3 * Copyright (c) 2011 Kieran Kunhya <kieran@kunhya.com>
5 * This file is part of Libav.
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavcodec/get_bits.h"
23 #include "libavcodec/put_bits.h"
24 #include "libavcodec/avcodec.h"
25 #include "libavcodec/mpeg4audio.h"
26 #include "libavutil/opt.h"
37 static const AVOption options[] = {
38 {"smc-interval", "StreamMuxConfig interval.",
39 offsetof(LATMContext, mod), FF_OPT_TYPE_INT, {.dbl = 0x0014}, 0x0001, 0xffff, AV_OPT_FLAG_ENCODING_PARAM},
43 static const AVClass latm_muxer_class = {
44 .class_name = "LATM/LOAS muxer",
45 .item_name = av_default_item_name,
47 .version = LIBAVUTIL_VERSION_INT,
50 static int latm_decode_extradata(LATMContext *ctx, uint8_t *buf, int size)
53 MPEG4AudioConfig m4ac;
55 init_get_bits(&gb, buf, size * 8);
56 ctx->off = ff_mpeg4audio_get_config(&m4ac, buf, size);
59 skip_bits_long(&gb, ctx->off);
61 /* FIXME: are any formats not allowed in LATM? */
63 if (m4ac.object_type > AOT_SBR && m4ac.object_type != AOT_ALS) {
64 av_log(ctx, AV_LOG_ERROR, "Muxing MPEG-4 AOT %d in LATM is not supported\n", m4ac.object_type);
65 return AVERROR_INVALIDDATA;
67 ctx->channel_conf = m4ac.chan_config;
68 ctx->object_type = m4ac.object_type;
73 static int latm_write_header(AVFormatContext *s)
75 LATMContext *ctx = s->priv_data;
76 AVCodecContext *avctx = s->streams[0]->codec;
78 if (avctx->extradata_size > 0 &&
79 latm_decode_extradata(ctx, avctx->extradata, avctx->extradata_size) < 0)
80 return AVERROR_INVALIDDATA;
85 static int latm_write_frame_header(AVFormatContext *s, PutBitContext *bs)
87 LATMContext *ctx = s->priv_data;
88 AVCodecContext *avctx = s->streams[0]->codec;
93 put_bits(bs, 1, !!ctx->counter);
96 init_get_bits(&gb, avctx->extradata, avctx->extradata_size * 8);
99 put_bits(bs, 1, 0); /* audioMuxVersion */
100 put_bits(bs, 1, 1); /* allStreamsSameTimeFraming */
101 put_bits(bs, 6, 0); /* numSubFrames */
102 put_bits(bs, 4, 0); /* numProgram */
103 put_bits(bs, 3, 0); /* numLayer */
105 /* AudioSpecificConfig */
106 if (ctx->object_type == AOT_ALS) {
107 header_size = avctx->extradata_size-(ctx->off + 7) >> 3;
108 ff_copy_bits(bs, &avctx->extradata[ctx->off], header_size);
110 ff_copy_bits(bs, avctx->extradata, ctx->off + 3);
112 if (!ctx->channel_conf) {
113 ff_copy_pce_data(bs, &gb);
117 put_bits(bs, 3, 0); /* frameLengthType */
118 put_bits(bs, 8, 0); /* latmBufferFullness */
120 put_bits(bs, 1, 0); /* otherDataPresent */
121 put_bits(bs, 1, 0); /* crcCheckPresent */
125 ctx->counter %= ctx->mod;
130 static int latm_write_packet(AVFormatContext *s, AVPacket *pkt)
132 AVIOContext *pb = s->pb;
135 uint8_t loas_header[] = "\x56\xe0\x00";
138 if (pkt->size > 2 && pkt->data[0] == 0xff && (pkt->data[1] >> 4) == 0xf) {
139 av_log(s, AV_LOG_ERROR, "ADTS header detected - ADTS will not be incorrectly muxed into LATM\n");
140 return AVERROR_INVALIDDATA;
143 buf = av_malloc(pkt->size+1024);
145 return AVERROR(ENOMEM);
147 init_put_bits(&bs, buf, pkt->size+1024);
149 latm_write_frame_header(s, &bs);
151 /* PayloadLengthInfo() */
152 for (i = 0; i <= pkt->size-255; i+=255)
153 put_bits(&bs, 8, 255);
155 put_bits(&bs, 8, pkt->size-i);
157 /* The LATM payload is written unaligned */
160 for (i = 0; i < pkt->size; i++)
161 put_bits(&bs, 8, pkt->data[i]);
166 len = put_bits_count(&bs) >> 3;
168 loas_header[1] |= (len >> 8) & 0x1f;
169 loas_header[2] |= len & 0xff;
171 avio_write(pb, loas_header, 3);
172 avio_write(pb, buf, len);
179 AVOutputFormat ff_latm_muxer = {
181 .long_name = NULL_IF_CONFIG_SMALL("LOAS/LATM"),
182 .mime_type = "audio/MP4A-LATM",
183 .extensions = "latm",
184 .priv_data_size = sizeof(LATMContext),
185 .audio_codec = CODEC_ID_AAC,
186 .video_codec = CODEC_ID_NONE,
187 .write_header = latm_write_header,
188 .write_packet = latm_write_packet,
189 .priv_class = &latm_muxer_class,