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"
38 static const AVOption options[] = {
39 {"smc-interval", "StreamMuxConfig interval.",
40 offsetof(LATMContext, mod), AV_OPT_TYPE_INT, {.dbl = 0x0014}, 0x0001, 0xffff, AV_OPT_FLAG_ENCODING_PARAM},
44 static const AVClass latm_muxer_class = {
45 .class_name = "LATM/LOAS muxer",
46 .item_name = av_default_item_name,
48 .version = LIBAVUTIL_VERSION_INT,
51 static int latm_decode_extradata(LATMContext *ctx, uint8_t *buf, int size)
54 MPEG4AudioConfig m4ac;
56 init_get_bits(&gb, buf, size * 8);
57 ctx->off = avpriv_mpeg4audio_get_config(&m4ac, buf, size * 8, 1);
60 skip_bits_long(&gb, ctx->off);
62 /* FIXME: are any formats not allowed in LATM? */
64 if (m4ac.object_type > AOT_SBR && m4ac.object_type != AOT_ALS) {
65 av_log(ctx, AV_LOG_ERROR, "Muxing MPEG-4 AOT %d in LATM is not supported\n", m4ac.object_type);
66 return AVERROR_INVALIDDATA;
68 ctx->channel_conf = m4ac.chan_config;
69 ctx->object_type = m4ac.object_type;
74 static int latm_write_header(AVFormatContext *s)
76 LATMContext *ctx = s->priv_data;
77 AVCodecContext *avctx = s->streams[0]->codec;
79 if (avctx->extradata_size > 0 &&
80 latm_decode_extradata(ctx, avctx->extradata, avctx->extradata_size) < 0)
81 return AVERROR_INVALIDDATA;
86 static int latm_write_frame_header(AVFormatContext *s, PutBitContext *bs)
88 LATMContext *ctx = s->priv_data;
89 AVCodecContext *avctx = s->streams[0]->codec;
94 put_bits(bs, 1, !!ctx->counter);
97 init_get_bits(&gb, avctx->extradata, avctx->extradata_size * 8);
100 put_bits(bs, 1, 0); /* audioMuxVersion */
101 put_bits(bs, 1, 1); /* allStreamsSameTimeFraming */
102 put_bits(bs, 6, 0); /* numSubFrames */
103 put_bits(bs, 4, 0); /* numProgram */
104 put_bits(bs, 3, 0); /* numLayer */
106 /* AudioSpecificConfig */
107 if (ctx->object_type == AOT_ALS) {
108 header_size = avctx->extradata_size-(ctx->off + 7) >> 3;
109 avpriv_copy_bits(bs, &avctx->extradata[ctx->off], header_size);
111 avpriv_copy_bits(bs, avctx->extradata, ctx->off + 3);
113 if (!ctx->channel_conf) {
114 avpriv_copy_pce_data(bs, &gb);
118 put_bits(bs, 3, 0); /* frameLengthType */
119 put_bits(bs, 8, 0xff); /* latmBufferFullness */
121 put_bits(bs, 1, 0); /* otherDataPresent */
122 put_bits(bs, 1, 0); /* crcCheckPresent */
126 ctx->counter %= ctx->mod;
131 static int latm_write_packet(AVFormatContext *s, AVPacket *pkt)
133 AVIOContext *pb = s->pb;
136 uint8_t loas_header[] = "\x56\xe0\x00";
139 if (pkt->size > 2 && pkt->data[0] == 0xff && (pkt->data[1] >> 4) == 0xf) {
140 av_log(s, AV_LOG_ERROR, "ADTS header detected - ADTS will not be incorrectly muxed into LATM\n");
141 return AVERROR_INVALIDDATA;
144 buf = av_malloc(pkt->size+1024);
146 return AVERROR(ENOMEM);
148 init_put_bits(&bs, buf, pkt->size+1024);
150 latm_write_frame_header(s, &bs);
152 /* PayloadLengthInfo() */
153 for (i = 0; i <= pkt->size-255; i+=255)
154 put_bits(&bs, 8, 255);
156 put_bits(&bs, 8, pkt->size-i);
158 /* The LATM payload is written unaligned */
161 for (i = 0; i < pkt->size; i++)
162 put_bits(&bs, 8, pkt->data[i]);
164 avpriv_align_put_bits(&bs);
167 len = put_bits_count(&bs) >> 3;
169 loas_header[1] |= (len >> 8) & 0x1f;
170 loas_header[2] |= len & 0xff;
172 avio_write(pb, loas_header, 3);
173 avio_write(pb, buf, len);
180 AVOutputFormat ff_latm_muxer = {
182 .long_name = NULL_IF_CONFIG_SMALL("LOAS/LATM"),
183 .mime_type = "audio/MP4A-LATM",
184 .extensions = "latm",
185 .priv_data_size = sizeof(LATMContext),
186 .audio_codec = CODEC_ID_AAC,
187 .video_codec = CODEC_ID_NONE,
188 .write_header = latm_write_header,
189 .write_packet = latm_write_packet,
190 .priv_class = &latm_muxer_class,