| /* |
| * raw ADTS AAC demuxer |
| * Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at> |
| * Copyright (c) 2009 Robert Swain ( rob opendot cl ) |
| * |
| * 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 "libavutil/avassert.h" |
| #include "libavutil/intreadwrite.h" |
| #include "avformat.h" |
| #include "avio_internal.h" |
| #include "internal.h" |
| #include "id3v1.h" |
| #include "id3v2.h" |
| #include "apetag.h" |
| |
| #define ADTS_HEADER_SIZE 7 |
| |
| static int adts_aac_probe(const AVProbeData *p) |
| { |
| int max_frames = 0, first_frames = 0; |
| int fsize, frames; |
| const uint8_t *buf0 = p->buf; |
| const uint8_t *buf2; |
| const uint8_t *buf; |
| const uint8_t *end = buf0 + p->buf_size - 7; |
| |
| buf = buf0; |
| |
| for (; buf < end; buf = buf2 + 1) { |
| buf2 = buf; |
| |
| for (frames = 0; buf2 < end; frames++) { |
| uint32_t header = AV_RB16(buf2); |
| if ((header & 0xFFF6) != 0xFFF0) { |
| if (buf != buf0) { |
| // Found something that isn't an ADTS header, starting |
| // from a position other than the start of the buffer. |
| // Discard the count we've accumulated so far since it |
| // probably was a false positive. |
| frames = 0; |
| } |
| break; |
| } |
| fsize = (AV_RB32(buf2 + 3) >> 13) & 0x1FFF; |
| if (fsize < 7) |
| break; |
| fsize = FFMIN(fsize, end - buf2); |
| buf2 += fsize; |
| } |
| max_frames = FFMAX(max_frames, frames); |
| if (buf == buf0) |
| first_frames = frames; |
| } |
| |
| if (first_frames >= 3) |
| return AVPROBE_SCORE_EXTENSION + 1; |
| else if (max_frames > 100) |
| return AVPROBE_SCORE_EXTENSION; |
| else if (max_frames >= 3) |
| return AVPROBE_SCORE_EXTENSION / 2; |
| else if (first_frames >= 1) |
| return 1; |
| else |
| return 0; |
| } |
| |
| static int adts_aac_resync(AVFormatContext *s) |
| { |
| uint16_t state; |
| |
| // skip data until an ADTS frame is found |
| state = avio_r8(s->pb); |
| while (!avio_feof(s->pb) && avio_tell(s->pb) < s->probesize) { |
| state = (state << 8) | avio_r8(s->pb); |
| if ((state >> 4) != 0xFFF) |
| continue; |
| avio_seek(s->pb, -2, SEEK_CUR); |
| break; |
| } |
| if (s->pb->eof_reached) |
| return AVERROR_EOF; |
| if ((state >> 4) != 0xFFF) |
| return AVERROR_INVALIDDATA; |
| |
| return 0; |
| } |
| |
| static int adts_aac_read_header(AVFormatContext *s) |
| { |
| AVStream *st; |
| int ret; |
| |
| st = avformat_new_stream(s, NULL); |
| if (!st) |
| return AVERROR(ENOMEM); |
| |
| st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
| st->codecpar->codec_id = s->iformat->raw_codec_id; |
| st->need_parsing = AVSTREAM_PARSE_FULL_RAW; |
| |
| ff_id3v1_read(s); |
| if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) && |
| !av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX)) { |
| int64_t cur = avio_tell(s->pb); |
| ff_ape_parse_tag(s); |
| avio_seek(s->pb, cur, SEEK_SET); |
| } |
| |
| ret = adts_aac_resync(s); |
| if (ret < 0) |
| return ret; |
| |
| // LCM of all possible ADTS sample rates |
| avpriv_set_pts_info(st, 64, 1, 28224000); |
| |
| return 0; |
| } |
| |
| static int handle_id3(AVFormatContext *s, AVPacket *pkt) |
| { |
| AVDictionary *metadata = NULL; |
| AVIOContext ioctx; |
| ID3v2ExtraMeta *id3v2_extra_meta = NULL; |
| int ret; |
| |
| ret = av_append_packet(s->pb, pkt, ff_id3v2_tag_len(pkt->data) - pkt->size); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| ffio_init_context(&ioctx, pkt->data, pkt->size, 0, NULL, NULL, NULL, NULL); |
| ff_id3v2_read_dict(&ioctx, &metadata, ID3v2_DEFAULT_MAGIC, &id3v2_extra_meta); |
| if ((ret = ff_id3v2_parse_priv_dict(&metadata, &id3v2_extra_meta)) < 0) |
| goto error; |
| |
| if (metadata) { |
| if ((ret = av_dict_copy(&s->metadata, metadata, 0)) < 0) |
| goto error; |
| s->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED; |
| } |
| |
| error: |
| av_packet_unref(pkt); |
| ff_id3v2_free_extra_meta(&id3v2_extra_meta); |
| av_dict_free(&metadata); |
| |
| return ret; |
| } |
| |
| static int adts_aac_read_packet(AVFormatContext *s, AVPacket *pkt) |
| { |
| int ret, fsize; |
| |
| retry: |
| ret = av_get_packet(s->pb, pkt, ADTS_HEADER_SIZE); |
| if (ret < 0) |
| return ret; |
| |
| if (ret < ADTS_HEADER_SIZE) { |
| return AVERROR(EIO); |
| } |
| |
| if ((AV_RB16(pkt->data) >> 4) != 0xfff) { |
| // Parse all the ID3 headers between frames |
| int append = ID3v2_HEADER_SIZE - ADTS_HEADER_SIZE; |
| |
| av_assert2(append > 0); |
| ret = av_append_packet(s->pb, pkt, append); |
| if (ret != append) { |
| return AVERROR(EIO); |
| } |
| if (!ff_id3v2_match(pkt->data, ID3v2_DEFAULT_MAGIC)) { |
| av_packet_unref(pkt); |
| ret = adts_aac_resync(s); |
| } else |
| ret = handle_id3(s, pkt); |
| if (ret < 0) |
| return ret; |
| |
| goto retry; |
| } |
| |
| fsize = (AV_RB32(pkt->data + 3) >> 13) & 0x1FFF; |
| if (fsize < ADTS_HEADER_SIZE) { |
| return AVERROR_INVALIDDATA; |
| } |
| |
| ret = av_append_packet(s->pb, pkt, fsize - pkt->size); |
| |
| return ret; |
| } |
| |
| AVInputFormat ff_aac_demuxer = { |
| .name = "aac", |
| .long_name = NULL_IF_CONFIG_SMALL("raw ADTS AAC (Advanced Audio Coding)"), |
| .read_probe = adts_aac_probe, |
| .read_header = adts_aac_read_header, |
| .read_packet = adts_aac_read_packet, |
| .flags = AVFMT_GENERIC_INDEX, |
| .extensions = "aac", |
| .mime_type = "audio/aac,audio/aacp,audio/x-aac", |
| .raw_codec_id = AV_CODEC_ID_AAC, |
| }; |