kozinski at samsung.com>

I'm getting

[evc @ 000001ee1ba7e960] An invalid frame was output by a decoder. This 
is a bug, please report it.
[vist#0:0/evc @ 000001ee1d47f220] Decoding error: Internal bug, should 
not have happened

With akiyo_cif.evc, so there's something wrong.

> ---
>   configure                 |   4 +
>   doc/decoders.texi         |  24 ++
>   doc/general_contents.texi |  10 +-
>   libavcodec/Makefile       |   1 +
>   libavcodec/allcodecs.c    |   1 +
>   libavcodec/libxevd.c      | 479 ++++++++++++++++++++++++++++++++++++++
>   6 files changed, 518 insertions(+), 1 deletion(-)
>   create mode 100644 libavcodec/libxevd.c
> 
> diff --git a/configure b/configure
> index e2370a23bb..cae3b666a5 100755
> --- a/configure
> +++ b/configure
> @@ -293,6 +293,7 @@ External library support:
>     --enable-libx264         enable H.264 encoding via x264 [no]
>     --enable-libx265         enable HEVC encoding via x265 [no]
>     --enable-libxeve         enable EVC encoding via libxeve [no]
> +  --enable-libxevd         enable EVC decoding via libxevd [no]
>     --enable-libxavs         enable AVS encoding via xavs [no]
>     --enable-libxavs2        enable AVS2 encoding via xavs2 [no]
>     --enable-libxcb          enable X11 grabbing using XCB [autodetect]
> @@ -1904,6 +1905,7 @@ EXTERNAL_LIBRARY_LIST="
>       libvorbis
>       libvpx
>       libwebp
> +    libxevd
>       libxeve
>       libxml2
>       libzimg
> @@ -3460,6 +3462,7 @@ libx265_encoder_deps="libx265"
>   libx265_encoder_select="atsc_a53"
>   libxavs_encoder_deps="libxavs"
>   libxavs2_encoder_deps="libxavs2"
> +libxevd_decoder_deps="libxevd"
>   libxeve_encoder_deps="libxeve"
>   libxvid_encoder_deps="libxvid"
>   libzvbi_teletext_decoder_deps="libzvbi"
> @@ -6835,6 +6838,7 @@ enabled libx265           && require_pkg_config libx265 x265 x265.h x265_api_get
>                                require_cpp_condition libx265 x265.h "X265_BUILD >= 89"
>   enabled libxavs           && require libxavs "stdint.h xavs.h" xavs_encoder_encode "-lxavs $pthreads_extralibs $libm_extralibs"
>   enabled libxavs2          && require_pkg_config libxavs2 "xavs2 >= 1.3.0" "stdint.h xavs2.h" xavs2_api_get
> +enabled libxevd           && require_pkg_config libxevd "xevd >= 0.4.1" "xevd.h" xevd_decode
>   enabled libxeve           && require_pkg_config libxeve "xeve >= 0.4.3" "xeve.h" xeve_encode
>   enabled libxvid           && require libxvid xvid.h xvid_global -lxvidcore
>   enabled libzimg           && require_pkg_config libzimg "zimg >= 2.7.0" zimg.h zimg_get_api_version
> diff --git a/doc/decoders.texi b/doc/decoders.texi
> index 09b8314dd2..6311af229f 100644
> --- a/doc/decoders.texi
> +++ b/doc/decoders.texi
> @@ -130,6 +130,30 @@ Set amount of frame threads to use during decoding. The default value is 0 (auto
>   
>   @end table
>   
> + at section libxevd
> +
> +eXtra-fast Essential Video Decoder (XEVD) MPEG-5 EVC decoder wrapper.
> +
> +This decoder requires the presence of the libxevd headers and library
> +during configuration. You need to explicitly configure the build with
> + at option{--enable-libxevd}.
> +
> +The xevd project website is at @url{https://github.com/mpeg5/xevd}.
> +
> + at subsection Options
> +
> +The following options are supported by the libxevd wrapper.
> +The xevd-equivalent options or values are listed in parentheses for easy migration.
> +
> +To get a more accurate and extensive documentation of the libxevd options,
> +invoke the command  @code{xevd_app --help} or consult the libxevd documentation.
> +
> + at table @option
> + at item threads (@emph{threads})
> +Force to use a specific number of threads
> +
> + at end table
> +
>   @section QSV Decoders
>   
>   The family of Intel QuickSync Video decoders (VC1, MPEG-2, H.264, HEVC,
> diff --git a/doc/general_contents.texi b/doc/general_contents.texi
> index c6a997bfd6..8e08f5ebc3 100644
> --- a/doc/general_contents.texi
> +++ b/doc/general_contents.texi
> @@ -351,6 +351,14 @@ Go to @url{https://github.com/mpeg5/xeve} and follow the instructions for
>   installing the XEVE library. Then pass @code{--enable-libxeve} to configure to
>   enable it.
>   
> + at section eXtra-fast Essential Video Decoder (XEVD)
> +
> +FFmpeg can make use of the XEVD library for EVC video decoding.
> +
> +Go to @url{https://github.com/mpeg5/xevd} and follow the instructions for
> +installing the XEVD library. Then pass @code{--enable-libxevd} to configure to
> +enable it.
> +
>   @section ZVBI
>   
>   ZVBI is a VBI decoding library which can be used by FFmpeg to decode DVB
> @@ -953,7 +961,7 @@ following image formats are supported:
>   @item Escape 124             @tab     @tab  X
>   @item Escape 130             @tab     @tab  X
>   @item EVC / MPEG-5 Part 1    @tab  X  @tab  X
> -    @tab encoding and decoding supported through external library libxeve
> +    @tab encoding and decoding supported through external libraries libxeve and libxevd
>   @item FFmpeg video codec #1  @tab  X  @tab  X
>       @tab lossless codec (fourcc: FFV1)
>   @item Flash Screen Video v1  @tab  X  @tab  X
> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index 2223e9f46c..d0b8438717 100644
> --- a/libavcodec/Makefile
> +++ b/libavcodec/Makefile
> @@ -1142,6 +1142,7 @@ OBJS-$(CONFIG_LIBX264_ENCODER)            += libx264.o
>   OBJS-$(CONFIG_LIBX265_ENCODER)            += libx265.o
>   OBJS-$(CONFIG_LIBXAVS_ENCODER)            += libxavs.o
>   OBJS-$(CONFIG_LIBXAVS2_ENCODER)           += libxavs2.o
> +OBJS-$(CONFIG_LIBXEVD_DECODER)            += libxevd.o
>   OBJS-$(CONFIG_LIBXEVE_ENCODER)            += libxeve.o
>   OBJS-$(CONFIG_LIBXVID_ENCODER)            += libxvid.o
>   OBJS-$(CONFIG_LIBZVBI_TELETEXT_DECODER)   += libzvbi-teletextdec.o ass.o
> diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
> index c317dd6da3..eb0abbb1fd 100644
> --- a/libavcodec/allcodecs.c
> +++ b/libavcodec/allcodecs.c
> @@ -819,6 +819,7 @@ extern LIBX264_CONST FFCodec ff_libx264_encoder;
>   extern const FFCodec ff_libx264rgb_encoder;
>   extern FFCodec ff_libx265_encoder;
>   extern const FFCodec ff_libxeve_encoder;
> +extern const FFCodec ff_libxevd_decoder;
>   extern const FFCodec ff_libxavs_encoder;
>   extern const FFCodec ff_libxavs2_encoder;
>   extern const FFCodec ff_libxvid_encoder;
> diff --git a/libavcodec/libxevd.c b/libavcodec/libxevd.c
> new file mode 100644
> index 0000000000..7c4922d46e
> --- /dev/null
> +++ b/libavcodec/libxevd.c
> @@ -0,0 +1,479 @@
> +/*
> + * libxevd decoder
> + * EVC (MPEG-5 Essential Video Coding) decoding using XEVD MPEG-5 EVC decoder library
> + *
> + * Copyright (C) 2021 Dawid Kozinski <d.kozinski at 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;
> +} 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();
> +
> +    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;
> +
> +    if (!pkt)
> +        return AVERROR(ENOMEM);
> +
> +    // obtain input data
> +    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);
> +
> +        return 0;
> +    }
> +
> +    if (pkt->size > 0) {
> +        int bs_read_pos = 0;
> +        XEVD_STAT stat;
> +        XEVD_BITB bitb;
> +        int nalu_size;
> +
> +        imgb = NULL;
> +
> +        while(pkt->size > (bs_read_pos + XEVD_NAL_UNIT_LENGTH_BYTE)) {
> +            memset(&stat, 0, sizeof(XEVD_STAT));
> +
> +            nalu_size = read_nal_unit_length(pkt->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_unref(pkt);
> +                ret = AVERROR_INVALIDDATA;
> +
> +                return ret;
> +            }
> +            bs_read_pos += XEVD_NAL_UNIT_LENGTH_BYTE;
> +
> +            bitb.addr = pkt->data + bs_read_pos;
> +            bitb.ssize = nalu_size;
> +
> +            /* 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_unref(pkt);
> +                ret = AVERROR_EXTERNAL;
> +
> +                return ret;
> +            }
> +
> +            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_unref(pkt);
> +
> +                    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);
> +            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);
> +                    ret = AVERROR_EXTERNAL;
> +                    av_packet_unref(pkt);
> +
> +                    return ret;
> +                } else if (xevd_ret == XEVD_OK_FRM_DELAYED) {
> +                    av_packet_unref(pkt);

Was the packet fully consumed here? As in, is bs_read_pos == pkt->size 
at this point? If not, you're dropping NALUs that should be passed to 
libxevd.

> +
> +                    return AVERROR(EAGAIN);
> +                } else { // XEVD_OK
> +                    if (!imgb) {
> +                        av_packet_unref(pkt);

Same question here. And I assume this would happen with 
XEVD_OK_OUT_NOT_AVAILABLE?

> +
> +                        return  AVERROR(EAGAIN);
> +                    }
> +
> +                    // got frame
> +                    ret = libxevd_image_copy(avctx, imgb, frame);
> +                    if(ret < 0) {
> +                        av_log(avctx, AV_LOG_ERROR, "Image copying error\n");
> +
> +                        imgb->release(imgb);
> +                        imgb = NULL;
> +
> +                        av_packet_unref(pkt);
> +
> +                        return ret;
> +                    }
> +
> +                    // use ff_decode_frame_props() to fill frame properties
> +                    ret = ff_decode_frame_props(avctx, frame);

ff_get_buffer() calls this, so it's not needed.
You however set the decoder as FF_CODEC_CAP_SETS_FRAME_PROPS, so 
ff_decode_frame_props_pkt() is not being called to fetch props from the 
last packet.

You probably need a FIFO of packet props and use that to fill frame 
props as you return them. It's a pity you can't propagate an opaque 
pointer to xevd_decode() and get it back in xevd_pull(). That would 
simplify things a lot.

> +                    if (ret < 0) {
> +                        imgb->release(imgb);
> +                        imgb = NULL;
> +
> +                        av_packet_unref(pkt);
> +                        av_frame_unref(frame);
> +
> +                        return ret;
> +                    }
> +
> +                    frame->pkt_dts = pkt->dts;
> +
> +                    // 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;
> +
> +                    av_packet_unref(pkt);

Again, were all the NALUs in the packet passed to libxevd?

> +                    return 0;
> +                }
> +            }
> +        }
> +    } 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");
> +            av_packet_unref(pkt);
> +
> +            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);
> +            av_packet_unref(pkt);
> +
> +            return AVERROR_EXTERNAL;
> +        } else { // XEVD_OK
> +            if (!imgb) {
> +                av_packet_unref(pkt);
> +
> +                return AVERROR_EXTERNAL;
> +            }
> +            // got frame
> +            ret = libxevd_image_copy(avctx, imgb, frame);
> +            if(ret < 0) {
> +                imgb->release(imgb);
> +                imgb = NULL;
> +
> +                av_packet_unref(pkt);
> +
> +                return ret;
> +            }
> +
> +            frame->pkt_dts = pkt->dts;
> +
> +            av_packet_unref(pkt);
> +
> +            // 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
> +};


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