/* * ADTS muxer. * Copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@smartjog.com> * Mans Rullgard <mans@mansr.com> * * 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 "libavcodec/get_bits.h" #include "libavcodec/put_bits.h" #include "libavcodec/codec_id.h" #include "libavcodec/codec_par.h" #include "libavcodec/packet.h" #include "libavcodec/mpeg4audio.h" #include "libavcodec/mpeg4audio_copy_pce.h" #include "libavutil/opt.h" #include "avformat.h" #include "apetag.h" #include "id3v2.h" #include "mux.h" #define ADTS_HEADER_SIZE 7 typedef struct ADTSContext { AVClass *class; int write_adts; int objecttype; int sample_rate_index; int channel_conf; int pce_size; int apetag; int id3v2tag; int mpeg_id; uint8_t pce_data[MAX_PCE_SIZE]; } ADTSContext; #define ADTS_MAX_FRAME_BYTES ((1 << 14) - 1) static int adts_decode_extradata(AVFormatContext *s, ADTSContext *adts, const uint8_t *buf, int size) { GetBitContext gb; PutBitContext pb; MPEG4AudioConfig m4ac; int off, ret; ret = init_get_bits8(&gb, buf, size); if (ret < 0) return ret; off = avpriv_mpeg4audio_get_config2(&m4ac, buf, size, 1, s); if (off < 0) return off; skip_bits_long(&gb, off); adts->objecttype = m4ac.object_type - 1; adts->sample_rate_index = m4ac.sampling_index; adts->channel_conf = m4ac.chan_config; if (adts->objecttype > 3U) { av_log(s, AV_LOG_ERROR, "MPEG-4 AOT %d is not allowed in ADTS\n", adts->objecttype+1); return AVERROR_INVALIDDATA; } if (adts->sample_rate_index == 15) { av_log(s, AV_LOG_ERROR, "Escape sample rate index illegal in ADTS\n"); return AVERROR_INVALIDDATA; } if (get_bits(&gb, 1)) { av_log(s, AV_LOG_ERROR, "960/120 MDCT window is not allowed in ADTS\n"); return AVERROR_INVALIDDATA; } if (get_bits(&gb, 1)) { av_log(s, AV_LOG_ERROR, "Scalable configurations are not allowed in ADTS\n"); return AVERROR_INVALIDDATA; } if (get_bits(&gb, 1)) { av_log(s, AV_LOG_ERROR, "Extension flag is not allowed in ADTS\n"); return AVERROR_INVALIDDATA; } if (!adts->channel_conf) { init_put_bits(&pb, adts->pce_data, MAX_PCE_SIZE); put_bits(&pb, 3, 5); //ID_PCE adts->pce_size = (ff_copy_pce_data(&pb, &gb) + 3) / 8; flush_put_bits(&pb); } adts->write_adts = 1; return 0; } static int adts_init(AVFormatContext *s) { ADTSContext *adts = s->priv_data; AVCodecParameters *par = s->streams[0]->codecpar; if (par->codec_id != AV_CODEC_ID_AAC) { av_log(s, AV_LOG_ERROR, "Only AAC streams can be muxed by the ADTS muxer\n"); return AVERROR(EINVAL); } if (par->extradata_size > 0) return adts_decode_extradata(s, adts, par->extradata, par->extradata_size); return 0; } static int adts_write_header(AVFormatContext *s) { ADTSContext *adts = s->priv_data; if (adts->id3v2tag) ff_id3v2_write_simple(s, 4, ID3v2_DEFAULT_MAGIC); return 0; } static int adts_write_frame_header(AVFormatContext *s, ADTSContext *ctx, uint8_t *buf, int size, int pce_size) { PutBitContext pb; unsigned full_frame_size = (unsigned)ADTS_HEADER_SIZE + size + pce_size; if (full_frame_size > ADTS_MAX_FRAME_BYTES) { av_log(s, AV_LOG_ERROR, "frame size too large: %u (max %d)\n", full_frame_size, ADTS_MAX_FRAME_BYTES); return AVERROR_INVALIDDATA; } init_put_bits(&pb, buf, ADTS_HEADER_SIZE); /* adts_fixed_header */ put_bits(&pb, 12, 0xfff); /* syncword */ put_bits(&pb, 1, ctx->mpeg_id); /* ID */ put_bits(&pb, 2, 0); /* layer */ put_bits(&pb, 1, 1); /* protection_absent */ put_bits(&pb, 2, ctx->objecttype); /* profile_objecttype */ put_bits(&pb, 4, ctx->sample_rate_index); put_bits(&pb, 1, 0); /* private_bit */ put_bits(&pb, 3, ctx->channel_conf); /* channel_configuration */ put_bits(&pb, 1, 0); /* original_copy */ put_bits(&pb, 1, 0); /* home */ /* adts_variable_header */ put_bits(&pb, 1, 0); /* copyright_identification_bit */ put_bits(&pb, 1, 0); /* copyright_identification_start */ put_bits(&pb, 13, full_frame_size); /* aac_frame_length */ put_bits(&pb, 11, 0x7ff); /* adts_buffer_fullness */ put_bits(&pb, 2, 0); /* number_of_raw_data_blocks_in_frame */ flush_put_bits(&pb); return 0; } static int adts_write_packet(AVFormatContext *s, AVPacket *pkt) { ADTSContext *adts = s->priv_data; AVCodecParameters *par = s->streams[0]->codecpar; AVIOContext *pb = s->pb; uint8_t buf[ADTS_HEADER_SIZE]; if (!pkt->size) return 0; if (!par->extradata_size) { uint8_t *side_data; size_t side_data_size; int ret; side_data = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA, &side_data_size); if (side_data_size) { ret = adts_decode_extradata(s, adts, side_data, side_data_size); if (ret < 0) return ret; ret = ff_alloc_extradata(par, side_data_size); if (ret < 0) return ret; memcpy(par->extradata, side_data, side_data_size); } } if (adts->write_adts) { int err = adts_write_frame_header(s, adts, buf, pkt->size, adts->pce_size); if (err < 0) return err; avio_write(pb, buf, ADTS_HEADER_SIZE); if (adts->pce_size) { avio_write(pb, adts->pce_data, adts->pce_size); adts->pce_size = 0; } } avio_write(pb, pkt->data, pkt->size); return 0; } static int adts_write_trailer(AVFormatContext *s) { ADTSContext *adts = s->priv_data; if (adts->apetag) ff_ape_write_tag(s); return 0; } #define ENC AV_OPT_FLAG_ENCODING_PARAM #define OFFSET(obj) offsetof(ADTSContext, obj) static const AVOption options[] = { { "write_id3v2", "Enable ID3v2 tag writing", OFFSET(id3v2tag), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, ENC}, { "write_apetag", "Enable APE tag writing", OFFSET(apetag), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, ENC}, { "write_mpeg2", "Set MPEG version to MPEG-2", OFFSET(mpeg_id), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, ENC}, { NULL }, }; static const AVClass adts_muxer_class = { .class_name = "ADTS muxer", .item_name = av_default_item_name, .option = options, .version = LIBAVUTIL_VERSION_INT, }; const FFOutputFormat ff_adts_muxer = { .p.name = "adts", .p.long_name = NULL_IF_CONFIG_SMALL("ADTS AAC (Advanced Audio Coding)"), .p.mime_type = "audio/aac", .p.extensions = "aac,adts", .priv_data_size = sizeof(ADTSContext), .p.audio_codec = AV_CODEC_ID_AAC, .p.video_codec = AV_CODEC_ID_NONE, .init = adts_init, .write_header = adts_write_header, .write_packet = adts_write_packet, .write_trailer = adts_write_trailer, .p.priv_class = &adts_muxer_class, .p.flags = AVFMT_NOTIMESTAMPS, };