| /* |
| * LATM/LOAS muxer |
| * Copyright (c) 2011 Kieran Kunhya <kieran@kunhya.com> |
| * |
| * This file is part of Libav. |
| * |
| * Libav 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. |
| * |
| * Libav 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 Libav; 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/avcodec.h" |
| #include "libavcodec/mpeg4audio.h" |
| #include "libavutil/opt.h" |
| #include "avformat.h" |
| #include "rawenc.h" |
| |
| typedef struct { |
| AVClass *av_class; |
| int off; |
| int channel_conf; |
| int object_type; |
| int counter; |
| int mod; |
| } LATMContext; |
| |
| static const AVOption options[] = { |
| {"smc-interval", "StreamMuxConfig interval.", |
| offsetof(LATMContext, mod), AV_OPT_TYPE_INT, {.dbl = 0x0014}, 0x0001, 0xffff, AV_OPT_FLAG_ENCODING_PARAM}, |
| {NULL}, |
| }; |
| |
| static const AVClass latm_muxer_class = { |
| .class_name = "LATM/LOAS muxer", |
| .item_name = av_default_item_name, |
| .option = options, |
| .version = LIBAVUTIL_VERSION_INT, |
| }; |
| |
| static int latm_decode_extradata(LATMContext *ctx, uint8_t *buf, int size) |
| { |
| GetBitContext gb; |
| MPEG4AudioConfig m4ac; |
| |
| init_get_bits(&gb, buf, size * 8); |
| ctx->off = avpriv_mpeg4audio_get_config(&m4ac, buf, size * 8, 1); |
| if (ctx->off < 0) |
| return ctx->off; |
| skip_bits_long(&gb, ctx->off); |
| |
| /* FIXME: are any formats not allowed in LATM? */ |
| |
| if (m4ac.object_type > AOT_SBR && m4ac.object_type != AOT_ALS) { |
| av_log(ctx, AV_LOG_ERROR, "Muxing MPEG-4 AOT %d in LATM is not supported\n", m4ac.object_type); |
| return AVERROR_INVALIDDATA; |
| } |
| ctx->channel_conf = m4ac.chan_config; |
| ctx->object_type = m4ac.object_type; |
| |
| return 0; |
| } |
| |
| static int latm_write_header(AVFormatContext *s) |
| { |
| LATMContext *ctx = s->priv_data; |
| AVCodecContext *avctx = s->streams[0]->codec; |
| |
| if (avctx->codec_id == CODEC_ID_AAC_LATM) |
| return 0; |
| |
| if (avctx->extradata_size > 0 && |
| latm_decode_extradata(ctx, avctx->extradata, avctx->extradata_size) < 0) |
| return AVERROR_INVALIDDATA; |
| |
| return 0; |
| } |
| |
| static int latm_write_frame_header(AVFormatContext *s, PutBitContext *bs) |
| { |
| LATMContext *ctx = s->priv_data; |
| AVCodecContext *avctx = s->streams[0]->codec; |
| GetBitContext gb; |
| int header_size; |
| |
| /* AudioMuxElement */ |
| put_bits(bs, 1, !!ctx->counter); |
| |
| if (!ctx->counter) { |
| init_get_bits(&gb, avctx->extradata, avctx->extradata_size * 8); |
| |
| /* StreamMuxConfig */ |
| put_bits(bs, 1, 0); /* audioMuxVersion */ |
| put_bits(bs, 1, 1); /* allStreamsSameTimeFraming */ |
| put_bits(bs, 6, 0); /* numSubFrames */ |
| put_bits(bs, 4, 0); /* numProgram */ |
| put_bits(bs, 3, 0); /* numLayer */ |
| |
| /* AudioSpecificConfig */ |
| if (ctx->object_type == AOT_ALS) { |
| header_size = avctx->extradata_size-(ctx->off + 7) >> 3; |
| avpriv_copy_bits(bs, &avctx->extradata[ctx->off], header_size); |
| } else { |
| avpriv_copy_bits(bs, avctx->extradata, ctx->off + 3); |
| |
| if (!ctx->channel_conf) { |
| avpriv_copy_pce_data(bs, &gb); |
| } |
| } |
| |
| put_bits(bs, 3, 0); /* frameLengthType */ |
| put_bits(bs, 8, 0xff); /* latmBufferFullness */ |
| |
| put_bits(bs, 1, 0); /* otherDataPresent */ |
| put_bits(bs, 1, 0); /* crcCheckPresent */ |
| } |
| |
| ctx->counter++; |
| ctx->counter %= ctx->mod; |
| |
| return 0; |
| } |
| |
| static int latm_write_packet(AVFormatContext *s, AVPacket *pkt) |
| { |
| AVIOContext *pb = s->pb; |
| PutBitContext bs; |
| int i, len; |
| uint8_t loas_header[] = "\x56\xe0\x00"; |
| uint8_t *buf; |
| |
| if (s->streams[0]->codec->codec_id == CODEC_ID_AAC_LATM) |
| return ff_raw_write_packet(s, pkt); |
| |
| if (pkt->size > 2 && pkt->data[0] == 0xff && (pkt->data[1] >> 4) == 0xf) { |
| av_log(s, AV_LOG_ERROR, "ADTS header detected - ADTS will not be incorrectly muxed into LATM\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| buf = av_malloc(pkt->size+1024); |
| if (!buf) |
| return AVERROR(ENOMEM); |
| |
| init_put_bits(&bs, buf, pkt->size+1024); |
| |
| latm_write_frame_header(s, &bs); |
| |
| /* PayloadLengthInfo() */ |
| for (i = 0; i <= pkt->size-255; i+=255) |
| put_bits(&bs, 8, 255); |
| |
| put_bits(&bs, 8, pkt->size-i); |
| |
| /* The LATM payload is written unaligned */ |
| |
| /* PayloadMux() */ |
| for (i = 0; i < pkt->size; i++) |
| put_bits(&bs, 8, pkt->data[i]); |
| |
| avpriv_align_put_bits(&bs); |
| flush_put_bits(&bs); |
| |
| len = put_bits_count(&bs) >> 3; |
| |
| loas_header[1] |= (len >> 8) & 0x1f; |
| loas_header[2] |= len & 0xff; |
| |
| avio_write(pb, loas_header, 3); |
| avio_write(pb, buf, len); |
| |
| av_free(buf); |
| |
| return 0; |
| } |
| |
| AVOutputFormat ff_latm_muxer = { |
| .name = "latm", |
| .long_name = NULL_IF_CONFIG_SMALL("LOAS/LATM"), |
| .mime_type = "audio/MP4A-LATM", |
| .extensions = "latm,loas", |
| .priv_data_size = sizeof(LATMContext), |
| .audio_codec = CODEC_ID_AAC, |
| .video_codec = CODEC_ID_NONE, |
| .write_header = latm_write_header, |
| .write_packet = latm_write_packet, |
| .priv_class = &latm_muxer_class, |
| }; |