1 /*
2 * Opus parser for Ogg
3 * Copyright (c) 2012 Nicolas George
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include <string.h>
23
24 #include "libavutil/intreadwrite.h"
25 #include "avformat.h"
26 #include "internal.h"
27 #include "oggdec.h"
28
29 struct oggopus_private {
30 int need_comments;
31 unsigned pre_skip;
32 int64_t cur_dts;
33 };
34
35 #define OPUS_SEEK_PREROLL_MS 80
36 #define OPUS_HEAD_SIZE 19
37
opus_header(AVFormatContext * avf,int idx)38 static int opus_header(AVFormatContext *avf, int idx)
39 {
40 struct ogg *ogg = avf->priv_data;
41 struct ogg_stream *os = &ogg->streams[idx];
42 AVStream *st = avf->streams[idx];
43 struct oggopus_private *priv = os->private;
44 uint8_t *packet = os->buf + os->pstart;
45 int ret;
46
47 if (!priv) {
48 priv = os->private = av_mallocz(sizeof(*priv));
49 if (!priv)
50 return AVERROR(ENOMEM);
51 }
52
53 if (os->flags & OGG_FLAG_BOS) {
54 if (os->psize < OPUS_HEAD_SIZE || (AV_RL8(packet + 8) & 0xF0) != 0)
55 return AVERROR_INVALIDDATA;
56 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
57 st->codecpar->codec_id = AV_CODEC_ID_OPUS;
58 st->codecpar->ch_layout.nb_channels = AV_RL8(packet + 9);
59
60 priv->pre_skip = AV_RL16(packet + 10);
61 st->codecpar->initial_padding = priv->pre_skip;
62 os->start_trimming = priv->pre_skip;
63 /*orig_sample_rate = AV_RL32(packet + 12);*/
64 /*gain = AV_RL16(packet + 16);*/
65 /*channel_map = AV_RL8 (packet + 18);*/
66
67 if ((ret = ff_alloc_extradata(st->codecpar, os->psize)) < 0)
68 return ret;
69
70 memcpy(st->codecpar->extradata, packet, os->psize);
71
72 st->codecpar->sample_rate = 48000;
73 st->codecpar->seek_preroll = av_rescale(OPUS_SEEK_PREROLL_MS,
74 st->codecpar->sample_rate, 1000);
75 avpriv_set_pts_info(st, 64, 1, 48000);
76 priv->need_comments = 1;
77 return 1;
78 }
79
80 if (priv->need_comments) {
81 if (os->psize < 8 || memcmp(packet, "OpusTags", 8))
82 return AVERROR_INVALIDDATA;
83 ff_vorbis_stream_comment(avf, st, packet + 8, os->psize - 8);
84 priv->need_comments--;
85 return 1;
86 }
87
88 return 0;
89 }
90
opus_duration(uint8_t * src,int size)91 static int opus_duration(uint8_t *src, int size)
92 {
93 unsigned nb_frames = 1;
94 unsigned toc = src[0];
95 unsigned toc_config = toc >> 3;
96 unsigned toc_count = toc & 3;
97 unsigned frame_size = toc_config < 12 ? FFMAX(480, 960 * (toc_config & 3)) :
98 toc_config < 16 ? 480 << (toc_config & 1) :
99 120 << (toc_config & 3);
100 if (toc_count == 3) {
101 if (size<2)
102 return AVERROR_INVALIDDATA;
103 nb_frames = src[1] & 0x3F;
104 } else if (toc_count) {
105 nb_frames = 2;
106 }
107
108 return frame_size * nb_frames;
109 }
110
opus_packet(AVFormatContext * avf,int idx)111 static int opus_packet(AVFormatContext *avf, int idx)
112 {
113 struct ogg *ogg = avf->priv_data;
114 struct ogg_stream *os = &ogg->streams[idx];
115 AVStream *st = avf->streams[idx];
116 struct oggopus_private *priv = os->private;
117 uint8_t *packet = os->buf + os->pstart;
118 int ret;
119
120 if (!os->psize)
121 return AVERROR_INVALIDDATA;
122 if (os->granule > (1LL << 62)) {
123 av_log(avf, AV_LOG_ERROR, "Unsupported huge granule pos %"PRId64 "\n", os->granule);
124 return AVERROR_INVALIDDATA;
125 }
126
127 if ((!os->lastpts || os->lastpts == AV_NOPTS_VALUE) && !(os->flags & OGG_FLAG_EOS)) {
128 int seg, d;
129 int duration;
130 uint8_t *last_pkt = os->buf + os->pstart;
131 uint8_t *next_pkt = last_pkt;
132
133 duration = 0;
134 seg = os->segp;
135 d = opus_duration(last_pkt, os->psize);
136 if (d < 0) {
137 os->pflags |= AV_PKT_FLAG_CORRUPT;
138 return 0;
139 }
140 duration += d;
141 last_pkt = next_pkt = next_pkt + os->psize;
142 for (; seg < os->nsegs; seg++) {
143 next_pkt += os->segments[seg];
144 if (os->segments[seg] < 255 && next_pkt != last_pkt) {
145 int d = opus_duration(last_pkt, next_pkt - last_pkt);
146 if (d > 0)
147 duration += d;
148 last_pkt = next_pkt;
149 }
150 }
151 os->lastpts =
152 os->lastdts = os->granule - duration;
153 }
154
155 if ((ret = opus_duration(packet, os->psize)) < 0)
156 return ret;
157
158 os->pduration = ret;
159 if (os->lastpts != AV_NOPTS_VALUE) {
160 if (st->start_time == AV_NOPTS_VALUE)
161 st->start_time = os->lastpts;
162 priv->cur_dts = os->lastdts = os->lastpts -= priv->pre_skip;
163 }
164
165 priv->cur_dts += os->pduration;
166 if ((os->flags & OGG_FLAG_EOS)) {
167 int64_t skip = priv->cur_dts - os->granule + priv->pre_skip;
168 skip = FFMIN(skip, os->pduration);
169 if (skip > 0) {
170 os->pduration = skip < os->pduration ? os->pduration - skip : 1;
171 os->end_trimming = skip;
172 av_log(avf, AV_LOG_DEBUG,
173 "Last packet was truncated to %d due to end trimming.\n",
174 os->pduration);
175 }
176 }
177
178 return 0;
179 }
180
181 const struct ogg_codec ff_opus_codec = {
182 .name = "Opus",
183 .magic = "OpusHead",
184 .magicsize = 8,
185 .header = opus_header,
186 .packet = opus_packet,
187 .nb_header = 1,
188 };
189