yading@11: /* yading@11: * ADTS muxer. yading@11: * Copyright (c) 2006 Baptiste Coudurier yading@11: * Mans Rullgard yading@11: * yading@11: * This file is part of FFmpeg. yading@11: * yading@11: * FFmpeg is free software; you can redistribute it and/or yading@11: * modify it under the terms of the GNU Lesser General Public yading@11: * License as published by the Free Software Foundation; either yading@11: * version 2.1 of the License, or (at your option) any later version. yading@11: * yading@11: * FFmpeg is distributed in the hope that it will be useful, yading@11: * but WITHOUT ANY WARRANTY; without even the implied warranty of yading@11: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU yading@11: * Lesser General Public License for more details. yading@11: * yading@11: * You should have received a copy of the GNU Lesser General Public yading@11: * License along with FFmpeg; if not, write to the Free Software yading@11: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA yading@11: */ yading@11: yading@11: #include "libavcodec/get_bits.h" yading@11: #include "libavcodec/put_bits.h" yading@11: #include "libavcodec/avcodec.h" yading@11: #include "libavcodec/mpeg4audio.h" yading@11: #include "avformat.h" yading@11: yading@11: #define ADTS_HEADER_SIZE 7 yading@11: yading@11: typedef struct { yading@11: int write_adts; yading@11: int objecttype; yading@11: int sample_rate_index; yading@11: int channel_conf; yading@11: int pce_size; yading@11: uint8_t pce_data[MAX_PCE_SIZE]; yading@11: } ADTSContext; yading@11: yading@11: #define ADTS_MAX_FRAME_BYTES ((1 << 13) - 1) yading@11: yading@11: static int adts_decode_extradata(AVFormatContext *s, ADTSContext *adts, uint8_t *buf, int size) yading@11: { yading@11: GetBitContext gb; yading@11: PutBitContext pb; yading@11: MPEG4AudioConfig m4ac; yading@11: int off; yading@11: yading@11: init_get_bits(&gb, buf, size * 8); yading@11: off = avpriv_mpeg4audio_get_config(&m4ac, buf, size * 8, 1); yading@11: if (off < 0) yading@11: return off; yading@11: skip_bits_long(&gb, off); yading@11: adts->objecttype = m4ac.object_type - 1; yading@11: adts->sample_rate_index = m4ac.sampling_index; yading@11: adts->channel_conf = m4ac.chan_config; yading@11: yading@11: if (adts->objecttype > 3U) { yading@11: av_log(s, AV_LOG_ERROR, "MPEG-4 AOT %d is not allowed in ADTS\n", adts->objecttype+1); yading@11: return -1; yading@11: } yading@11: if (adts->sample_rate_index == 15) { yading@11: av_log(s, AV_LOG_ERROR, "Escape sample rate index illegal in ADTS\n"); yading@11: return -1; yading@11: } yading@11: if (get_bits(&gb, 1)) { yading@11: av_log(s, AV_LOG_ERROR, "960/120 MDCT window is not allowed in ADTS\n"); yading@11: return -1; yading@11: } yading@11: if (get_bits(&gb, 1)) { yading@11: av_log(s, AV_LOG_ERROR, "Scalable configurations are not allowed in ADTS\n"); yading@11: return -1; yading@11: } yading@11: if (get_bits(&gb, 1)) { yading@11: av_log(s, AV_LOG_ERROR, "Extension flag is not allowed in ADTS\n"); yading@11: return -1; yading@11: } yading@11: if (!adts->channel_conf) { yading@11: init_put_bits(&pb, adts->pce_data, MAX_PCE_SIZE); yading@11: yading@11: put_bits(&pb, 3, 5); //ID_PCE yading@11: adts->pce_size = (avpriv_copy_pce_data(&pb, &gb) + 3) / 8; yading@11: flush_put_bits(&pb); yading@11: } yading@11: yading@11: adts->write_adts = 1; yading@11: yading@11: return 0; yading@11: } yading@11: yading@11: static int adts_write_header(AVFormatContext *s) yading@11: { yading@11: ADTSContext *adts = s->priv_data; yading@11: AVCodecContext *avc = s->streams[0]->codec; yading@11: yading@11: if (avc->extradata_size > 0 && yading@11: adts_decode_extradata(s, adts, avc->extradata, avc->extradata_size) < 0) yading@11: return -1; yading@11: yading@11: return 0; yading@11: } yading@11: yading@11: static int adts_write_frame_header(ADTSContext *ctx, yading@11: uint8_t *buf, int size, int pce_size) yading@11: { yading@11: PutBitContext pb; yading@11: yading@11: unsigned full_frame_size = (unsigned)ADTS_HEADER_SIZE + size + pce_size; yading@11: if (full_frame_size > ADTS_MAX_FRAME_BYTES) { yading@11: av_log(NULL, AV_LOG_ERROR, "ADTS frame size too large: %u (max %d)\n", yading@11: full_frame_size, ADTS_MAX_FRAME_BYTES); yading@11: return AVERROR_INVALIDDATA; yading@11: } yading@11: yading@11: init_put_bits(&pb, buf, ADTS_HEADER_SIZE); yading@11: yading@11: /* adts_fixed_header */ yading@11: put_bits(&pb, 12, 0xfff); /* syncword */ yading@11: put_bits(&pb, 1, 0); /* ID */ yading@11: put_bits(&pb, 2, 0); /* layer */ yading@11: put_bits(&pb, 1, 1); /* protection_absent */ yading@11: put_bits(&pb, 2, ctx->objecttype); /* profile_objecttype */ yading@11: put_bits(&pb, 4, ctx->sample_rate_index); yading@11: put_bits(&pb, 1, 0); /* private_bit */ yading@11: put_bits(&pb, 3, ctx->channel_conf); /* channel_configuration */ yading@11: put_bits(&pb, 1, 0); /* original_copy */ yading@11: put_bits(&pb, 1, 0); /* home */ yading@11: yading@11: /* adts_variable_header */ yading@11: put_bits(&pb, 1, 0); /* copyright_identification_bit */ yading@11: put_bits(&pb, 1, 0); /* copyright_identification_start */ yading@11: put_bits(&pb, 13, full_frame_size); /* aac_frame_length */ yading@11: put_bits(&pb, 11, 0x7ff); /* adts_buffer_fullness */ yading@11: put_bits(&pb, 2, 0); /* number_of_raw_data_blocks_in_frame */ yading@11: yading@11: flush_put_bits(&pb); yading@11: yading@11: return 0; yading@11: } yading@11: yading@11: static int adts_write_packet(AVFormatContext *s, AVPacket *pkt) yading@11: { yading@11: ADTSContext *adts = s->priv_data; yading@11: AVIOContext *pb = s->pb; yading@11: uint8_t buf[ADTS_HEADER_SIZE]; yading@11: yading@11: if (!pkt->size) yading@11: return 0; yading@11: if (adts->write_adts) { yading@11: int err = adts_write_frame_header(adts, buf, pkt->size, yading@11: adts->pce_size); yading@11: if (err < 0) yading@11: return err; yading@11: avio_write(pb, buf, ADTS_HEADER_SIZE); yading@11: if (adts->pce_size) { yading@11: avio_write(pb, adts->pce_data, adts->pce_size); yading@11: adts->pce_size = 0; yading@11: } yading@11: } yading@11: avio_write(pb, pkt->data, pkt->size); yading@11: yading@11: return 0; yading@11: } yading@11: yading@11: AVOutputFormat ff_adts_muxer = { yading@11: .name = "adts", yading@11: .long_name = NULL_IF_CONFIG_SMALL("ADTS AAC (Advanced Audio Coding)"), yading@11: .mime_type = "audio/aac", yading@11: .extensions = "aac,adts", yading@11: .priv_data_size = sizeof(ADTSContext), yading@11: .audio_codec = AV_CODEC_ID_AAC, yading@11: .video_codec = AV_CODEC_ID_NONE, yading@11: .write_header = adts_write_header, yading@11: .write_packet = adts_write_packet, yading@11: };