From 0ca36b4de76e10578e23199c2932682c0f510e31 Mon Sep 17 00:00:00 2001 From: Kieran Kunhya Date: Tue, 6 Sep 2011 20:05:27 +0100 Subject: Add LATM muxer Signed-off-by: Janne Grunau --- libavformat/latmenc.c | 190 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 190 insertions(+) create mode 100644 libavformat/latmenc.c (limited to 'libavformat/latmenc.c') diff --git a/libavformat/latmenc.c b/libavformat/latmenc.c new file mode 100644 index 0000000000..8d67b5a615 --- /dev/null +++ b/libavformat/latmenc.c @@ -0,0 +1,190 @@ +/* + * LATM/LOAS muxer + * Copyright (c) 2011 Kieran Kunhya + * + * 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" + +typedef struct { + int off; + int channel_conf; + int object_type; + int counter; + int mod; +} LATMContext; + +static const AVOption options[] = { + {"smc-interval", "StreamMuxConfig interval.", + offsetof(LATMContext, mod), FF_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 = ff_mpeg4audio_get_config(&m4ac, buf, size); + 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->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; + ff_copy_bits(bs, &avctx->extradata[ctx->off], header_size); + } else { + ff_copy_bits(bs, avctx->extradata, ctx->off + 3); + + if (!ctx->channel_conf) { + ff_copy_pce_data(bs, &gb); + } + } + + put_bits(bs, 3, 0); /* frameLengthType */ + put_bits(bs, 8, 0); /* 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 (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]); + + 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", + .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, +}; -- cgit v1.2.3