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mirror of https://git.ffmpeg.org/ffmpeg.git synced 2024-12-29 19:02:21 +00:00
ffmpeg/libavformat/latmenc.c
Andreas Rheinhardt 03b04eef72 avformat: Enforce one-stream limit where appropriate
Several muxers (e.g. pcm muxers) did not check the number
of streams even though the individual streams were not
recoverable from the muxed files. This commit changes
this by using the FF_OFMT_MAX_ONE_OF_EACH flag
where appropriate.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2024-03-22 23:57:19 +01:00

279 lines
8.9 KiB
C

/*
* LATM/LOAS muxer
* Copyright (c) 2011 Kieran Kunhya <kieran@kunhya.com>
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; 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/codec_id.h"
#include "libavcodec/codec_par.h"
#include "libavcodec/packet.h"
#include "libavcodec/mpeg4audio.h"
#include "libavcodec/mpeg4audio_copy_pce.h"
#include "libavutil/opt.h"
#include "avformat.h"
#include "internal.h"
#include "mux.h"
#include "rawenc.h"
#define MAX_EXTRADATA_SIZE 1024
typedef struct LATMContext {
AVClass *av_class;
int off;
int channel_conf;
int object_type;
int counter;
int mod;
uint8_t buffer[0x1fff + MAX_EXTRADATA_SIZE + 1024];
} LATMContext;
static const AVOption options[] = {
{"smc-interval", "StreamMuxConfig interval.",
offsetof(LATMContext, mod), AV_OPT_TYPE_INT, {.i64 = 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(AVFormatContext *s, uint8_t *buf, int size)
{
LATMContext *ctx = s->priv_data;
MPEG4AudioConfig m4ac;
if (size > MAX_EXTRADATA_SIZE) {
av_log(s, AV_LOG_ERROR, "Extradata is larger than currently supported.\n");
return AVERROR_INVALIDDATA;
}
ctx->off = avpriv_mpeg4audio_get_config2(&m4ac, buf, size, 1, s);
if (ctx->off < 0)
return ctx->off;
if (ctx->object_type == AOT_ALS && (ctx->off & 7)) {
// as long as avpriv_mpeg4audio_get_config works correctly this is impossible
av_log(s, AV_LOG_ERROR, "BUG: ALS offset is not byte-aligned\n");
return AVERROR_INVALIDDATA;
}
/* FIXME: are any formats not allowed in LATM? */
if (m4ac.object_type > AOT_SBR && m4ac.object_type != AOT_ALS) {
av_log(s, 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)
{
AVCodecParameters *par = s->streams[0]->codecpar;
if (par->codec_id == AV_CODEC_ID_AAC_LATM)
return 0;
if (par->codec_id != AV_CODEC_ID_AAC && par->codec_id != AV_CODEC_ID_MP4ALS) {
av_log(s, AV_LOG_ERROR, "Only AAC, LATM and ALS are supported\n");
return AVERROR(EINVAL);
}
if (par->extradata_size > 0 &&
latm_decode_extradata(s, par->extradata, par->extradata_size) < 0)
return AVERROR_INVALIDDATA;
return 0;
}
static void copy_bits(PutBitContext *pb, const uint8_t *src, int length)
{
int words = length >> 4;
int bits = length & 15;
int i;
for (i = 0; i < words; i++)
put_bits(pb, 16, AV_RB16(src + 2 * i));
if (bits)
put_bits(pb, bits, AV_RB16(src + 2 * words) >> (16 - bits));
}
static void latm_write_frame_header(AVFormatContext *s, PutBitContext *bs)
{
LATMContext *ctx = s->priv_data;
AVCodecParameters *par = s->streams[0]->codecpar;
int header_size;
/* AudioMuxElement */
put_bits(bs, 1, !!ctx->counter);
if (!ctx->counter) {
/* 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 = (par->extradata_size - (ctx->off >> 3)) * 8;
copy_bits(bs, &par->extradata[ctx->off >> 3], header_size);
} else {
// + 3 assumes not scalable and dependsOnCoreCoder == 0,
// see decode_ga_specific_config in libavcodec/aacdec.c
copy_bits(bs, par->extradata, ctx->off + 3);
if (!ctx->channel_conf) {
GetBitContext gb;
int ret = init_get_bits8(&gb, par->extradata, par->extradata_size);
av_assert0(ret >= 0); // extradata size has been checked already, so this should not fail
skip_bits_long(&gb, ctx->off + 3);
ff_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;
}
static int latm_write_packet(AVFormatContext *s, AVPacket *pkt)
{
LATMContext *ctx = s->priv_data;
AVCodecParameters *par = s->streams[0]->codecpar;
AVIOContext *pb = s->pb;
PutBitContext bs;
int i, len;
uint8_t loas_header[] = "\x56\xe0\x00";
if (par->codec_id == AV_CODEC_ID_AAC_LATM)
return ff_raw_write_packet(s, pkt);
if (!par->extradata) {
if(pkt->size > 2 && pkt->data[0] == 0x56 && (pkt->data[1] >> 4) == 0xe &&
(AV_RB16(pkt->data + 1) & 0x1FFF) + 3 == pkt->size)
return ff_raw_write_packet(s, pkt);
else {
uint8_t *side_data;
size_t side_data_size;
int ret;
side_data = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA,
&side_data_size);
if (side_data_size) {
if (latm_decode_extradata(s, side_data, side_data_size) < 0)
return AVERROR_INVALIDDATA;
ret = ff_alloc_extradata(par, side_data_size);
if (ret < 0)
return ret;
memcpy(par->extradata, side_data, side_data_size);
} else
return AVERROR_INVALIDDATA;
}
}
if (pkt->size > 0x1fff)
goto too_large;
init_put_bits(&bs, ctx->buffer, pkt->size+1024+MAX_EXTRADATA_SIZE);
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() */
if (pkt->size && (pkt->data[0] & 0xe1) == 0x81) {
// Convert byte-aligned DSE to non-aligned.
// Due to the input format encoding we know that
// it is naturally byte-aligned in the input stream,
// so there are no padding bits to account for.
// To avoid having to add padding bits and rearrange
// the whole stream we just remove the byte-align flag.
// This allows us to remux our FATE AAC samples into latm
// files that are still playable with minimal effort.
put_bits(&bs, 8, pkt->data[0] & 0xfe);
copy_bits(&bs, pkt->data + 1, 8*pkt->size - 8);
} else
copy_bits(&bs, pkt->data, 8*pkt->size);
flush_put_bits(&bs);
len = put_bytes_output(&bs);
if (len > 0x1fff)
goto too_large;
loas_header[1] |= (len >> 8) & 0x1f;
loas_header[2] |= len & 0xff;
avio_write(pb, loas_header, 3);
avio_write(pb, ctx->buffer, len);
return 0;
too_large:
av_log(s, AV_LOG_ERROR, "LATM packet size larger than maximum size 0x1fff\n");
return AVERROR_INVALIDDATA;
}
static int latm_check_bitstream(AVFormatContext *s, AVStream *st,
const AVPacket *pkt)
{
int ret = 1;
if (st->codecpar->codec_id == AV_CODEC_ID_AAC) {
if (pkt->size > 2 && (AV_RB16(pkt->data) & 0xfff0) == 0xfff0)
ret = ff_stream_add_bitstream_filter(st, "aac_adtstoasc", NULL);
}
return ret;
}
const FFOutputFormat ff_latm_muxer = {
.p.name = "latm",
.p.long_name = NULL_IF_CONFIG_SMALL("LOAS/LATM"),
.p.mime_type = "audio/MP4A-LATM",
.p.extensions = "latm,loas",
.priv_data_size = sizeof(LATMContext),
.p.audio_codec = AV_CODEC_ID_AAC,
.p.video_codec = AV_CODEC_ID_NONE,
.p.subtitle_codec = AV_CODEC_ID_NONE,
.flags_internal = FF_OFMT_FLAG_MAX_ONE_OF_EACH,
.write_header = latm_write_header,
.write_packet = latm_write_packet,
.p.priv_class = &latm_muxer_class,
.check_bitstream= latm_check_bitstream,
.p.flags = AVFMT_NOTIMESTAMPS,
};