[FFmpeg-devel] [PATCH 2/2] Provided support for MPEG-5 EVC (Essential Video Coding) codec

Dawid Kozinski d.kozinski at samsung.com
Thu Aug 11 15:36:47 EEST 2022


- Added muxer for EVC format (MP4, raw)
- Added demuxer for EVC format (MP4)
- Added evc extension to the list of extensions for ff_mov_demuxer
- Added information to moov atom

Signed-off-by: Dawid Kozinski <d.kozinski at samsung.com>
---
 libavformat/evc.c    | 461 +++++++++++++++++++++++++++++++++++++++++++
 libavformat/evc.h    | 147 ++++++++++++++
 libavformat/evcdec.c | 142 +++++++++++++
 3 files changed, 750 insertions(+)
 create mode 100644 libavformat/evc.c
 create mode 100644 libavformat/evc.h
 create mode 100644 libavformat/evcdec.c

diff --git a/libavformat/evc.c b/libavformat/evc.c
new file mode 100644
index 0000000000..9297fa5d5c
--- /dev/null
+++ b/libavformat/evc.c
@@ -0,0 +1,461 @@
+/*
+ * EVC helper functions for muxers
+ * Copyright (c) 2022 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 "libavutil/intreadwrite.h"
+#include "libavcodec/get_bits.h"
+#include "libavcodec/golomb.h"
+#include "avformat.h"
+#include "avio.h"
+#include "evc.h"
+#include "avio_internal.h"
+
+// The length field that indicates the length in bytes of the following NAL unit is configured to be of 4 bytes
+#define EVC_NAL_UNIT_LENGTH_BYTE        (4)  /* byte */
+#define EVC_NAL_HEADER_SIZE             (2)  /* byte */
+
+// rpl structure
+typedef struct RefPicListStruct {
+    int poc;
+    int tid;
+    int ref_pic_num;
+    int ref_pic_active_num;
+    int ref_pics[EVC_MAX_NUM_REF_PICS];
+    char pic_type;
+
+} RefPicListStruct;
+
+// The sturcture reflects SPS RBSP(raw byte sequence payload) layout
+// @see ISO_IEC_23094-1 section 7.3.2.1
+//
+// The following descriptors specify the parsing process of each element
+// u(n) - unsigned integer using n bits
+// ue(v) - unsigned integer 0-th order Exp_Golomb-coded syntax element with the left bit first
+typedef struct EVCSPS {
+    int sps_seq_parameter_set_id;   // ue(v)
+    int profile_idc;                // u(8)
+    int level_idc;                  // u(8)
+    int toolset_idc_h;              // u(32)
+    int toolset_idc_l;              // u(32)
+    int chroma_format_idc;          // ue(v)
+    int pic_width_in_luma_samples;  // ue(v)
+    int pic_height_in_luma_samples; // ue(v)
+    int bit_depth_luma_minus8;      // ue(v)
+    int bit_depth_chroma_minus8;    // ue(v)
+
+    // @note
+    // Currently the structure does not reflect the entire SPS RBSP layout.
+    // It contains only the fields that are necessary to read from the NAL unit all the values
+    // necessary for the correct initialization of EVCDecoderConfigurationRecord
+
+    // @note
+    // If necessary, add the missing fields to the structure to reflect
+    // the contents of the entire NAL unit of the SPS type
+
+} EVCSPS;
+
+typedef struct EVCNALUnitArray {
+    uint8_t  array_completeness;
+    uint8_t  NAL_unit_type;
+    uint16_t numNalus;
+    uint16_t *nalUnitLength;
+    uint8_t  **nalUnit;
+} EVCNALUnitArray;
+
+/**
+ * @brief Specifies the decoder configuration information for ISO/IEC 23094-1 video content.
+ * @see ISO/IEC 14496-15:2021 Coding of audio-visual objects — Part 15:
+ *      Carriage of network abstraction layer (NAL) unit structured video in the ISO base media file format
+ */
+typedef struct EVCDecoderConfigurationRecord {
+    uint8_t  configurationVersion;          // 8 bits
+    uint8_t  profile_idc;                   // 8 bits
+    uint8_t  level_idc;                     // 8 bits
+    uint32_t toolset_idc_h;                 // 32 bits
+    uint32_t toolset_idc_l;                 // 32 bits
+    uint8_t  chroma_format_idc;             // 2 bits
+    uint8_t  bit_depth_luma_minus8;         // 3 bits
+    uint8_t  bit_depth_chroma_minus8;       // 3 bits
+    uint16_t pic_width_in_luma_samples;     // 16 bits
+    uint16_t pic_height_in_luma_samples;    // 16 bits
+    uint8_t  reserved;                      // 6 bits '000000'b
+    uint8_t  lengthSizeMinusOne;            // 2 bits
+    uint8_t  num_of_arrays;                 // 8 bits
+    EVCNALUnitArray *array;
+} EVCDecoderConfigurationRecord;
+
+typedef struct NALU {
+    int offset;
+    uint32_t size;
+} NALU;
+
+typedef struct NALUList {
+    NALU *nalus;
+    unsigned nalus_array_size;
+    unsigned nb_nalus;          ///< valid entries in nalus
+} NALUList;
+
+static int get_nalu_type(const uint8_t *bits, int bits_size)
+{
+    int unit_type_plus1 = 0;
+
+    if (bits_size >= EVC_NAL_HEADER_SIZE) {
+        unsigned char *p = (unsigned char *)bits;
+        // forbidden_zero_bit
+        if ((p[0] & 0x80) != 0)
+            return -1;
+
+        // nal_unit_type
+        unit_type_plus1 = (p[0] >> 1) & 0x3F;
+    }
+
+    return unit_type_plus1 - 1;
+}
+
+static uint32_t read_nal_unit_length(const uint8_t *bits, int bits_size)
+{
+    uint32_t nalu_len = 0;
+
+    if (bits_size >= EVC_NAL_UNIT_LENGTH_BYTE) {
+
+        int t = 0;
+        unsigned char *p = (unsigned char *)bits;
+
+        for (int i = 0; i < EVC_NAL_UNIT_LENGTH_BYTE; i++)
+            t = (t << 8) | p[i];
+
+        nalu_len = t;
+        if (nalu_len == 0)
+            return 0;
+    }
+
+    return nalu_len;
+}
+
+// @see ISO_IEC_23094-1 (7.3.2.1 SPS RBSP syntax)
+static int evcc_parse_sps(const uint8_t *bs, int bs_size, EVCDecoderConfigurationRecord *evcc)
+{
+    GetBitContext gb;
+    int sps_seq_parameter_set_id;
+    EVCSPS sps;
+
+    if (init_get_bits8(&gb, bs, bs_size) < 0)
+        return 0;
+
+    sps.sps_seq_parameter_set_id = get_ue_golomb(&gb);
+
+    if (sps_seq_parameter_set_id >= EVC_MAX_SPS_COUNT)
+        return 0;
+
+    // the Baseline profile is indicated by profile_idc eqal to 0
+    // the Main profile is indicated by profile_idc eqal to 1
+    sps.profile_idc = get_bits(&gb, 8);
+
+    sps.level_idc = get_bits(&gb, 8);
+
+    sps.toolset_idc_h = get_bits(&gb, 32);
+    sps.toolset_idc_l = get_bits(&gb, 32);
+
+    // 0 - monochrome
+    // 1 - 4:2:0
+    // 2 - 4:2:2
+    // 3 - 4:4:4
+    sps.chroma_format_idc = get_ue_golomb(&gb);
+
+    sps.pic_width_in_luma_samples = get_ue_golomb(&gb);
+    sps.pic_height_in_luma_samples = get_ue_golomb(&gb);
+
+    sps.bit_depth_luma_minus8 = get_ue_golomb(&gb);
+    sps.bit_depth_chroma_minus8 = get_ue_golomb(&gb);
+
+    evcc->profile_idc = sps.profile_idc;
+    evcc->level_idc = sps.level_idc;
+    evcc->toolset_idc_h = sps.toolset_idc_h;
+    evcc->toolset_idc_l = sps.toolset_idc_l;
+    evcc->chroma_format_idc = sps.chroma_format_idc;
+    evcc->bit_depth_luma_minus8 = sps.bit_depth_luma_minus8;
+    evcc->bit_depth_chroma_minus8 = sps.bit_depth_chroma_minus8;
+    evcc->pic_width_in_luma_samples = sps.pic_width_in_luma_samples;
+    evcc->pic_height_in_luma_samples = sps.pic_height_in_luma_samples;
+
+    return 0;
+}
+
+static int evcc_array_add_nal_unit(uint8_t *nal_buf, uint32_t nal_size,
+                                   uint8_t nal_type, int ps_array_completeness,
+                                   EVCDecoderConfigurationRecord *evcc)
+{
+    int ret;
+    uint8_t index;
+    uint16_t numNalus;
+    EVCNALUnitArray *array;
+
+    for (index = 0; index < evcc->num_of_arrays; index++)
+        if (evcc->array[index].NAL_unit_type == nal_type)
+            break;
+
+    if (index >= evcc->num_of_arrays) {
+        uint8_t i;
+
+        ret = av_reallocp_array(&evcc->array, index + 1, sizeof(EVCNALUnitArray));
+        if (ret < 0)
+            return ret;
+
+        for (i = evcc->num_of_arrays; i <= index; i++)
+            memset(&evcc->array[i], 0, sizeof(EVCNALUnitArray));
+        evcc->num_of_arrays = index + 1;
+    }
+
+    array    = &evcc->array[index];
+    numNalus = array->numNalus;
+
+    ret = av_reallocp_array(&array->nalUnit, numNalus + 1, sizeof(uint8_t *));
+    if (ret < 0)
+        return ret;
+
+    ret = av_reallocp_array(&array->nalUnitLength, numNalus + 1, sizeof(uint16_t));
+    if (ret < 0)
+        return ret;
+
+    array->nalUnit      [numNalus] = nal_buf;
+    array->nalUnitLength[numNalus] = nal_size;
+    array->NAL_unit_type           = nal_type;
+    array->numNalus++;
+
+    /*
+     * When the sample entry name is 'evc1', the default and mandatory value of
+     * array_completeness is 1 for arrays of all types of parameter sets, and 0
+     * for all other arrays.
+     */
+    if (nal_type == EVC_SPS_NUT || nal_type == EVC_PPS_NUT)
+        array->array_completeness = ps_array_completeness;
+
+    return 0;
+}
+
+static void evcc_init(EVCDecoderConfigurationRecord *evcc)
+{
+    memset(evcc, 0, sizeof(EVCDecoderConfigurationRecord));
+    evcc->configurationVersion = 1;
+    evcc->lengthSizeMinusOne   = 3; // 4 bytes
+}
+
+static void evcc_close(EVCDecoderConfigurationRecord *evcc)
+{
+    uint8_t i;
+
+    for (i = 0; i < evcc->num_of_arrays; i++) {
+        evcc->array[i].numNalus = 0;
+        av_freep(&evcc->array[i].nalUnit);
+        av_freep(&evcc->array[i].nalUnitLength);
+    }
+
+    evcc->num_of_arrays = 0;
+    av_freep(&evcc->array);
+}
+
+static int evcc_write(AVIOContext *pb, EVCDecoderConfigurationRecord *evcc)
+{
+    uint8_t i;
+    uint16_t j, aps_count = 0, sps_count = 0, pps_count = 0;
+
+    av_log(NULL, AV_LOG_TRACE,  "configurationVersion:                %"PRIu8"\n",
+           evcc->configurationVersion);
+    av_log(NULL, AV_LOG_TRACE,  "profile_idc:                         %"PRIu8"\n",
+           evcc->profile_idc);
+    av_log(NULL, AV_LOG_TRACE,  "level_idc:                           %"PRIu8"\n",
+           evcc->level_idc);
+    av_log(NULL, AV_LOG_TRACE,  "toolset_idc_h:                       %"PRIu32"\n",
+           evcc->toolset_idc_h);
+    av_log(NULL, AV_LOG_TRACE, "toolset_idc_l:                        %"PRIu32"\n",
+           evcc->toolset_idc_l);
+    av_log(NULL, AV_LOG_TRACE, "chroma_format_idc:                    %"PRIu8"\n",
+           evcc->chroma_format_idc);
+    av_log(NULL, AV_LOG_TRACE,  "bit_depth_luma_minus8:               %"PRIu8"\n",
+           evcc->bit_depth_luma_minus8);
+    av_log(NULL, AV_LOG_TRACE,  "bit_depth_chroma_minus8:             %"PRIu8"\n",
+           evcc->bit_depth_chroma_minus8);
+    av_log(NULL, AV_LOG_TRACE,  "pic_width_in_luma_samples:           %"PRIu16"\n",
+           evcc->pic_width_in_luma_samples);
+    av_log(NULL, AV_LOG_TRACE,  "pic_height_in_luma_samples:          %"PRIu16"\n",
+           evcc->pic_height_in_luma_samples);
+    av_log(NULL, AV_LOG_TRACE,  "lengthSizeMinusOne:                  %"PRIu8"\n",
+           evcc->lengthSizeMinusOne);
+    av_log(NULL, AV_LOG_TRACE,  "num_of_arrays:                       %"PRIu8"\n",
+           evcc->num_of_arrays);
+    for (i = 0; i < evcc->num_of_arrays; i++) {
+        av_log(NULL, AV_LOG_TRACE, "array_completeness[%"PRIu8"]:               %"PRIu8"\n",
+               i, evcc->array[i].array_completeness);
+        av_log(NULL, AV_LOG_TRACE, "NAL_unit_type[%"PRIu8"]:                    %"PRIu8"\n",
+               i, evcc->array[i].NAL_unit_type);
+        av_log(NULL, AV_LOG_TRACE, "numNalus[%"PRIu8"]:                         %"PRIu16"\n",
+               i, evcc->array[i].numNalus);
+        for (j = 0; j < evcc->array[i].numNalus; j++)
+            av_log(NULL, AV_LOG_TRACE,
+                   "nalUnitLength[%"PRIu8"][%"PRIu16"]:                 %"PRIu16"\n",
+                   i, j, evcc->array[i].nalUnitLength[j]);
+    }
+
+    /*
+     * We need at least one SPS.
+     */
+    for (i = 0; i < evcc->num_of_arrays; i++)
+        switch (evcc->array[i].NAL_unit_type) {
+        case EVC_APS_NUT:
+            aps_count += evcc->array[i].numNalus;
+            break;
+        case EVC_SPS_NUT:
+            sps_count += evcc->array[i].numNalus;
+            break;
+        case EVC_PPS_NUT:
+            pps_count += evcc->array[i].numNalus;
+            break;
+        default:
+            break;
+        }
+    if (!sps_count || sps_count > EVC_MAX_SPS_COUNT)
+        return AVERROR_INVALIDDATA;
+
+    /* unsigned int(8) configurationVersion = 1; */
+    avio_w8(pb, evcc->configurationVersion);
+
+    /* unsigned int(8) profile_idc */
+    avio_w8(pb, evcc->profile_idc);
+
+    /* unsigned int(8) profile_idc */
+    avio_w8(pb, evcc->level_idc);
+
+    /* unsigned int(32) toolset_idc_h */
+    avio_wb32(pb, evcc->toolset_idc_h);
+
+    /* unsigned int(32) toolset_idc_l */
+    avio_wb32(pb, evcc->toolset_idc_l);
+
+    /*
+     * unsigned int(2) chroma_format_idc;
+     * unsigned int(3) bit_depth_luma_minus8;
+     * unsigned int(3) bit_depth_chroma_minus8;
+     */
+    avio_w8(pb, evcc->chroma_format_idc << 6 |
+            evcc->bit_depth_luma_minus8  << 3 |
+            evcc->bit_depth_chroma_minus8);
+
+    /* unsigned int(16) pic_width_in_luma_samples; */
+    avio_wb16(pb, evcc->pic_width_in_luma_samples);
+
+    /* unsigned int(16) pic_width_in_luma_samples; */
+    avio_wb16(pb, evcc->pic_height_in_luma_samples);
+
+    /*
+     * bit(6) reserved = '111111'b;
+     * unsigned int(2) chromaFormat;
+     */
+    avio_w8(pb, evcc->lengthSizeMinusOne | 0xfc);
+
+    /* unsigned int(8) numOfArrays; */
+    avio_w8(pb, evcc->num_of_arrays);
+
+    for (i = 0; i < evcc->num_of_arrays; i++) {
+        /*
+         * bit(1) array_completeness;
+         * unsigned int(1) reserved = 0;
+         * unsigned int(6) NAL_unit_type;
+         */
+        avio_w8(pb, evcc->array[i].array_completeness << 7 |
+                evcc->array[i].NAL_unit_type & 0x3f);
+
+        /* unsigned int(16) numNalus; */
+        avio_wb16(pb, evcc->array[i].numNalus);
+
+        for (j = 0; j < evcc->array[i].numNalus; j++) {
+            /* unsigned int(16) nalUnitLength; */
+            avio_wb16(pb, evcc->array[i].nalUnitLength[j]);
+
+            /* bit(8*nalUnitLength) nalUnit; */
+            avio_write(pb, evcc->array[i].nalUnit[j],
+                       evcc->array[i].nalUnitLength[j]);
+        }
+    }
+
+    return 0;
+}
+
+int ff_isom_write_evcc(AVIOContext *pb, const uint8_t *data,
+                       int size, int ps_array_completeness)
+{
+    EVCDecoderConfigurationRecord evcc;
+    int ret = 0;
+
+    if (size < 8) {
+        /* We can't write a valid evcC from the provided data */
+        return AVERROR_INVALIDDATA;
+    } else if (*data == 1) {
+        /* Data is already evcC-formatted */
+        avio_write(pb, data, size);
+        return 0;
+    }
+
+    evcc_init(&evcc);
+
+    int nalu_type;
+    size_t nalu_size;
+    unsigned char *bits = (unsigned char *)data;
+    int bytes_to_read = size;
+
+    while (bytes_to_read > EVC_NAL_UNIT_LENGTH_BYTE) {
+
+        nalu_size = read_nal_unit_length(bits, EVC_NAL_UNIT_LENGTH_BYTE);
+        if (nalu_size == 0) break;
+
+        bits += EVC_NAL_UNIT_LENGTH_BYTE;
+        bytes_to_read -= EVC_NAL_UNIT_LENGTH_BYTE;
+
+        if (bytes_to_read < nalu_size) break;
+
+        nalu_type = get_nalu_type(bits, bytes_to_read);
+        uint8_t *nalu_buf = bits;
+
+        switch (nalu_type) {
+        case EVC_APS_NUT:
+        case EVC_SPS_NUT:
+        case EVC_PPS_NUT:
+            ret = evcc_array_add_nal_unit(nalu_buf, nalu_size, nalu_type, ps_array_completeness, &evcc);
+            if (ret < 0)
+                goto end;
+            else if (nalu_type == EVC_SPS_NUT)
+                ret = evcc_parse_sps(nalu_buf, nalu_size, &evcc);
+            if (ret < 0)
+                goto end;
+            break;
+        default:
+            break;
+        }
+
+        bits += nalu_size;
+        bytes_to_read -= nalu_size;
+    }
+
+    ret = evcc_write(pb, &evcc);
+
+end:
+    evcc_close(&evcc);
+    return ret;
+}
+
diff --git a/libavformat/evc.h b/libavformat/evc.h
new file mode 100644
index 0000000000..d7b93d521d
--- /dev/null
+++ b/libavformat/evc.h
@@ -0,0 +1,147 @@
+/*
+ * EVC helper functions for muxers
+ * Copyright (c) 2022 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
+ */
+
+#ifndef AVFORMAT_EVC_H
+#define AVFORMAT_EVC_H
+
+#include <stdint.h>
+#include "libavutil/rational.h"
+#include "avio.h"
+
+/**
+ * @see ISO_IEC_23094-1_2020, 7.4.2.2 NAL unit header semantic
+ *      Table 4 – NAL unit type codes and NAL unit type classes
+ */
+enum EVCNALUnitType {
+    EVC_NOIDR_NUT            = 0,
+    EVC_IDR_NUT              = 1,
+    EVC_RSV_VCL_NUT02        = 2,
+    EVC_RSV_VCL_NUT03        = 3,
+    EVC_RSV_VCL_NUT04        = 4,
+    EVC_RSV_VCL_NUT05        = 5,
+    EVC_RSV_VCL_NUT06        = 6,
+    EVC_RSV_VCL_NUT07        = 7,
+    EVC_RSV_VCL_NUT08        = 8,
+    EVC_RSV_VCL_NUT09        = 9,
+    EVC_RSV_VCL_NUT10        = 10,
+    EVC_RSV_VCL_NUT11        = 11,
+    EVC_RSV_VCL_NUT12        = 12,
+    EVC_RSV_VCL_NUT13        = 13,
+    EVC_RSV_VCL_NUT14        = 14,
+    EVC_RSV_VCL_NUT15        = 15,
+    EVC_RSV_VCL_NUT16        = 16,
+    EVC_RSV_VCL_NUT17        = 17,
+    EVC_RSV_VCL_NUT18        = 18,
+    EVC_RSV_VCL_NUT19        = 19,
+    EVC_RSV_VCL_NUT20        = 20,
+    EVC_RSV_VCL_NUT21        = 21,
+    EVC_RSV_VCL_NUT22        = 22,
+    EVC_RSV_VCL_NUT23        = 23,
+    EVC_SPS_NUT              = 24,
+    EVC_PPS_NUT              = 25,
+    EVC_APS_NUT              = 26,
+    EVC_FD_NUT               = 27,
+    EVC_SEI_NUT              = 28,
+    EVC_RSV_NONVCL29         = 29,
+    EVC_RSV_NONVCL30         = 30,
+    EVC_RSV_NONVCL31         = 31,
+    EVC_RSV_NONVCL32         = 32,
+    EVC_RSV_NONVCL33         = 33,
+    EVC_RSV_NONVCL34         = 34,
+    EVC_RSV_NONVCL35         = 35,
+    EVC_RSV_NONVCL36         = 36,
+    EVC_RSV_NONVCL37         = 37,
+    EVC_RSV_NONVCL38         = 38,
+    EVC_RSV_NONVCL39         = 39,
+    EVC_RSV_NONVCL40         = 40,
+    EVC_RSV_NONVCL41         = 41,
+    EVC_RSV_NONVCL42         = 42,
+    EVC_RSV_NONVCL43         = 43,
+    EVC_RSV_NONVCL44         = 44,
+    EVC_RSV_NONVCL45         = 45,
+    EVC_RSV_NONVCL46         = 46,
+    EVC_RSV_NONVCL47         = 47,
+    EVC_RSV_NONVCL48         = 48,
+    EVC_RSV_NONVCL49         = 49,
+    EVC_RSV_NONVCL50         = 50,
+    EVC_RSV_NONVCL51         = 51,
+    EVC_RSV_NONVCL52         = 52,
+    EVC_RSV_NONVCL53         = 53,
+    EVC_RSV_NONVCL54         = 54,
+    EVC_RSV_NONVCL55         = 55,
+    EVC_UNSPEC_NUT56         = 56,
+    EVC_UNSPEC_NUT57         = 57,
+    EVC_UNSPEC_NUT58         = 58,
+    EVC_UNSPEC_NUT59         = 59,
+    EVC_UNSPEC_NUT60         = 60,
+    EVC_UNSPEC_NUT61         = 61,
+    EVC_UNSPEC_NUT62         = 62
+};
+
+enum {
+    // 7.4.3.2: aps_video_parameter_set_id is u(4).
+    EVC_MAX_APS_COUNT = 32,
+
+    // 7.4.3.1: sps_seq_parameter_set_id is in [0, 15].
+    EVC_MAX_SPS_COUNT = 16,
+
+    // 7.4.3.2: pps_pic_parameter_set_id is in [0, 63].
+    EVC_MAX_PPS_COUNT = 64,
+
+    // 7.4.5: slice header slice_pic_parameter_set_id in [0, 63]
+    EVC_MAX_SH_COUNT = 64,
+
+    // E.3.2: cpb_cnt_minus1[i] is in [0, 31].
+    EVC_MAX_CPB_CNT = 32,
+
+    // A.4.1: in table A.1 the highest level allows a MaxLumaPs of 35 651 584.
+    EVC_MAX_LUMA_PS = 35651584,
+
+    EVC_MAX_NUM_REF_PICS = 21,
+
+    // A.4.1: pic_width_in_luma_samples and pic_height_in_luma_samples are
+    // constrained to be not greater than sqrt(MaxLumaPs * 8).  Hence height/
+    // width are bounded above by sqrt(8 * 35651584) = 16888.2 samples.
+    EVC_MAX_WIDTH  = 16888,
+    EVC_MAX_HEIGHT = 16888,
+
+    // A.4.1: table A.1 allows at most 22 tile rows for any level.
+    EVC_MAX_TILE_ROWS    = 22,
+    // A.4.1: table A.1 allows at most 20 tile columns for any level.
+    EVC_MAX_TILE_COLUMNS = 20,
+
+    // A.4.1: table A.1 allows at most 600 slice segments for any level.
+    EVC_MAX_SLICE_SEGMENTS = 600,
+
+    // 7.4.7.1: in the worst case (tiles_enabled_flag and
+    // entropy_coding_sync_enabled_flag are both set), entry points can be
+    // placed at the beginning of every Ctb row in every tile, giving an
+    // upper bound of (num_tile_columns_minus1 + 1) * PicHeightInCtbsY - 1.
+    // Only a stream with very high resolution and perverse parameters could
+    // get near that, though, so set a lower limit here with the maximum
+    // possible value for 4K video (at most 135 16x16 Ctb rows).
+    HEVC_MAX_ENTRY_POINT_OFFSETS = EVC_MAX_TILE_COLUMNS * 135,
+};
+
+int ff_isom_write_evcc(AVIOContext *pb, const uint8_t *data,
+                       int size, int ps_array_completeness);
+
+#endif // AVFORMAT_EVC_H
\ No newline at end of file
diff --git a/libavformat/evcdec.c b/libavformat/evcdec.c
new file mode 100644
index 0000000000..58dc671d24
--- /dev/null
+++ b/libavformat/evcdec.c
@@ -0,0 +1,142 @@
+/*
+ * RAW EVC video demuxer
+ *
+ * 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 "libavcodec/get_bits.h"
+#include "libavcodec/golomb.h"
+#include "libavcodec/internal.h"
+
+#include "rawdec.h"
+#include "avformat.h"
+
+// The length field that indicates the length in bytes of the following NAL unit is configured to be of 4 bytes
+#define EVC_NAL_UNIT_LENGTH_BYTE        (4)  /* byte */
+
+#define EVC_NAL_HEADER_SIZE             (2)  /* byte */
+#define MAX_SPS_CNT                     (16) /* defined value in EVC standard */
+
+// NALU types
+// @see ISO_IEC_23094-1_2020 7.4.2.2 NAL unit header semantics
+//
+#define EVC_NUT_NONIDR                  (0)  /* Coded slice of a non-IDR picture */
+#define EVC_NUT_IDR                     (1)  /* Coded slice of an IDR picture */
+#define EVC_NUT_SPS                     (24) /* Sequence parameter set */
+#define EVC_NUT_PPS                     (25) /* Picture paremeter set */
+#define EVC_NUT_APS                     (26) /* Adaptation parameter set */
+#define EVC_NUT_FD                      (27) /* Filler data */
+#define EVC_NUT_SEI                     (28) /* Supplemental enhancement information */
+
+typedef struct EVCParserContext {
+    int got_sps;
+    int got_pps;
+    int got_idr;
+    int got_nonidr;
+} EVCParserContext;
+
+static int get_nalu_type(const uint8_t *bits, int bits_size)
+{
+    int unit_type_plus1 = 0;
+
+    if(bits_size >= EVC_NAL_HEADER_SIZE) {
+        unsigned char *p = (unsigned char *)bits;
+        // forbidden_zero_bit
+        if ((p[0] & 0x80) != 0) {
+            av_log(NULL, AV_LOG_ERROR, "Cannot get bitstream information. Malformed bitstream.\n");
+            return -1;
+        }
+
+        // nal_unit_type
+        unit_type_plus1 = (p[0] >> 1) & 0x3F;
+    }
+
+    return unit_type_plus1 - 1;
+}
+
+static uint32_t read_nal_unit_length(const uint8_t *bits, int bits_size)
+{
+    uint32_t nalu_len = 0;
+
+    if(bits_size >= EVC_NAL_UNIT_LENGTH_BYTE) {
+
+        int t = 0;
+        unsigned char *p = (unsigned char *)bits;
+
+        for(int i=0; i<EVC_NAL_UNIT_LENGTH_BYTE; i++) {
+            t = (t << 8) | p[i];
+        }
+
+        nalu_len = t;
+        if(nalu_len == 0) {
+            av_log(NULL, AV_LOG_ERROR, "Invalid bitstream size!\n");
+            return 0;
+        }
+    }
+
+    return nalu_len;
+}
+
+static int parse_nal_units(const AVProbeData *p, EVCParserContext *ev)
+{
+    int nalu_type;
+    size_t nalu_size;
+    unsigned char *bits = (unsigned char *)p->buf;
+    int bytes_to_read = p->buf_size;
+
+    while(bytes_to_read > EVC_NAL_UNIT_LENGTH_BYTE) {
+
+        nalu_size = read_nal_unit_length(bits, EVC_NAL_UNIT_LENGTH_BYTE);
+        if(nalu_size == 0) break;
+
+        bits += EVC_NAL_UNIT_LENGTH_BYTE;
+        bytes_to_read -= EVC_NAL_UNIT_LENGTH_BYTE;
+
+        if(bytes_to_read < nalu_size) break;
+
+        nalu_type = get_nalu_type(bits, bytes_to_read);
+
+        bits += nalu_size;
+        bytes_to_read -= nalu_size;
+
+        if (nalu_type == EVC_NUT_SPS)
+            ev->got_sps++;
+        else if (nalu_type == EVC_NUT_PPS)
+            ev->got_pps++;
+        else if (nalu_type == EVC_NUT_IDR )
+            ev->got_idr++;
+        else if (nalu_type == EVC_NUT_NONIDR)
+            ev->got_nonidr++;
+    }
+
+    return 0;
+}
+
+static int evc_probe(const AVProbeData *p)
+{
+    EVCParserContext ev = {0};
+    int ret = parse_nal_units(p, &ev);
+
+    if (ret == 0 && ev.got_sps && ev.got_pps && (ev.got_idr || ev.got_nonidr > 3))
+        return AVPROBE_SCORE_EXTENSION + 1;  // 1 more than .mpg
+
+    return 0;
+}
+
+FF_DEF_RAWVIDEO_DEMUXER(evc, "raw EVC video", evc_probe, "evc", AV_CODEC_ID_EVC)
-- 
2.17.1





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