/* * Opus parser for Ogg * Copyright (c) 2012 Nicolas George * * 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 <string.h> #include "libavutil/intreadwrite.h" #include "avformat.h" #include "internal.h" #include "oggdec.h" struct oggopus_private { int need_comments; unsigned pre_skip; int64_t cur_dts; }; #define OPUS_SEEK_PREROLL_MS 80 #define OPUS_HEAD_SIZE 19 static int opus_header(AVFormatContext *avf, int idx) { struct ogg *ogg = avf->priv_data; struct ogg_stream *os = &ogg->streams[idx]; AVStream *st = avf->streams[idx]; struct oggopus_private *priv = os->private; uint8_t *packet = os->buf + os->pstart; if (!priv) { priv = os->private = av_mallocz(sizeof(*priv)); if (!priv) return AVERROR(ENOMEM); } if (os->flags & OGG_FLAG_BOS) { if (os->psize < OPUS_HEAD_SIZE || (AV_RL8(packet + 8) & 0xF0) != 0) return AVERROR_INVALIDDATA; st->codec->codec_type = AVMEDIA_TYPE_AUDIO; st->codec->codec_id = AV_CODEC_ID_OPUS; st->codec->channels = AV_RL8 (packet + 9); priv->pre_skip = AV_RL16(packet + 10); st->codec->delay = priv->pre_skip; /*orig_sample_rate = AV_RL32(packet + 12);*/ /*gain = AV_RL16(packet + 16);*/ /*channel_map = AV_RL8 (packet + 18);*/ if (ff_alloc_extradata(st->codec, os->psize)) return AVERROR(ENOMEM); memcpy(st->codec->extradata, packet, os->psize); st->codec->sample_rate = 48000; av_codec_set_seek_preroll(st->codec, av_rescale(OPUS_SEEK_PREROLL_MS, st->codec->sample_rate, 1000)); avpriv_set_pts_info(st, 64, 1, 48000); priv->need_comments = 1; return 1; } if (priv->need_comments) { if (os->psize < 8 || memcmp(packet, "OpusTags", 8)) return AVERROR_INVALIDDATA; ff_vorbis_stream_comment(avf, st, packet + 8, os->psize - 8); priv->need_comments--; return 1; } return 0; } static int opus_duration(uint8_t *src, int size) { unsigned nb_frames = 1; unsigned toc = src[0]; unsigned toc_config = toc >> 3; unsigned toc_count = toc & 3; unsigned frame_size = toc_config < 12 ? FFMAX(480, 960 * (toc_config & 3)) : toc_config < 16 ? 480 << (toc_config & 1) : 120 << (toc_config & 3); if (toc_count == 3) { if (size<2) return AVERROR_INVALIDDATA; nb_frames = src[1] & 0x3F; } else if (toc_count) { nb_frames = 2; } return frame_size * nb_frames; } static int opus_packet(AVFormatContext *avf, int idx) { struct ogg *ogg = avf->priv_data; struct ogg_stream *os = &ogg->streams[idx]; AVStream *st = avf->streams[idx]; struct oggopus_private *priv = os->private; uint8_t *packet = os->buf + os->pstart; int ret; if (!os->psize) return AVERROR_INVALIDDATA; if ((!os->lastpts || os->lastpts == AV_NOPTS_VALUE) && !(os->flags & OGG_FLAG_EOS)) { int seg, d; int duration; uint8_t *last_pkt = os->buf + os->pstart; uint8_t *next_pkt = last_pkt; duration = 0; seg = os->segp; d = opus_duration(last_pkt, os->psize); if (d < 0) { os->pflags |= AV_PKT_FLAG_CORRUPT; return 0; } duration += d; last_pkt = next_pkt = next_pkt + os->psize; for (; seg < os->nsegs; seg++) { next_pkt += os->segments[seg]; if (os->segments[seg] < 255 && next_pkt != last_pkt) { int d = opus_duration(last_pkt, next_pkt - last_pkt); if (d > 0) duration += d; last_pkt = next_pkt; } } os->lastpts = os->lastdts = os->granule - duration; } if ((ret = opus_duration(packet, os->psize)) < 0) return ret; os->pduration = ret; if (os->lastpts != AV_NOPTS_VALUE) { if (st->start_time == AV_NOPTS_VALUE) st->start_time = os->lastpts; priv->cur_dts = os->lastdts = os->lastpts -= priv->pre_skip; } priv->cur_dts += os->pduration; if ((os->flags & OGG_FLAG_EOS)) { int64_t skip = priv->cur_dts - os->granule + priv->pre_skip; skip = FFMIN(skip, os->pduration); if (skip > 0) { os->pduration = skip < os->pduration ? os->pduration - skip : 1; os->end_trimming = skip; av_log(avf, AV_LOG_DEBUG, "Last packet was truncated to %d due to end trimming.\n", os->pduration); } } return 0; } const struct ogg_codec ff_opus_codec = { .name = "Opus", .magic = "OpusHead", .magicsize = 8, .header = opus_header, .packet = opus_packet, .nb_header = 1, };