[FFmpeg-devel,3/3] Provided support for MPEG-5 EVC (Essential Video Coding) codec

diff --git a/doc/muxers.texi b/doc/muxers.texi
index b6cafaa5fd..1fc1c0de3e 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -2122,6 +2122,12 @@  DTS Coherent Acoustics (DCA) audio.
 
 Dolby Digital Plus, also known as Enhanced AC-3, audio.
 
+@subsection evc
+
+MPEG-5 Essential Video Coding (EVC) / EVC / MPEG-5 Part 1 EVC video.
+
+Extensions: evc
+
 @subsection g722
 
 ITU-T G.722 audio.
diff --git a/libavformat/Makefile b/libavformat/Makefile
index 1416bf31bd..39b23b754f 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -249,6 +249,8 @@  OBJS-$(CONFIG_HCOM_DEMUXER)              += hcom.o pcm.o
 OBJS-$(CONFIG_HDS_MUXER)                 += hdsenc.o
 OBJS-$(CONFIG_HEVC_DEMUXER)              += hevcdec.o rawdec.o
 OBJS-$(CONFIG_HEVC_MUXER)                += rawenc.o
+OBJS-$(CONFIG_EVC_DEMUXER)               += evcdec.o rawdec.o
+OBJS-$(CONFIG_EVC_MUXER)                 += rawenc.o
 OBJS-$(CONFIG_HLS_DEMUXER)               += hls.o hls_sample_encryption.o
 OBJS-$(CONFIG_HLS_MUXER)                 += hlsenc.o hlsplaylist.o avc.o
 OBJS-$(CONFIG_HNM_DEMUXER)               += hnm.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 8b84b52c64..2c64009291 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -148,6 +148,8 @@  extern const AVInputFormat  ff_ea_cdata_demuxer;
 extern const AVInputFormat  ff_eac3_demuxer;
 extern const AVOutputFormat ff_eac3_muxer;
 extern const AVInputFormat  ff_epaf_demuxer;
+extern const AVInputFormat  ff_evc_demuxer;
+extern const AVOutputFormat ff_evc_muxer;
 extern const AVOutputFormat ff_f4v_muxer;
 extern const AVInputFormat  ff_ffmetadata_demuxer;
 extern const AVOutputFormat ff_ffmetadata_muxer;
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@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)
diff --git a/libavformat/isom_tags.c b/libavformat/isom_tags.c
index 62e60470a8..0245cfb999 100644
--- a/libavformat/isom_tags.c
+++ b/libavformat/isom_tags.c
@@ -145,6 +145,8 @@  const AVCodecTag ff_codec_movvideo_tags[] = {
     { AV_CODEC_ID_H264, MKTAG('d', 'v', 'a', '1') }, /* AVC-based Dolby
Vision derived from avc1 */
     { AV_CODEC_ID_H264, MKTAG('d', 'v', 'a', 'v') }, /* AVC-based Dolby
Vision derived from avc3 */
 
+    { AV_CODEC_ID_EVC,  MKTAG('e', 'v', 'c', '1') }, /* EVC/MPEG-5 */
+
     { AV_CODEC_ID_VP8,  MKTAG('v', 'p', '0', '8') }, /* VP8 */
     { AV_CODEC_ID_VP9,  MKTAG('v', 'p', '0', '9') }, /* VP9 */
     { AV_CODEC_ID_AV1,  MKTAG('a', 'v', '0', '1') }, /* AV1 */
diff --git a/libavformat/mov.c b/libavformat/mov.c
index 3ec0ea2361..6b2c03e44c 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -9038,7 +9038,7 @@  const AVInputFormat ff_mov_demuxer = {
     .long_name      = NULL_IF_CONFIG_SMALL("QuickTime / MOV"),
     .priv_class     = &mov_class,
     .priv_data_size = sizeof(MOVContext),
-    .extensions     =
"mov,mp4,m4a,3gp,3g2,mj2,psp,m4b,ism,ismv,isma,f4v,avif",
+    .extensions     =
"mov,mp4,m4a,3gp,3g2,mj2,psp,m4b,ism,ismv,isma,f4v,avif,evc",
     .flags_internal = FF_FMT_INIT_CLEANUP,
     .read_probe     = mov_probe,
     .read_header    = mov_read_header,
diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index b7b2f46a17..347ea72897 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -1377,6 +1377,16 @@  static int mov_write_hvcc_tag(AVIOContext *pb,
MOVTrack *track)
     return update_size(pb, pos);
 }
 
+static int mov_write_evcc_tag(AVIOContext *pb, MOVTrack *track)
+{
+    int64_t pos = avio_tell(pb);
+
+    avio_wb32(pb, 0);
+    ffio_wfourcc(pb, "evcC");
+
+    return update_size(pb, pos);
+}
+
 /* also used by all avid codecs (dv, imx, meridien) and their variants */
 static int mov_write_avid_tag(AVIOContext *pb, MOVTrack *track)
 {
@@ -1626,6 +1636,16 @@  static int mov_get_h264_codec_tag(AVFormatContext
*s, MOVTrack *track)
     return tag;
 }
 
+static int mov_get_evc_codec_tag(AVFormatContext *s, MOVTrack *track)
+{
+    int tag = track->par->codec_tag;
+
+    if (!tag)
+        tag = MKTAG('e', 'v', 'c', 'i');
+
+    return tag;
+}
+
 static const struct {
     enum AVPixelFormat pix_fmt;
     uint32_t tag;
@@ -1707,6 +1727,8 @@  static unsigned int mov_get_codec_tag(AVFormatContext
*s, MOVTrack *track)
             tag = mov_get_mpeg2_xdcam_codec_tag(s, track);
         else if (track->par->codec_id == AV_CODEC_ID_H264)
             tag = mov_get_h264_codec_tag(s, track);
+        else if (track->par->codec_id == AV_CODEC_ID_EVC)
+            tag = mov_get_evc_codec_tag(s, track);
         else if (track->par->codec_id == AV_CODEC_ID_DNXHD)
             tag = mov_get_dnxhd_codec_tag(s, track);
         else if (track->par->codec_type == AVMEDIA_TYPE_VIDEO) {
@@ -2264,6 +2286,9 @@  static int mov_write_video_tag(AVFormatContext *s,
AVIOContext *pb, MOVMuxContex
         mov_write_avcc_tag(pb, track);
         if (track->mode == MODE_IPOD)
             mov_write_uuid_tag_ipod(pb);
+    }
+    else if (track->par->codec_id ==AV_CODEC_ID_EVC) {
+        mov_write_evcc_tag(pb, track);
     } else if (track->par->codec_id == AV_CODEC_ID_VP9) {
         mov_write_vpcc_tag(mov->fc, pb, track);
     } else if (track->par->codec_id == AV_CODEC_ID_AV1) {
@@ -5968,6 +5993,7 @@  int ff_mov_write_packet(AVFormatContext *s, AVPacket
*pkt)
     if ((par->codec_id == AV_CODEC_ID_DNXHD ||
          par->codec_id == AV_CODEC_ID_H264 ||
          par->codec_id == AV_CODEC_ID_HEVC ||
+         par->codec_id == AV_CODEC_ID_EVC ||
          par->codec_id == AV_CODEC_ID_TRUEHD ||
          par->codec_id == AV_CODEC_ID_AC3) && !trk->vos_len &&
          !TAG_IS_AVCI(trk->tag)) {
@@ -7604,6 +7630,7 @@  static const AVCodecTag codec_mp4_tags[] = {
     { AV_CODEC_ID_H264,            MKTAG('a', 'v', 'c', '3') },
     { AV_CODEC_ID_HEVC,            MKTAG('h', 'e', 'v', '1') },
     { AV_CODEC_ID_HEVC,            MKTAG('h', 'v', 'c', '1') },
+    { AV_CODEC_ID_EVC,             MKTAG('e', 'v', 'c', '1') },
     { AV_CODEC_ID_MPEG2VIDEO,      MKTAG('m', 'p', '4', 'v') },
     { AV_CODEC_ID_MPEG1VIDEO,      MKTAG('m', 'p', '4', 'v') },
     { AV_CODEC_ID_MJPEG,           MKTAG('m', 'p', '4', 'v') },
diff --git a/libavformat/rawenc.c b/libavformat/rawenc.c
index 26099cb1c1..48dedfa375 100644
--- a/libavformat/rawenc.c
+++ b/libavformat/rawenc.c
@@ -401,6 +401,19 @@  const AVOutputFormat ff_hevc_muxer = {
 };
 #endif
 
+#if CONFIG_EVC_MUXER
+AVOutputFormat ff_evc_muxer = {
+    .name              = "evc",
+    .long_name         = NULL_IF_CONFIG_SMALL("raw EVC video"),
+    .extensions        = "evc",
+    .audio_codec       = AV_CODEC_ID_NONE,
+    .video_codec       = AV_CODEC_ID_EVC,
+    .write_header      = force_one_stream,
+    .write_packet      = ff_raw_write_packet,
+    .flags             = AVFMT_NOTIMESTAMPS,
+};
+#endif
+
 #if CONFIG_M4V_MUXER
 const AVOutputFormat ff_m4v_muxer = {
     .name              = "m4v",