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/intreadwrite.h"
25 #include "avio_internal.h"
31 #define ADTS_HEADER_SIZE 7
33 static int adts_aac_probe(AVProbeData *p)
35 int max_frames = 0, first_frames = 0;
37 const uint8_t *buf0 = p->buf;
40 const uint8_t *end = buf0 + p->buf_size - 7;
44 for (; buf < end; buf = buf2 + 1) {
47 for (frames = 0; buf2 < end; frames++) {
48 uint32_t header = AV_RB16(buf2);
49 if ((header & 0xFFF6) != 0xFFF0) {
51 // Found something that isn't an ADTS header, starting
52 // from a position other than the start of the buffer.
53 // Discard the count we've accumulated so far since it
54 // probably was a false positive.
59 fsize = (AV_RB32(buf2 + 3) >> 13) & 0x1FFF;
62 fsize = FFMIN(fsize, end - buf2);
65 max_frames = FFMAX(max_frames, frames);
67 first_frames = frames;
70 if (first_frames >= 3)
71 return AVPROBE_SCORE_EXTENSION + 1;
72 else if (max_frames > 100)
73 return AVPROBE_SCORE_EXTENSION;
74 else if (max_frames >= 3)
75 return AVPROBE_SCORE_EXTENSION / 2;
76 else if (first_frames >= 1)
82 static int adts_aac_read_header(AVFormatContext *s)
87 st = avformat_new_stream(s, NULL);
89 return AVERROR(ENOMEM);
91 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
92 st->codecpar->codec_id = s->iformat->raw_codec_id;
93 st->need_parsing = AVSTREAM_PARSE_FULL_RAW;
96 if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) &&
97 !av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
98 int64_t cur = avio_tell(s->pb);
100 avio_seek(s->pb, cur, SEEK_SET);
103 // skip data until the first ADTS frame is found
104 state = avio_r8(s->pb);
105 while (!avio_feof(s->pb) && avio_tell(s->pb) < s->probesize) {
106 state = (state << 8) | avio_r8(s->pb);
107 if ((state >> 4) != 0xFFF)
109 avio_seek(s->pb, -2, SEEK_CUR);
112 if ((state >> 4) != 0xFFF)
113 return AVERROR_INVALIDDATA;
115 // LCM of all possible ADTS sample rates
116 avpriv_set_pts_info(st, 64, 1, 28224000);
121 static int handle_id3(AVFormatContext *s, AVPacket *pkt)
123 AVDictionary *metadata = NULL;
125 ID3v2ExtraMeta *id3v2_extra_meta = NULL;
128 ret = av_append_packet(s->pb, pkt, ff_id3v2_tag_len(pkt->data) - pkt->size);
130 av_packet_unref(pkt);
134 ffio_init_context(&ioctx, pkt->data, pkt->size, 0, NULL, NULL, NULL, NULL);
135 ff_id3v2_read_dict(&ioctx, &metadata, ID3v2_DEFAULT_MAGIC, &id3v2_extra_meta);
136 if ((ret = ff_id3v2_parse_priv_dict(&metadata, &id3v2_extra_meta)) < 0)
140 if ((ret = av_dict_copy(&s->metadata, metadata, 0)) < 0)
142 s->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED;
146 av_packet_unref(pkt);
147 ff_id3v2_free_extra_meta(&id3v2_extra_meta);
148 av_dict_free(&metadata);
153 static int adts_aac_read_packet(AVFormatContext *s, AVPacket *pkt)
157 // Parse all the ID3 headers between frames
159 ret = av_get_packet(s->pb, pkt, FFMAX(ID3v2_HEADER_SIZE, ADTS_HEADER_SIZE));
160 if (ret >= ID3v2_HEADER_SIZE && ff_id3v2_match(pkt->data, ID3v2_DEFAULT_MAGIC)) {
161 if ((ret = handle_id3(s, pkt)) >= 0) {
171 if (ret < ADTS_HEADER_SIZE) {
172 av_packet_unref(pkt);
176 if ((AV_RB16(pkt->data) >> 4) != 0xfff) {
177 av_packet_unref(pkt);
178 return AVERROR_INVALIDDATA;
181 fsize = (AV_RB32(pkt->data + 3) >> 13) & 0x1FFF;
182 if (fsize < ADTS_HEADER_SIZE) {
183 av_packet_unref(pkt);
184 return AVERROR_INVALIDDATA;
187 ret = av_append_packet(s->pb, pkt, fsize - pkt->size);
189 av_packet_unref(pkt);
194 AVInputFormat ff_aac_demuxer = {
196 .long_name = NULL_IF_CONFIG_SMALL("raw ADTS AAC (Advanced Audio Coding)"),
197 .read_probe = adts_aac_probe,
198 .read_header = adts_aac_read_header,
199 .read_packet = adts_aac_read_packet,
200 .flags = AVFMT_GENERIC_INDEX,
202 .mime_type = "audio/aac,audio/aacp,audio/x-aac",
203 .raw_codec_id = AV_CODEC_ID_AAC,