3 * Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at>
4 * Copyright (c) 2009 Robert Swain ( rob opendot cl )
6 * This file is part of FFmpeg.
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 #include "libavutil/avassert.h"
24 #include "libavutil/intreadwrite.h"
26 #include "avio_internal.h"
32 #define ADTS_HEADER_SIZE 7
34 static int adts_aac_probe(const AVProbeData *p)
36 int max_frames = 0, first_frames = 0;
38 const uint8_t *buf0 = p->buf;
41 const uint8_t *end = buf0 + p->buf_size - 7;
45 for (; buf < end; buf = buf2 + 1) {
48 for (frames = 0; buf2 < end; frames++) {
49 uint32_t header = AV_RB16(buf2);
50 if ((header & 0xFFF6) != 0xFFF0) {
52 // Found something that isn't an ADTS header, starting
53 // from a position other than the start of the buffer.
54 // Discard the count we've accumulated so far since it
55 // probably was a false positive.
60 fsize = (AV_RB32(buf2 + 3) >> 13) & 0x1FFF;
63 fsize = FFMIN(fsize, end - buf2);
66 max_frames = FFMAX(max_frames, frames);
68 first_frames = frames;
71 if (first_frames >= 3)
72 return AVPROBE_SCORE_EXTENSION + 1;
73 else if (max_frames > 100)
74 return AVPROBE_SCORE_EXTENSION;
75 else if (max_frames >= 3)
76 return AVPROBE_SCORE_EXTENSION / 2;
77 else if (first_frames >= 1)
83 static int adts_aac_read_header(AVFormatContext *s)
88 st = avformat_new_stream(s, NULL);
90 return AVERROR(ENOMEM);
92 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
93 st->codecpar->codec_id = s->iformat->raw_codec_id;
94 st->need_parsing = AVSTREAM_PARSE_FULL_RAW;
97 if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) &&
98 !av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
99 int64_t cur = avio_tell(s->pb);
101 avio_seek(s->pb, cur, SEEK_SET);
104 // skip data until the first ADTS frame is found
105 state = avio_r8(s->pb);
106 while (!avio_feof(s->pb) && avio_tell(s->pb) < s->probesize) {
107 state = (state << 8) | avio_r8(s->pb);
108 if ((state >> 4) != 0xFFF)
110 avio_seek(s->pb, -2, SEEK_CUR);
113 if ((state >> 4) != 0xFFF)
114 return AVERROR_INVALIDDATA;
116 // LCM of all possible ADTS sample rates
117 avpriv_set_pts_info(st, 64, 1, 28224000);
122 static int handle_id3(AVFormatContext *s, AVPacket *pkt)
124 AVDictionary *metadata = NULL;
126 ID3v2ExtraMeta *id3v2_extra_meta = NULL;
129 ret = av_append_packet(s->pb, pkt, ff_id3v2_tag_len(pkt->data) - pkt->size);
131 av_packet_unref(pkt);
135 ffio_init_context(&ioctx, pkt->data, pkt->size, 0, NULL, NULL, NULL, NULL);
136 ff_id3v2_read_dict(&ioctx, &metadata, ID3v2_DEFAULT_MAGIC, &id3v2_extra_meta);
137 if ((ret = ff_id3v2_parse_priv_dict(&metadata, &id3v2_extra_meta)) < 0)
141 if ((ret = av_dict_copy(&s->metadata, metadata, 0)) < 0)
143 s->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED;
147 av_packet_unref(pkt);
148 ff_id3v2_free_extra_meta(&id3v2_extra_meta);
149 av_dict_free(&metadata);
154 static int adts_aac_read_packet(AVFormatContext *s, AVPacket *pkt)
159 ret = av_get_packet(s->pb, pkt, ADTS_HEADER_SIZE);
163 if (ret < ADTS_HEADER_SIZE) {
164 av_packet_unref(pkt);
168 if ((AV_RB16(pkt->data) >> 4) != 0xfff) {
169 // Parse all the ID3 headers between frames
170 int append = ID3v2_HEADER_SIZE - ADTS_HEADER_SIZE;
172 av_assert2(append > 0);
173 ret = av_append_packet(s->pb, pkt, append);
175 av_packet_unref(pkt);
178 if (!ff_id3v2_match(pkt->data, ID3v2_DEFAULT_MAGIC)) {
179 av_packet_unref(pkt);
180 return AVERROR_INVALIDDATA;
182 ret = handle_id3(s, pkt);
189 fsize = (AV_RB32(pkt->data + 3) >> 13) & 0x1FFF;
190 if (fsize < ADTS_HEADER_SIZE) {
191 av_packet_unref(pkt);
192 return AVERROR_INVALIDDATA;
195 ret = av_append_packet(s->pb, pkt, fsize - pkt->size);
197 av_packet_unref(pkt);
202 AVInputFormat ff_aac_demuxer = {
204 .long_name = NULL_IF_CONFIG_SMALL("raw ADTS AAC (Advanced Audio Coding)"),
205 .read_probe = adts_aac_probe,
206 .read_header = adts_aac_read_header,
207 .read_packet = adts_aac_read_packet,
208 .flags = AVFMT_GENERIC_INDEX,
210 .mime_type = "audio/aac,audio/aacp,audio/x-aac",
211 .raw_codec_id = AV_CODEC_ID_AAC,