- Provided AVInputFormat structure describing EVC input format (ff_evc_demuxer) Signed-off-by: Dawid Kozinski <d.kozinski@samsung.com> --- libavformat/Makefile | 1 + libavformat/allformats.c | 1 + libavformat/evcdec.c | 124 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 126 insertions(+) create mode 100644 libavformat/evcdec.c diff --git a/libavformat/Makefile b/libavformat/Makefile index a14a759c1f..af175d2097 100644 --- a/libavformat/Makefile +++ b/libavformat/Makefile @@ -251,6 +251,7 @@ 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 diff --git a/libavformat/allformats.c b/libavformat/allformats.c index 615d2bc3b1..e4cc112b90 100644 --- a/libavformat/allformats.c +++ b/libavformat/allformats.c @@ -150,6 +150,7 @@ 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; diff --git a/libavformat/evcdec.c b/libavformat/evcdec.c new file mode 100644 index 0000000000..ffb7449c4d --- /dev/null +++ b/libavformat/evcdec.c @@ -0,0 +1,124 @@ +/* + * 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 "libavcodec/evc.h" + +#include "rawdec.h" +#include "avformat.h" + +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) { // Cannot get bitstream information. Malformed bitstream. + 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) { // Invalid bitstream size + 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_SPS_NUT) + ev->got_sps++; + else if (nalu_type == EVC_PPS_NUT) + ev->got_pps++; + else if (nalu_type == EVC_IDR_NUT ) + ev->got_idr++; + else if (nalu_type == EVC_NOIDR_NUT) + 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