/* * AV1 Annex B demuxer * Copyright (c) 2019 James Almer <jamrial@gmail.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 "config.h" #include "libavutil/common.h" #include "libavutil/opt.h" #include "libavcodec/av1_parse.h" #include "avformat.h" #include "avio_internal.h" #include "internal.h" typedef struct AnnexBContext { const AVClass *class; AVBSFContext *bsf; uint32_t temporal_unit_size; uint32_t frame_unit_size; AVRational framerate; } AnnexBContext; static int leb(AVIOContext *pb, uint32_t *len) { int more, i = 0; uint8_t byte; *len = 0; do { unsigned bits; byte = avio_r8(pb); more = byte & 0x80; bits = byte & 0x7f; if (i <= 3 || (i == 4 && bits < (1 << 4))) *len |= bits << (i * 7); else if (bits) return AVERROR_INVALIDDATA; if (++i == 8 && more) return AVERROR_INVALIDDATA; if (pb->eof_reached || pb->error) return pb->error ? pb->error : AVERROR(EIO); } while (more); return i; } static int read_obu(const uint8_t *buf, int size, int64_t *obu_size, int *type) { int start_pos, temporal_id, spatial_id; int len; len = parse_obu_header(buf, size, obu_size, &start_pos, type, &temporal_id, &spatial_id); if (len < 0) return len; return 0; } static int annexb_probe(const AVProbeData *p) { AVIOContext pb; int64_t obu_size; uint32_t temporal_unit_size, frame_unit_size, obu_unit_size; int seq = 0; int ret, type, cnt = 0; ffio_init_context(&pb, p->buf, p->buf_size, 0, NULL, NULL, NULL, NULL); ret = leb(&pb, &temporal_unit_size); if (ret < 0) return 0; cnt += ret; ret = leb(&pb, &frame_unit_size); if (ret < 0 || ((int64_t)frame_unit_size + ret) > temporal_unit_size) return 0; cnt += ret; temporal_unit_size -= ret; ret = leb(&pb, &obu_unit_size); if (ret < 0 || ((int64_t)obu_unit_size + ret) >= frame_unit_size) return 0; cnt += ret; temporal_unit_size -= obu_unit_size + ret; frame_unit_size -= obu_unit_size + ret; avio_skip(&pb, obu_unit_size); if (pb.eof_reached || pb.error) return 0; // Check that the first OBU is a Temporal Delimiter. ret = read_obu(p->buf + cnt, FFMIN(p->buf_size - cnt, obu_unit_size), &obu_size, &type); if (ret < 0 || type != AV1_OBU_TEMPORAL_DELIMITER || obu_size > 0) return 0; cnt += obu_unit_size; do { ret = leb(&pb, &obu_unit_size); if (ret < 0 || ((int64_t)obu_unit_size + ret) > frame_unit_size) return 0; cnt += ret; avio_skip(&pb, obu_unit_size); if (pb.eof_reached || pb.error) return 0; ret = read_obu(p->buf + cnt, FFMIN(p->buf_size - cnt, obu_unit_size), &obu_size, &type); if (ret < 0) return 0; cnt += obu_unit_size; switch (type) { case AV1_OBU_SEQUENCE_HEADER: seq = 1; break; case AV1_OBU_FRAME: case AV1_OBU_FRAME_HEADER: return seq ? AVPROBE_SCORE_EXTENSION + 1 : 0; case AV1_OBU_TILE_GROUP: case AV1_OBU_TEMPORAL_DELIMITER: return 0; default: break; } temporal_unit_size -= obu_unit_size + ret; frame_unit_size -= obu_unit_size + ret; } while (frame_unit_size); return 0; } static int annexb_read_header(AVFormatContext *s) { AnnexBContext *c = s->priv_data; const AVBitStreamFilter *filter = av_bsf_get_by_name("av1_frame_merge"); AVStream *st; int ret; if (!filter) { av_log(c, AV_LOG_ERROR, "av1_frame_merge bitstream filter " "not found. This is a bug, please report it.\n"); return AVERROR_BUG; } st = avformat_new_stream(s, NULL); if (!st) return AVERROR(ENOMEM); st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; st->codecpar->codec_id = AV_CODEC_ID_AV1; st->need_parsing = AVSTREAM_PARSE_HEADERS; st->internal->avctx->framerate = c->framerate; // taken from rawvideo demuxers avpriv_set_pts_info(st, 64, 1, 1200000); ret = av_bsf_alloc(filter, &c->bsf); if (ret < 0) return ret; ret = avcodec_parameters_copy(c->bsf->par_in, st->codecpar); if (ret < 0) { av_bsf_free(&c->bsf); return ret; } ret = av_bsf_init(c->bsf); if (ret < 0) av_bsf_free(&c->bsf); return ret; } static int annexb_read_packet(AVFormatContext *s, AVPacket *pkt) { AnnexBContext *c = s->priv_data; uint32_t obu_unit_size; int ret, len; retry: if (avio_feof(s->pb)) { if (c->temporal_unit_size || c->frame_unit_size) return AVERROR(EIO); goto end; } if (!c->temporal_unit_size) { len = leb(s->pb, &c->temporal_unit_size); if (len < 0) return AVERROR_INVALIDDATA; } if (!c->frame_unit_size) { len = leb(s->pb, &c->frame_unit_size); if (len < 0 || ((int64_t)c->frame_unit_size + len) > c->temporal_unit_size) return AVERROR_INVALIDDATA; c->temporal_unit_size -= len; } len = leb(s->pb, &obu_unit_size); if (len < 0 || ((int64_t)obu_unit_size + len) > c->frame_unit_size) return AVERROR_INVALIDDATA; ret = av_get_packet(s->pb, pkt, obu_unit_size); if (ret < 0) return ret; if (ret != obu_unit_size) return AVERROR(EIO); c->temporal_unit_size -= obu_unit_size + len; c->frame_unit_size -= obu_unit_size + len; end: ret = av_bsf_send_packet(c->bsf, pkt); if (ret < 0) { av_log(s, AV_LOG_ERROR, "Failed to send packet to " "av1_frame_merge filter\n"); return ret; } ret = av_bsf_receive_packet(c->bsf, pkt); if (ret < 0 && ret != AVERROR(EAGAIN) && ret != AVERROR_EOF) av_log(s, AV_LOG_ERROR, "av1_frame_merge filter failed to " "send output packet\n"); if (ret == AVERROR(EAGAIN)) goto retry; return ret; } static int annexb_read_close(AVFormatContext *s) { AnnexBContext *c = s->priv_data; av_bsf_free(&c->bsf); return 0; } #define OFFSET(x) offsetof(AnnexBContext, x) #define DEC AV_OPT_FLAG_DECODING_PARAM static const AVOption annexb_options[] = { { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, INT_MAX, DEC}, { NULL }, }; static const AVClass annexb_demuxer_class = { .class_name = "AV1 Annex B demuxer", .item_name = av_default_item_name, .option = annexb_options, .version = LIBAVUTIL_VERSION_INT, }; AVInputFormat ff_av1_demuxer = { .name = "av1", .long_name = NULL_IF_CONFIG_SMALL("AV1 Annex B"), .priv_data_size = sizeof(AnnexBContext), .read_probe = annexb_probe, .read_header = annexb_read_header, .read_packet = annexb_read_packet, .read_close = annexb_read_close, .extensions = "obu", .flags = AVFMT_GENERIC_INDEX, .priv_class = &annexb_demuxer_class, };