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path: root/libavformat/oggparseopus.c (plain)
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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
29struct 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
38static 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
46 if (!priv) {
47 priv = os->private = av_mallocz(sizeof(*priv));
48 if (!priv)
49 return AVERROR(ENOMEM);
50 }
51
52 if (os->flags & OGG_FLAG_BOS) {
53 if (os->psize < OPUS_HEAD_SIZE || (AV_RL8(packet + 8) & 0xF0) != 0)
54 return AVERROR_INVALIDDATA;
55 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
56 st->codecpar->codec_id = AV_CODEC_ID_OPUS;
57 st->codecpar->channels = AV_RL8(packet + 9);
58
59 priv->pre_skip = AV_RL16(packet + 10);
60 st->codecpar->initial_padding = priv->pre_skip;
61 /*orig_sample_rate = AV_RL32(packet + 12);*/
62 /*gain = AV_RL16(packet + 16);*/
63 /*channel_map = AV_RL8 (packet + 18);*/
64
65 if (ff_alloc_extradata(st->codecpar, os->psize))
66 return AVERROR(ENOMEM);
67
68 memcpy(st->codecpar->extradata, packet, os->psize);
69
70 st->codecpar->sample_rate = 48000;
71 st->codecpar->seek_preroll = av_rescale(OPUS_SEEK_PREROLL_MS,
72 st->codecpar->sample_rate, 1000);
73 avpriv_set_pts_info(st, 64, 1, 48000);
74 priv->need_comments = 1;
75 return 1;
76 }
77
78 if (priv->need_comments) {
79 if (os->psize < 8 || memcmp(packet, "OpusTags", 8))
80 return AVERROR_INVALIDDATA;
81 ff_vorbis_stream_comment(avf, st, packet + 8, os->psize - 8);
82 priv->need_comments--;
83 return 1;
84 }
85
86 return 0;
87}
88
89static int opus_duration(uint8_t *src, int size)
90{
91 unsigned nb_frames = 1;
92 unsigned toc = src[0];
93 unsigned toc_config = toc >> 3;
94 unsigned toc_count = toc & 3;
95 unsigned frame_size = toc_config < 12 ? FFMAX(480, 960 * (toc_config & 3)) :
96 toc_config < 16 ? 480 << (toc_config & 1) :
97 120 << (toc_config & 3);
98 if (toc_count == 3) {
99 if (size<2)
100 return AVERROR_INVALIDDATA;
101 nb_frames = src[1] & 0x3F;
102 } else if (toc_count) {
103 nb_frames = 2;
104 }
105
106 return frame_size * nb_frames;
107}
108
109static int opus_packet(AVFormatContext *avf, int idx)
110{
111 struct ogg *ogg = avf->priv_data;
112 struct ogg_stream *os = &ogg->streams[idx];
113 AVStream *st = avf->streams[idx];
114 struct oggopus_private *priv = os->private;
115 uint8_t *packet = os->buf + os->pstart;
116 int ret;
117
118 if (!os->psize)
119 return AVERROR_INVALIDDATA;
120 if (os->granule > (1LL << 62)) {
121 av_log(avf, AV_LOG_ERROR, "Unsupported huge granule pos %"PRId64 "\n", os->granule);
122 return AVERROR_INVALIDDATA;
123 }
124
125 if ((!os->lastpts || os->lastpts == AV_NOPTS_VALUE) && !(os->flags & OGG_FLAG_EOS)) {
126 int seg, d;
127 int duration;
128 uint8_t *last_pkt = os->buf + os->pstart;
129 uint8_t *next_pkt = last_pkt;
130
131 duration = 0;
132 seg = os->segp;
133 d = opus_duration(last_pkt, os->psize);
134 if (d < 0) {
135 os->pflags |= AV_PKT_FLAG_CORRUPT;
136 return 0;
137 }
138 duration += d;
139 last_pkt = next_pkt = next_pkt + os->psize;
140 for (; seg < os->nsegs; seg++) {
141 next_pkt += os->segments[seg];
142 if (os->segments[seg] < 255 && next_pkt != last_pkt) {
143 int d = opus_duration(last_pkt, next_pkt - last_pkt);
144 if (d > 0)
145 duration += d;
146 last_pkt = next_pkt;
147 }
148 }
149 os->lastpts =
150 os->lastdts = os->granule - duration;
151 }
152
153 if ((ret = opus_duration(packet, os->psize)) < 0)
154 return ret;
155
156 os->pduration = ret;
157 if (os->lastpts != AV_NOPTS_VALUE) {
158 if (st->start_time == AV_NOPTS_VALUE)
159 st->start_time = os->lastpts;
160 priv->cur_dts = os->lastdts = os->lastpts -= priv->pre_skip;
161 }
162
163 priv->cur_dts += os->pduration;
164 if ((os->flags & OGG_FLAG_EOS)) {
165 int64_t skip = priv->cur_dts - os->granule + priv->pre_skip;
166 skip = FFMIN(skip, os->pduration);
167 if (skip > 0) {
168 os->pduration = skip < os->pduration ? os->pduration - skip : 1;
169 os->end_trimming = skip;
170 av_log(avf, AV_LOG_DEBUG,
171 "Last packet was truncated to %d due to end trimming.\n",
172 os->pduration);
173 }
174 }
175
176 return 0;
177}
178
179const struct ogg_codec ff_opus_codec = {
180 .name = "Opus",
181 .magic = "OpusHead",
182 .magicsize = 8,
183 .header = opus_header,
184 .packet = opus_packet,
185 .nb_header = 1,
186};
187
generated by cgit at 2024-05-17 06:28:55 (GMT)